A boom in renewable energy shows no sign of petering out, with investors greedy for shares in wind-generator companies which are booking huge new sales.

Two sales announcements in Germany this week illustrated why a giddy bidding war has developed between Indian and French interests for one of the main German builders of rotor-turbines, Repower.

Nordex, a company based in the German port-city of Rostock, said Friday it had just landed an order for 120 turbines with an option for 100 more, the biggest order since the company was founded in 1985.

Customer Babcock and Brown was initially purchasing 289 megawatts of generating capacity for wind parks in Portugal and France, said Nordex, which is also to supply foundations, transformers and electrical systems.

If all options were exercised, the contract would be worth more than 700 million euros ($950 million). The contract fitted Nordex’s aim of raising sales by 50 percent yearly, an executive, Thomas Richterich, said.

Hamburg-based Repower said it had won a Californian order for 75 wind generators with a total capacity of 150 megawatts for Enxco, a US unit of French power company EDF Energies Nouvelles.

Each of the huge generators has a rotor diameter of 92 metres.

Analysts say the worldwide orders are driven by legislative pressure on power companies to reduce carbon-dioxide emissions and generate at least some of their electricity using wind or the sun.

Investors see no sign the trend will end soon.

Nordex shares shot up 8 percent Friday morning to 27.45 euros on German markets before settling to 25.40.

Repower Systems shares were steady at 156.95 euros, well ahead of the current offers of 150 euros per share from Suzlon of India and 140 euros from Areva, the French nuclear-power group.

Earlier this week, Repower raised new equity with institutional investors happy to pay 151.50 euros per share, a clear hint that investment professionals expect a counter-bid from Areva.

A Repower spokeswoman said Friday the Hamburg-based company’s board would comment next week on the Suzlon bid. Previously Repower said both bidders would make good parents.

Shares in Nordex, and another company, Vestas Wind Systems, have been driven higher by takeover speculation.

German manufacturers of solar-power equipment have also been boosted by the renewable trend.

Solar World, which opened a new wafer-production plant at Freiberg in Germany’s Saxony state Friday, said it would continue to add wafer capacity at the site, doubling output by 2009 compared to today.

The company said it was even contemplating quadrupling output, which is measured by the power-generation capacity of the photovoltaic cells it makes: 1,000 megawatts per year was conceivable.

Solar World mainly sells its modules to owners of homes and other buildings seeking energy self-sufficiency.

Germany’s pre-2005 government of Social Democrats and Greens chose renewable energy as a technology where Germans could lead the world.

That bet has turned out a good one, but an electrical industry group, VDE, is cautioning that Germany actually spends too little on research into better energy technology.

‘Japan is spending 30 dollars per capita on energy research, and even the United States spends 10 dollars a head. Here in Germany it is only 6.20 dollars,’ said VDE spokesman Wolfgang Schroeppel.

He said annual federal grants of 400 million euros for energy research in Germany were just not enough to sustain the lead. He demanded Berlin hike the budget to one billion euros annually.

Schroeppel warned that only 8 percent of all research and development spending in Germany was devoted to energy topics, and in the European Union the rate was even worse, 3 percent.