Will sun still shine on Germany solar power industry?

It has between a third and a half of the world's photo-voltaic cells - but in this heartland of solar energy, the industry sees dark clouds looming.

Subsidies are falling. Makers of solar panels have gone bankrupt.

Thousands of employees, fearing for their jobs, have just held a demonstration in Berlin.

Mainstream, influential magazines run headlines like Solar Subsidy Sinkhole: Re-evaluating Germany's Blind Faith in the Sun.

And if solar is being eclipsed in the world's green heartland, can its future be brighter elsewhere?

The source of the immediate woe is a cut in subsidies by 30% in the next year.

The government says that's because of the great success of the scheme: so great has been the demand for solar panels because of the lower price that the budget for it has been far exceeded.

But now the subsidy is being cut, the industry is finding it tougher.

Some German manufacturers of solar panels have gone out of business. All feel a chiller wind.

Ina von Spies is one of the executives at Q.Cells which makes solar panels.

"There's a lot of pressure on the makers of solar panels because we have a very, very high over-supply and that makes it very difficult to sell the products we produce at a reasonable price," she told the BBC.

Cut-price competition from China hasn't helped German producers either.

Some makers of solar-panels say the German government made a mistake by not making sure that when subsidies went to German installers of these photo-voltaic cells, it would be German manufacturers that got the money in the end - rather than Chinese ones who were quick to spot a market.

The subsidy, they say, should have helped German industry too.

But there is also broader questioning of whether Germany's embrace of solar power was wise. It is not the sunniest country.

"We should deploy solar energy where the sun is shining - in Spain, Italy or North Africa, but not in Germany," says Professor Fritz Vahrenholt, chief executive of the big energy company, RWE Innology.

He says Germany gets the same amount of sunshine as the US state of Alaska, while Spain gets three times as much - and that means that Spanish solar power could be a third cheaper than that in Germany.

Prof Vahrenholt has written a book called Die Kalte Sonne - The Cold Sun - which is sceptical of global warming being caused by human activity, and because of this scepticism, questions the need for the switch into alternatives to carbon fuels.

He told the BBC that the way the solar subsidy works in Germany means it is a redistribution of money from poor to rich, because people in apartment blocks do not have solar panels and tend to be poorer than those who own their own homes and so can put them on their roofs.