Wind energy opponents who say that producing electricity using the power of the wind is not efficient would do well to take a look at a new graphic using UK Government data which shows that thermal sources of electricity – gas, coal, nuclear, waste/biomass, oil and other – lose massive amounts of energy as waste heat, compared to almost 0% for renewables.
Gas accounts for 48% of the UK’s electricity supply and, of the 372 Terra-Watt hours of electricity it produces per year, 54% of this is lost as heat. Coal, meanwhile, accounts for 28% producing 297 TWh, loses an even higher proportion – 66%. Nuclear – accounting for 16% of the energy supply with 162 TWh, loses 65% and oil – 3% of the supply with 51 TWh – loses 77%.
Renewable energy – which all together accounts for 4% of the UK’s electricity supply producing 14 TWh – loses less than one percent. So, under this measure, renewable energy is 100% efficient.
Wind energy opponents centre their arguments on the ‘capacity factor’ of a wind farm. Wind farms do not operate at wind speeds of less than 4 metres per second, and they are shut down to prevent damage during gale force winds of 25 metres/second or more, or for maintenance. But conventional power stations also do not operate all the time – they stop generating electricity during maintenance or breakdowns.
Comparing the outputs of both sources does show that conventional power stations produce power at a level compared to their theoretical maximum that is currently higher than the level for wind energy. Wind power’s capacity factor is around 30% onshore and 40% offshore, increasing year on year as more wind turbines come online and technology improves. Meanwhile, data from the German Association of Energy and Water Industries (Bundesverband der Energie und Wasserwirtschaft) shows that fossil fuels are often below 50%, even in winter.
A pat there for wind, but wait to see more in our next post.