electricity demand

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UK energy demand

Friday 18 July 2008 by Chris Goodall | 4 comments


Elizabeth Kolbert looked at the Swiss 2,000-Watt Society project in the New Yorker of 7 July. Her interviewees provided estimates of the energy use of the typical Swiss inhabitant. The figures added up to about 5,000 watts. To be clear, this means each person is responsible for about five kilowatts of continuous energy use. This includes home electricity and gas, personal transport, industry, and office. To keep us in the ease and comfort we have got used to we are consuming, directly and indirectly, enough energy to keep two electric kettles boiling continuously, or driving a fuel-efficient car four hours in every day.

This article looks at the composition of energy demand in the UK. The figures are then broken down by sector and by fuel. The numbers are used in the introduction to Ten Technologies to Save the Planet (Profile Books, November 2008), where I try to assess whether we are likely to be able to use technology to reduce fossil fuel demand substantially.

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Trends in UK domestic electricity use

Wednesday 20 February 2008 by Chris Goodall | 9 comments

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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Zero-carbon homes may look nice but they aren’t cheap

Monday 14 January 2008 by Chris Goodall | 10 comments

The Lighthouse by Potton
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.

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UK offshore wind farm development

Wednesday 12 December 2007 by Chris Goodall | 11 comments

The UK government has announced an intention to allow offshore wind farm development around most of the UK. John Hutton suggested that about 33 GW capacity could be added by 2020. This would provide about 25% of current UK electricity demand (which is itself rising by 1 to 2% per year).

Simple calculations suggest that this change may add about 15-25% to UK electricity bills. Offshore wind is more expensive to construct and operate than onshore wind farms. The announcement may suggest that the government believes that offshore wind can be pushed through but that onshore farms are likely to be successfully opposed. The big push for offshore wind seems to mean that the government is losing faith in nuclear.

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Household batteries

Wednesday 12 December 2007 by Chris Goodall | 2 comments

Inventions that take the breath away with their simplicity and elegance are rare. The new rechargeable batteries from USBCell qualify for this honour. As their name indicates, they are AA batteries that are recharged by the USB port on a laptop or other powered device. They are not cheap, but will repay the investment by being far easier to recharge than conventional rechargeable AAs.

The carbon savings from these batteries are not large. My calculation is that they might save 10kg of CO2 a year in a household full of portable devices. But they will, of course, reduce the waste going into landfill.

The company that makes the batteries has won some important awards for its innovation. More importantly, it also has some extremely interesting views on the evolution of home electricity demand. It correctly points out that a larger and larger fraction of home energy is used in 12V, not 240V appliances. We waste a lot of energy switching 240V AC down to 12V DC. Its next products include a box that will allow all DC devices (phones, handheld consoles, laptops) to be efficiently charged. Eventually, it will be possible to use cheap(-ish) solar power collectors to charge all the battery DC devices in the home. The savings in carbon would be worthwhile (but probably outweighed by the purchase of one extra TV).

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Smart metering

Wednesday 12 December 2007 by Chris Goodall | No comments

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.

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26m servers in data centres use 2% of world electricity

Monday 15 October 2007 by Chris Goodall | 1 comment

BT’s green credentials are well established. It is the largest commercial buyer of renewable electricity in the UK, emphasises the importance of carbon reduction across the organisation, and pushes voice and video conferencing at an unconvinced customer base. In any international ranking, BT’s sustainability measures get high marks.

But BT has the same problem as many other organisations: its server farms are growing in number and size. The increased power consumption in its data centres explains why the organisation’s electricity demand is growing. Eventually, its brand image will suffer as critics suggest that its public stance on green issues is not matched by its internal behaviour.

BT’s electricity use is about half a percent of the UK’s total, and its server farms represent over 10% of its energy consumption. BT says that data centre use is rising at 40% a year, and the company’s emphasis on growing video businesses, such as BT Vision, is likely to increase data storage and transmission demands into the foreseeable future.

BT’s response has been to attack the power use of the server with radical measures that set best practice elsewhere in the world. Its new data centres use fresh air cooling, not air conditioning, and the company runs its machines at much higher temperatures than used to be considered possible. Since cooling servers uses at least as much power as running them, this is an important step. The second major innovation is to run the farms on DC power, cutting the very significant losses in the multiple AC to DC conversions in a conventional centre. Better ‘loading’ of the computers helps as well. A well-utilised machine uses only a little more power than an intermittently under-employed server. BT claims that these measures can reduce the typical power consumption of a server farm by 60%.

Across the world, data centre energy consumption is becoming a bigger issue. The world has about 26m servers pumping out data day and night. Estimates suggest that they use about 2% of all electricity produced and global growth is probably around 15% a year. BT’s innovations may be a useful model for others to follow. But the unfortunate fact is that at current growth rates the maximum efficiency gains will be wiped out in less than four years.

In an intriguing trend, some companies are dealing with apparently unquenchable growth in data traffic by beginning to move away from thousands of servers based on PC technology towards huge single computers with lower total energy costs. Who said the mainframe was dead?

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Holding back the unstoppable tide of green claims

Monday 15 October 2007 by Chris Goodall | No comments

The Advertising Standards Authority is struggling to hold the line on the advertising of environmental benefits. In June, the Authority put out a series of instructions trying to impose clearer conditions on advertisers. But it continues to have to adjudicate on a series of difficult decisions. Last week saw a wind power developer taken to task for over-estimating the carbon savings from turbines. The Authority had to decide which type of power station would produce less power as a result of a new wind farm – coal or gas. It took advice from the National Grid and proceeded to tick npower off, even though the power company was following rules previously set down by the ASA itself.

In at least one other country, the advertising regulator has thrown in the towel and told some advertisers simply to stop advertising green claims. Reuters reports that Norway’s Consumer Ombudsman has told car advertisers that ‘We ask that…phrases such as “environmentally friendly”, “green”, “clean”, “environmental car”, “natural” or similar descriptions not be used in marketing cars.’

We cannot be far away from this sort of rule in the UK. Green claims are almost invariably contentious and difficult to prove. We simply don’t have an accounting system that can deal yet with carbon. Advertisers are going to be forced to avoid any but the most clear-cut and well-documented savings.

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Domestic Combined Heat and Power

Monday 1 October 2007 by Chris Goodall | 16 comments

Ceres Power, a £150m AIM-listed company, recently demonstrated its new Combined Heat and Power product. This power plant is targeted at ordinary domestic homes. Combining an efficient central heating boiler with a fuel cell that converts gas to electricity, the new product has excited the City. Ceres is extremely optimistic about sales of the device, based on the cash and carbon dioxide savings it says can be achieved.

The Ceres fuel cell (on the left) is incorporated into an ordinary domestic condensing boiler (on the right)

Ceres promises reductions in utility bills of £300 a year and 2.5 tonnes savings in carbon dioxide for the typical UK house. Our short report shows why we think that these savings are unlikely even in the most appropriate UK installation. In fact, the emissions reductions are likely to be minimal and the reductions in the electricity bill will not easily justify the approximately £1,000 extra cost of the CHP cell.

Micro CHP is a difficult proposition. Other companies have found that it is hard to make substantial savings in domestic installations. CHP is not well suited to rapidly fluctuating and unpredictable demand for electricity and hot water.

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