IF I HAD needed persuading, Libby Purves would have persuaded me. For the past fortnight
T2 has been pursuing a quest to identify the greatest British invention in history, and by Wednesday a shortlist of five had been decided by
Times readers’ votes: vaccination; the bicycle; the computer; electricity; and (as best runner-up) the electric light. Today the winner is announced. Given the chance to go all misty-eyed, we British seldom pass it up: naturally the bicycle triumphed. But there can be no doubt which invention won the debate if not the vote. It was the candidate canvassed by Libby in Thursday’s
T2: electricity.
Just glance at the four headings under which T2 chose to group its inventions: medicine, transport, “the way we live” and industry. The editor put electricity into the industry category, but in fact it has made vast contributions in each of the other three. Most of our trains, all our households and the central nervous systems of every hospital are electric. As a medium for the transmission of energy and information, electricity is non-pareil.
One thing holds it back. One thing stands between electricity and world domination, keeping alive its only serious competitor: oil. There is but one reason why fossil fuels retain their grip as sources of heat and (via the internal combustion engine) motion. Our failure — Britain’s and the world’s — to invent an adequate electric battery is the sole cause of our dependence upon fossil fuels. Everything else — air pollution, global warming, rising sea-levels — flows from that.
Sometimes it is what stares us in the face that we most readily overlook. We dwell on our small failures because we can imagine overcoming them; but we hardly try to picture what life would be like if the really big blocks to our progress were to disappear because these blocks are so familiar a part of our mental furniture that we cease to notice them. Perhaps you have never stopped to ask why there are no battery-powered helicopters, propeller-aircraft or lifts, why most electrical power comes to you along cables and wires whereas nobody would try to connect his oil-fired central-heating boiler by pipe to a refinery, or why the very idea of continuously fuelling a bus through a lowered scoop dragged along a small diesel duct running down the middle of the road, would be laughed off as absurd.
In each case the reason is the same. The magic of oil is not (as we sometimes assume) its potency as a fuel, but the ease with which it can be stored and transported. The magic of oil is its portability, not its punch.
Here are some salient and surprising little facts about batteries. Expressed in joules per kilogram, a jerry-can of petrol stores more than a hundred times the energy a typical car battery can store. If you emptied your car battery’s rubbery shell of its lead and acid contents, and replaced them with a few lumps of coal the energy stored could take your car farther than a charged battery could. To put it bluntly, batteries are terrible at storing power. So pitiful is our battery technology that in a pathetic attempt to store electrical power we (electrically) pump lake-size quantities of water uphill at night in Wales, then run it back down through generating turbines in the day. And we beg householders to buy their electricity (at half-price) at night and heat up boxes of bricks with it (Economy 7 storage heaters).
It is true that a range of high-tech dry-cell batteries has now been developed which are better, joules per gram, than the traditional lead-acid battery, but they are not that much better — not even in the same league as an equivalent weight of petrol — and they are expensive, polluting and not generally rechargeable. The impression we have that batteries are getting smaller and their life longer is explained mostly by the development of lower-energy lights and electronic equipment that takes less power.
Here are some facts about carbon-based fuels. A kilogram of petrol or diesel stores around 50 million joules of energy. The equivalent for coal is about 27 million. Wood varies wildly, but might be about 5 million. A car battery offers less than half a million: less than a tenth the power of firewood. Sixty motorists filling their tanks on garage forecourts are transferring energy at a rate equivalent to the whole output of a medium-size coal-fired power station.
Energy stored in oil is portable; energy stored in batteries hardly is. This generation knows it, cursing as our torches dim, our mobile phones fizzle out, our laptop screens go blank, our TV camera/recorders cut, and we trip on the lead of the electric hover-mower whose cable won’t quite reach that grass border.
Here are some facts about electricity transmitted and distributed as most of our power stations’ output must be: down conducting cables and wires. As much as 10 per cent of it is lost: “leaked” into the ether by the resistance offered by all conductors, which simply heat up. In Britain and America, urbanised countries, the figure is around 7 per cent. In countries with longer distances from power source to point of consumption the figures can be much higher.
This loss in the power that we do transmit is calculable. The loss in power that we don’t (because the wastage and the cost of the cabling would be unacceptable) is incalculable. The Sahara desert might supply half the world with solar-generated power, if there were any practical way we could carry it to where it was needed. “Green” sources of energy — wind, wave, solar, tidal, geothermic — are disadvantaged by being in the wrong place. So is Saudi Arabian oil, but it is portable, so we use oil and coal to generate electricity.
Which is a pity, because about half the energy locked in fossil fuel is wasted when we deliver it via a heat-driven power station. Oil is more efficiently exploited when we burn it directly in our homes and cars. And so we live in an age when every man keeps at home and carries with him when he travels, a range of small furnaces and explosion-driven engines. Battery-powered cars and buses never quite make the grade — too much battery, too little power — and rail locomotives need a cat’s cradle of overhead cables, or run on electricity but carry their own inboard motors to generate it.
Meanwhile mankind has spent a hundred years, and money and time beyond calculation, developing and finessing one of the most stupidly Heath-Robinson devices ever invented: the internal combustion engine, with its thousands of moving parts. The petrol engine should have been a curiosity, a technological cul-de-sac, but we have blasted through the dead end with sheer effort and money, because there seemed no other way.
Trillions of dollars and millions of careers are poured into sparking and lubricating and cooling, into mixing fuel and air, into lead substitutes, into valves and rings and rods, pumps, gaskets and seals, pistons and bearings, clutches, gears and synchromesh, mufflers and catalytic converters — a bewildering host of delicate and fiddling devices of often fiendish intricacy, plus all the electronics which now go with them. Almost none of this is required by the simple electric motor.
And all because oil is portable. Yet a motor car struggles to deliver between 20 and 40 per cent of the energy it consumes, while an electric motor delivers 80 to 90 per cent, using a power source — electricity — which can be generated in almost infinite quantities, without a whiff of smoke or a smidgeon of oil. An electric motor needs no clutch or gearing; it can steal back its own fuel, through regenerative braking; and it emits nothing. Yet it remains the Cinderella of locomotion while, indoors, Britain makes millions of enclosed fires in hearths and boilers for heating. Such is the price of our failure to find a way to store or carry electrical power. I know what my Great British Invention would have to be.
