The renewables, like wind and solar, are intermittent.
How on Earth are we going to heat and light our homes in winter without using fossil fuels? OK, let me explain:
The renewables accounted for 30% of our electricity last year and the proportion is growing all
the time. But despite frequent fluctuations in wind speeds and the amount of electricity
we get from all the renewables, the grid can cope:
We can store energy, we can share energy with other countries
and we can reduce demand from industrial consumers
to cover short term dips. We are already storing energy in giant water
reservoirs like this one, Dinorwig in Wales. It helps balance demand by releasing water
to turn turbines when the grid needs extra electricity.
There are loads of ways of storing energy to meet any shortfall. Energy companies are
already using industrial scale batteries which are charged by using excess wind and solar power
and released when we need it. Soon, we will use the electricity stored in electric cars
to balance the grid too. We also share electricity with other countries
via interconnectors. The government has just ordered three more. These allow us to share
electricity with our neighbours, including using Norway’s huge hydro powered reservoirs
when our wind power drops. We will also soon be able to share power with Iceland, tapping
into its vast reserves of geothermal power. But it doesn’t just flow one way – we
can help other countries by exporting our excess wind power to them when they need it.
And with the UK having far more wind capacity around our coastline than we need, that could
be a very valuable export market. And it’s cheap. The latest offshore wind
auctions came in at nearly half the cost of the Hinkley nuclear power plant. And stacks of big industrial users have agreed
to reduce the amount of electricity they draw from the grid to help cover fluctuations.
Some businesses turn off their air conditioning and supermarkets can keep refrigerators cold
even if they don’t draw electricity for a few hours. But we also have to decarbonise gas.
The first step is to reduce demand. A national programme of home insulation will reduce the
need for gas by at least 50%. Then we need to change how we get our gas.
Some experts think we can meet our needs with biogas from anaerobic digestion plants that
turn waste like sewage and grass into biogas. But others say we may only get around half
what we need. We now know how to store hydrogen in the gas
grid and burn that instead of fossil fuels. When burnt, hydrogen combines with oxygen
to produce water – there is no pollution. We extract hydrogen from water by using renewable
energies like solar and wind power. This is called Power to Gas.
We know it is safe because Singapore and Hong Kong already use hydrogen in their grids. In this country,
Leeds has been chosen to run a trial of hydrogen. Under the H21 programme, the city will be
converting its boilers and cookers to run on hydrogen. And the brilliant part is that the gas grid
has enough capacity to provide seasonal energy storage to back up the electricity grid. So
we can now store excess solar and wind power as hydrogen and that store could last for
months. We sometimes have to let wind turbines stand
idle if the electricity isn’t needed by the grid but in future, that excess power,
which is effectively free, can be making hydrogen to store in the gas grid. The UK Government
is aiming to have carbon-free gas and electricity by the year 2060. But we can’t wait that long. Scientists like
Professor Stephen Hawking have warned that the runaway greenhouse effect could kill us
all. Warming in the Arctic is now accelerating so fast that permafrost is melting, releasing
methane, which is 25 times more powerful a greenhouse gas than carbon dioxide. Ah, so we can light and heat our homes,
even in the dead of winter, with energy that doesn’t cost the Earth!