A Big Battery

There are very few genuinely innovative energy products. The problem with energy is that the laws of physics limit what can be done and when it can be done. In the case of electrical energy we have the means of generating electricity from non fuel sources, – wind and light – but until now no really easy means of storing the electricity that we can generate. Attempts to feed solar and wind generated power into a grid fail to be effective in large emission reductions; because of the intermittency of the source of energy we need to have large power stations running on standby by, wasting fuel and creating emissions, to cover the times when the wind does not blow and the sun produces no light. Continue reading

A Solar Field in Andalusia

The problem with generating electricity from all renewables is that there is no safe and environmentally friendly way to store electricity. With photovoltaic panels the electricity can onbly be generated in daytime and mostly electricity is need at night in larger quantities than in day time. That means that all PV power has to be backed by fossil fuel electrical generation (you cannot use nuclear because it takes too long to start up and switch off a nuclear plant) and there are inevitably very large emissions created when the fossil fuel plant and stops. Continue reading

Storing thermal and electrical energy

The thing that differentiates solar thermal from all other forms of renewable clean energy is that you can safely and easily store heat. However you generate your electricity – be it by wind or photovoltaics – storing electricity safely and cleanly is a real problem. You can build banks of environmentally damaging batteries using precious rare earths and store electricity thus. Continue reading

Hope for redressing climate change

Humans need hope. It provides them a means of escape from problems that seemed impossible to solve. Throughout history humans have been face with what seemed impossible situations, but hope has given them to means to fight overwhelming odds that threatened them. Continue reading

British Telecom will not become wind farmers

British Telecom has indicated that it will not be spending £250 million on a wind farms. The idea was that by building a series of UK wind farms it could generate about 25% of its own electricity usage, making it that bit more “green” as a telecommunications company. The reason for its decision not to invest wind in wind farms is a little complex, but it is worth examining in detail.

There are not many UK incentives for green energy and of those that exist; those for generation of electricity are the most generous by far. It has always been hard to understand why we should have a “green electricity” policy instead of a “green energy” policy, because electrical energy is almost impossible to store in an environmentally friendly way, whereas heat energy is very easy to store in an environmentally friendly way. Continue reading

Solar concentrators in the desert

There has been talk about building a huge array of solar concentration mirrors in a desert to generate electricity. There are already a number of plants that do this. The mirrors concentrate the rays of the sun and the energy is converted from radiation into heat. The heat is used to create steam which drives a steam turbine generator producing current. Continue reading

Electric cars which you can use for electricity storage

Sometimes you need vision to identify a solution to a problem and the hardest thing is to think laterally to solve the problem. Storing electricity is hard to do, especially in large quantities. In the home you store heat in your radiators and in your hot water cylinders and tanks but you do not usually store electricity save in the batteries of a few hand held devices. 

If we could easily store electricity we could save a great deal of energy. Electricity power stations operate most efficiently when they run at constant rates, but the demand fluctuates greatly. So we waste a lot of fossil fuel is generating electricity that no one uses and which we cannot store. If we could store it we would generate less of the stuff, thereby emitting fewer pollutants and less carbon dioxide. 

To store electricity on a large scale is very hard. You can build highly inefficient large batteries but these have their own environmental problems. You can build a dam and create a lake below the dam. When you have surplus electricity you wish to store, you can pump the water up to the dam. When you want to use the electricity you can let it flow back to the lake through generators which feed current back into the grid. There is actually one of these storage sites in North Wales, but they use land, a scarce resource close to urban areas, and flooding land has several bad environmental effects including the release of carbon dioxide and methane from rotting vegetation. 

There  might be other ways of storing electricity but no one could think of them until eleven years ago when Willett Kempton of the University of Delaware and Steven Letendre of Green Mountain College thought about electric cars.  They reasoned (eleven years ago), before a single electric car was available for sale, that if every car in the United States was powered by electricity the battery storage capacity of all those cars would have much greater capacity than all the US  electricity generating utilities.

They also knew that all cars spend much more time idle and not being driven than they spend being used. In fact cars spend 95% of their time doing nothing with their engines turned off. Why not use the massive batteries in electric car for storing grid electricity when the cars are not working and draw out the power if necessary when the cars are idle? The critical part of this thinking was to recognise that electric vehicles are not just a load but also offer storage possibilities. They also recognised that instead of renewable electricity export to the grid (which often is inefficient and often happens when the grid does not need the current) the batteries of electric cars can be used to store domestically produced renewable electricity from your PV system or your local wind turbine. 

In 1997 there were no commercially produced electric car and the computer software and hard ware industry was a lot less sophisticated and a lot more expensive than it is today. There was no broadband. Now in 2008 researchers at the University of Delaware (Willett Kempton again) have found a way to use electric cars and hybrid cars as an intermediate store of electricity. A prototype has even been produced by a Californian company, A C Propulsion, whose car has an inboard computer using broadband over the plug in electric cable that connects the car to the mains.  

When you have several thousand vehicles so connected there is a critical mass which can store electricity generated when no one wants it, and put back the current in peak times, provided the car is not being used. It saves a lot of wasted electricity, and prevents carbon emissions and enables generating stations to operate more efficiently with lower baseloads. 

If we can get past the prototype stage and if we can get broadband sent over electricity cables with sockets created specially for electric cars all over London, we can significantly reduce emissions using fleets of electric cars. I should say “might” because we have to understand the down side (there are always down sides); we have to factor in the environmental cost of batteries, for example.  

If it works it might well help transport be significantly less carbon intensive and in the very long term reduce the need for so many fossil fuel or nuclear power stations. 

To prevent catastrophic climate change we must to use all available technologies appropriately and devices, modify behaviour, act imaginatively and think laterally. I have never been convinced of the environmental benefits of the electric car, which I fear simply moves emissions from city centres to power stations. If we can use electric cars as electricity stores then the argument in their favour is compelling.

Wind Turbines – John Hutton’s blustery way

We have had one of the “we are going to one day perhaps” announcements from the government about building “up to” 7000 offshore wind turbines. The story starts big – all UK homes will be powered by wind by 2020 but the small print reveals this to be an aspiration, rather than a policy. Continue reading