The German army has identified a series of wind park projects as a threat to national security and blocked investments worth 1.5 billion euros because it fears spinning wind turbines will interfere with its radar systems. The Bundeswehr has launched an investigation into the impact of the wind turbines planned for northern Germany's coastal area amid concerns they could compromise air defense -- because they could in theory provide a shield for enemy aircraft.

Residents near Dortmund were evacuated this week after the ground collapsed around a geothermal heat pump, while in another German town, almost 190 buildings have now been damaged by a geothermal project gone awry.

Fresh concerns have emerged over the future of BP's alternative energy business after a fire broke out at one of the company's largest solar power installations in Germany. The incident on June 21 destroyed nearly 200 sq m of one of the world's largest roof-mounted solar panel arrays on a warehouse complex in Bürstadt, near Mannheim.

After the industry's recent boom years, wind power providers and experts are now concerned. The facilities may not be as reliable and durable as producers claim. Indeed, with thousands of mishaps, breakdowns and accidents having been reported in recent years, the difficulties seem to be mounting. Gearboxes hiding inside the casings perched on top of the towering masts have short shelf lives, often crapping out before even five years is up. In some cases, fractures form along the rotors, or even in the foundation, after only limited operation. Short circuits or overheated propellers have been known to cause fires. All this despite manufacturers' promises that the turbines would last at least 20 years.