The Rational Optimist_ How Prosperity Evolves - Matt Ridley [161]
A big contribution will surely come from solar power, the least land-hungry of the renewables. Once solar panels can be mass-produced at $200 per square metre and with an efficiency of 12 per cent, they could generate the equivalent of a barrel of oil for about $30. Then, instead of drilling for $40 oil, everybody will be rushing to cover their roofs, and large parts of Algeria and Arizona with cheap solar panels. Most of Arizona gets about six kilowatt-hours of sunlight per square metre per day so, assuming 12 per cent efficiency, it would take about one-third of Arizona to supply Americans with all their energy: a lot of land, but not unimaginable. Apart from cost, solar’s big problem, like wind’s, is its intermittent nature: it does not work at night, for instance.
But the obvious way to go low-carbon is nuclear. Nuclear power plants already produce more power from a smaller footprint, with fewer fatal accidents and less pollution than any other energy technology. The waste they produce is not an insoluble issue. It is tiny in volume (a Coke can per person per lifetime), easily stored and unlike every other toxin gets safer with time – its radioactivity falls to one-billionth of the starting level in two centuries. These advantages are growing all the time. Better kinds of nuclear power will include small, disposable, limited-life nuclear batteries for powering individual towns for limited periods and fast-breeder, pebble-bed, inherent-safe atomic reactors capable of extracting 99 per cent of uranium’s energy, instead of 1 per cent as at present, and generating even smaller quantities of short-lived waste while doing so. Modern nuclear reactors are already as different from the inherently unstable, uncontained Chernobyl ones as a jetliner is from a biplane. Perhaps one day fusion will contribute, too, but do not hold your breath.
The Italian engineer Cesare Marchetti once drew a graph of human energy use over the past 150 years as it migrated from wood to coal to oil to gas. In each case, the ratio of carbon atoms to hydrogen atoms fell, from ten in wood to one in coal to a half in oil to a quarter in methane. In 1800 carbon atoms did 90 per cent of combustion, but by 1935 it was 50:50 carbon and hydrogen, and by 2100, 90 per cent of combustion may come from hydrogen – made with nuclear electricity, most probably. Jesse Ausubel predicts that ‘if the energy system is left to its own devices, most of the carbon will be out of it by 2060 or 2070.’
The future will feature ideas that are barely glints in engineers’ eyes right now – devices in space to harness the solar wind, say, or the rotational energy of the earth; or devices to shade the planet with mirrors placed at the Lagrange Point between the sun and the earth. How do I know? Because ingenuity is rampant as never before in this massively networked world and the rate of innovation is accelerating, through serendipitous searching, not deliberate planning. When asked at the Chicago World Fair in 1893 which invention would most likely have a big impact in the twentieth century, nobody mentioned the automobile, let alone the mobile phone. So even more today you cannot begin to imagine the technologies that will be portentous and commonplace in 2100.
They may not even tackle man-made carbon, but may go for the natural cycle instead. Each year more than 200 billion tonnes of carbon are removed from the atmosphere by growing plants and plankton, and 200 billion tonnes returned to it by