Near the end of the world

Perhaps it will go down in history. At 4pm on 10 February, Jocelyn Bell Burnell is giving a lecture at the Royal Society in London which dismisses scare stories about the end of the world being imminent. At exactly the same moment, at the Palais des Beaux-Arts in Brussels, a group of power company executives, EU officials and academic researchers will discuss the best way to ensure that the lights stay on in Europe at a time of climate crisis, rising electricity costs and creaking power-grid infrastructure. Here's the rub - decisions taken at the Brussels meeting might make Professor Bell Burnell's assurances look catastrophically foolish.

Not that the Brussels executives plan to bring about the much-hyped 2012 apocalypse that the Mayans are said to have predicted. But scientists have warned that tweaking the power grids in Europe and America could make them a little more likely to usher in the end of western civilisation.

Making power systems more efficient entails operating them at higher voltages over ever larger areas. This minimises losses of electrical energy (grids lose just over 7 per cent of their power output during transmission). However, it also makes the grids much more vulnerable to the vagaries of the sun.

Our star might be 93 million miles away, but it can certainly make its presence felt. In 1989, six million Quebeckers spent at least nine hours without electricity because the sun had melted the copper wiring in the state energy company's transformers. The outage happened when a solar flare - a gob of plasma ejected by the sun - hit the earth's magnetic field. The impact induced a catastrophic current surge in Canada's electrical networks.

Electricity grids that cover whole countries act as extremely efficient antennae, creating and channelling huge currents if the earth's magnetic field is provoked by the sun's ejections. The higher the voltage a grid carries, the more efficient the channelling.

Darkness falls

That is why experts worry about China's plans to implement a low-loss, 1,000-kilovolt grid. It is twice the maximum voltage of the US grid, and therefore twice as vulnerable to solar ejection events. Earth's magnetic field normally acts protectively to confine the effects of solar storms to high latitudes, but these kinds of high-efficiency grid open up the possibility of blackouts happening everywhere.

In 2008, a Nasa committee reported the worst-case scenario for the US grid. It warned that a not-unprecedented solar hit could leave 130 million Americans without electricity for more than a year. It could take four years to recover fully, during which time there would be little or no way to run basic services such as water delivery and health care. The likely cost - $2trn in the first year alone - would make Hurricane Katrina look like a storm in a teacup.

It is 150 years since the sun last hit us that hard, but never say never, professor. We are approaching a peak in the sun's activity: the 11-year solar cycle will reach a maximum in the first half of 2013. And who knows what efficiency-improving tweaks might be made to our grids before then?

Tags:Science