Clive Best

Wind Farms are being proposed as the most effective renewable energy source for the UK, but is this based on any hard evidence? I have come to the conclusion that Wind Energy does not make sense. The environmental damage caused by building them far exceeds any benefit in clean energy production. The show stopper is that they are very unreliable because on average they run at only 30% output because the wind is unpredictable. This means that no matter how much wind energy is built the Grid will need to rely on an equal amount of reserve (fossil) energy production when the wind isn’t blowing. Often flat air with high pressure conditions occur during mid winter leading to very cold temperatures.

The latest wind turbines generate a peak power of 2 Mw,  and are 130 m high with a rotor diameter of 80m. Due to wind shadow these need to spaced about 800m apart.  Therefore for a wind farm to produce the same energy at full output as a single nuclear plant of 1.5 Gw it needs to contain 700 such turbines covering  an area of about 500 square kilometers. Each turbine needs to excavate a massive foundation base from the earth filled with reinforced concrete weighing thousands of tons causing a huge impact on the countryside. They would need replacing every 10-20 years - although my guess is that they would quickly be abandoned as white elephants leaving vast areas of eyesore consisting of decaying concrete and steel structures. This is simply a repeat of the sixties concrete tower block planning scandal.

The real problem though is simply that wind is so unreliable. The average load factor of windmills in Britain is 30% because the wind has to be just right to reach peak output. Too little and no energy is produced and too much causes   the turbines to shut down in order to protect them from damage.  This consequently increases the effective area of our wind 1.5 Gw farm to 1000 sq km (probably 3000 sq km using the figures from ref 1.). The real show stopper though is that occasionally the whole country is windless and national output would fall to essentially zero.  This means that wind power can never replace fossil fuels because we will always need reserve core capacity - and the only non fossil source is nuclear.

So why does private industry and electricity utilities promote and build new wind farm developments in Britain ? The reason is simple - they receive huge  subsidies from the government ! These subsidies are actually financed by the consumers through surcharges on their electricity bills. There are two political mechanisms that fund the subsidies: the first called Renewable Options and the second a Climate Change Levy. The first is a requirement that by 2010 10% of electricity is generated from renewable sources for each utility company. If this is not achieved the utility company pays a fine because it doesn’t hold sufficient certificates called Renewable Obligation Certificates (ROC). No utility would fund wind power without these certificates which were originally worth 30 pounds/Mwh, but  are now traded on open markets at sums of around 50 pounds/MWh. These ROC certificates are funding wind farms to the tune of around 1 billion pounds per year. Taken together with CCL the effective subsidy on wind power generation is now 60 pounds/MWh. This means for the utilities that the effective value of every watt of electricity generated by Wind has  3 times the value as that generated by fossil fuels. It is no wonder they are all keen to build wind farms. Over a 25 year period the effective subsidy for each Wind turbine  of 1 Mw is 3.5 Million pounds! Without this subsidy no-one would be building wind farms today as they are simply not cost effective. For comparison : the generating costs  of nuclear energy is $30 per MWh including construction and decommissioning costs (ref 2).

The other problem with wind power is the environmental damage they cause to the natural countryside. To make a significant contribution to Britain’s energy 10% of available countryside would need to be handed over to wind power. Apart from their visual impact, these towers  kill bats and rare birds of prey like Eagles, and  cause documented noise pollution for nearby homes. They concentrate in some of the  most beautiful areas of the country - hills and western coastlines, yet despite this still give no guarantee of continuous energy supply. Windless conditions across the UK is not an infrequent occurence,and perhaps worse it is unpredictable.  Wave energy suffers from the same problem, and only tidal energy is a predictable renewable.

The world needs to get off fossil fuels not just because of CO2 emissions but because these resources are finite and insecure. However, the only viable alternative for the foreseeable future is nuclear energy. Current generating costs of nuclear power are among the cheapest available, roughly about the same as coal. Critics argue that nuclear power received hidden subsidies in the past because of weapons work. However, this is irrelevant today as that money has already spent and there are no subsidies at all for nuclear today. The environmental footprint of nuclear power plane is a tiny fraction of a wind farm and has the  advantage of 90% load factor and predictable  availability.

The political pressure of the climate change and environmental lobby has caused governments to pledge targets for CO2 emissions. Political expediency and subsidies are now  leading us down the renewable path based on figures that just don’t add up. Some renewable energy is probably a good idea - especially predictable sources like Hydro and tidal energy, but wind energy should be restricted to just a few percent of  production, or we will regret our folly once these towers rot and decay when subsidies are removed.

Right now the only non fossil fuel option that makes sense to me is nuclear power.  I understand long standing opposition  to nuclear power but this is driven by prejudice -  and unfortunately the maths says that  other options are  currently pie in the sky.

Ref 1: Sustainable Energy - without the hot air. David MacKay. http://www.withouthotair.com/

Ref 2: http://www.world-nuclear.org/info/inf02.html

One thing that will not be addressed in Copenhagen is the damage done by an  ever growing human population on the natural balance of the Earth. This is  the real elephant in the room which eventually we must have to face up to. Even if we eliminate completely CO2 emissions from energy production by developed countries we humans will continue to degrade the earth while our numbers increase.

These are the back of the envelope calculations of Mankind’s emissions of CO2 resulting just from there being 7-9 billion of us on the planet whether we burn fossil fuels or not.

1. Breathing : People on average breath in about 7 litres a minute of air. The air we breath out contains 4% CO2. In affect we are burning food(carbon) in oxygen to provide the energy to keep warm and  active. Each one of us therefore emits about 0.3 liters of CO2 a minute weighing 0.6 gm, or 0.3 tons of CO2 per year. The current population is 7 billion and UN  forecasts a population  of 9-10 billion by 2100. Lets take a nice round figure of 10**10 people as the maximum human population. This gives:

Yearly CO2 emissions through breathing :  3 Gigatons/year

2. Domesticated Cattle breathing: Cattle are a key source of sustainance to many people throughout Africa and the rest of the world. The world populaion of domesticated cows is about 2 billion. Each cow produces about 1.5 tons of CO2 just by breathing. Methane emissions from cows humans and agricuture are completely ignored here

Yearly CO2 emissions through of domesticated cows : 3 Gigatons/year

3. Agriculture, Deforestation through burning and land clearance. As ever increasing numbers of people demand food  more from the available arable land so the pressures on natural envirnments and especialy forests increase. Forests are a key sink of the carbon cycles.

Figures resulting from deforestation from FAO : 2-4 Gigatons CO2/year

4. Finally the emissions of CO2 from Burning of Fossil fuels by developed and developing nations - Industrialisation. The agreements hoped to be reached  in  Copenhagen focus entirely on man-made (western industrial) induced emissions of CO2 high energy production. The current global figures for all CO2 emissions caused by the burning of fossil fuels  in 2008 is:

Yearly emissions fossil fuels: 5 Gtons CO2/year.

There are important measures that can be agreed in Copenhagen to reduce emissions of CO2 by industrialised countries. Yet these can only delay catastrophy while population levels increase beyond sustainable levels.

I have just finished reading the book “Sustainable Energy without the Hot Air” by David MacKay who is a professor of physics at Cambridge University. It is a breath of fresh air which cuts through all the politics to analyse our real options for a future without fossil fuels. The news for Britain and most of Europe is not good unless we expand Nuclear Power. The problem is that the energy density of renewable energy is way too small. The most promising renewable for Britain is wind energy, although it is still currently 3 times more expensive than nuclear. The key problem is that the area of land needed to make a big impact is vast. If one covered 10% of the surface of Britain (all the windy parts) in wind farms one could power about 20 light bulbs per person. This is a huge area of land, would have a massive impact on the countryside and represents  roughly twice the total number of wind turbines in existence today (US + Europe combined). However even then it  only produces about half the energy currently  consumed by car transport per person. A future transport system without fossil fuels would most likely have to be electrically generated by these same wind turbines or something else !

Solar energy for Britain will not make a large contribution and is best used for water heating. However it can produce large power if allowed to cover vast areas  in deserts using optical concentrators (mirrors and lenses) plus photovoltaic farms. This means that the US could conceivably replace most of its fossil fuel requirements with a solar energy farm covering most of Utah. Europe would have to import energy from Libya or Tunisa where huge solar energy farms the size of Yorkshire  would need to be placed in the Sahara desert. Again though we would be dependent for energy security on foreign supplies.

Wave power is too ineffective compared to wind. Tidal power however is fairly economic for a smallish contribution at specific sites like the Severn estuary and tidal pools like the Wash, and has the advantage that it is reliable (unlike wind speed). Biofuels and Biomass burning is just a non-starter. Britain could only sustain < 1 million stone age men burning wood and living on the borderline from the available land. Applying science to exploit non-nuclear  renewable energy based in Britain could perhaps sustain  a population of 10 million with a moderate standard of living. The current population is 60 million.

The only possible way for Britain (and northern Europe) to be sustainable in the medium term without fossil fuels is a 10 fold expansion in Nuclear (Fission) energy. Renewables can provide a significant contribution but a core energy supply which is 100% guaranteed is essential. Eventually nuclear fusion might  provide a long term stable energy “nirvana” with  endless supply -  but this is still a distant dream and despite ITER is still not a certainty. I believe that it is achievable within  50 years given the willpower and the commitment.

It is very attractive and fashionable  to take an emotional  political/ideological/religious stance on energy and climate change but the numbers have to add up, and quite frankly they don’t without nuclear.  To pretend that  a future built just on green renewable energy  can sustain a world population of 9 billion  is simply daft.