As followers of this blog will know the RSPB has put in a planning application for a wind turbine at our headquarters at the Lodge in Bedfordshire.
We think this is vitally important if we are going to lead the way in reducing our carbon footprint and help halt the climate change which will push many species towards extinction if we do nothing.
If you want to hear more about why we are taking this big step then our conservation director Martin Harper laid out the argument clearly and passionately in his blog on Friday.
But if you’re not afraid to get technical and you want to have a look at this project in more detail then I wanted to take this opportunity to lay out all the figures in one place. I should issue a health warning here and now though, there’s enough numbers here to make your head dizzy.
If it gets the go ahead the wind turbine will be 100 metres at its highest point, with a rotor diameter of 53 metres. It will be taller than the nearby electricity pylons and half the height of the Sandy Heath television mast located across the road from The Lodge.
In terms of energy production our initial wind speed data suggests the turbine could produce 2.36 million kWh per annum1, which is enough to power the equivalent of approximately 550 medium-sized homes.
At our current rate of consumption, this means the turbine should generate the equivalent of up to two thirds of the RSPB’s total UK electricity needs across 127 sites, ranging from single person offices to our UK HQ housing over 500 staff.
The wind turbine is predicted to reduce UK carbon emissions by just over 1,000 tonnes of CO2 every year. This single wind turbine is expected to directly reduce RSPB The Lodge’s carbon emissions from energy usage by up to 61%.
Wind turbines will typically ‘pay back’ the energy used during the manufacturing process in less than 8 months. Our turbine’s full carbon debt should be cleared within the first year of operation, which means its subsequent 20-25 years of operation will provide carbon-free power.
A wind turbine at the Lodge will reduce the RSPB’s greenhouse gas emissions by 3% per person each year. The Government’s target to source 15% of energy from renewables by 2020 and the Scottish Government’s target to obtain 100% of electricity from renewables by 2020.
Wind turbines are designed to operate when the wind speed is between 3 m/s (a light breeze) and 25 m/s (storm conditions). Although our surveys have shown that there is low bat activity in the area bat the turbine will be programmed to switch off below 7m/s during peaks in bat activity to reduce any risk of bat mortality. This will reduce the output of the turbine by approximately 3%. In severe storms, when winds reach a speed of 25 m/s or more, the turbine will automatically shut down due to health and safety requirements set by the turbine manufacturers.
The turbine is located at least 640m away from the nearest house, and there are fewer than 50 residences within 1km of the site. It will be in place producing electricity for 25 years and will have circular concrete foundations approximately 12m in diameter.
So there we go, and don’t say I didn’t warn you about the numbers. Now I think I need a head massage, my brain is hurting...