Wednesday at Clean Tech 2007

In the middle of vacation, I'm taking some time to try to cover the Clean Tech 2007 conference in Santa Clara.  I arrived Wednesday morning, missing most of the keynote speeches. When I got to the auditorium, Vinod Khosla was speaking.  He was getting near the end of his presentation and toward the Q&A.

Vinod Khosla

Khosla's claims were a great deal more realistic than some here might have expected.  Among the eminently sensible things he said during his talk and the Q&A were:

  • (in response to a question including the statement that the power generation industry does not reward innovation):
    1. His goal is 80% replacement of fossil fuels
    2. The country needs an HVDC grid to move South Dakota wind power to New York or Arizona solar to Texas and LA
    3. One of the essential elements is a smart grid (this topic would be addressed in more detail by the next speaker)
  • For biofuels incentives and subsidies, the definition needs to be nonfood inputs rather than a narrower specification.
  • Grid capacity is a barrier to solar thermal technology (and presumably others).

Khosla made complete sense at the big-picture level.  It may be that he only falls down when he's arguing for his own interests.

K. Brass, GE Ecomagination

K. Brass from GE (Ecomagination) followed Khosla, and began by going over the population of Asia and the technological trends going on there.

She went over a series of slides with the conclusion that it is completely unsustainable for Asia to follow the same path as the history of the West.  I think we can heartily agree with this.

She said that GE's business was finding needs and meeting them. The new products will have two major performance criteria:  operating performance and environmental performance.

GE has set some ambitious goals for 2010:

  • $20 B revenue
  • $1.5 B R&D
  • Greenhouse footprint 1% reduction from 2004 baseline despite greater production.

This seems ambitious (it was the most ambitious of the 3 plans presented to the CEO) but GE seems to be trying to set an example.

Brass went over several things I remember poorly:

  • "White space" ideas
  • Re-lamping is an important measure.  Modern high-efficiency lighting creates improvements in both cost/energy and appearance/feel.
  • Ecomagination defines new ways to interact with customers.  If this sounds reminiscent of the Clue Train Manifesto, it may not be a coincidence.
  • GE is turning organic content of wastewater into energy.  I didn't catch anything which indicated that this was more than the classic sewage-plant methane capture, but if it leads to more and better conversion of waste to resources it can only be a good thing.
  • Municipal SOlid Waste.  Brass went over the current practice and the potential:
    • Current practice is landfills, which are bulky and polluting.
    • Incineration/gasification reduces volume immensely and generates energy, albeit possibly with pollution issues.
    • Plasma gasification is the ne plus ultra, offering an 80:1 reduction in volume and greatly improved cleanliness.  I don't know if this is practical in the near term, and I didn't catch much from Brass on that issue.

She offered up a number of points of consensus:

  1. We are living in an increasingly carbon-constrained world.
  2. Renewables will be a part of the solution, but only a part.
  3. Nuclear power is needed and is becoming big.
  4. Renewables require better grid technology (the smart grid and HVDC systems mentioned by Khosla).

She went on to some things GE is doing to make it happen.  The LMS 100 gas turbine hits 44% simple-cycle efficiency.  This is way above previous gas turbines, and changes a lot of the economics of power.  These turbines can receive construction permits today.

GE acquired Enron's wind power unit in 2002.  GE's technological expertise offers a number of synergies for wind:

  • Rail supplies robust gearboxes and power converters
  • Plastics supplies resins for blades
  • Financial services double RE investment to $3B by 2008.

GE is into multifunction building components such as PV roofing.

I got a note on the cost of CO2 scrubbing from post-combustion gases.  The number I have is $42/ton, presumably with amine scrubbing.  There are a lot of efficiency and other measures which will reduce carbon emissions for less than this, and carbon taxes or caps may shift the economics far enough to make air-fuel (as opposed to oxy-fuel) combustion uncompetitive.  We'll see.

Henry Courtwright

Ms. Brass was followed by Henry Courtwright, who came to talk about EPRI and its efforts in this area.  His intro went into CO2 emissions from the electric power sector.  Currently ~2500 million metric tons/year, the Business As Usual projection has it rising to ~3.3 billion metric tons/year by 2030.  This appears to have dire consequences (if it is possible; I did not get to ask about peak coal).  His presentation of the EPRI program for 2030 covered 7 points:

  1. Efficiency:  Reduce electric demand growth by 30%.
  2. Renewables:  The standard projection is for 30 GW of RE generation by 2030.  EPRI thinks this can be more than doubled, to 70 GW.
  3. Nuclear:  An increase of 64 GW (presumably an increase, because current capacity is about 90 GW) would further reduce CO2 emissions.
  4. Coal efficiency:  Today's best plants get about 38% efficiency.  Courtwright believes this can be increased to 49%, which reduces both fuel costs and CO2 emissions [albeit not enough].
  5. Carbon capture and storage.  This is a post-2020 wedge [too late, more likely than not] and Courtwright did not get into the energy cost of this option.  He described several technologies for both CO2 scrubbing and oxygen separation for oxyfuel combustion, with nothing about timeframe, pilot projects or cost.
  6. PHEVs:  He touched on the aspects of liquid-fuel replacement (displacing carbon-containing liquid fuels with electricity from sequestered or carbon-free powerplants) and the V2G possibilities.
  7. Distributed Energy Resources:  This includes building-integrated PV and the like, and has the effect of removing the transmission and distribution costs and losses from the system.

It seemed to be a pretty comprehensive list.

He then went into a brief description of EPRI itself.  It's a world-wide association of electric utilities, other industries and governments.  It is a non-profit which supports research programs (this includes outfits like AC Propulsion).

After this, he went into the required technology for these improvements:

  1. Effciency.  He touched on several points:
    • The "natural" efficiency improvement would be about 13%.  This is inadequate.
    • Utility and state efficiency initiatives would lead to roughly 5% improvement.
    • The total potential for improvement is 26-40%.  This led into a listing of means to achieve it.
  2. "Prices to devices".  This involves smart devices and the information systems to get power price information to them.  The devices would manage their power consumption to achieve the least cost to the consumer (which also minimizes the peak demands on generation and transmission assets).
  3. Ocean power, wave and tide.
  4. Improved hydropower and biomass systems.
  5. Hydrogen.  He didn't give much detail on this, and I doubt that he would have had any response to the criticisms of hydrogen systems from Ulf Bossel or others.

With this, the session went to Q&A.  I was able to get two questions to him.

I asked about local solar-thermal generation, using the convention center itself as an example (it has several acres of surface over the parking structure).  Courtwright stated that this would be handled better by PV, because of the reduced maintenance requirements.  He didn't mention, and I didn't have time to ask, if the thermal output of something like a Stirling dish system could run absorption chillers or other equipment to shift the balance in its favor.

My second question was about direct-carbon fuel cells and their potential to boost powerplant efficiency to nearly 80%.  Courtwright said that this was in the early stages and wasn't sufficiently developed to put into a firm projection for 2030.

Another question dealt with carbon emission projections.  Courtwright said that the improvements would include a shift from today's 40% share borne by electricity to some 70% in the future.  With technologies like PHEV, this seems very practical.

In the one-on-one which followed, I also got a chance to ask him about ice-storage as a mature technology for DSM.  He said it had once been popular, interest had dropped as energy became cheaper (in the 80's, I suppose), and it was a rising star once again.  I mentioned the Ice Bear but he refused to talk specifics.

I kicked around a bit after that, but I didn't find any energy-technology talk of note until after the poster session.

Halley K. Dickey, UTC

Halley Dickey of UTC spoke on the subject of modular geothermal generation systems.  The system he described is really quite clever, leveraging a great deal of equipment already in large-scale production for other purposes.  The essence of the system is a vapor-cycle engine using common organic fluids as the working fluid.  Carrier has made large-scale centrifugal vapor-compression water chillers for many years, and it happens that this centrifugal compressor is easily adapted to a vapor turbine.  The size produces a machine of 225 kW capacity, and the existing production volumes allow a 16-week period from order to delivery.  This machinery is currently produced in 3 plants world-wide, none of which are running more than 1 shift.  Increasing the plant utilization could lead to rapid expansion of the geothermal resource.

Dickey touched on the nature of the geothermal resource.  With the vapor-cycle engine, heat sources too cool for conventional systems become practical for electric production.  Hot water is a byproduct of today's oil and gas production, but it is mostly ignored or even treated as a difficulty.  If this hot water could produce electricity, it could both eliminate the local emissions from diesel generators to run the well apparatus and produce power for sale.  This ability to use low-temperature resources could double the size of the geothermal market.  How low?  Dickey talked about a site in Alaska which exploits the availability of groundwater at 40°F as a heat sink to make productive use of a heat source at only 165°F.  This is apparently the lowest temperature geothermal generation system in production.

Cost came next.  Dickey cited a generator unit cost of $1350/kW, with installed cost in the region of $2500/kW.  The details of wells and other plumbing might come to considerably more, but if they have already been drilled for oil or gas production they would not factor into the incremental cost of electricity.  He claimed a cost in the region of 4¢/kWh from such a system.

B. Cinnamon, Akeena Solar

Last came B. (Barry?  I didn't catch his name) Cinnamon for Akeena Solar.  His company makes PV systems for installation at consumer sites.  The economics are complicated, but he claims that the various California and Federal RE credits make a household PV system pay off in as little as 9.9 years given current cost trends.  The prospect of a much greater Federal tax credit could drop the payback to the region of 6 years.

I got most of the details of this in pictures which I can't get to right now, but he claimed that the state derived benefits which made such a high tax credit worthwhile.  A large part of this was the reduction in the cost of the electric transmission and distribution network.  Another element is grid reliability.  During recent heat waves, 25 kW pole transformers were literally exploding because they were forced to transmit 30 kW or more for hours on end.  Just one house on a block with a 5 kW PV system would reduce that net load to 25 kW, putting the transformer back within its design ratings and eliminating most of the failures.

I wanted to ask him about the economics of PV vs. solar thermal for the likes of the convention center, but time ran out first.

I had some other interesting one-on-one conversations afterward, but there was nothing else to report on.  Well, perhaps one thing.  Whoever supplied the Merlot for the open bar afterwards has a very smooth, tasty product.

And that ends my reporting from Day 1 of Clean Tech 2007.  More tomorrow.

1. The convention center's system is exorbitantly priced, and Santa Clara's MetroFi system is highly unreliable where I've been able to get a connection.
2. Tiger Direct seems to think that 25% of rated lifespan is sufficient for a laptop battery, and shipping a replacement to one's shipping address on the East coast when one is at a motel on the West is customer service.  I take exception to both assertions.

The overall impression is that progress will come from incremental improvements and system changes, not silver bullets. Most of the ideas look far more expensive than what has been considered so far.

The Carrier/UTC ORC mentioned above looks like this:

There are 2 installed at Chena Hot Springs
There up to 135 more to be installed in Utah.

EP. I am sure you recognized as I did that any vapor system able to work well with low temps is a candidate for solar thermal on that same roof. Would be good to hear what the UTC people think of that relative to PV.

Low-temperature solar-thermal is an oxymoron. Your system efficiency is less than the Carnot efficiency (T_hot-T_cold)/T_hot regardless of the working fluid you use. There are plenty of fluids in industrial use that vapourize at lower temperatures then water: they're used in your air conditioner and refrigerator.

Carnot efficiency in solar power systems is not as important as dollar efficiency. Flat plate solar thermal can easily provide 100C temps which can be cheaply stored for long periods of time. A lower carnot efficiency does lead to the need for larger equipment for each watt of output. Wind turbines are a good example of a large device with poor thermal efficiency but excellent dollar efficiency.

Wind turbines make a poor counterpoints, with a maximum efficiency of 59% (Betz law), of which 45% is typically achieved.

Wind turbines DO NOT WORK on thermal principals.

Make sure you do not confuse Thermal differentials with Kinetic energy differentials.

Thank you.

First thermal differentials create the wind. Second careful measurements show a temperature difference between upwind and downwind spaces around the blades.

Sigh. I had no desire to repeat a thermo 1 lecture at this late stage in my life, but on thinking about it, decided that it might be good to do so as background information for those who might be misled by the above two entries. (Sorry, EP, all of the below is elementary and you need go no further. Have a good vacation.)

"Low temperature solar thermal" bears no internal contradictions (oxymoron- a congregation of contradictory words). Elementary thermodynamics declares that any temperature difference between heat source and sink allows a reversible heat engine receiving heat from the high temperature source to produce power at an efficiency equal to the temperature difference between source and sink divided by the high temperature (Carnot efficiency).

Thus a flat plate solar receiver, delivering heat at say 200C (473K), might allow a reversible engine rejecting heat to atmosphere at 50C (323K), an efficiency of 150/473 = 31%

But, alas, we all know that there is no such thing as areversible heat engine in real life, except perhaps one running infinitely slowly, producing no power.

Experience shows that real vapor cycles (steam, organics, etc operating on the Rankine cycle) might deliver an efficiency perhaps 60% of Carnot, or higher if all components are highly efficient. Thus a real vapor machine operating as above might have an efficiency somewhat above 15%, which must be further attenuated by other component efficiencies such as those of the absorber, alternator, electronic convereter and all the rest of reality.

This brings up a source of common errors. Efficiency is unfortunately, variously defined and often misused and/or confused. The carnot efficiency above refers to the CYCLE efficiency of an ideal machine. The COMPONENT efficiency, is quite different; it is defined as the ratio of component performance relative to an ideal machine performance. In the case of an expander in an ordinary vapor cycle, its efficiency may be defined as its power output divided by the ideal power output (mass flow rate times isentropic enthalpy drop from receiver pressure to rejector pressure). This may range from zero ( a throttling valve) to very high, approaching 100%.

In a reversible thermal machine, all components must have 100% efficiency, even though the ideal cycle efficiency might be say, a mere 30%.

What I was getting at in my remark above, is that IF there is a very good vapor expander available, THEN relatively low temperature vapor cycle systems might give good overall performance, and one should always consider this possiblilty when judging relative merits of the several solar power opportunities.

Disclosure- I am not a fan of PV- reasons given above. PV gets far too much money, and I and my poverty-ridden fellow thermal machine enthusiasts, get little or none. Drat!. Nevertheless, grieviously burdened by futile PV envy tho I might be, I shall now return to my nap.

The Synergetic Power group of MIT Grads built a low-tech solar trough Organic Rankine Cycle CSP plant with simple sheet metal solar troughs, low-boiling point fluid and a vane air motor for a turbine. They received a Ignite Award and a grant from the World Bank to build a beta site in Lesotho, South Africa.

pdf brochure

They are claiming 1 kW peak output from 14m2 of trough collectors. Assuming 1kw solar radiation peak, this is around 7% efficiency. The only real consideration in solar thermal power generation efficiency is the cost of the system per output kW.

Thanks, rohar1 for bringing this one to my attention. I had missed it somehow. Serves as excellent demonstration of what I was saying. Even with quite low component efficiency (car components are mediocre), a moderate temperature solar thermal system can get fairly low cost/kw-hr.

And beat PV!

BTW, during my efforts in Africa, I found that the locals liked things they could fix, even when they needed a lot of fixing- as long as the thing was doing them some good.

So who can fix a PV panel after a goat jumps on it?

I might even start contributing to the old ME department again. Might even let them know how to make a far better(simpler, cheaper, longer lived) system (he hehe).

Did anyone talk about PRT( Personal Rapid Transit) or podcars? Dropping vehicle weight by a factor of 10 should reduce the grid impact and adding PV may actually create a net input to the grid instead of a load. Zero emissions, reduced traffic fatalities and reduced traffic are welcome also.

Why is Sweden the only country with a prototype?
Vectus PRT test track without PV

Concept Podcars with PV

Hello Realist,

I am not an engineer, but imagine if the economics can be further improved by the overhead piping being dual purpose:

1. External railbed for the pods.

2. Internal fluid transport of water, fuel, natgas, sewage, or whatever. Communication fiber optics or electrical powerlines could also be safely shielded internal to these pipes. Additional income generated by billing for transit of these vital resources.

The US has millions of miles of decaying subterranean spiderweb infrastructure. My fear is that postPeak energy costs will be so high that the subsequent digging up of all this dirt to replace the underground spiderwebs once again will be totally unaffordable. Thus my dual-purpose Spiderwebriding concept. Another benefit is that any leaks will be immediately identifiable and convenient to repair. Water will soon be too expensive in many areas to tolerate any leaks. I have posted in the TOD archives many previous discussions of this concept.

Bob Shaw in Phx,Az Are Humans Smarter than Yeast?

Great point. Let me know if the Pheonix city council is interested.

Hello Realist,

Thxs for responding. Obviously, the best way to leverage this concept is for a national Spiderweb Engineering Standard. I have no idea what this would all entail, but establishing a uniform set of national construction codes similar to the current RR & TOD codes would be a good beginning.

Sorry, I am not much of a political animal. I have no clout at all with the local leaders of my Asphalt Wonderland. My hope is that those, who are more political Phoenicians, might be reading TOD, then pushing for rapid local change.

Bob Shaw in Phx,Az Are Humans Smarter than Yeast?

** comment withdrawn **

A PRT pilot project is being built at London Heathrow Terminal 5. That is a working pilot not a prototype; carrying real passengers, due to start operation next year. BAA (British Airports) have bought in to the technology suppliers, and, if no major problems at T5, plan to roll out to the rest of Heathrow and other airports. Definitely one to watch IMHO.

ATS Begins Heathrow Pilot

ATS have started the work programme under contract to BAA which will lead to the Pilot operation at Heathrow. The planned route for the pilot is from the N3 passenger car park to the new Heathrow Terminal 5. The route requires 4.2 km of track including station loops, and 18 vehicles. The guideway will connect into the Multi Story Car Park at T5 to provide a station at the entrance to the Terminal. The system will open for carrying passengers in Summer 2008 following the opening of T5 in March 2008.

With the almost-advent of plug hybrids (PHVs), how feasible would it be to allow private PHVs that conform to certain interface standards, to attach as needed to a grid used by trolleys?

E.g., one lane (the HOV) could be fitted with overhead power cables that trolley buses and PHVs would use. The trolleys too, would have on board power storage that would allow them to disconnect from the power line temporarily; e.g., to stop at a bus stop or overtake etc. It would then reconnect on the fly using an intelligent plugging system.

The grid could gradually be built out, just as HOV lanes, to provide longer drives for PHVs and of course for mass-transit trolleys. The main advantage being that more and more of the transport function would be switched to electricity that is hopefully made with near-zero carbon emissions.

Yes, there is a standards committee forming to allow dockable pod cars. You would probably want to leave anything more than 200 lbs batteries on the ground because it defeats the purpose of the system. A 500 lb car uses much less energy to accelarate than a 5000 lb vehicle with steel safety bars, air bags, and all of the parasitic weight that burns oil. PEC (Parasitic Energy Consumption) is a good measure to think about.

Vecicle PEC
Walking 1
Pod Car 3
Car 275
Light Rail 310

The referenced site says:

Light Rail has a PEC of 310, 3 tons of vehicle per 200 lb passenger

3 tons of vehicle per passenger?!? What, is the thing empty? You're out by an order of magnitude. Take, as an example, a relatively heavy car used by Calgary Transit: the SD 160 has 60 seats, can carry 200 (lots of room for standees), and weighs 42 tonnes.

The only way this is 3 tonnes of vehicle per passenger is if there are 14 people on it, which would make it look almost completely empty. Generally speaking in peak periods there are plenty of standees, but let's suppose there are no standees at all: 60 people, 42 tonnes, that's 0.7 tonnes per person, not 3! If it's full that's 0.21 tonnes per person - about the same as you claim for a prototype "Pod Car".

It gets better. The SD 160 is relatively heavy: 42 tonnes for a 25 m vehicle. The Siemens Combino is 28 tonnes for a 27 m vehicle. 2/3 the weight for about the same capacity - now you're at as little as 0.14 vehicle tonnes per passenger, significantly below what you claim for a "Pod Car".

Your average low floor transit bus weighs 12 tonnes and has seats for about 40 and room for maybe 70-80 full. That's 0.3 tonnes per seated person and maybe as little as 0.15 vehicle tonnes per passenger.

F=ma. Yes, you will need more force to accelerate a larger mass at the same rate. That does not mean, however, that a lighter vehicle will be more efficient at constant speed. What matters is the force required to overcome frictional losses; at high speed this is overwhelmingly air resistance, and at more "normal" transit speed it includes a fair component of rolling resistance. Steel wheel vehicles have far less rolling resistance to overcome than rubber-tired vehicles, in fact the coefficient of friction is an order of magnitude smaller for steel on steel! At a low speed where rolling friction dominates, the same force would be required to maintain the speed of a rail vehicle weighing 10 times as much as a rubber-tired vehicle!

I mention this because you have come up with some magical new measurement ("Parisitic Energy Consumption") which bears no relationship to reality. The universe doesn't work like that. You just multiply by the number of stop-starts?!? No consideration for, for example, recovery of energy through dynamic braking? No consideration of speed, or of the power required to maintain that speed?

In the real world what matters is energy consumption per passenger moved over a certain distance. Let me know when these promoters have some real energy consumption results, not made-up comparisons using useless metrics calculated with bogus data.

Remember that the trolley must accelerate and stop at least 10x more times than the pod car. The energy to accelerate is much more than the 2kw that you need to overcome wind resistance. Urban light rail rarely goes over 30mph anyway, so wind is not a big factor. Rail lines are possible with pod cars as well; they don't necessarily use rubber tires.

We will have real data when the London ULTra system goes on line but before then, we will have to estimate the data. Since you raised the issue, I'll do some more digging around for more solid data but I suspect they are close.

The claimed enery consumption for the Vectus PRT is here:

They claim: "660 watt-hours per vehicle - kilometer at 45km/h"

This is for a four person vehicle.

so, assuming the car is full, thats 0.165 kwh/person/km

Looking at it another way each car is consuming 29.7 kwh per hour of operation. 0.745 watts = 1 horsepower (sorry, I still think in "old units") so it seems they are claiming that it takes 40 horsepower input to the system to push each 4 person car along at 28 m.p.h., inclusive of losses.

Not exactly "mind blowing" efficiency in my opinion.;

Checking out these specs:

we see that in battery mode the Prius is drawing up to 21 kw from its battery vs. 29 kw for the Vectus PRT. Hard for me to see an energy argument for this PRT vs. a plug in hybrid Prius type vehicle, unless I'm missing something...

Something must be wrong. My friend get 600 watt hours per mile doing 50mph in his Ford S-10 ev conversion with 2000 lbs of batteries. The total weight is over 5000 lbs. I don't know what Vectus is doing to get 660 watt hours per km but something is very wrong here, other pod car concepts claim 2kw continuous instead of 29kw. I wonder what the ULTra system claims.

At page 9 of this pdf:

The ULTra system claims energy consumption of 0.55 MJ /passenger/kilometer, again for a 4 person car with a design speed of 40 km/hr

So: 0.55 MJ per person * 4 people in the car = 2.2 MJ per car per km

1 kwh = 3.6 MJ so thats 0.611 kwh/car/km. essentially the same as the Vectus PRT, though the ULTra is only going 40 km/hr, not 45.

According to their numbers, cars are 8.0MJ per car per km (using 4 passengers). A 4x improvement seems like an improvement to me. I do agree that they have not done thier engineering very well since the average Battery electric vehicle runs at 400 watt hours per mile [before subtracting 30%-50% for battery losses]. But since most trips are solo, the ULTra will get 152 watt hours per mile with one person. Considering today's solo driver, with a 23mpg car, uses 1580 watt hours per mile, we have a 10x reduction in carbon emissions for city driving with the ULTra. Once you add PV and avoid the battery nightmare, there is no comparison.

math error. Make that 254 watt hr/mile for the ULTra with one passenger.

Siemens study of Combino trams in service:

In service in Basel over 56 days: 7215.7 km, 19.1 km/h avg, 18 908 kWh consumed, 7870 kWh recovered, 1.53 kWh/km.

In service in Potsdam over 41 days: 6633.3 km, 27.05 km/h avg, 17 575 kWh consumed, 5358 kWh recovered, 1.84 kWh/km.

Let's take the higher speed, more energy-consuming service: that's 1842 Watt-hours per km, or 2950 Watt-hours per mile (since that's the measure you're using) for a vehicle carrying 65 passengers on average.

45 Watt-hours per passenger-mile!

At 245 Watt-hours per passenger mile the Pod thingies aren't even close. The particular service studied is two to three times as efficient as some of the heavier light rail vehicles with faster average service speeds. Some light rail cars also lack regenerative braking. Calgary claims 3.23 kWh/vehicle-km, which is 5.17 kWh/vehicle-mile, or almost triple the consumption of the Combino trams (despite very similar size of vehicle). Nevertheless, that figure is still roughly twice as efficient as the figure you quoted for pod cars.

This is more than a little different than the "pod cars have 1/100 the parasitic energy consumption" story that the pod car proponents are putting forth as the basis of comparison. It is either a gross error, or intellectual dishonesty in a blatant attempt to deceive. I invite you to investigate the facts in the real world, as they point to light rail in service today being more energy efficient than what you are proposing.

I would certainly support a "pod car" system over a highway filled with cars, but suggesting energy efficiency relative to light rail is a reason to build a pod car system is, to go all British on you just for a second, STUFF AND NONSENSE. A person interested in intellectual honesty would remove the section on "parisitic energy consumption", or replace it with one discussing actual energy consumption - something like "isn't it amazing that a car dedicated to one person could be almost as efficient as a light rail transit system" would be a whole lot more honest.

But train / tram cars don't carry 65 people on average.

Go to any train station or tram stop and spend a full day there. In one direction; against the commuter flow, all the trains/trams will be almost empty.

Except during the morning and evening peak, almost all the trains/trams will be empty in both directions. This is because passengers will only use the service regularly if they are guarenteed minimum service levels.

Most of the time train/tram systems move air from one place to another, on average they are not efficient.

The pods will move on demand. No demand, they just sit there. Clearly during the rush hours there will need to be a recycling of empty pods, but there will be much less pointless movements than in a rail system.

Stop-Start are the major waste of energy in commuter travel.

Kinetic Energy = 1/2 mass times velocity squared.

Every Start-Stop requires reapplying power to establish kinetic energy. PEC is a ratio of the moving mass divided by the mass you wish to move time the typical number of Start-Stops. The more Parasitic Mass, the greater the waste.

The light rail cars in Minneapolis weigh 50 tons. Take the number of trips per year times the 50 tons per car divided by yearly number of passengers and you get about 3 tons per person. Jammed packed they might get down to 1,000 pounds per person. But jam packed, JPods get down to 87 pounds per person.

JPods and other PRT solutions have only one Start-Stop in a typical commute. So the ratio of Parasitic Mass and PEC are useful but not precise.

Bill James
It costs less to move less

What is the watt-hour per mile estimate for jpods?

Fully loaded, 1700 pounds up a grade, against a wind our plan is to max out at 6kW. I will get the precise numbers. The rolling resistance is very low. A 10 year old can easily push our demo JPod with 4 adults. I will get an actual reading.

It seems you simply are unwilling to actually consider what I am saying. I'm sorry to have to burst your bubble.

Yes, these trams do carry an estimated 65 people per vehicle on average. That isn't particularly surprising, if you've seen light rail systems in places where they are well used. 65 is not as many as you might think: remember, the tram is 27 metres (89 feet) long - that's more than twice as long as a transit bus. In rush hour I would bet the average load would be well over 100. Besides, even with 1/6 as many people - about a dozen per vehicle on average, the light rail system studied would STILL be as energy efficient as the claim posted here for pods.

Yes, the energy consumption figures include starting and stopping. Did you miss the point in the example that I boldfaced that nearly half the energy used in propulsion is recovered on braking? Clearly boldface is insufficient...

I am well aware that kinetic energy is proportional to mass, but I am at a loss as to how you jump from this to any conclusions about overall energy use. Please read what I wrote about frictional losses. That is what matters. Yes, extra mass can result in higher energy consumption but mass is not the be-all and end-all. As I pointed out, a rail vehicle 10 times as heavy as a rubber-tired vehicle would not require any extra power to overcome rolling friction!

Stop-Start are the major waste of energy in commuter travel.

In internal-combustion engine vehicles, yes, in electric vehicles with regenerative braking: not really.

Most of the time train/tram systems move air from one place to another, on average they are not efficient.

If a train is mostly empty most of the time then of course it is not going to be efficient. What you see is not what is typical of rail systems, however. Hint: World != United States.

I understand what you are saying, with good regen systems, you can recover 40-50% of your losses. However, there are non-engineering reasons why light rail and bus systems have failed to catch on in middle class families.

  • 1. they are too slow
  • 2. they don't do to the right place
  • 3. they are very expensive.
  • 4. they compete for space with cars.

    You have convinced me that pod cars and light rail have similar energy requirements. However, these other factors offer some very compelling reasons for cities to consider PRT. Let's see which mayor will have the foresight to do it.
  • Light rail systems have failed to catch on in middle class families?!? By what measure? It is common for new light rail systems to attract a significant portion of their ridership from those who would otherwise have driven.

    1. they are too slow
    2. they don't do to the right place
    3. they are very expensive.
    4. they compete for space with cars.

    Too slow for what? What matters is travel time. If you live in a city that has places people want to go that are not separated by large parking lots and highways, then the distance you have to travel may be half as far. I would rather travel half as far at half the speed! It's more comfortable, safer, and more energy efficient. I would also be less reliant on mechanical means of travel and (gasp) might have the option of riding my bike or even walking there!

    Point 2 is rather silly. It's obvious you've never actually visited a city with a good light rail system. You can't just plunk a light rail system on top of suburbia-with-highways and expect the same sort of convenience as in cities which are walkable.

    They are not expensive relative to the alternatives. This argument is old and tired, and easily contradicted by many studies of road costs.

    They compete for space with cars if the political system is such that that is allowed. Rail systems can be easily completely grade separated if you want to avoid that competition for space, but this is really a backward way of looking at things - why not, instead, devote just a small percentage of road space to the rail lines and leave the 95% of the remaining road system to cars?

    The "pod system" solution is to elevate the line everywhere. And you say rail is "too expensive"! Kettle, pot, ...

    You and I will never agree because, I think, we approach urban planning from different attitudes. I think cities need to be compact, you likely have no problem with sprawl. I think highways are an incredible waste of space, you likely think they are necessary and a Good Thing. I think it is possible to build cities where many, in fact most, people can live without a car by choice. You probably think this is fantasy.

    this and this and this or this:

    versus, say, this and this and this:

    Oh, and if you grass over the tracks, you have no problems with cars
    getting in the way. :-)

    I am English; and have spent the last three years working for a joint venture between two rail installation companies working on the London Underground.

    LU has the biggest metro system in the world, and one of the most densly packed, famous for it's overcrowding due to chronic decades long under-investment.

    Check out table 6.7 of the government's department for transport statitistics:

    and you will see that the average number of passengers per train wanders between 100 and 120. Given a typical six car train that is less than twenty per carriage.

    Even in London the Tube spends most of it's time moving air around.

    This is hugely wasteful in energy.

    Amazing. Do they have numbers on watt-hours per mile?

    I'm getting more convinced that pod cars are the way to go. Building a whole new system will probably cost less than maintaining the highway system, buying gas and replacing our car fleet with hybrids, not to mention defending oil tankers and Iraqi pipelines. Even the most sucessful light rail system in Europe has not significantly impact carbon emissions. It is time for new thinking on transportation.

    I'm getting more convinced that pod cars are the way to go

    You have been a cheerleader since the beginning ! i.e. 110% convinced already.

    Even the most sucessful light rail system in Europe has not significantly impact carbon emissions

    WRONG !!

    Taxi 2000 /jPod is just another gadgetbahn. Unproven and decades away from widespread implementation. Costs and durability are unknown now, but serious problems can be forseen. (Working girls doing their tricks in the pods and leaving gooey condoms, etc. is one. Cleaning in general will be problematic and probably expensive).

    The danger is that Taxi 2000/jPod will draw resources from things that we know work, know the costs of, know the durability and safety of for a host of unknown unknowns.

    See MetroMover in Miami for a gadgetbahn failure with impeccable credentials (Westinghouse promoted and sold it) and a GREAT story. Operationally, costs were 4x to 6x what was promised. OOPS !

    We do not have time or resources fro another gadgetbahn failure (see also Las Vegas, Jacksonville airport).

    Best Hopes for Proven solutions,


    MetroMover is a heavy rail system with all the problems that I've outlined. No wonder it failed.

    If you are concerned about the high tech control systems, then install manual controls and let people control their own pod cars. It will still be much safer than teenagers driving around in 6000 lb SUVs on Saturday night. Pod cars are small electric trains, there is not much there that needs to be proven.

    The issue is public acceptable and I think it will be easier politically to build over existing highways. How are you going to get people in your town to stop driving so we can install a light rail system when trips take twice as long? That will take more decades than podcars. No doubt there are engineering issues to sort out, but the lure of non-stop trips lower the barrier to public acceptance (which is a tougher nut than the engineering).

    On the cleaning issue, each user could have a swipe car to gain access (and pay fees), so those problems can be solved by allowing the next user to report "a mess".

    Perhaps you are an electric car fan. If that is the case, the batteries are also an unproven technology. The ARB ZEB plans show mass production starting 2025-2030. What are we going to do with 100m dead exotic battery packs? Low tech pod cars, with the right design, could be scaled up much faster. Bicycles may be the only other proven solution. Am I missing something?

    Am I missing something?

    Ironically, a grip on reality ;-)

    Whatever. When there is a pod service from outside my door to wherever I want to go, I might start using it. Until then, I'm with Alan. Proven simple technology that is cost effective is all we need.

    MetroMover is a heavy rail system with all the problems that I've outlined. No wonder it failed

    HARDLY !
    (a building was built around the pathway)

    MetroRail, which is heavy rail, is turning into a great success as Miami voters have voted funding to expand the system to 103 miles (dark brown 2015+ plans).

    Pod cars are small electric trains, there is not much there that needs to be proven

    Wrong ! Pod cars are suspended monorails, not "electric trains". Very few suspended monorails in operation anywhere in the world.

    Life expectancy of the pods ? Wear items on the traction motors ? Switch life time & failure modes (effects of ice and accumulated bird droppings on switches)?

    What happens when someone lights up a cigarette and sets off the fire alarm (Personal experience, this shut down the entire Las Vegas monorail system for over an hour as I waited on the platform).

    Plenty of people use the new and established Urban Rail systems. As gas prices rise, the #s grow.

    As I noted in a visit to Miami in 2004, 15 of 23 construction cranes were within 3 blocks of a Metro station. Residences and offices were clustering around the open 20 miles as the rest were being built out.

    I have established a list of on-the-shelf systems that people will ride if they are funded and built.

    Best Hopes for Reality Based Planning,


    I have no problem in other nations working out the bugs and proving new systems. The USA can import the technology once proven in operations for a decade or two. The US is *SO* far behind that we cannot waste time, money or other resources on experiments. My view on this will change once we are spending more than $50 billion/year on new Urban rail systems.

    Great article. From what I can tell $150B will get us a 6% reduction in CO2 emissions. Since the IPCC report recommends a 60% reduction (which means 90% in the US). How much will light rail cost to get us to 90%?

    If you want an independent analysis, check out this comprehensive study of PRT in Northern NJ by Prof. Alain L. Kornhauser at Princeton. The title is Orf 467 Transportation Systems Analysis, Fall 2004/5. He does a county by county analysis. I'm not a backer of a particular implementation but the concept of PRT in general. I think the monorail idea is unproven so perhaps we need a two rail design to reduce risk.

    Perhaps NASA can be put on the project instead of trying to put a man on the Moon again.

    How much will light rail cost to get us to 90% ?

    Interesting question.

    I think your arbitrary adjustment of the goal from the 60% reductions to 90% reductions will not happen (i.e. the US will not voluntarily agree to an extra 75% reduction below a 60% reduction). None the less.

    The service density would be close to what we had in the US in circa 1916-1920, with an Urban form to match. Slightly over 500 cities and towns with urban rail systems, or at least one line. Cutoff appeared to be towns of 25,000. (Today, in France, the cutoff appears to be about 100,000 to get a new tram line).

    Bicycles were not perfected then, so an ideal mix with be more bicycling and less Urban Rail than 90 years ago. Grenoble France would be a good example of a bicycle-tram mix to minimize oil based transportation. Perhaps the cutoff would be towns in the 40,000 to 50,000 range today.

    As with France, larger cities first and work down the list.

    In the 1920 Census, 54,253,282 of 106,021,537 Americans lived in Urban areas.

    So roughly 5 times the effort with roughly twentyfive times the wealth and three times the population of the 1897-1916 period in building new Urban Rail systems. As then, primacy in right of way would go to the electric streetcar, but shared ROW would be common (see downtown streets of New Orleans today).

    Best Hopes,


    A key point about JPods. We do not intend to solve the world's problem. Our focus is to solve someone's problem profitably.

    We define profit as the value customers are willing to pay minus the cost to compete. As such we look for niches where our solution can dominate. It would be silly of us to say we are going to replace cars or trains. I think for the first 5 years we will deploy in great numbers connecting exiting modes together with on-demand service.

    If you could take a cab or a bus between the airport and train station which would you prefer. Most will take the cab if the cost is OK. We can offer cab service at lower cost than it costs to operate the bus. Better service, lower cost, we profit.

    For those concern about wasting taxpayer subsidies on JPods, please do not. I believe it will be rare for us to sell systems to cities. We are a inventive group, we want to invent not attend meetings about why 17th Century technology should be applied to the 21st Century.

    Based on riders per day, the most successful form of public transportation is the elevator. JPods are just a network of horizontal elevators. The technology is very simple. We can do simple things.

    "realist" said:

    Amazing. Do they have numbers on watt-hours per mile?

    Yes. Page 9 of the London Underground Environment Report - 2005 gives the figure as 151 Wh/km, which is 242 Wh/mile.

    kagiso wrote:

    This is hugely wasteful in energy.

    No, it isn't. It's the same as the hypothetical claim for Pods, which PRT proponents are claiming are far more efficient than mass transit. Stated in terms USians might understand, LU's consumption is 141 passenger-miles-per-gallon gasoline equivalent, even with only 19 people per vehicle. Keep in mind that only 40% of LU's rolling stock uses regenerative braking - their energy use can decrease significantly over time as they replace older rolling stock. As Alan pointed out, many train operators do not bother to make up shorter trains for off-peak service - it requires some effort, especially with trains that consist of a mixing of driving cars and trailer cars. If LU were to make smaller trains they could easily halve their energy usage in the off-peak. Alan is completely correct: an LU train with the capacity for as many as 1000 passengers gets the gasoline energy equivalent of 7.4 USmiles per USgallon, which is about the same as a diesel bus. Trains are very cheap to operate.

    Now, LU cars (according to Wikipedia) are 17.77 m long, making the quoted average of (say) 120 on a 6-car, 107 m long train equivalent to about 30 on a 27 metre long tram. So the average occupancy I quoted from the Siemens tram study had double the average occupancy of LU. That is not so hard to believe, given the ability to tailor supply to demand more easily by simply decreasing frequency. It is also possible that the distribution of sources and destinations is more evenly spread out on the studied line than in London.

    An 8 car train uses about as much energy as one bus.

    The labor cost/energy cost balance is such that it is not yet worthwhile to uncouple cars from the train after morning rush hour and recouple them again in mid-afternoon. Alter that ratio and energy efficiency will increase.

    However, many systems use shorter trains overnight and on weekends (the labor/energy balance works for that). Few systems will uncouple cars if it requires even a few people to stand.


    During a power shortage in Washington DC last summer, DC Metro cut top speed down to 40 mph (adds just a few minutes to schedule times since most schedule time is spent @ station stops and accelerating/decelerating). Reduced electrical consumption by about 15% I was told.

    I'll ask again - why are you a 'better' solution than the RUF idea?


    I think you slipped a digit on the old calculator there :)

    I didn't see that 8 MJ number you mention, I just took the 1 person number I found and multiplied by 4 to get the 4 person value, but fine, lets use your values... If we start with 8MJ / 3.6 (conversion to kwh) = 2.22 kwh/car/km with 4 people

    then / 4 = 0.555 kwh person/km

    converting to miles then * 1.609 = 0.893kwh = 893 watt hours per person per mile, not 152 as you say, or did I miss something?

    No, that is not what I meant, sorry for the confusion.

    The 8 MJ applies to gas cars not PRT. My main point is that most trips are single occupancy so it doesn't make sense to multiple by 4 and talk about "per car" energy usage. PRT is much better than gasoline and batteries just are not ready. The energy consumption for pure electric cars (published on the Idaho National Lab site) seems comparable but it is not clear to me that they are factoring battery loses and I'm not sure how they simulate driving patterns. The cost of batteries is still out of reach of production cars (and have been for decades) so we should implement PRT while increasing funding for battery research.

    Are you willing to risk the planet and hope for a miracle battery?The cost of failure is very high.

    If you don't like PRT, then we should go with an overhead wire or buried wire running electric vehicles but that doesn't solve the traffic problem. Light rail is too disruptive and has too many non-engineering barriers. PRT solves the right of way issue by going up. Steel and concrete supplies should be sufficient to build the system once we redirect highway money. It only costs $10m per mile.

    Typo in my last: 1 h.p. = 745 watts, not 0.745 watts. The calculation result is still correct, just put the "0." in by mistake

    The interesting thing about Ultra is that BAA have decided to go ahead on commercial grounds. This is not a publicly subsidised experiment.

    If you look at the case studies:

    their analysis for Heathrow claims reduced operating costs as well as a good NPV compared to the existing shuttle bus system. It also claims reduced emmissions compared to buses, which must mean substantially reduced emmissions compared to cars (automobiles).

    Now normally I would be very sceptical about claims from innovative transport technology companies, but the fact that BAA has invested in the company, and is building the system suggests to me they have probably checked the numbers pretty carefully. If so, then this system should be commercially competetive in any location that has high density bus use, and I guess would be commercially competitive versus light rail and metro rail systems.

    The passenger advantages of privacy and speed (as you don't stop at all the intermediate stops on your journey) are likely to make it very popular with the public.

    With regard to fuel use the benefits are subtler compared to light rail / Metro. Outside rush hour there will be far less return journeys carrying air back against the flow of people. Also at quiet times you won't need to run a regular service carrying air backwards and forwards in both directions. Even in busy, high density London, most tube trains are empty most of the time. Unless you are travelling in the morning and evening peaks you can usually get a seat with no neighbours. This may explain some of the discrepancies noted in the figures above.

    Personally I think this is a technology that has come of age, and I can see it spreading like wild fire.

    Monorail proponents always see monorails spreading like wild fire. Any day now. Any... day... NOW.

    I would suggest that any system with thousands of individual vehicles and switches under centralized software control is unlikely to work well at all times - or, perhaps, at all. Those who suggest otherwise have probably never seen the workings of software companies, especially those involved in safety-critical software. I wouldn't touch a large, automated Pod Car system with a 19 thousand foot pole.

    18 vehicles and 4.2 km is a toy system by comparison. I honestly hope it works well, and I certainly support such a system over diesel buses, but, again... PRT is not the panacea that PRT proponents suggest it is, and I think it very unlikely it ever will be. But then, I believe in cities where people interact, rather than highways and people in their own cocoons.

    As a PRT developer, we are all for toy systems. When I started using the Internet it operated at 300 baud, a toy system. It iterated to what we have today.

    Our patent is on using distributed collaborative computer networks to move physical packets; a Physical-Internet. It will start with small networks and iterate often.

    Bill James
    It costs less to move less

    When I started using the Internet it operated at 300 baud, a toy system. It iterated to what we have today.

    You might want to get your facts straight in this area as well. Your connection to a machine with Internet connectivity may have been at 300 bits per second, but I very much doubt any significant links were anywhere near that slow, ever. Take a look at RFC 662 which deals with the problem of Multics being slow, and mentions transmitting over ARPANET at 40,000 bits per second. In 1974.

    If you don't know what ARPANET is then I'd suggest you stop saying anything at all about the Internet. Your ignorance is showing.

    Here, I'll help you out: At about 10:30 PM on October 29'th, 1969, the connection was established over a 50 kbps line provided by the AT&T telephone company, and a two node ARPANET was born.

    50 kbps is 50,000 bits per second. That's a tad more than 300 bits per second.

    I also agree with you that central control will not work for large complex systems.

    Our approach is like bees in a hive; a distributed collaborative network where individuals only interact with other individuals relative to their task at the time.

    Instead of a central processor handling thousands of trips, the network manages one trip, thousands of time.

    Bill James
    It costs less to move less

    Sort of like... traffic regulations and traffic lights. Except instead of thousands of distributed points of failure based on human beings you have thousands of distributed points of failure based on vehicle electronics and communications systems, with, unless I'm missing something (I apologize if I am) no human override.

    Good luck with that.

    Outside rush hour there will be far less return journeys carrying air back against the flow of people. Also at quiet times you won't need to run a regular service carrying air backwards and forwards in both directions.

    Unless there is an infinite supply of pods, empty pods will still have to travel around the system ;-)

    I can see pods replacing shuttle buses, but these are a tiny niche. Note that the application here is taking people from their car to another form of transport. Unfortunately I can see pods replacing walking. Instead of walking the short distance from car park to shopping mall, people will travel by pod from car to mall.

    A pod network makes great science fiction (e.g. Minority Report), but I find it hard to see who will build the infrastructure to make it widely applicable.

    Comparing physical transport to the internet is a completely bogus analogy. Information can be miniaturized; people can't. That is why computers can become millions of times faster but the average speed of traffic in London is the same as it was 100 years ago.

    Comparing physical transport to the internet is a completely bogus analogy.

    Ah, but Bill James' company uses the trademark "Physical Internet", so I doubt you will convince him of the limitations of such an analogy.

    A pod network makes great science fiction (e.g. Minority Report), but I find it hard to see who will build the infrastructure to make it widely applicable.

    Ah, you just don't have Bill James' vision - or his patent.

    Bill James' company is actively seeking investors. I, on the other hand, have absolutely no business interests related to transportation. I am here only to set the record straight, as lies such as "Mass transit is worse, typically moving 3 tons to move a person" should not go unchallenged. So, how about it, Bill James, given all the evidence to the contrary will you at least remove that one claim from your web site and investor presentation?

    (Need I reiterate? 3 tons per person would be only 4 people on a bus, for example. If your bus system carries 4 people per bus on average then you live in a place which cannot be served by buses! In which case you probably own a car to take you to town...)

    If you want an independent analysis, check out this comprehensive study of PRT in Northern NJ by Prof. Alain L. Kornhauser at Princeton. The title is Orf 467 Transportation Systems Analysis, Fall 2004/5. He does a county by county analysis. I'm not a backer of a particular implementation but the concept of PRT in general.

    Unless there is an infinite supply of pods, empty pods will still have to travel around the system ;-)

    Empty pod cars are an additional cost but empty buses and empty rail cars have a much higher cost. Parking lots for pod cars will be much smaller than parking lots for cars. Imagine what you can do with all that extra real estate.

    There is money in them thar hills!

    Imagine converting half the streets in a residential area to parks by removing cars from the suburbs. In cities, you could increase housing density.

    A pod network makes great science fiction

    Some of the best ideas came out of good science fiction, but a more accurate term is urban planning. Hydrogen fuel cells and cellulosic ethanol are closer to fiction than electric vehicles. Have you ever seen an electric bus in San Francisco? Imagine some concrete instead of an overhead wire. Add some PV cells for a roof and you have a real system.

    Empty pod cars are an additional cost but empty buses and empty rail cars have a much higher cost.

    The peak capacity required will be the same whether it is pods or rail cars. e.g. 20,000 rail car seats vs 20,000 pod cars seats. Just swapping rail cars for pods cars achieves very little. If the off peak requirement is 1000 seats, you just trade empty pod cars for empty rail cars. No advantage.

    Some of the best ideas came out of good science fiction,

    Being a fan of science fiction I have researched this. No practical development ever came out of science fiction. Invariably the science preceded the fiction. True A.C.Clarke who is a SF author invented geostationary communications satellites, but that was not presented as a work of science fiction.

    As for futuristic electric vehicles, the first electric tram operated in 1881. Don't get me wrong, I like electric vehicles, if I could get in my EV, tap in the dest and sit back I think it would be great.

    The problem is how will the current infrastructure be converted; I don't see it happening. What exactly is the advantage of having cars run on tracks anyway? Computer guided electric cars are a more likely evolution. If the pod is under computer control, it doesn't need to be in a track. It can just follow a wire in the ground, or a white line, or a car in front, GPS whatever.

    Turning cars into small trains is more of a 19th century idea, than a 21st century one. Even adding solar panels, it's still a half-bake idea. Infrastructure costs, dammit!

    We have planty of money to spend. The US expenditure on petroleum prodocts and highway taxes is $900B per year (assuming $3 gas). If you add the car idustry there is another $300B. Most of that money is exported to other countries.
    The main barrier to light rail is the fact that trips take twice as long as driving. Even it were free, most wouldn't use it.

    The main win for PRT is the speed besides the efficiency. The system should be cheaper than our current CO2 generation machine. Global warming is coming and we need to launch a big project after the next crisis. Check out the Princeton study on PRT in NJ to get a detailed analysis. PV was not included but if we include PV, it avoids having to expand the capacity of the grid. That is a huge savings.

    I never thought I would get to comment on this on TOD, but with Tiger Direct, you get what you pay for...see the complaints filed with the Florida BBB...

    Khosla's claims were a great deal more realistic than some here might have expected.

    He has moments of clarity. But you said you didn't see the first of his talk. In his standard ethanol presentation, the misleading claims are front-loaded.

    Doesn't seem like there is much discussion of biofuels there. Was that not on the agenda?

    [This is not a knock on you or in anyway related to an Oil Co. signing your paycheque]

    Lately API (the American Petroleum Institute) has been complaining that they are afraid of committing capital to fossil fuels because bio-fuels may siphon demand from fossil fuels. If these fellows are running scared perhaps there is something to bio-fuels after all. Ethanol via fermentation is probably not the way to go but there is that and other alternatives.

    Biofuels should be encouraged via active government tax policy. A 50-100c tax credit per gallon, to be reduced on a sliding scale to zero when wholesale gasoline/diesel cross a threshold price (say 2.50/gallon).

    An escalating pollution+carbon tax on fossil fuels (e.g. gasoline and diesel) would be nice too.

    Straight up isn't going to happen. The US has the LOWEST taxes on Gasoline of all 1st world nations.

    Unless some miracle happens, and the tax passes good luck. I agree with a sound mind that taxing gasoline or all FF in general and redirecting this tax to alternative transportation or wind power/solar/nuclear solutions.

    Hi chem,

    re: "If these fellows are running scared perhaps there is something to bio-fuels after all."

    Another possibility: their "scared" has not much to do with the reasons they give for it.

    If these fellows are running scared perhaps there is something to bio-fuels after all.

    I already commented on this yesterday:

    I am going to call BS on this one. If the oil companies believed that it was actually possible for biofuels to displace 20% of gasoline, they would be investing billions in biofuels. Instead, I see this as more of a scapegoat in case refinery expansions don't happen as planned. I have no love lost for the (corn) ethanol industry, but this time I don't think the criticism is warranted.

    Aniya has also commented along similar lines below. It has nothing, IMO, to do with running scared. I think this is a political, attention-deflecting move. I have yet to meet anyone within the industry who thinks biofuels can displace 20% of gasoline - unless there is a massive reduction in gasoline usage. But, they can point to that and deflect some criticism for failing to expand as fast as the politicians think they should.

    I agree.

    It's easier to blame the biofuel boogeyman than the real monster, Peak Oil.

    That, and the fact that they probably see wealth permanently declining in the USA and increasing in Asia and so they'd prefer to make money over there than over here.


    The backlash against ethanol has already begun.

    Not the least from the livestock growers who are paying for all this.

    And *they* supply the fast food industry, and the supermarket industry. Both of whom are politically quite influential.

    ADM may have created its own enemy.

    If these fellows are running scared perhaps there is something to bio-fuels after all.

    I don't see the contradiction. There doesn't have to be anything to biofuels to make it economic nonsense to invest in refinery capacity. All that takes is a tiny demand shift.

    Even if the total potential of biofuels is only a few percent of current use, that, in combination with fuel economy regulations, makes it ludicrous to invest in anything to do with an oil refinery. After all, gasoline demand is quite inelastic.

    Any such investment will not come to fruition for some time, making even more risky. And it's quite evident from all the political yowling that anyone who builds anything is not going to be allowed any risk premium, because that is about to be criminalized for "gouging". (And, to boot, next year is an election year. So look for the stupid public to get the shortages it so richly deserves.)

    >>(And, to boot, next year is an election year. So look for the stupid public to get the shortages it so richly deserves.)<<

    All help in squeezing the fossil folks is welcome.

    I am having a hard time buying this refinery issue. I think that refineries are operating at a level that is just enough to prevent a run down in commercial crude oil inventories because crude oil is in short supply.

    The economics are complicated, but he claims that the various California and Federal RE credits make a household PV system pay off in as little as 9.9 years given current cost trends. The prospect of a much greater Federal tax credit could drop the payback to the region of 6 years.

    How much of the costs are covered by these credits?

    What would be the payback time without them?

    The cost of PV depends entirely on your projections for future interest rates for financing versus inflation in the price of electricity, and the time period you are willing to amortize them over (25 years? 40 years?).

    Alright everyone, I have a GOOD question.

    I have been searching for data on the rate of depreciation in the efficacy of solar panels over time. (photo voltaic cells, the effect was theoretically understood by einstein, and it was what he won the nobel prize for)

    My basic knowledge of PV systems tells me that proper hole/extra electron crystal defects becoming less optimal over time in some manner. I was wondering if anyone knew the rate at which this occurs. This is an important factor in assessing the ability of solar panels to provide LONG TERM energy for the planet.

    Thanks for responses in advance. I will likely post this one more time in another thread if i cannot get some response. (only once more)


    Solar PV manufacturers' ratings generally include long-term power output (at standard conditions, i.e. efficiency of conversion). For example, the BP solar warranty guarantees ≥ 90% of initial efficiency at ten years and ≥ 80% at 25 years.

    If the decay ia an exponential approach to zero (that is an assumption with weak support) then the time constant seems to be ≈ 100 years, i.e. a half life of about 70 years.

    Edit: added "long-term" to first sentence.

    The half life of PV solar probably has more to do with the prevalence of hailstorms and other external events, than any intrinsic property of the silicon / glass / copper...

    You are right to question the long term reliability. They are hardly elegant systems. First pn junctions will be damaged by cosmic radiation. I presume they are OK with UV etc, but where is the data? Then there is water ingress in the cells and terminations [extremely likely in the UK]. Then there should be corrosion due to DC flow, anodising etc.

    Since these are serial arrays to generate useful voltages, reliability drops by factor [n] serial connected cells. Parallel arrays will lose current delivery.

    I hardly think the manufacurers or gravy-train academics or gov organisations are going to give us real world numbers

    Hi pond,

    Many hazards, it seems.

    So, the question, perhaps becomes, what is the replacement (energy) cost and how to plan for that?

    re: "Paralell arrays..." Are there any ways of building overlap into the system? Or, do they do this already?

    re: "gravy-train" academics - ? It seems a little survey of systems in operation might be quite useful. Has anyone done this?

    The Toronto Exibition Place 100kW Solar PV demonstration project was installed last fall and cost $1.1 million ($11 CDN/peak watt), which it only hits for a few hours through solar noon in the summer.

    They estimated 22 years to reclaim the investment at $0.42/kWh under Ontario's Standard Offer Program. Which is allowing $0.42/kWh for PV and $0.11 for all other renewable systems.

    You can watch Exibition Palace the live output stats (requires flash) of the 100kWh installation in Toronto.

    There is only data since last August and they should have a much better month this June, but the 100kW Solar PV installation worst functional month was 1.8MWh (January) and best was 13MWh so far. At the $0.42/kWh this translates to $756-$5460 per month or 16-121 years to reclaim the investment. At a more reasonable $0.11/kWh wholesale this is $198-$1430/month or 64-462 years to break even on the investment.

    I would think the real annual output will land in the center and at the $0.42/kWh rate, they will reclaim the $1.1 million in around 40 years if the panels output doesn't degrade severely through that period. The contract is a fixed 20 years at $0.42/kWh, after that they are on their own with degraded panels.

    So, if PV cost drops, the efficiency improves and the panels don't degrade for at least 20 years and you are willing to pay 4x the Canadian average retail price for electricity, have no power at night or for 3 months of the winter, things are looking good for Solar PV in Canada.

    Ontario's Standard Offer Program has attracted several planned 10 MW Solar PV projects with the $0.42 kWh rate. Rather that put up 100 million worth of solar PV, a good scam could install 10 MW of diesel generators and fake cardboard solar PV farms and make a profit. You would just have to make sure you power down at night or whenever the sun is behind the clouds so the power authority doesn't catch on.

    When the guy selling you Solar PV claims you can recover the costs in 10 years with a bunch of rebates, that might be true based on retail peak electrical cost in the southwestern US. This is also calculated by the guy selling you Solar PV and if you check his resume he probably sold used cars at some point.

    Caveat Emptor

    I live in Canada, and it's a pretty dumb place to build solar panels (period). (Above the 49th parallel)

    Wind Farm the praries, Hydro Quebec/Northern Ontario(pretty much anything in the shield), use the Tidal resources in the bay of fundy to get some rediculous number of watts, (10 m deep differential for nearly the entire bay*the area of the bay). I think I have heard 10's of gigawatts from a fully blocked bay.

    Durability of Solar panels:

    Sharp Corp., maker of solar cells and panels, says they should be good for 20 years.
    Interestingly, Sharp gives the lifespan of other components in the system at about 10 years, in other words the panels will outlast other parts. Most people never think to compare solar components to the durability of current HVAC components such as air conditiors and central heating units or furnaces, which normally age out in not much over 10 years.

    Schüco in Europe also uses the 20 year durability number, and claims the panels to be resistant to UV light and pollution

    California installer Electroroof gives 20 year warrentee, but goes further saying “with a much longer projected service life”. They also point to the added advantages of protecting the roof from damge by UV degradation and reducing heat absorbing into the building in warm/hot climates (such as California) The roof life is thus measurably extended, and the thermal characteristics of the building improved.

    Efforts are underway to certify the reliabilty, durability and performance of solar panels and components:
    Underwriters’ Laboratories of Canada (ULC) and Bodycote Testing Group (BTG) Take Action to: “Certify the Sun’s Energy!”

    Examples of Sharp Solar installations:

    The PV option is growing very fast, and mainstream mulit national customers are beginning to use the solar option, such as major retail stores including WalMart, and large commercial firms with vast areas of flat roof space nation wide.

    The methods of large commercial installation are becoming more and more rationalized, so that with future installations, costs will be reduced, and system integration improved.
    Dupont Corp and German German manufacturer, alwitra Flachdachsysteme GmbH. for example have worked to create a system that is completely installed by the roofer:

    We must not be surprised if the reliability of solar panels comes under withering attack. Since only time can give us proof, this issue is a perfect tool to use to attempt to sow distrust of the solar option in the minds of potential customers and investors, slow progress, and attempt to hobble development of solar before it can get out of the crib.

    Pondlife’s sentence is a perfect example:
    “You are right to question the long term reliability. They are hardly elegant systems.” (compared to?)
    “First pn junctions will be damaged by cosmic radiation” (citation, evidence?...when will damage be noticable, 10 years, 20, 50? Are outdoor utility operated electric grids noticably damaged by cosmic radiation?
    “Then there should be corrosion due to DC flow, anodising etc.”
    There should? We would hope if the system is well designed, there should not, at least not to a degree that would degrade the system before the warrentee on system runs out (one assumes the manufacturer-installer having to stand behind the warrentee hopes not!)

    Sustainable Wiki, as another example of the type of attacks the solar industry will face, states as a disadvantage of PV systems:
    “High energy cost- Require much energy to produce (although not more then they will eventually produce themselves, contrary to some rumors) [verification needed](look on moodle for a citation on this)”

    Note the way in which “some rumors” are now spread yet again in a back handed denial of the rumors! Is there ANY scientific evidence that PV solar is, or anywhere near energy negative in their construction compared to the energy they will deliver? Can PV solar have a negative EROEI? Of course not, but the only possible citation is listed as “moodle”.
    I went to a
    It was a “course management system designed to help educators who want to create quality online courses.” I could find no discussion of solar at all, so I cannot refute the bogus "rumor" using "Moodle" until I find out what it is.

    One is already hearing idiotic stories that PV solar panels are so heavy they will cave the roof of a building in, they will consume vast quanties of rare minerals to manufacture, they will consume millions of acres of virgin land (even though they are best put on roof space or in "brownbelt industrial areas) they will create dangerous power spikes and valleys that will destabilize the grid, on and on and on.

    The public has proven to be very prone to believeing such wild attacks (witness how effective many of the bogus attacks on hybrid automobiles have been (and the attacks on plug hybrids will be far more slanderous and deceitful) and wind power have been. It seems the only alternative that gets any positive press is bio fuel (????)

    Years ago, in a business management class, I was exposed to a test. A businessman had said that vested interests had almost killed his business before it could get off the ground, by spreading lies, false rumors, and innuendo against his product. A business consultant told him he was making excuses, business couldn’t be done that way, and if his product was good, it could not be so easily slandered. They argued this, and came up with a test both could agree on. They would have a story placed in the newspaper and a few trade publications, proclaiming a product that, even though it did not exist would threaten the stability of a long standing industry if it did exist.

    They agreed on a pet birth control device. It would be an “electric chastity” harness, that an owner would put on a female dog, placed in such a way that if another dog attempted to mount the female, he would receive a small electric shock that would “deter” his effort and send him packing.

    Within days, there were stories in the newspapers that this device had electrocuted several dogs according to “informed” veterinarians, or that it had “backfired” and killed or injured the female dog wearing it. Other stories had said the device would cost in the hundreds of dollars, even though no price had been discussed in the original announcement, and still others were saying they didn’t know, but there could be danger to a child if they tried to pet the dog, and the child could be painfully shocked, etc, etc. Some veterinarians had already contacted animal rights groups to forbid this dangerous device

    Now, NOT ONE of the devices had ever been produced or delivered, it was a fictional product!

    Of course, the bread and butter work of veterinarians has always been spaying and neutering dogs and cats. Faced with a threat to this lucrative business, they went on the attack and began to spread stories before the device that might damage their income could ever reach production. The truth was not an issue, they were faced with a threat and they fought it, before it could ever be born.

    Make no mistake, the PV solar industry, the plug hybrid auto, advanced batteries and wind are taking on industries MUCH more powerful than veterinarians.

    The lies, slander and outragous attacks they will face have already began.
    And you ain’t seen nothin’ yet.....

    Roger Conner Jr.
    Remember we are only one cubic mile from freedom

    Here's an interesting history of amazing power-saving inventions that were mysteriously "suppressed."

    This 1959 Opel modified by Shell (the oil company) engineers got 373 mpg back in 1973 -- winning a company contest for fuel efficiency. They even published a book about it!

    The list of "solutions" by the bigwigs is not very impressive. And "podcars"? Please. I'll take trains any day. They work just fine. Most people in the US have no experience with a proper train system, which is in use in the rest of the developed world (Europe, Japan, Hong Kong, Singapore, Korea etc). With a proper train system, an urban dweller doesn't need a car at all.

    The public has proven to be very prone to believeing such wild attacks (witness how effective many of the bogus attacks on hybrid automobiles have been (and the attacks on plug hybrids will be far more slanderous and deceitful) and wind power have been. It seems the only alternative that gets any positive press is bio fuel (????)

    I can remember the same sort of stuff against ethanol when it first came out in the 1970s.

    It seems to be the same for just about anything - resistance to change.

    A little story, since the Indy 500 runs this weekend. Remember in the 1960s, Mario Andretti drove the 1st ever turbine, and almost won? There was cheering when the car broke down on the last lap. Three turbines ran the next year, AND THEN THEY WERE BANNED!

    The Indy 500 had always proclaimed itself the testing ground for the development of new and improved automotive technology, so this was a pretty ironic move. But it was a pretty popular one - people overwhelming HATED the turbines. Why? Partially because they were quiet and didn't create that deafening roar. But mainly just because it was different and new, and people felt uncomfortable with that.

    It is a shame, because turbines were an interesting technology and should have been given a fair trial. I don't know what our situation would look like today if we were all driving cars with turbines instead of ICE engines. Maybe we'd be better off, maybe worse. But now we'll never know.

    You have put your finger on a real and dangerous phenomenon.

    Very well put.

    To quote Napoleon Bonaparte: "God is on the side with the best artillery"

    & the Fossil Fuel interests have trillions in artillery.

    However, no slur on Napoleon, But there was Waterloo ;-)

    I hardly think the manufacurers or gravy-train academics or gov organisations are going to give us real world numbers.

    So, the manufacturers who are giving long-term warranties on panels are planning on doing what to escape the liability when their products don't meet them?

    First pn junctions will be damaged by cosmic radiation.

    Diodes and transistors are similarly vunerable as they also contain pn junctions. However, conventional devices can generally take tens of grays (radiation hardened devices would take 100 times that). Cosmic rays are unfortunately usually measured in sieverts (at 300 to 1000 μSv/year) i.e. ≤1 mGy/y in tissue. Energy deposited in Si would probably be higher, however even at 100 mGy/y it would take centuries to reach a failure-likely total dose. Alternatively if it's somewhat faster, this effect might be responsible for a substantial fraction of the known output degradation.

    The more dangerous cosmic-ray-induced failure mode is single event failure where a single particle hit in a vunerable location causes a destructive current surge through a reverse biased junction. However solar cells do not have enough stray carrier gain (no lateral parasitic SCRs) to create a self-sustaining current flow, and the inherently low bias voltage will limit the pulse energy. Thus I think that singe event burnout could not affect an entire cell; it may be capable of producing small (μm ∅) "dead spots" but I rate that as unlikely.

    Cosmic Rays? Cosmic Rays? The junction in a typical solar cell is typically just loaded with defects, as doesn't actually have to be very good. This is easy to see as the reverse resistance is often just a few ohms, in contrast with dozens of megohms, or more, for a large-area power rectifier, which does need a good junction. Large-area power rectifiers last a long time, despite avalanche multiplication of any charge deposited by cosmic rays (which are not stopped by even the heaviest likely packaging.) And some satellites have been up for as long as 20 years as so under heavy radiation (which is mostly not cosmic rays but does reach the junctions, which are almost at the surface.) This notion of cosmic rays being a serious threat is just nonsense.

    If panel reliability due to open circuits in series strings ever proves to be an issue, each cell could be paralleled by a reverse-connected schottky rectifier. This might cost as much as a whole cent per cell, as even a very bad schottky rectifier, utterly useless for any other application, will do. So far as I have seen on real-world panels, no one has yet deemed this necessary. A more likely result of corrosion may be a short circuit, and the loss of an occasional cell to a short circuit is not a problem.

    Water ingress is a known (and tough) problem. The car industry, for example, has for many years constructed devices that are far more complex and vulnerable than a solar panel. Cars work most of the time. The issue is manageable.

    There are panels that have been out there for many years, so we don't need to rely entirely on academics (whose real problem, sometimes, is not so much the gravy train as it is a certain disdain for addressing the real world) for our information.

    Parts of my system are 10 years old now, 3 months ago when I lasted tested it all of my panels where still putting out at better then 95% of rated power. (some have been under seawater in the past and are still putting out)

    My problem with Panels are rusting of the terminals and wiring that lead to less power getting to my batteries. (just a maintenance issue)

    Damage to panels by wind and salt spray is my biggest problem down here. (a replacement issue)


    Off Grid, Off Mainland, current profession:Beach Bum

    20 Year Warranty on Power Output at 80%, according to United Solar for their roofing laminate.

    The failing component is probably the polymers and goo and stuff, which don't hold up indefinitely in direct sunlight. I just had the old fashioned composite shingles replaced on this house, they were supposed to last 15 or 20 years, but only made it 8 in the Texas sun.

    Polymers indeed don't mix well with sunlight. However, a typical solar panel will be built on the back side of a sheet of tempered glass, as this is the cheapest and sturdiest transparent support. The glass retards the deterioration of the "goo" by absorbing much of the ultraviolet. The glass provides mechanical support, so the "goo" doesn't have to stand up as well as plastic that needs to be self-supporting. In addition, since the "goo" need not be highly rigid, there is extra flexibility to choose a more UV resistant sort of "goo". And we already know that "goo" used as the middle layer of automobile glass can last for a very very long time. So the issue is certainly manageable. (Naturally, somewhere along the line, someone will screw up and use the wrong material, and that will bring out a large chorus of nattering naysayers. But stuff like that happens with every conceivable product and technology, so ignore them. I'd be a lot more worried about the intermittency issues, and the long-run issue of having the entire economy utterly at the mercy of the vagaries of the weather.)

    But goo is flexible. I don't know precisely what United Solar's shingles are made of, but glass probably wouldn't be flexible enough. They are designed to replace composite roofing shingles.

    I like the company enough I've put some of my retirement account money into it. They must have done at least some research on the solar life of their goo, if they feel confident enough to warranty the product for 20 years.

    Thank you guys very much, the empirical data is good because it indicates 'real world conditions' even if it is sparse. Cosmic radiation typically disperses in the upper atmosphere/stratosphere/exosphere so I am not too worried about that. (I wonder about satellites)

    I was aware that solar cells require maintenance, and being SS(solid state) devices that they would probably outlast the materials they are attached to. Also how feasible is it to open up solar panels to replace dead cells. To my knowledge, most cells are laminated front and back...

    Anyways, thanks a bunch, the toronto exhibit stuff was also very useful.