Green shift is already leaving our energy system hugely vulnerable

See Here’s how to prepare for Britain’s net zero switch – buy a generator by Matt Ridley.

"Green shift is already leaving our energy system hugely vulnerable

‘If Ed Miliband has a plan to deal with the volatility and intermittency of renewable energy, he is yet to reveal it’ Heathcliff O’Malley

Energy is already ludicrously expensive. Making it more unreliable will only compound our misery.

In November 2021, Storm Arwen gave me a four-day taste of life without electricity. There were many lessons to be learned, namely: three candles are not enough to read a book by, a diesel car is a help for recharging your phone, and woodfires are a blessing.

Afterwards I bought a generator and have needed it twice since. As the country rushes into reliance on unreliable power, I may need it more often.

Ed Miliband, the Energy Secretary, wants to double onshore wind, quadruple offshore and treble solar capacity. If he has a plan to deal with the resulting volatility and intermittency, he has yet to reveal it.

The Hornsea wind farm tripping off on Aug 9, 2019 led to a massive blackout. Wind droughts can last for days and even years: in 2021, offshore wind output was at 34pc of capacity, compared with 45pc the year before.

There is a lot wrong with relying on wind and solar power for electricity. They are more expensive than using gas, and they require a lot of steel, concrete and rare metals, the creation of which generates emissions. Wind turbines can kill birds and spoil local views.

But the biggest problem, which remains unsolved, is that they are unpredictable and therefore unreliable. On a cold, still winter evening, when we need a lot of power, wind and solar contribute the square root of sod all. The more wind turbines we build the more expensive it becomes to maintain a back-up system of gas-fired power stations that goes unused for much of the time.

The risk of blackouts may be highest down South. Executives from the National Grid’s Energy Systems Operator (ESO) have privately warned that there is an increasing risk of power cuts in the South East by 2028, as Britain builds wind farms in the North and struggles to get their juice to the South.

Regionalised electricity prices would incentivise building power stations near to customers, but that is resisted by wind farm developers. They prefer generating power in windy Scotland or the North Sea and getting the consumer to pick up the tab for building many pylons to move power to London.

Yet even Green Party MPs are objecting to pylons in their constituencies. Hence, a £2bn subsea cable from eastern Scotland to County Durham is planned – but don’t bet on it: the £1.2bn Western Link between Scotland and Wales was four years late, and has had repeated outages. These costs only add to the price of electricity.

Moreover, the transmission grid is increasingly challenged by unpredictable volatility in net demand from the local distribution grid. The more people put solar panels on their roofs, and require the grid to take their power when the sun shines, the harder it gets to manage the supply and keep the frequency of the alternating current close to the all-important 50 hertz.

Of course, blackouts will be less common than price spikes. Britain already has some of the highest electricity prices in the world for industrial users – one major reason for our stagnant economy – and has domestic prices that are two and a half times those of America and more than four times those of China.

And those numbers are heading up, not down. To keep the lights on, the grid increasingly relies on investors building facilities that can be fired up quickly. These people will demand and get high prices during emergencies and are licking their lips at the growing volatility of Britain’s grid. Ironically, the fastest-responding gas stations are open-cycle ones, with higher emissions than combined-cycle plants.

The central problem is that you cannot store electricity affordably – not like you can store a pile of coal. Batteries are vastly expensive on the scale required. To store just a day’s worth of electricity for the UK would require a battery that would cost £300bn. Pumped storage (using spare power to pump water uphill) could be cheaper, but we don’t have nearly enough mountains. Compressed-air storage, making hydrogen with spare power and other such schemes are all achingly expensive and impractical.

It gets worse. If we all do as we are told and install electric heat pumps instead of gas boilers to keep our homes warm on those cold, still winter days, the demand for reliable power will massively increase. If we also switch to electric cars (which use more power per mile on cold, dark days), the problem is greater still.

At the moment, government policy appears to be to rely on interconnectors from abroad.

Britain is now Europe’s second-biggest net importer of electricity, after Italy. This is not only expensive; it’s a huge vulnerability.

Wind speeds are generally well correlated across neighbouring countries, so a wind drought in Britain will often coincide with one in Germany leaving both countries trying to import nuclear power from France and coal-fired power from the Netherlands.

Besides, the effect of an interconnector is to bid up prices in the exporting country. Norway has already passed a law allowing it to cut off its interconnector and the people of Iceland are balking at seeing their cheap hydro and geothermal power sent to Britain because of the effect on their domestic electricity prices.

Conversely, generators in Germany’s neighbours resent having cheap electricity dumped in their grids through interconnectors when the sun is shining.

As Kathryn Porter of Watt-Logic put it in a forthcoming report, “relying on interconnectors could prove to be a huge gamble, and one we will only know we have lost when it is too late”.

The more we rely on unreliables, the less secure and affordable our electricity becomes."