From your hearth the nimble flame…
Whence relief and comfort came.
My final hope rests on this proposition: that I have been looking at the problem the wrong way round. I have been thinking about electricity and heating fuel as almost everyone has been thinking about them since construction of the national grid began in 1926: as commodities supplied over great distances from major sources. But there is an entirely different way of responding to the question of how our energy might be generated. It’s generally described as ‘micro generation’ or ‘the energy internet’.2 In its pure form, it involves scrapping the national grid.
Instead of producing a large amount of power in a few places, the energy internet produces small amounts of power everywhere. Instead of using long-distance transmission cables to deliver it, it merely links up hundreds of micro generators in a local distribution web. With the help of a new kind of energy company, people buy electricity and heat either from tiny power stations built to serve their housing estates or, in effect, from each other. The local web should be more or less self-sufficient, but linked to other local webs to enhance its security.3
Greenpeace, which has become a powerful advocate of the energy internet, describes it thus:
Buildings, instead of being passive consumers of energy, would become power stations, constituent parts of local energy networks… In Greenpeace’s vision… coal-fired power stations have been closed and their surrounding webs of pylons dismantled, restoring swathes of countryside… nearly all the input energy is put to use – not just a fraction as with traditional, centralized fossil-fuel plant.4
It’s an inspiring idea. But will it survive examination? The first question to ask is whether the technologies work, or, to be more precise, work at something approaching a reasonable price.
The two main sources of renewable power Greenpeace proposes for the energy internet are solar panels and micro wind turbines. I want to believe in them. But the more I read the less convinced I become.
Solar photovoltaic electricity – power produced from panels of light-sensitive cells – is unintrusive and silent. It upsets no one. The infrastructure it requires already exists, in the form of the south-facing roofs on our houses, factories and offices. It is not quite a zero-carbon technology (solar panels in Europe take between two and four years to produce as much energy as is used in their manufacture5), but it generates far fewer emissions per watt than our fossil fuel burners. But those who want solar power to supply a high proportion of the electricity used by countries like the United Kingdom encounter two basic problems: there isn’t enough sun, and it shines at the wrong time.
The man who has done the most to promote solar electricity in the UK is Jeremy Leggett, chief executive of the company Solar Century, which equips buildings with solar cells. I have known him for years and have great respect for him, not least because, while I sit on my backside telling other people what to do, he spends his time doing it. But some of his statements reinforce my impression that we should be cautious about the claims of those who have something to sell. In his book Half Gone – which otherwise has many virtues – he says,
Even in the cloudy UK, more electricity than the nation currently uses could be generated by putting PV roof tiles on all suitable roofs.6
This is a big claim to make. Because strong claims require strong support, you would expect it to come from a good source: a peer-reviewed academic journal or a government report, for example. Here is the reference Leggett gives:
‘Solar Energy: brilliantly simple’, BP pamphlet, available on UK petrol forecourts.7
The Energy Technology Support Unit (ETSU), in its report to the government seeking to determine how much renewable energy the country has, calculated that if all the roofs in the United Kingdom were covered in solar panels, and solar electricity could magically be produced at the same rate at all points of the compass, the ‘maximum practicable resource’ would be 266 terawatt hours (TWh) per year.8 The UK currently uses some 400 TWh. If my optimistic assumptions about energy efficiency are correct, this could be reduced to 300 TWh by 2030. But unless you are extremely rich, you will not install solar panels at all points of the compass. They are most efficient when they are facing roughly south. If ETSU’s estimate were divided by four, that would give us 66.5 TWh. But this takes no account of the cost. When the unit confined its estimates to the amount of electricity which could be produced at 7 pence per kilowatt hour or less (at the time this was roughly the retail price of electricity) it found that the technical potential of roofs in the United Kingdom was 0.5 terawatt hours, or one 800th of our current consumption.9
Part of the reason is expressed in the table below.
location |
latitude |
mean daily solar radiation (kWh/m2) |
Stockholm |
59.35 N |
2.52 |
London |
51.52 N |
2.55 |
Freiburg (Germany) |
48.00 N |
3.04 |
Oviedo (northern Spain) |
43.35 N |
3.18 |
Geneva |
46.25 N |
3.31 |
Nice |
43.65 N |
4.03 |
Porto (Portugal) |
41.13 N |
4.26 |
Heraklion (Crete) |
35.33 N |
4.44 |
Sde Boker (Israel) |
30.90 N |
5.70 |
Source: Tyndall Centre for Climate Change Research.10 126
While solar panels might pay for themselves in Jerusalem or San Diego,* they are a less attractive proposition in London.
The Unit’s estimate is far too harsh, however. There are good reasons (which I will discuss in a moment) to assume that the price will fall much faster than it predicted. It might one day make economic sense to clad every south-facing roof, in which case, if ETSU’s estimates are correct, solar panels could indeed produce 66.5 TWh – or 22 per cent – of our electricity. But we would immediately encounter the next problem: that the supply of electricity is poorly matched to demand.
In hot countries – as I mentioned in Chapter 6 – electricity use peaks in the middle of a summer day when the air conditioners are turned up. In cold countries, it peaks on winter evenings. If there is one thing of which you can be certain – perhaps the only thing in this field of which you can be certain – it is that the sun does not shine in cold countries on winter evenings.
So even if, by some miraculous technological leap, we were able to produce 300 TWh per year from solar panels on our south-facing roofs, only some of it could be used. There would be a massive surge of production in the summer, during the middle of the day, and hardly anything worth having during the winter, especially when we needed it most. And in a small country like the United Kingdom, when night falls anywhere, it falls everywhere. The energy storage and standby power it required would make a solar economy impossible in a country at this latitude, even if we covered every square metre of ground with panels.
This is not to suggest that solar power is useless here. There is still a high demand for electricity during summer days, and much of that could be met by the sun. If we changed the times of day when we use the most electricity, we might, in the summer, be able to match demand to the surge in production. We could, for example – having loaded them before going out to work in the morning – set our future washing machines and dishwashers to start running at noon.12 We can also store electricity for some hours in batteries, so the peak production at midday can be used when we come home in the evening. But it cannot be cheaply stored for use later in the year.
The mismatch between supply and demand also makes a nonsense of another claim propounded by the solar advocates: that a household equipped with solar panels can sell more electricity to the grid than it buys. Technically, this might be true. But it will be selling power when demand – and therefore the price – is fairly low, and buying it when demand and the price are high. Solar panels on our roofs could make a significant contribution – perhaps 5 or 10 per cent – to solving our electricity problem. But to suggest that they could provide the whole answer is unhelpful and misleading.
Here are some estimates of the cost of electricity produced by rooftop solar power:
source |
cost per kilowatt hour |
Performance and Innovation Unit, 10 Downing Street – |
‘around 70 pence’ |
Robert Gross, Imperial College – present day, global13 |
30–80 cents |
|
(17–46 pence) |
Performance and Innovation Unit, 10 Downing Street – in 2020, |
10–16 pence |
The table below gives an estimate of how the cost of saving carbon by generating electricity from solar panels in the UK compares to the cost of saving it by other means. The figures are derived from the standard international means of estimating future costs, developed by the International Energy Agency.* This does not make it definitive – nothing in this subject is. The minus figure (for onshore wind) reflects the expectation that by 2020 it will be cheaper than other forms of electricity generation.
Jeremy Leggett correctly points out that the price of small-scale
type of generation |
cost in 2020 – low estimate (£ per tonne |
cost in 2020 – high estimate (£ per tonne |
onshore wind |
−40 |
130 |
nuclear power |
105 |
180 |
wave |
120 |
430 |
energy crops |
135 |
185 |
carbon capture and storage tacked |
160 |
200 |
offshore wind |
160 |
480 |
new gas plants with carbon capture |
180 |
200 |
tidal |
250 |
690 |
new coal plants with carbon |
460 |
560 |
solar photovoltaic energy |
2200 |
3200 |
Source: UK Department of Trade and Industry.15
solar electricity should be compared to the retail rather than the wholesale price of power, because, being on the roof, it is delivered directly to the household without the help of an electricity company. Even so, the estimates in the first table suggest that it is, at present, massively more expensive than either electricity from conventional power stations or electricity from wind farms. (The average retail price was 9.7 pence in November 2005 and 8.7 pence in November 2004.16) Even if the price of solar power falls as quickly as the prime minister’s office proposes, it could still exceed the retail price of electricity in 2020, not least because the analysts expect that to fall as well. But its price is likely to keep falling, and Downing Street suggests that it ‘could become cost competitive with retail electricity in the UK around 2025’.17
Jeremy Leggett also makes the point that covering a building with photovoltaic panels can be cheaper than covering it with ‘prestige cladding’, which is the term architects use to mean fancy façades.18 This might be true. But solar cladding won’t produce much electricity unless it covers south-facing walls not shaded by other buildings. As many buildings with expensive façades are in the commercial districts, where they are likely to be shaded by others, this limits its application.
Here are two facts you seldom see on the same page. Solar photovoltaic cells pay for themselves after 25 to 35 years.19 Solar photovoltaic cells have a life expectancy of 25 to 30 years.20,21 At the moment you cannot make your money back. This relationship will soon start to improve, however. Some researchers believe that, with the help of new methods such as the use of silicon spheres, dye-sensitized cells and nanotechnology, the cost of photovoltaic cells could fall as swiftly as costs in the semiconductor industry have fallen.22,23
The prospects for micro wind power are less promising. The problem is this: you can produce reasonable amounts of electricity from wind only when it is blowing strongly and fairly consistently. If winds are weak or gusty or turbulent, wind turbines are a waste of time. In built-up areas, winds tend to be weak, gusty and turbulent. Here’s what Paul Gipe, the author of one of the leading books on micro wind, says.
Wind turbines should always be located as far away from trees, buildings and other obstructions as practical to minimize the effect of turbulence and maximize exposure to the wind. Turbulence is caused by the wake from buildings and trees in the wind’s path. Turbulence can wreak havoc on a wind machine, rapidly shortening its life. Buildings and trees also drastically reduce the energy that is available to a wind machine.24
Building for a Future magazine recommends that wind turbines be placed a minimum of 11 metres above any obstacle within 100 metres.25 So if your house is at least as high as all the houses in your street and the surrounding streets, and as high as any nearby tree, you could get away with an 11-metre pole. If not, you will have to build a minor hazard to aircraft. The higher it is, the less likely you are to receive planning permission, and the more likely you are – because of the lateral thrust exerted – to inflict serious damage to your house. Otherwise, ‘A highly turbulent site in which the turbine swings erratically might rob you of 80–90 per cent of your potential energy.’26 Even if you can find a smooth flow of wind, in built-up areas it won’t be strong enough: ‘Very few installations are likely to experience more than the equivalent of 4 metres per second average windspeed.’27
At an average wind speed of 4 metres per second, a large micro turbine (1.75 metres in diameter is about as biga device as you would wish to attach to your home) will produce something like 5 per cent of the electricity used by an average household.28 The most likely contribution micro wind will make to our energy problem is to infuriate everyone. It will annoy the people who have been fooled by the claims of some of the companies selling them (that they will supply half or even more of their annual electricity needs). It will enrage the people who discover that their turbines have caused serious structural damage to their homes. It will turn mild-mannered neighbours, suffering from the noise of a yawing and stalling windmill, into axe murderers. If you wished to destroy people’s enthusiasm for renewable energy, it is hard to think of a better method.
The only instances in which micro wind turbines might be useful, cost-effective and acceptable to the neighbours is when they have been erected in remote parts of the countryside or built into the structure of tower blocks. In the latter case, they are likely already to be above the line of surrounding buildings. At least a couple of designers have patented aerodynamic towers which will drive wind up into the turbines. One of them, Bill Dunster, claims that his structure raises wind speeds by two or three times.29,30
But another source of electricity recommended by Greenpeace is likely to be more reliable. This is something called ‘domestic combined heat and power’.
When I report that our power stations have an average efficiency of 38.5 per cent, I mean that the majority of the energy they produce escapes in the form of heat. Using government figures, the energy campaigner Chris Dunham has shown that our demand for heat is roughly equal to the heat wasted by our thermal power stations.*
The micro generation enthusiasts hope to turn two problems into one solution.
The idea, at its simplest, is that instead of using a boiler to produce only hot water and heating for your home, you use a tiny power station to produce heat and electricity at the same time. In 2007, a gas-burning generator called a WhisperGen, which uses an external combustion engine and is already on sale in New Zealand, will be sold in the UK. It costs about 25 per cent more than an ordinary boiler, but the company which markets it says that it will pay for its extra costs within four years, as your energy bill falls by around £150 a year.32,33 Because both the heat and power are used, the efficiency of an engine like this is somewhere between 70 and 90 per cent.34 (It produces about twice as much heat as electricity.) It makes no more noise than a refrigerator.35 In fact, the same kind of engines are used to provide heat and internal power for submarines, because they are so quiet. As boilers tend to die after about twenty years,36 the nation’s entire stock of domestic heating equipment could, with the right incentives, be switched to mini power stations before 2030.
The plan propounded by Greenpeace and others is still more cunning. In the winter, when you want heat as well as electricity, you use your mini power station (a domestic combined heat and power plant) to produce them both at the same time. In the summer, when you want electricity without heat, you use a solar panel. In both cases you can use a battery to store electricity. The Tyndall Centre for Climate Change Research suggests that four industrial lead acid batteries would store enough power to cover the gaps in both summer and winter.37 Your house, though reliant on gas, would become independent of the grid.
It’s a brilliant notion, but will it work? Technically, the answer is ‘yes’. The technology is proven, the cost of the heat and power unit (if not the solar panel) is low; and, with the help of the battery, the output of heat and electricity can be closely matched to people’s demands. The WhisperGen’s external combustion engine* produces about 6.6 times as much heat as electricity.38 Friends of the Earth calculates that if 10 million homes installed heat and power units, they would produce about 30 terawatt hours of electricity a year – 7.5 per cent of the country’s total requirement.39 There are 24.5 million households in the United Kingdom,40 and they consume some 29 per cent of the UK’s electricity,41 so if everyone equipped their homes with this machine, we’d generate about 74 per cent of our own electrical power. Other machines have a better ratio of electricity to heat: in principle, our homes could produce all the electricity they need from combined heat and power burners.
Unfortunately, the contribution these mini power stations make to preventing climate change is less convincing. The company which markets the WhisperGen system claims that it will save about a fifth of the carbon a household’s supply of gas and electricity would otherwise produce.42 A report by the Energy Saving Trust, which is funded by the government, estimates that if micro generation (a mixture of combined heat and power, solar electricity and micro wind) supplied our homes with 220 terawatt hours of energy – which is about 42 per cent of the energy our houses use* – it would save just over 6 per cent of our household emissions.44 This suggests that if we generated all the energy we needed in our homes by micro generation, we would cut our household carbon emissions by just 14 per cent. And the report is more generous to micro wind than it deserves.
District heating systems use the same principle – combined heat and power – but on a slightly larger scale. Heat from a small power station, serving a tower block, a housing estate, a suburb or perhaps even a whole town, is circulated by pipes into people’s homes. This system, like all good things, is widely used in Scandinavia. In Helsinki, for example, 98 per cent of heating comes from district schemes of one kind or another.45 The advantage of district heating, especially if it serves offices and factories as well as homes, is that the power supply doesn’t have to fluctuate as much, as demand is more consistent.46 It can make more effective use of other sources of heat, such as the ground-sourced heat pumps I discussed in Chapter 6. It is also popular in Germany, supplying, for example, the Reichstag in Berlin. The surplus heat the Reichstag’s system produces in the summer is pumped, in the form of hot water, into porous rocks 300 metres below the surface, then pumped back up to heat the building in the winter.47
Regrettably, district heating systems are harder and more expensive to attach to an existing development than to incorporate into a new one: streets, pavements and floors have to be excavated to lay the pipes.48 But it is difficult to think of a good reason why district heating should not be installed whenever a new housing estate is built. On second thoughts, there is one good reason: that the new homes would be so well constructed they need no heating at all.
If micro generation is to become a more effective means of reducing carbon emissions, it must switch from gas to another kind of fuel. I have already explored the potential, with a growing sense of hopelessness, of biomass, biogas, solar hot water, ground-sourced heat pumps and geothermal energy. Some of these could be used to help decarbonize the energy internet – wood chips or pellets, for example, work well in district heating systems – but their potential contribution, as I have shown, is limited.
This appears to leave us with just one option: the most abundant element on earth. Hydrogen behaves rather like a fossil fuel, in that it burns with a nimble flame and can provide several different kinds of power. But it produces, when it combusts, nothing but water. So we should not be surprised to find that it has become the environmentalists’ Red Lion or Powder of Projection: the alchemical catalyst which could change everything.
There are several means of producing it. Unfortunately their costs, as costs often are, are inversely proportional to their environmental impacts. The table below gives the figures produced by the National Academy of Engineering in the United States. These prices include distribution and delivery.
Hydrogen is made from coal mostly by bashing the fuel into powder and passing steam and oxygen through it. It is made from natural gas by heating it and reacting it with steam.49 It is made through electrolysis – as anyone who didn’t manage to escape from their chemistry lessons at school will remember – by passing an electric current through water. The last method is the philosopher’s stone. The electricity could be produced from renewable power. You could generate
Source: The National Academy of Engineering.50
from thin air and water a fuel which is dense, storable and transportable. If it could be produced, carried and burnt cheaply, it could replace our fossil fuel economy while ensuring that we need scarcely change the way we live.
But it shouldn’t be hard to see that the last method will always be expensive. Electricity is a refined manufactured product. Using it as a raw material to produce another kind of fuel is a novel species of extravagance. The National Academy says that the efficiency of producing hydrogen from electricity is just 30 per cent.51 In other words, 70 per cent of the useful energy produced by our wind turbines or power stations would be lost. The re-forming of natural gas, by contrast, is about 72 per cent efficient.52
If renewable electricity is priced at just 2 pence per kilowatt hour, hydrogen produced by this means and delivered to people’s homes would cost twice as much as natural gas.53 Hydrogen produced from natural gas, even after the carbon dioxide has been captured and stored, is likely to cost households only 50 per cent more than the gas itself.*
Because, for the reasons I discuss below, we would need to consume less hydrogen than natural gas to produce the same amount of electricity and heat, this means the price we pay for fuel would stay roughly the same. But because the device in which it is burnt, at least in the early years, is likely to cost more, as I will show below, the overall price of heating and electricity will be higher than it is today.
So at first sight it seems that the re-forming of gas, accompanied by carbon capture and storage, should supply our hydrogen. Where there are power stations today, there should be hydrogen factories tomorrow. Eighty per cent or more of the carbon dioxide they produce can be buried.
In the carbon capture and storage system I described in Chapter 5, the carbon dioxide is stripped out of the exhaust gases produced when natural gas is burnt to make electricity. In the case of hydrogen, it is separated and captured before the gas is burnt. Apart from that, there is no substantial difference: the carbon dioxide is piped away and buried as before.
At first, hydrogen could be mixed with natural gas, using the existing pipeline network: a concentration of 10 or 15 per cent would apparently make no difference to the performance of our boilers.56 But as we began to produce more of it, and to install machines designed to burn it, it would have to be transported separately. Liquefying the gas (because it has to be kept at minus 259° or below) uses up about 35 per cent of the energy it contains.57 Piping it by itself would require an entirely new network, as pure hydrogen would cause our gas pipes to become brittle.58 We could, of course, use the existing pipelines to shift natural gas very close to where the hydrogen will be needed and build small steam re-forming plants to produce it on the spot. But then the carbon dioxide could not be buried. So it seems as if the only viable options are either to build a new piping system, alongside the gas pipes, to move molecular hydrogen around the country; or to replace the natural gas pipes with hydrogen pipes as they reach the end of their lives; or to shift it by truck, ship or train. All these means appear to be viable, though pipelines are likely to be both more energy-efficient and more convenient for the customers. The US National Academy of Engineering reports that, while molecular hydrogen ‘is a uniquely difficult commodity to ship on a wide scale’,
about 9 million tons of hydrogen are manufactured annually in the United States and transported for chemical and fuel manufacturing as a low- or high-pressure gas via pipelines and trucks… Much experience worldwide has been achieved over many years to make these transportation modes safe and efficient.59
The energy needed to compress it to 5,000 pounds per square inch (which is two and a half times higher than required for high-pressure piping60) amounts to between 4 and 8 per cent of the energy the hydrogen contains.61 Transporting it as a gas at high pressure, in other words, is much more efficient than transporting it as a liquid. Building a hydrogen pipeline is expensive, however. The pipes must be 50 per cent greater in diameter than gas pipes, and the materials of higher quality.62 These costs have already been taken into account in the calculations I made above, which suggest that hydrogen delivered to consumers will cost about 50 per cent more than natural gas.
There might be another way of doing it, however. As the energy expert Dave Andrews suggested to me, if hydrogen were produced from electricity by means of mini-electrolysers in the home, the waste heat (which accounts for the 70 per cent loss of energy when extracting hydrogen from water) could be used to keep the house warm. This would help to pay for the costs of conversion. When the wind was blowing strongly, the surplus power it produced could be used to generate hydrogen and heat. When it dropped, the hydrogen could be used to provide heat and electricity. This means, however, that hydrogen would have to be stored at home.
In either case, hydrogen could be burnt in boilers very similar to those which use natural gas: the difference would be that it produced no carbon dioxide emissions. But a further possible advantage of using this element is that it can also produce both heat and electricity in a device called a fuel cell. This is a kind of battery, which uses a gas as its chemical energy source rather than a solid or a liquid. It generates a higher proportion of electricity to heat than an external combustion engine such as a WhisperGen, and no effluent but water. It makes no noise and responds almost instantaneously to demand. Already, fuel cells exist with electricity production efficiencies of around 60 per cent.63 This is probably too good for our homes: a less-efficient fuel cell would match the ratio of heat to electricity we need more closely.
Fuel cells are currently more expensive than other kinds of micro generators: even the most optimistic estimate suggests that if they were widely commercialized today, they would be around four times the price, for example, of a diesel engine with the same output.64 Most authorities suggest they are more expensive than this. But with an installation programme backed by the government, the cost could fall swiftly. The Tyndall Centre for Climate Change Research says that combined heat and power systems run by fuel cells may be ‘economically viable by 2009’.65 They will also need to be scaled down if they are to be widely used in houses: at the moment they are several times as big as combined heat and power units running on natural gas,66 which are about the size of an ordinary boiler. Their lifetime, which is currently quite short, needs to be extended. Taking all this into account, it might be more realistic to consider replacing our gas boilers with hydrogen boilers providing heat and electricity, rather than with fuel cells.
But both boilers and fuel cells are useless without fuel. Micro generation of this kind, unless it uses domestic electrolysers, is impossible without the creation of a hydrogen storage and delivery network. As a hydrogen storage and delivery network would be useless without micro generators to supply, we are confronted with the classic chicken and egg problem of a switch to a new technology. Neither half of the system can function until the other half does. In other words, the establishment of a hydrogen distribution system would need to be assisted – both strategically and financially – by government.
It would be foolish to pretend that there are no environmental problems associated with a hydrogen economy. If hydrogen leaks and finds its way into the troposphere, it becomes, by indirect means, a greenhouse gas.* In the stratosphere, it appears to accelerate the depletion of ozone.68 Any system we use must be well sealed. If the hydrogen is made from coal, as the US government proposes,69 this will result in a massive boost for the quarrying industry. Even if it is made from natural gas, it means sustaining our dependence on a fossil fuel, which is often associated with ugly infrastructure, dodgy deals with unpleasant governments, habitat destruction and the displacement of local people.70
But the gas does appear to provide us with a fairly cheap means of generating heat and electricity, while greatly reducing our carbon emissions. Taking into account the losses involved in carbon capture and storage and hydrogen transport, we could achieve a total carbon saving of about 80 per cent. The combination of the energy efficiencies I discussed in Chapter 4 and new kinds of fuel pushes us beyond my target of a 90 per cent cut in household carbon emissions. But to get there would require a massive and extremely ambitious government programme, swapping the natural gas distribution system for a hydrogen network. It also means that every boiler which dies between 2010 and 2030 must be replaced with a boiler burning hydrogen or a hydrogen fuel cell. This is a tall order, but it could – just – lie within the realms of possibility. Household electrolysers, producing hydrogen from low-carbon electricity, could be quicker and easier to develop and install than a new pipeline network. The cost of the fuel is likely to remain higher, however, though it would be suppressed if the electrolysers work only when there is surplus wind power.
But if we did scrap the national grid, could a micro power system work, without repeatedly plunging us into darkness? The answer, which I realize is not entirely reassuring, is ‘probably’.
Every household is linked to its neighbours to form a miniature version of the national grid: a generating ‘island’. This island can in turn be connected to the surrounding micro grids to offer more security. Electricity can be automatically traded, with the help of smart meters, between households: if someone’s generator fails, others can fill the gap.71 There will be little need for extra backup generators, as everyone’s machine supports everyone else’s.
Greenpeace says that this system will be more secure than the national grid:
It would deliver an electricity supply far less vulnerable to massive system failure as a result of sabotage or extreme weather.72
The House of Lords suggests it would offer the same degree of security:
This model is in principle no better or worse than the national one for responding to coherent changes in demand… There would be technical issues to resolve, including the need for synchronization between islands, but these could be overcome.73
The Tyndall Centre starts confidently:
We find that there is no fundamental technological reason why microgrids cannot contribute an appreciable part of the UK energy demand…
but later qualifies its enthusiasm:
In a microgrid, frequency stability becomes critical… because the system is small the problem is much more difficult to manage to the same standard as is normal in a utility system… Control of power quality will be the biggest issue for a microgrid. Voltage dips, flickers, interruptions, harmonics, DC levels, etc., will all be more critical in a small system with few generators.74
But these problems, it says, can be overcome with the help of batteries, which will respond ‘fast enough to ensure adequate frequency control’.
Greenpeace argues that the costs of a system like this would not be as high as they first appear because we would not have to pay so much to maintain and rebuild the national grid, or pay for the electricity lost in transmission (about 7.5 per cent of the total75). It points out that only 52 per cent of the capital cost of electricity is incurred by generation: the rest pays for carriage and distribution.76 The International Energy Agency estimates that electricity suppliers in the European Union must invest $1.35 trillion between now and 2030 to keep the system running, of which $648 billion must be spent on the transmission and distribution networks.77 If some of this money were instead spent on building hydrogen pipelines, the switch to an energy internet would start to look less painful.
But, exciting as the idea is, I have come to believe that the dismantling of the national grid would be a mistake: it would be to succumb to the aesthetic fallacy. There is still a huge demand – from industry, offices and the people who light our streets and run our trains – for electricity which isn’t accompanied by heat. In fact, it seems to me that far from shutting the network down, we might need to expand it. New cables would enable us to extract electricity from the best ambient sources, far from our coasts. By drawing power from a large area of land and sea, a wider grid would make renewable resources more reliable. By connecting us to the networks of other countries, and the wide range of electricity sources they can exploit, it could reduce the ‘system costs’ of keeping demand and supply in balance. I hate pylon lines, but I cannot help concluding that we need more of them.
So I might have the answer. Our homes have the greatest requirement for heat. A micro-generation system using solar panels and either hydrogen boilers or hydrogen fuel cells would supply their heat and their electricity. Either they could make their own hydrogen from electricity supplied by the grid, or they could obtain it from a pipeline network. Perhaps most importantly – as far as public acceptability is concerned – this system demands no more time and trouble for householders than they currently spend on managing their supplies of energy: in other words, none whatsoever. Everything comes on and goes off at the flick of a switch and, in principle, works as smoothly as our heat and electricity systems do today.
Around half of our grid-based electricity could be supplied, as I suggested in Chapter 6, by means of a few very large power stations burning methane – either in the form of natural gas or the effluvium from underground coal gasification – and burying the carbon dioxide they produce. The other half, if my meta-guess is correct, could be provided by offshore wind and wave machines.
This transformation would require some bold politics and some ambitious engineering. But it isn’t a manned mission to Mars. Everything I have proposed here is, as far as I can tell, already technically possible and more or less economically feasible. The question is whether it can be done in time. If it can, I might have saved myself from frightful nemesis. I will not have to become an aromatherapist.