Electricity Consumption Around the Home
Posted by Chris Vernon on July 1, 2006 - 10:03am in The Oil Drum: Europe
The approaching energy gap will most acutely affect the electricity supply as nuclear plants are decommissioned, gas becomes scarce and environmental legislation closes older coal infrastructure over the next decade. I recently picked up a Brennenstuhl plug in power meter from eBay so I could quantify just where all those kWh were going and see what realistic potential there is for conservation.
The national energy debate tends to be focused on the supply side however it would appear the most effective actions (at least from the situation we find ourselves in now) are likely to be those focusing on the demand side.
Source: Which Green.
My latest bill charged me 8.67p per kWh but there was also £12.87 quarterly standing charge making the actual cost for each of my 667 kWh used between 01 Feb and 30 Apr 2006 11.13p. From that bill it would appear that I use an average of 7.4kWh per day at a cost of around 84 pence. Apart from the kettle, hot water is all heated with gas.
Some items have a single power rating that doesn't vary much, for example a light bulb, for items like that I've just listed that spot measurements. For some items the power consumption varies continually (computer, television) and other items have a discreet duty cycle where over a period of time they turn on and off (fridge).
The table below lists the manufactures stated figure (where easily available) and my measurements.
Click to enlarge.
A little background information on the computers, computer 1 is an Intel Pentium 4 2.8C running at 3GHz with an ATI 9800PRO graphics card and four hard drives. Computer 2 is an AMD Duron 600MHz with a PCI graphics card and two hard drives. The laptop is a Pentium 4 M 2.0GHz.
The first point to note is the manufactures stated figures are on the high side, they should be taken as maximums rather than typical. Other than that the startling thing is just how much energy is consumed by devices on standby.
Of those measured the standby total comes to 168W, multiplying by 24 hours makes 4kWh per day. That's more than half my total electricity consumption! Just to sanity check that I've estimated some activity factors for the balance of power consumption between off/standby and consumption during usage and that totals less than 3kWh leaving a little bit extra for the compact florescent light bulbs, washing machine and a few other bits and pieces I didn't measure.
The potential here is enormous. If all ~20 million houses in the country are wasting 4kWh per day that's 29 TWh per year or around 7% of the countries total electricity consumption. Perhaps my house isn't typical (4 CRTs), my data does seem high compared to the 2000 Californian paper below but I doubt it's hugely atypical.
Looking at it another way this standby consumption represents 3.3GW of base load or 37% (29 TWh out of 80 TWh) of the output from the countries nuclear fleet. Over a third of our nuclear fleet exists to serve the standby consumption of domestic devices? If commercial standby consumption was also considered (all the printers, photocopiers, monitors etc left on over night) I expect the figure would rise to over half of the nuclear fleet.
Perhaps this wouldn't be quite so alarming if it wasn't so avoidable. As far as I know there is no technical reason why any appliance can't have a standby mode consuming less than one watt. This is supported by the International Energy Agency's global initiative called the One Watt Plan.
What is the IEA's 1-watt Plan?The oldest item I own with a plug on it is around 12 years old so it is reasonable to expect that virtually all items with a plug could be replaced in less time than it would take to build the equivalent nuclear power stations to serve them.
In 1999, the IEA1 proposed that all countries harmonise energy policies to reduce standby power use to no more than one watt per device. The proposal contained 3 elements:
- Participating countries would seek to lower standby to below 1 watt in all products by 2010
- Each country would use measures and policies appropriate to its own circumstances
- All countries would adopt the same definition and test procedure
There does seem to be movement in the right direction, unfortunately the improvements in standby consumption aren't happening fast enough with the common arguments of any UK unilateral action falling foul of EU trading legislation and the additional cost of manufacturing region specific versions of appliances. The low standby power consumption guidelines are currently voluntary.
In the meantime it would appear simple behavioural changes can have a dramatic impact. Turning appliances off at the wall when not in use would halve my electricity bill. To achieve widespread behavioural change however isn't easy, especially when electricity is just something paid for once a quarter and is still relatively cheap. Micro-generation and smart metering would help people both quantify their electricity usage and to understand where their power was going.
The numbers are clear, suggesting domestic appliances are responsible for wasting a large amount of electricity and supporting the argument it is easier to save a kWh than to generate one.
From one perspective there is also encouragement here since it shows just how much low hanging fruit there is, how much slack there is in the system, slack that we'll need to take up over the next decade so maybe it's a good thing it's there.
Further reading:
A paper entitled Whole-House Measurements of Standby Power Consumption was presented at The Second International Conference on Energy Efficiency in Household Appliances, Naples (Italy), September 2000.
Abstract:
We investigated the variation in standby power consumption in ten California homes. Total standby power in the homes ranged from 14-169 W, with an average of 67 W. This corresponded to 5%-26% of the homes' annual electricity use. The appliances with the largest standby losses were televisions, set-top boxes and printers. The large variation in the standby power of appliances providing the same service demonstrates that manufacturers are able to reduce standby losses without degrading performance. Replacing existing units with appliances with 1 W or less of standby power would reduce standby losses by 68%.
http://eetd.lbl.gov/EA/Reports/45967.pdf
BBC News Online:
TV 'sleep' button stands accused 22Jan06
Britons waste the equivalent of around two power stations' worth of electricity each year by leaving TV sets and other gadgets on standby.
http://news.bbc.co.uk/1/hi/sci/tech/4620350.stm
We could use those remote control power switches for hard to reach sockets [Lidl supermarket had a cheap '4 from one remote' a few months ago] or for trickier setups like Hifi, IT, AV stuff you can buy sequential start power strips:
http://www.olson.co.uk/sequential.htm
that would control the order of powerup allowing a single on/off point.
Many people would be MUCH better off with 2 small chest freezers instead of 1 large upright, because:
You have safety for failure of one freezer
You can clean one at a time.
You can rotate stuff by date easier
You waste less electric with a lid versus door
and - the BIG point..
You could clean one outside, then leave it out the house in summer [out of the rain, naturally] so the waste heat was left outside. Your house would be cooler, the freezer would run less, less consumption.
I have never understood why fridges in general are not designed to use a vent pipe to the outside for losing warm air. A simple lever/gate could retain the heat indoors in winter months. In commercial situations this could save a fortune in air-conditioning etc.
Unfotunately I cant see anyone trying to make this stuff easy or popular and, as you say, more gadgets = more standby power[unless you are diligent].
it's a good area to think about.
I've got a Killawatt meter and checked out consumption of systems an standby. Similar, in fact higher numbers to Chris'.
I then got hold of remote control sockets from MAplins which allow the TV, VCR, DVD and computers to be contolled easlity even though the outlets are 'behind the setee'. Using these and I definitely saw a fall in consumption. Main waste now is from my son (budding rock star) who leaves a 400watt studio he built in the attic on quite often. I check every evening and turn it off when I find it flaring power...
On the gas boilers, older ones tend to be around 78% efficent, the newest ones 93%. So there could be savings there - new boiler costs about a grand though. I saved 45% of gas consumption by inslating the atic properly and turning down thermostats - easy and no real sacrifices needed.
If you want to check your own boilers efficiency (UK) there is a very extensive database of boiler types right here.
http://www.sedbuk.com/
Next for me - solar hot water.
I also have got hold of a kw Honda generator (400 pounds off eBay), for when the lights start to flicker this coming winter or next....
energy security of the UK IT SHOULD
BAN THE SALE OF GOOD WITH STANDBUY
BUTTONS.In the long term it would save
everybody money,and cut greenhouse gases.
If you could only buy low energy lightbulbs
as well. Electrical consumption would be
significantly reduced
(Background - family of four including two young kids in a medium sized,
middle-aged semi that I have tried to peak-proof in the last two years).
My total consumption is similar, 750 KWh in 3 months, but details are
different in one or two areas.
All the items I tested on stand-by barely registered on the meter - 1 or 2
watts at the most. This surprised me, but most of them are only a few years
old. A lot of gadgets have separate plug in transformers, and these also
use only 1-2 watts when the appliance is switched off. Clearly, the industry has got a lot better, but I suspect most people leave set-top boxes running and don't even press the stand-by
button most of the time. That is certainly true in my family (apart from me)!
My big energy burners are the ones you would expect - tumble dryer
(used once a week in cold, wet weather only), large fridge-freezer
(doors constantly being opened by hungry little fingers), kettle
(caffiene-addicted wife) and wireless router (only 23 watts but left on 24/7
in a shut drawer to keep out of range of little fingers...)
We have two bedside lamps rated at 20 Watts DC (but actually consume
40W each - obviously very inefficient transformers!) No, I don't know why we
bought them.
The meter provided no big shocks, but it did confirm we have been on the
right lines in reducing (or not increasing) our consumption. My bills
have gone up considerably after my household went from one to two to
four people, and I have found it a constant struggle to educate my family and
organise and re-organise the household to make it easy and convenient
NOT to waste energy.
The major item I have not tested is teh washing machine, also the oldest
applience in the house. If anyone knows any way of teaching toddlers how
to eat and play without getting all their clothes covered in jam, yoghurt and
mud I would be very pleased to know!
... send 'm to grandma? Worked for you, I guess?
Just kidding ;-)
Here's an extract:
The real concern I have is the virtual absence of regulatory action which has allowed the sale (or more accurately 'give away' upon taking out a 12 month Sky TV contract) of digi-boxes with such a poor standby power specification. While it's technically feasible to produce equipment with (say) a 1 watt standby power consumption corners have effectively been cut with result that standby power demand is some 10 or 20 times what is achievable. To compound the situation consumers have been replacing more traditional TV's with plasma screen models (and with much larger screens) with the net result that such TV's consume up to 4x power of earlier models.
UK plc and consumers are going to pay an extremely heavy price for such lax consideration of domestic energy consumption. As we have discussed on other threads the lead time for power stations is such that most of the extra energy required to drive all this extra household equipment will have to be imported....and at prices which may well reach $100/boe. The ongoing march of UK N Sea oil and gas declines could well increase UK's annual import bill by £16m per day from now thru 2014; the only real question here is 'how soon will the (economic) music stop?'
Indeed, I'm hoping the Energy Review will say something in this area. In the PowerSwitch response to the consultation we wrote this:
Incidentally the problem of legacy equipment is potentially even worse for domestic gas fired boilers which are much longer lasting and considerably more expensive to replace than consumer electronics; furthermore they are more vital in that one can more readily do without electronic equipment than heating. As UK gas supplies become more expensive and potentially scarcer recession-hit households are likely to experience difficulties funding increased gas charges.
The recommendations submitted by PowerSwitch to the Energy Review should be implemented without delay; such action should have been taken years ago before such a large base of energy hungry legacy equipment was allowed to accumulate. We need to go much further and introduce inverted energy tariffs now whereby households are allocated a block of gas / electricity units up to 50% of average domestic consumption at a low tariff with rates for units in excess of this level incurring progressively much higher tariffs. In this way households using (say) 200% of average consumption will find themselves paying 400% of average bills versus current c80%. This change would eliminate the abusrd situation where currently proliferate consumption is rewarded by lower unit tariffs.
On a practical level I've wired my PC and peripherals via a 13 socket strip with the switch in easy reach thus everything can be turned off when not in use. Achieving the same result for digi-boxes, VCR and DVD recorders etc is far more problematic as the equipment is designed to be powered 24/7 - digiboxes actually go thru a lengthy power up sequence including a system demo and I can't see many households being prepared to sit through such a start-up sequence every day not to mention having to reset preferences on recording equipment etc. Even so, inverted energy tariffs and rising utility bills may well focus the mind!
I've recently bought a house which has no gas connection. Due to the insane capital cost of connecting to the gas main (just outside in the street) plus installing Gas central heating we're quite happy to run all electric heating/cooking. Plus we've recently added air conditioning as south west England gets quite hot these days.
First I'd like to take to task all those that wish to remove the so-called perverse pricing incentives for increased consumption. We have cheaper electricity at certain times of the day and night to allow us to economically run off peak heating systems in the winter and air con during the summer. This is simply demand led pricing, we get cheaper power off peak because the power companies are trying to stimulate demand (or push some of the variable demand to off peak times eg washing machines/tumble driers).
In our situation we certainly don't get cheaper power if magically double our consumption. The cost benefits are there to incentivise us to help balance the load on the grid and allow us to heat our home affordably. Even at 4.5p/kWh the power co are still making money.
The suggestion of allowing each house cheap power up to a certain value for heating/cooking lighting and then increased power thereafter has merit, but who gets to decide what a reasonable level is. It would vary massively for different values of insulation/efficiency. Lets not forget that here in the UK we're cursed with a huge amount of 100+ year old housing stock, which isn't about to disappear anytime soon. Laughably much of our very recent housing stock is just as inefficient as the stuff built just pre and post WW2. I should know, my house is but 20 years old and is draughtier and less well insulated than my parents 1930's semi detached. Where I live it seems modern housing is built down to a price, not up to a standard.
So how do you decide what is required for a given house for its base load heating/cooking. What about size? Would you get a bigger allowance for more sq meters? You'd certainly need it for a large family home vs. a small starter flat.
The whole scheme is just ripe for political interference, with extra "base" allowance being granted if you're "poor", on benefits, an asylum seeker, labour voter etc etc. Soon those who can be squeezed for extra cash will end up subsidizing those voted in a certain way. Don't think this will happen? It already is with council tax. More central govt. cash making its way to "favoured" areas, with other areas having to increase council tax to cover costs. Unsurprisingly favoured areas happen to be mainly Labour controlled. I would not be surprised in the slightest if the opposite happened under a Conservative govt. Both sides are as bad as each other.
No, if anything the energy markets should remain free of this kind of political interference. Price should be set by the open market. The Govt. role should be limited to long term strategic policy making to encourage efficiency and encourage new gen. capacity to be built in a way which will not leave the UK venerable either economically or socially. We will not be able to compete with other economies in the next 30 to 50 years if we make the wrong decisions now. Further power outages will make UK plc a very unattractive place for business if allowed to occur, so to say that we will have to curb demand is slightly naive. Sure, efficiency can help, but to expect industry to simply switch off to help reduce carbon emissions/reduce fuel consumption is not going to happen. Industry will simply relocate elsewhere.
If we're not careful that elsewhere will be France, with its nice stable nuclear capacity.
I don't quite understand your point here, you say we can't accept power outages but also say we can't try and curb demand? How does that sit with the reality of the depleting North Sea, a worn out nuclear fleet and unacceptable CO2 emissions from coal? What are your energy and economic expectations over the 30 to 50 year timescale?
Agreed on the scope for political interference in taxation - however, a unit pricing system based on 'later units cost more' could be easily instituted and surely sends the right market signal.
I understand your frustrations, but the post seems more in the nature of a whinge, rather than containing any usable suggestions. The crunch is coming, it will be real, and it is based on a combination of real physical shortage and price. It will not be wished away and will require a demand side response. In the Free Market I believe this is called 'Demand Destruction' and the extreme manifestation is people (usually those least able to pay) 'freezing in the dark'.... surely not what you are advocating?
Would reducing our standby consumption really reduce the number of power stations we need? My point is that we are talking about standby consumption:- when people get home in the evening and turn on their TVs, HiFis, PCs etc much of this standby consumption turns into full load consumption. Hence reducing standby consumption may reduce our overall energy use, but have little effect on peak energy requirement. As the total number of power stations is governed more by peak energy demand, reducing standby consumption may not remove the need for replacing our aging fleet of nuclear power stations (complete with cracking cores http://news.bbc.co.uk/1/hi/uk/5149650.stm ).
even at peak demand times. The number of gadgets on standby in
many houses exceed the number of people in the house, so it seems likely
that this will not be a significant factor. I would not be surprised if
75% of the items are STILL on standby at any given time even at peak
demand, but I just picked that number out of the air. I'm sure a
fairly simple survey could be done to get an accurate figure.
I am very much of the opinion we will need dynamic demand management
to avoid rolling blackouts, whatever generation policy we chose, and
from a GW perspective, the standby power wastage is unforgivable.