THE PRESSURE GROUP Extinction Rebellion has garnered considerable publicity in recent weeks with its demands for policy changes to mitigate Global Warming. Their demands are very generalised but include the UK economy becoming carbon neutral by 2025 and reliant on renewable energy.
At the other end of the knowledge spectrum, the government advisory group – the Committee on Climate Change (CCC) issued a report in May 2019, making many specific proposals for the UK to become carbon neutral by 2050. Low carbon electricity must triple by 2050; offshore wind installations are to increase by a factor of ten and total electricity increase by a factor of three or four. These are revolutionary changes to the electricity supply network and will introduce massive engineering challenges. It is less obvious that they will also incur catastrophic risks that have not previously existed – comparable or worse than the problem they are intended to solve. This needs to be publicised since the reckless schemes are not being scrutinised.
Since the discovery of fire by Homo Sapiens, we have employed a range of energy sources that have generally developed in three directions. They have become ever more concentrated, more diverse and more amenable to human control. Firewood gave way to charcoal, but with industrial expansion and population growth, we converted to coal, then oil, natural gas and nuclear energy – the most concentrated of all – 50,000 times greater than wood.
A nuclear reactor is comparable in size to a detached house, but can supply a million homes with electricity continuously for a year. Reverting to the wind and sun is a move in the contrary direction. Renewables are not only very diffuse, requiring thousands of installations, but vary in unpredictable ways and are not amenable to human control. This is a substantial functional loss when supplying a commodity – electricity – that is required with almost 100 per cent continuity of supply.
Security of supply is provided by optimising three factors – reliability, redundancy and diversity. Power station plant is very reliable; redundancy is achieved by having unused capacity even at the time of peak demand. Diversity is achieved via a mixture of fuels. The fuels are supplied independently and do not suffer from what is known as common-mode failure. In other words, an interruption to one is unlikely to be seen simultaneously in another. This diversity is compromised with renewables and can be considered as the Achilles Heel. Wind and solar are weather-dependent and will expose our society to a risk at an unprecedented level if the suggestion that they supply 70 or 80 per cent of our electricity ever comes to fruition.
We have a vast quantity of data from energy websites showing that during freezing anticyclones (a time of peak demand), the energy supply from wind and solar can decline to only a few hundred MW. Such conditions frequently last for several days but can extend to two weeks or more. Wind power can also vary over a very wide range at less critical times of the year.
July 2021 had many days with little wind power. On Wednesday 21st July, output was only 300 MW at 6.30 am. Over the next four hours as demand increased through the working day, it fell to less than 200 MW at 11 am – only 0.7 per cent of our requirement. There were a few days when it reached 5000MW but we expect electricity to be available continuously. To date these swings have been accommodated because conventional coal, gas and nuclear stations can still fill the generation gap. In the CCC model, only 15-20 per cent of installed capacity may be conventional thermal, leaving a dangerous shortfall.
The CCC in recommending the massive expansion of renewables has based its forecasts on days with good performance but ignored the failures. It has been grossly deficient in not undertaking any rigorous fault analysis to identify hazards and combinations of events that would derail this new generation model. It naively assumes that all systems will operate faultlessly at optimum performance in perpetuity.
Extreme climate events may indeed be more common as CO2 levels rise, (in which case, common sense would advise against an increase in weather-dependent power sources) but there are other hazards. The most severe plausible risk is one that could not merely have a detrimental effect on electricity generation, but could cause cataclysmic problems for our digital society that depends on electricity for almost every function.
The atmosphere is regularly affected by more dramatic effects than pollution from fossil fuels. Serious volcanic eruptions occur every few decades. The ejected particles and gases can cause observable falls in the temperature of the Earth.
Mount St Helens and Mt Pinatubo occurred less than 40 years ago. Two comparable events occurred in the 19th century – Krakatoa 1883 and Mt Tambora 1815. In Europe devastating eruptions have occurred at Vesuvius, Santorini and Laki in Iceland 1783. Tambora produced what is known as the “Year without a Summer”. The skies were so dark with significant cooling that crops failed in Europe and North America. There were famines and significant loss of life. The debris from the eruption remained suspended in the atmosphere until the following year. Any similar event occurring at a time of high dependence on solar and wind power would paralyse electricity generation and the working of our society. The recent eruption of Mt Etna shows that not all of Europe is stable and passive.
Over the centuries, we have reduced our vulnerability to environmental changes by bringing energy supplies under human control. We are far less vulnerable to extreme weather events, but some storms and heat waves still pose a risk to human welfare. Some of the CCC policies will reverse this increased control and introduce greater risks than the problem that their complacent proposals are designed to ameliorate. It would seem that some of the greatest threats have not even been contemplated. The CCC must be pressed to rectify this omission.
Photo of Mount Etna Volcano and Catania below it in Sicily Italy by Alberto Masnovo via Adobe Stock.