Nuclear power – good or bad?

As the UK general election campaign draws to a close in its own inimitable way, all three main parties are committed to reducing CO2 emissions and promoting a low carbon economy. One policy difference between the Liberal Democrats and the other two involve nuclear power. The Lib Dems are against it; the Tories and Labour are all for it. Who’s right?

The three arguments against nuclear power are that it’s expensive, dangerous and unnecessary. Taking each issue in turn:

One nuclear power station costs about £3bn and delivers about 1GW of power. An offshore windfarm delivering the same amount of power would cost about £6bn.

Since the Chernobyl accident in 1986 there have been 443 nuclear power stations producing 16% of the entire world’s electricity with no significant accidents. The World Health Organisation estimates that a total of 4000 people will eventually die prematurely as a result of the Chernobyl disaster.  While this is a terrible toll, it is less than the 4000 miners who die every year in Chinese coal mines, or 24,000 people who die every year as a result of pollution from coal fired power stations.

We could generate all the electricity we need in the UK from wind – if we were prepared to cover an area the size of Wales with windmills. If not, we’re going to need an alternative source, and that’s probably going to be nuclear. For a well informed discussion on how the numbers for electricity generation add up, and why nuclear is probably going to be part of the mix, see David MacKay’s excellent book and website Sustainable Energy without the Hot Air.

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Sunny side up

According to the International Energy Agency one megawatt-hour of electricity costs around $10 from a coal fired power stations, $60 from an offshore wind farm and $400 from a solar photovoltaic (PV) system, which is why some environmentalists argue that we should focus our energy on wind and wave power, not solar.

But prices have started to drop, partly because silicon has become cheaper, but mainly because of low cost Chinese companies entering the market. Half the world’s production capacity of solar PV panels is now in China, and this proportion is set to increase.

Now that the UK has joined Germany and Spain to provide generous feed in tariffs for domestic PV, expect this market to continue to grow.

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How to change the world

Imagine this frightening, but plausible, scenario. Sometime in the next twenty or thirty years CO2 levels in the atmosphere have reached 450 ppm and triggered runaway global warming. The Greenland ice sheets are melting, sea levels are rising rapidly, and millions of the earth’s population are in peril. Even if CO2 emissions fell to zero, the accumulated CO2 in the atmosphere would continue to drive temperatures upwards. What do we do then?

One answer is geo-engineering – combating the effects of climate change without actually reducing emissions.

We know it works

The most popular approach would be to inject sulphur into the atmosphere, mimicking the effects of volcanic eruptions which block out the sunlight and so reduce global temperatures. Ten kilogramme of sulphur could offset the warming effects of a million tonnes of carbon dioxide. You could get it into the atmosphere by balloon, from military air-to-air refuelling aircraft, or even by adding it to conventional aircraft fuel.

If you don’t like the idea of adding more gunk into the atmosphere, how about launching millions of tiny mirrors into space, and having them reflect some of the sun’s light directly away from earth? Much more expensive, but somehow more environmentally friendly.

Alternatively, how about encouraging the growth of CO2 absorbing plankton in the world’s oceans, by feeding them more iron?

None of these methods is currently feasible, for ethical, political and financial reasons, but in a few decades time we might be more desperate. Watch this space.

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