The Rational Optimist_ How Prosperity Evolves - Matt Ridley [115]
The Newcomen steam engine worked at 1 per cent efficiency – that is to say it converted 1 per cent of the heat from burning coal into useful work. Watt’s engine was 10 per cent efficient and rotated much faster. Otto’s internal combustion engine was about 20 per cent efficient and faster still. A modern combined-cycle turbine is about 60 per cent efficient at making electricity from natural gas and runs at 1,000 rpm. Modern civilisation therefore gets more and more work out of each tonne of fossil fuel. This increasing efficiency would, you might think, gradually reduce the need to burn so much coal, oil and gas. As a country goes through an industrial revolution, at first more and more people join the fossil-fuel system – i.e., they start to use fossil fuels in both their work and their home – so more and more gets used. The ‘energy intensity’ (watts per dollar of GDP) actually rises. This happened in China in the 1990s, for example. Then later, once most people are in the system, efficiency does start to bite and energy intensity starts to fall. This is happening in India today. The United States now uses one-half as much energy per unit of GDP as it did in 1950. The world is using 1.6 per cent less energy for each dollar of GDP growth every year. Surely now energy usage will eventually also start to fall?
That is what I thought, until one day I tried to have an unnecessary conversation on a mobile telephone while a man was using a leaf-blower nearby. Even if everybody lags his loft and switches to compact fluorescent light bulbs, and throws out his patio heaters and gets his power from more efficient power stations, and loses his job in a steel plant but gets a new one in a call centre, the falling energy intensity of the economy will be offset by the new opportunities wealth brings to use energy in new ways. Cheap light bulbs let people plug in more lights. Silicon chips use so little power that they are everywhere and in aggregate their effect mounts up. A search engine may not use as much energy as a steam engine, but lots of them soon add up. Energy efficiency has been rising for a very long time and so has energy consumption. This is known as the Jevons paradox after the Victorian economist Stanley Jevons, who put it thus: ‘It is wholly a confusion of ideas to suppose that the economical use of fuel is equivalent to a diminished consumption. The very contrary is the truth. As a rule, new modes of economy will lead to an increase of consumption.’
I am not saying fossil fuels are irreplaceable. I can easily envisage a world in 2050 in which fossil fuels have declined in importance relative to other forms of energy. I can envisage plug-in hybrid cars that use cheap off-peak (nuclear) electricity for their first twenty miles; I can imagine vast solar-power farms exporting electricity from sunny deserts in Algeria or Arizona; I can imagine hot-dry-rock geothermal plants; above all, I foresee pebble-bed, passive-safe, modular nuclear reactors everywhere. I can even imagine wind, tide, wave and biomass energy making small contributions, though these should be a last resort because they are so expensive and environmentally destructive. But this I know: we will need the watts from somewhere. They are our slaves. Thomas Edison deserves the last word: ‘I am ashamed at the number of things around my house and shops that are done by animals – human beings, I mean – and ought to be done by a motor without any sense of fatigue or pain. Hereafter a motor must do all the chores.’
Chapter Eight
The invention of invention: increasing returns after 1800
He who receives an idea from me, receives instruction himself without lessening mine; as he who lights his taper at mine, receives light without darkening me.
THOMAS JEFFERSON
Letter to Isaac McPherson
The phrase