“Keep the carbon in the ground,” is a regular chant from climate march protesters and campaigners. It is a launch pad to insisting on renewable energy sources to sustain our needs.
But with the desire from our Prime Minister to power all homes with offshore wind power by 2030, what are the trade offs for installing and relying upon sources of energy that are non-fossil fuel based?
Reports in June said that 47% of the UK’s energy in the first quarter of the year came from renewable energy. These are figures from the Department of Business, Energy and Industrial Strategy. Add in biomass and nuclear and the figure rose to 62% of our energy.
These figures were record levels, comparing favourably to the previous summer quarter of 39% and 52%.
Wind power generated 30% between January and March, notably high levels in February when there were two major storms.
The UK electricity grid running without coal for a couple of months (a total of 67 days) this summer has been well trumpeted.
The drive towards renewable energies – wind and solar – is because coal causes carbon emissions. And the aim under the Paris Agreement is to cut these so that global temperatures do not rise more then 1.5C by 2050.
According to the US Energy Information Administration: “Coal with a carbon content of 78% and a heating value of 14,000 Btu (British temperature unit) per pound emits about 204.3 pounds of carbon dioxide per million Btu when completely burned. Complete combustion of 1 short ton (2,000 pounds) of this coal will generate about 5,720 pounds (2.86 short tons) of carbon dioxide.”
Wind turbines, by comparison, produce nothing – after construction. One report estimates that coal is 90 times more carbon intensive than wind. The footprint of natural gas is 40 times larger.
Calculated over the expected lifetime of a wind turbine (20-25 years) and including the manufacturing, carbon emissions for turbines are less than 5% compared to coal. Constructing a wind turbine requires steel, which at present requires coal to make it. There are suggestions that hydrogen could be used instead. It is also estimated that construction costs of a wind turbine will be repaid within six to eight months, given the energy it generates.
Conservationists worry about the costs to wildlife. When the Prime Minister made his pledge, stories that seabirds would be in danger were recycled. The RSPB said man had to find a way to work in harmony with nature.
In the same week, Power for People reported that their Adjournment Debate, about facilitating local groups running power companies, had a potentially record turnout among MPs. The group aims to see the introduction of the Local Electricity Bill, to spark a community energy revolution.
Onshore, obstacles to wind turbine farms include visual pollution. Little is recorded as to whether windmills of centuries past – which produced flour – had similar objections. The effects of carbon emissions are not so obvious to any NIMBYs as the essentials of making bread were four centuries ago.
Various reports suggest that birds can suffer as a result of wind turbines, on or off land. Puffin populations have halved in five years, the RSPB told the Telegraph. Wind turbines build offshore could be yet another threat, they said. Not the only threat, we must note. Pollution, climate change and over fishing of their prey were other factors. And the turbines threat was only a “could”.
Bats and other birds are known to not be able to avoid turbines. However, one solution is to build in sonic booms that sound when they come too close. On land, there are also concerns about the amount of noise they make. But, in wide open fields – or maybe next to motorways – the extra noise would be negligible to their surroundings.
Off-road wind farms would need roads – or at least tracks – to be build to them in order to maintain them, and to lay the cables to transport the energy. Careful use of land, or previously industrial land where coal mines have been, might be the best places, then.
Off shore, seabeds could be disturbed to lay the cables and dig the trenches for the turbines. This could impact nature’s food chain. Sites will have to be chosen carefully.
In conclusion, the human race does need to find a better way to source its energy. The wind that is all around us seems an obvious sources. Battery storage to harness the energy, rather than pay suppliers to turn it off, seems another solution. But we really will have to work closely with nature to ensure that the solution to one problem does not cause others.