Sustainable Energy – without the hot air

Having written the previous article about solar or nuclear, I thought I’d better check my facts and I came across a very interesting book called Sustainable Energy – without the hot air (available free online) by the late Professor David MacKay from the University of Cambridge and Chief Scientific Adviser to the UK Department of Energy and Climate Change. He goes into considerable detail to explain the energy problem we face in a digestible and interesting style.

I’ve not read the whole thing yet, but for those short on time there’s a handy 10-page synopsis. Here’s a relevant quote from page 4 about two clear conclusions made in part 1 of the book:

First, for any renewable facility to make an appreciable contribution – a contribution at all comparable to our current consumption – it has to be country-sized. To provide one quarter of our current energy consumption by growing energy crops, for example, would require 75% of Britain to be covered with biomass plantations. To provide 4% of our current energy consumption from wave power would require 500 km of Atlantic coastline to be completely filled with wave farms. Someone who wants to live on renewable energy, but expects the infrastructure associated with that renewable not to be large or intrusive, is deluding himself.

Second, if economic constraints and public objections are set aside, it would be possible for the average European energy consumption of 125 kWh/d per person to be provided from these country-sized renewable sources. The two hugest contributors would be photovoltaic panels, which, covering 5% or 10% of the country, would provide 50 kWh/d per person; and offshore wind farms, which, filling a sea-area twice the size of Wales, would provide another 50 kWh/d per person on average.

Such an immense panelling of the countryside and filling of British seas with wind machines (having a capacity five times greater than all the wind turbines in the world today) may be possible according to the laws of physics, but would the public accept and pay for such extreme arrangements? If we answer no, we are forced to conclude that current consumption will never be met by British renewables. We require either a radical reduction in consumption, or significant additional sources of energy – or, of course, both.

It’s rather interesting if you read the whole synopsis. The book presents five energy plans for Britain showing different mixes of the carbon-free options to represent different political complexions.

Clear in all of these plans is the small amount coming from the type of solar (PV) that Cleve Hill are proposing. Professor MacKay proposes that ‘solar in deserts’ is the key thing that will make a difference:

Any plan that doesn’t make heavy use of nuclear power or “clean coal” has to make up the energy balance using renewable power bought in from other countries. The most promising renewable for large-scale development is concentrating solar power in deserts. Concentrating solar power uses various combinations of moving mirrors, molten salt, steam, and heat engines to generate electricity.”

There’s a sixth plan in the book – plan M – which lies roughly in the middle of the other plans and shows Britain with every conceivable carbon energy source mapped out.