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