Solar House competition

For those who missed seeing this on the news (grin) there is a student competition on the Mall in Washington D.C. this week.  Some 18 colleges have brought houses to the Mall and re-erected them for the competition.  Not only must the solar panels power the house (including fridge, hot water, air conditioning etc) but it must also power an electric car.  One might say it is a little more immediately practical than the solar car race that DOE also sponsors.  

At present Colorado appears to be winning the competition.  I won't get there until Sunday (for another meeting) so will miss seeing them before they are disassembled, but for those who have the chance, it may give you the ability to see what sort of a lifestyle we may have to adapt to in the not-to-distant future.  And, to be honest, apart from being a little cramped it is not all that bad. But go and judge for yourself.  ("Cos, since we are not winning, ol' grump here thinks they may be scoring aesthetics a bit too high, relative to efficiency).

Oddly enough, solar powered homes don't have to be "cramped" at all really. Too many people fail to study the efficiencies and gains made in earth sheltered housing built with concrete and steel instead of wood framing. Such homes can even be made completely passive for heating and cooling, taking advantage of the underground mass. And therein lies an interesting observation - well designed passively heated/cooled solar powered homes can actually be more efficient by being somewhat larger than smaller by exploiting more underground surface area to use for storing and extracting heat. When you couple earth sheltered or earth bermed housing with solar electrical production, you can have a very comfortable home. And properly designed, you even get plenty of sunlight along the south face.
In fact the walls of my favourite type of house - Straw bale - have an insulation 'R' value of up to 20, compared to an 'R' value of about 2 for conventional timber-framed houses.

Straw-balw houses also have a very aesthetic look about them.

And they are not just for hot climes, either.  At the very bottom of the South Island here in NZ, a company has done very well building some beautiful straw-bale homes that withstand several feet of snow each year.

One doesn't necessarily have to go to a earth-sheltered home to get those benefits. A good example is 'The Passive Solar House', by James Kachadorian.  (A good book, that desperately needs to be updated.)

Also, typical strawbale construction also includes a fairly massive heat-sink, partly in the plaster on the interior of the walls but mostly in the foundation and perhaps the ground below and around the foundation.

Most of the green building crowd is pretty down on concrete and steel because of the high embodied energies of these materials, never mind their abyssmal insulative qualities.

The jury is still out on which building method is the greenest. There are very opinionated camps in support of almost every method.

Taking advantage of the temperature differential between the surface and underground (usually the inverse of each other) is a big key to heating and cooling. The New Mexico Indians built their dwellings at just the right point where the radiant heat from the day's sun would "heat" the homes at night when the desert temperatures would fall dramatically.

Passive solar is a pretty good investment if only builders would start to design stuff right.

Cramped? You guys think those places are cramped? Only the ones without decent windows look cramped. The rest seem like paradise, at least from over here in Tokyo...
I really should get down there.  I caught myself not being fair, criticising some for looking so much like solar houses, and others for not looking solar at all.  Looking at each webpage, I tried to think of one word that described my visual reaction to the entry:
Cal-Poly - Wall
Concordia - Cottage
Colorado - Panels
Cornell - Lids
Crowder - Cabin
Florida - Glass
Madrid - Duplex
Maryland - Diner
Mass - Double-wide
Michigan - Quonset
Missouri - Catalog
NYIT - Sheds
Pitt - Wooden
Puerto Rico - Face
RISD - Garage
Texas - Lake
VPI - Drive-up
Wash - Airport
During the late 1970s and early 1980s I was very much interested in solar energy and did some amateur dabbling in various aspects of it. One of the things that I made a few crude attempts at doing was to analyze domestic solar heating in terms of the amount of energy invested in creating the system and how many long it took of absorbing solar energy to pay back that energy.

 I no longer have those calculations, but I do recall being rather surprised at how many years it took to recoupe the energy invested ( I vaguely recall a number like 6 or 7 years). The big problem in doing such an analysis is deciding where to draw the envelope, and that question leads to all sorts of arguments as to what should and should not be included.  

Does anyone have a handle on this question or who could lead me to a website that addresses it?   I would think (hope) that the energy payback period has improved  over the last 25 years.  But I suppose that my main point is that the attractiveness of a domestic solar heating system should be viewed not just in financial terms but in terms of energy payback (the two not being the same). After all, isn't that the whole point of the thing in the first place?

Check out this guy. He really seems to know what he is talking about.

checkout RETScreen international .  Among other things, there is an introduction to the concept of using perforated metal sheeting as a solar collector .  
I was unaware of the concept .  For those of us who are  not engineers , I think that some homes could be retrofitted with minimal cost and minimal skill .  It is my WAG that such a system would repay its cost over one winter .  
An aside: I have the impression that few people are aware of , or willing to discuss, scaling .  How many people are really willing to live on 5% of the energy which they consume now .  How many people really buy the hydrogen hoax ?        
Since solar efficiency has increased and cost per watt has somewhat decreased, the payback period is reduced.  The EROEI goes from very low (1.x) to moderate (13) depending on what assumptions you wish to make and what religion you believe in.

One could argue that
  a) even if EROEI is relatively low, it is still a better use of current cheap energy than pouring it down a auto gas tank.
  b) homeowners decide based on purchase price payback, not EROEI.

the people I talked to at the solar home tour a couple of weeks ago are thinking more about what the payback period is on utility savings and home value rather than strict EROEI.  This requires some guessing at future energy prices.  While in the past, it looked like the payback period was as long as 25 years, the payback period has improved to the point that solar is on the edge of looking like a reasonable investment, regardless of what you believe about the grid.  I toured 900-1500 square foot homes that were very comfy, and the people had the same amenities as I, running on 900-1.2 kWatt solar systems.  The 900 kWatt system was installed for 7,800 total, including replacing main breaker panel and some old wiring that was below code. With $3000 federal tax credit, perhaps $2000 energy buy-back credits (Colorado), and estimated $4000 increased home value, it seemed like he was ahead of the game before even adding in the negative balance he has consistently run on his utility bill, and the fact that electric rates may begin marching up rather steeply.  A common thread with the people who install solar is that they become aware of where every watt is going, and by using those watts efficiently, they find they can live comfortably on fewer than most people think possible.

I am trying to work it into my remodeling plans, if I can figure out the wickets to not lose any valuable tax credits.  (Complete 1924 bungalow remodel, which my wife would appreciate having insulated before winter!)

c) If oil is underpriced today, then even an EROEI of 1 is good; buying a $10,000 solar installation with an EROEI of 1 is like buying and storing $10,000 worth of gasoline, except you don't need the tank.

Or something like that.

typos: 900 Watts, $2000 Federal tax credit.  The tax credit and corresponding / conflicting state rebates get confusing.  
Gee, I wonder how much energy was expended in hauling all that crap to DC?  Seeing as most folks are going to see it on the 'net instead of in person anyway, couldn't they have virtualized the event somehow?

For a bunch of folks concerned about saving energy, it seems they missed an obvious conservation step.


Then there would be no sort of control to be able to say which designs work better. The one from cal-poly will of course work better in Pasadena (assuming that's the city the cal poly is from) than from any school in the north. Bring them all to one place for a week so they share the same environment.

While it's easy to call the move a waste, one of the problems with alternative energy is that most of them don't scale up to the sizes needed. Well, in this case it's a small scale thing. If this were every single grade school building a house and relocating it, and the knowledge/techniques that they were demonstrating we're all known (think paper model volcanoes), then it would be a big waste.

A huge number of people visit the DC mall every week who would not otherwise be exposed to this stuff.  It is a good investment.

Perhaps to maximize the investment, we could take this opportunity to contact our representatives and encourage them to take a look at what our college kids can do, and challenge them to do as well in their sustainable energy policy measures.