Back in 1970, on Easter Sunday afternoon, my car broke down. I was driving my family from Indiana to West Virginia in a venerable Dodge Dart that had cost me $80 the year before. Helpless, I rang the doorbell of the nearest house. The owner was sympathetic and fortunately knew the local car-wrecker, whom he called. This man came quickly, opened the bonnet (hood to him) and diagnosed a defunct alternator. He removed one from a similar car in his yard and the repair was completed in less than an hour. We drove off, full of respect for the helpfulness of Americans, appreciation of the value of recycling, and the relevance of electricity to the running of a car.
It is so easy to take electricity for granted. I remember a time in Britain when most homes in the countryside had no electric supply and relied on oil that had, in earlier generations, come from vegetable sources or from whales but since the mid-19th century has come from fossil fuels. In the rich world, we have become complacent through a period of abundant energy from these fuels. Now we are facing the inevitability of increasing shortages that will require to be made good as far as possible by increased production and use of electricity from renewable sources. Where does all this electricity come from? Can we ever produce enough for our and the Earth's growing population's needs?
What is electricity?
Many of us will have noticed sparks when putting on synthetic polyester shirts or blouses in the dark. Static electricity was known to the Ancient Greeks when they polished amber jewellery – electron is Greek for amber. But they didn't know that all animal life runs on electricity, the passage of charged ions across cell membranes and along nerves. The discovery of this animal electricity is attributed to Luigi and his wife Luisa Galvani in 1787, when they showed that electricity could flow along a metal wire and a dead frog's muscles contracted when given a shock. The shock came from static electricity stored in a Leyden jar, a simple device that had been invented some 30 years before and made into a storage battery by Benjamin Franklin. In principle, the same direct current shock is used today to restart an arrested heart (See SR,
24 March 2021).
This was the start of something big: a great upsurge in scientific curiosity about this new form of energy. The same man who had discovered methane, Alessandro Volta, showed in 1800 that electricity, made by connecting two different metals by a fluid such as saline or an acid, could be stored in a stack of such components, the first true battery.
Two decades later, Hans Ørsted showed that a magnetic field was produced when electricity flowed down a wire and Michael Faraday showed this could cause rotation by electromagnetic induction, leading to Edinburgh's James Clerk Maxwell (whom many rank with Newton and Einstein) working out the physical laws governing electricity in the 1860s.
The conversion of mechanical to electrical energy and vice versa was transformative. In addition, Nikola Tesla had invented a coil that could transform electricity from low to high voltage and had also invented the alternator mentioned above, to transform direct into alternating current. These two inventions allowed electricity to be distributed through wires more efficiently and supplies to industry and homes became safer. Sir Charles Parsons had invented the steam turbine generator, initially powered by coal, but large windmills had already been used to charge batteries. The world was set on a path to the use of electricity in our houses, streets, transport, and workplaces. We were to become dependent on it.
Our dependence on electricity
It is easy to imagine life without electricity at home or work. At home, a coal fire, wind to dry the washing, and muscle power were once all that was available to the housewife. In medicine, candles and oil lights were used to examine a patient or to perform an operation. Now we have electro-diagnosis with cardiographs and encephalographs to measure the activity of heart and brain, X-rays, CT scans, and magnetic resonance scans and ultrasound to see within us, diathermy in surgery, and the automated machinery that allows our genes and blood constituents to be investigated at the molecular level.
All this and the systems that run our computers and heat and ventilate our hospitals stem from these early discoveries. Now we are faced with the need for a similar surge of innovation to allow us to withstand the worst of what climate change brings. Electricity will be central to this.
Electric power is measured in kilowatt hours (kWh) and the average home in the UK uses about 10kWh daily, though many use far more. All electric devices have a power rating, for example a 100-Watt bulb, a 300-Watt refrigerator, a 1,200-Watt dishwasher, or a 1,500-Watt coffee machine. Multiply by the hours used and you find out how many Watt hours you have used, but since this is usually a large number, it is divided by 1,000 to give kWh.
A good example is a hairdryer, which may have a power rating of 2,000W. Used for 10 minutes every day for a month (say five hours), it consumes about 10kWh of electric energy. A 300-Watt refrigerator, on for 24 hours a day, will consume 216kWh per month. My electric car takes 40kWh to charge fully and gives me 200 miles if driven sensibly (as it always is).
Think of all these things in your house or workplace and you will understand your electricity bill. My supplier, who provides wind-generated electricity, charges me 19.5 pence per kWh at present (I anticipate it will rise substantially). I manage to reduce the cost by having solar panels, which generate about 3,000kWh per year.
Reducing demand
Once you think about electricity in this way, it's easy to reduce your demand, your costs, and your carbon footprint. If you buy from a green supplier, you will have a low one anyway though you may pay more per kWh. When you boil a kettle, think of James Watt who played a key role in starting this climate problem but who also, alongside Cavendish, pointed to the possible solution in the relationship of hydrogen to water (SR,
28 September 2021).
Before you buy an electric gadget, look at its wattage. Every time you switch something on, ask yourself if it is necessary. Don't forget to switch it off. Dry your washing on the line if you can and dry your hair with a towel. Switch the TV off if there's only rubbish on. Every little helps to reduce your bills and the UK's carbon footprint.
It's rather like getting vaccinated: you are acting to benefit yourself but also the rest of humanity. We 60 million or so people in the UK used about 290 million million Watt hours (290 terawatt hours, TWh) of electricity in 2020, but this was about 50TWh less than we used in 2005. This probably reflects more efficient gadgets and some appreciation of the need to reduce consumption – it can be done.
It is encouraging to see that wind and solar produced over 40% of this electricity, a percentage that is growing rapidly with the development especially of offshore wind turbines. But there is still an enormous challenge. Wind gives us about 76TWh and solar 13TWh annually. Nuclear provides about 60TWh and hydro 8TWh, leaving around 40% of our electricity, 119TWh, still generated by fossil fuels. This is what we must replace.
The challenge
The problem is greater in that this only applies to electricity. As well as eliminating the 40% generated using fossil fuels, we need to replace our consumption of oil and gas for other purposes, primarily transport and domestic heating. We can no longer allow these commodities to be burnt, although some will still be needed as a chemical feedstock. A glance at your utility bill and your expenditure on travel and fuelling your cars will show you the size of this problem at a personal level. Average gas consumption in a UK home is c13,000kWh per year and heating a large house can multiply this several-fold.
On a population scale, the UK's energy consumption includes oil for transport, virtually all of which needs to be replaced by electricity. The total annual fuel consumption in the UK transport sector, which is about 40% of all energy consumed, is around 660TWh. The challenge is to replace this and the 119TWh from fossil fuels, mainly gas, used in electricity production – a total of an extra 779TWh of electricity supply – and to do it quickly. This need for an increase by 170% of current generation seems very unlikely to be achieved quickly, showing that reductions in our demand must accompany increased production.
An average electric car consumes about 200kWh per 1,000 kilometres, making it about five times more energy efficient than petrol or diesel ones, so widespread substitution of fossil-fuelled vehicles by electric ones will help reduce the total energy demand. Scrapping of fossil-fuelled vehicles cannot come too soon.
This, I hope, makes clear the size of the problem. It will require all of us to reduce our travel and domestic energy costs substantially while the climate becomes more unpredictable and the pressures on prices and from migration increase. In addition to this increase in generation, governments also must solve the problems of storage and distribution of electricity, and of how to cover periods when wind and solar generation do not match demand.
There will continue to be a need for nuclear generation, and I hope smaller more efficient reactors will prevent all this having to be imported. I am not sure that our politicians in general appreciate the significance of this energy problem, but I hope that it will become clear to them at COP26.
To end on a more optimistic note, the UK total energy consumption rose by 60% between 1948 and 1998 but since then has fallen progressively and renewables have largely replaced coal. Our total energy consumption is now at a similar level to that of our smaller population in the 1950s – a remarkable achievement. During the lockdown, there was a further sharp fall to 1948 levels. Decarbonising transport and changes in personal behaviour can make a huge difference and allows the UK to lead the world out of the crisis, as unknowingly we led into it. Older and wealthier people must take the lead. We owe it to the young and those in poorer countries who are already bearing the brunt of the adverse consequences of climate change.
As for the Dodge Dart, it and its second-hand alternator served me well for two years and I sold it to the Professor of Medicine for $80, helping towards our fare home by ship. I hope bits of it are still being recycled by car-wreckers in the USA.
Anthony Seaton is Emeritus Professor of Environmental and Occupational Medicine at Aberdeen University and Senior Consultant to the Edinburgh Institute of Occupational Medicine. The views expressed are his own
