Nuclear power in Germany: The reasons behind Chancellor Merkel's U-turn

In a decade, one of the world's biggest economies will have switched off the power stations that currently supply just under a quarter of its needs.

What will take up the slack? Those who applaud the move as bold and principled say renewable energy, much of it from wind farms.

And, they add, the gap will be smaller as more efficient buildings and machines become available. The official commission reckons that Germany could cut its electricity use by 10% through this increased efficiency.

More sceptical voices say some of that might happen - but some of it won't, and that will mean renewed life for coal-fired power stations.

It might also, they say, offer attractive new business opportunities to the nuclear industry in the countries bordering Germany.

Unintended consequences

France has shown no sign of falling out of love with nuclear, and Poland is just falling in love with it, intending to build two atomic power stations.

The possibility of unintended consequences was raised by the Swedish environment minister who is not by any means a fan of nuclear power.

The country has decided to phase out its nuclear stations, leaving them run to the end of their planned lives rather than abruptly shutting them.

Swedish Environment Minister Andreas Carlgren said Germany's decision meant an "uneven energy policy" in Europe, so Germany will "most probably need to increase the import of nuclear energy from France".

He added: "There is a risk they will not manage as quickly to halt the dependency on fossil fuels, especially coal-based energy."

He said that by setting a deadline, there was a risk of "missing the most important issue - that we need to manage the double challenge of both reducing our dependency on nuclear and reducing climate change".

The German official commission set up to study the nuclear issue after the crisis at Japan's Fukushima plant called for pragmatism.

It wants the route to a nuclear-free future to be planned away from the hothouse of electoral politics.

Chancellor Angela Merkel said the intention was to devise a system that was "safe, reliable and economically viable".

Nein danke

Wind power is a great hope of the Green movement which has put pressure on Chancellor Merkel's government by beating the ruling coalition in a string of regional elections.

But that raises issues of what Mrs Merkel calls the "architecture" of the distribution grid. The big wind farms are planned for the North Sea while many of the atomic power stations are in the south, convenient for Stuttgart and Munich.

Energy companies say that this means a new north-south line of high-voltage cables and pylons, what is sometimes called an "energy autobahn".

Already, protest groups in the beautiful heart of the country are opposed to a big expansion of the grid through their region. "Atomkraft, nein danke" but also "pylons, no thanks" is the message they are sending out.

The energy companies have warned that a failure to rejig the grid would mean power blackouts.

Business has been muted in its reaction to the end of nuclear power, though there is some unease.

The economic council of Chancellor Merkel's own party said it was worried about the cost implications of switching from nuclear.

Its president, Kurt Lauk, said: "I've heard lots about a phase-out of nuclear power but little about the costs of phasing in renewable energy."

Strength or weakness?

It is clear that the politics of nuclear power were changed by the disaster in Japan - and may be changed further by Germany's decision.

Chancellor Merkel originally undid the previous government's decision to phase out nuclear. She has now reversed again to a position that may see it end even faster than under the initial policy.

Her opponents will say that she has bowed in the face of a string of strong showings by the Greens in regional elections.

Her defenders might argue that democracy is about listening to voters, and that the whole assessment of nuclear was changed by Fukushima.

One of the things the commission she appointed looked at in a new way, for example, was the result of very unlikely events such as aircraft crashing (or being crashed into) nuclear reactors.

Different sets of probabilities threw up different assessments of viability for nuclear power - and Mrs Merkel, a scientist, recognised the new reality. So might run her defence.

But bowing to the popular view can look like wisdom. It can also look like weakness.