BT announced that it was bringing out a new range of home phones with much improved energy efficiency. The claim is that ‘the new handsets boast power units designed specifically to consume around half the power of previous units’. BT said that almost all its extensive home phone range would contain the new energy-saving technology by mid-2008. Its press release gave very precise figures for the amount of CO2 saved – comparing the savings if all home phones incorporated the new technology to taking ‘57,000 cars off the road for a year’.
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In most countries electricity use is rising. The increase is gradual in developed areas, averaging only 1 or 2% a year. In the UK, the pattern was similar but recent years have tended to show declining growth rates, partly perhaps as a result of increasing prices.
One of the most interesting features of recent UK trends has been the flattening in electricity use in the home. This change is somewhat surprising. Improvements in home energy efficiency, through such things as the use of compact fluorescent light bulbs and high quality white goods, have usually been thought to have been outweighed by increases in the number and power use of consumer electronics. Large LCD TVs are, for example, much heavier electricity users than the old-fashioned TVs that they replace. Today’s games consoles are much more powerful than ones of five years ago.
So the reasons are not clear, but monthly year-on-year growth in domestic consumption of electricity has fallen to below zero in the last year or so. Is this a temporary change brought about by the steep increases in prices over the period 2005-6, which will be unwound when people get habituated to higher costs? Or is this a real change in household behaviour?
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| The Lighthouse by Potton |
Carbon Commentary has visited two sites to look at the costs of building houses under the new rules (not yet mandatory) established by the Code for Sustainable Homes (CSH). By 2016, all new UK homes will have to have no net carbon emissions (‘Level 6’) and the implications for construction techniques are profound. Today, most homes are built to about Level 1, or possibly 2. To get to Level 6 will require huge changes in how houses are built, heated, and ventilated. And they will need expensive renewable energy technologies built into the home as well.
At Wimpey’s 145-home development in Milton Keynes, construction costs of houses at Level 3 are running at ‘100-110%’ more than standard. The self-build company Potton is offering a Level 6 design (one of the first in the UK) for an even more expensive £180 a square foot, up from about £75 for a standard Level 3 model. This takes the construction cost of a standard 1,000 sq ft (92 sq metre) home up from £75,000 to £180,000. Much of the increment comes from the need to install large amounts of renewable electricity generation. Some of the cost premium over today’s badly insulated homes will eventually erode as builders get better at building air-tight houses. But we shouldn’t be in any doubt about the huge implications of the CSH for builders, landowners, and buyers.
The world understands ‘smart metering’ in many different ways. Gordon Brown used the expression in his first speech on climate change. He meant devices that give visual real-time indication of electricity consumption, largely in homes. To the UK Conservative Party (see this issue of Carbon Commentary) it means conventional meters that can record the export of electricity from a house, as well as its use.
Smart meters are much more useful than either of these two definitions suggest. Their primary value will be to adjust the price of electricity depending on the level of demand. This frightens politicians because they fear the backlash from users complaining of the horrendous cost of peak-time electricity use. But if we are to increase the percentage of electricity coming from intermittent and/or unreliable sources, smart meters are a necessity.
After decades of foot-dragging, the UK construction industry has begun to see the importance of good insulation and higher environmental performance. Large housebuilders are beginning voluntarily to build their major developments to a better standard than required by building regulations.
Housebuilders also see the increasing commitment by government to increasing the mandatory standards for home insulation and other environmental characteristics. By 2016, all new homes will have to be ‘zero carbon’.
A report just released by estate agents Knight Frank examines whether buyers are prepared to pay the cost of the eco-improvements. The answer seems to be a cautious ‘yes’.
Energy efficiency improvements often do not deliver reductions in energy use. For example, when a householder installs better insulation, the energy savings are sometimes much less than would have been predicted. Sometimes this is because the insulation was badly fitted, but it is often because the householder runs the heating at a higher temperature when the house is better insulated. This is called the ‘rebound’ effect: when it becomes cheaper or more effective to use energy, people use more of it.
The many studies into this effect have produced a wide variety of different estimates for the size of this effect. Most cluster between 10 and 30%. This means that energy efficiency improvements generally result in a large net benefit. But these studies only capture the direct effect on consumers and businesses. A study from the UK’s Energy Research Centre shows that the economy-wide impact may be much larger. For example, lower heating bills may mean that householders are rich enough to take more flights. At an even higher level of abstraction, better economy-wide energy efficiency (through, say, improvements in steel-making technologies) may encourage more rapid economic growth, which in turn raises energy use.
Some economists think that the economy-wide rebound from energy efficiency gains is very large – perhaps over 100%. A figure over 100% suggests that total energy consumption rises after energy efficiency improvements. The tentatively stated view of a new report by the UK Energy Research Centre is that the true number is somewhat lower than this and may be around 50%, although it could be a great deal higher.
Government projections for the impact of energy saving measures never take the rebound effect into account. Policy-makers trying to reduce global emissions need to adjust their thinking to reflect the much lower than expected efficacy of energy saving programmes.
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