It's a drab morning in Bremerhaven. A construction fence is rattling in the wind. The sign in front of it tells us the site is destined to be the "Offshore-Terminal Bremerhaven (OTB)". Behind it - a yawning void, and a distinct lack of construction noise. Nothing but the screeching of the seagulls.

Construction work on the port to ship turbines for the offshore wind energy industry was stopped by a court order in May. BUND, the German branch of the multinational environmentalist group Friends of the Earth had succesfully campaigned against the plans. The conservation group says the reforms of the Renewable Energy Act (EEG) mean the port is no longer needed, as new restrictions have been put on the expansion of offshore wind. They say the port would also mean the loss of substantial parts of the mudflat habitat in the Weser river, and pose a threat to the adjacent marschland nature reserve Luneplate .

It sounds paradoxical: Germany's Energiewende, the environmentally friendly shift to renewable forms of energy, in conflict with conservation? Controversial changes which restrict the expansion of environment-friendly windpower being used as a trump card by conservationists? Isn't climate protection the same as the protection of nature?

Technology takes over the countryside

"There are a lot of synergies between climate and nature protection, because climate protection is an essential requirement for the preservation of certain habitats and biodiversity," says Kathrin Ammermann, head of the conservation and renewable energies section at the Federal Agency for Nature Conservation (BfN). Nevertheless, there are quite few points of conflict with particular expansion projects for renewable energies, she says.

To Reinhard Klenke, conservation researcher at the Helmholtz Center for Ecological Research, the conflict potential is obvious: "With the rise of the Energiewende, new ways of land use are emerging, with a lot of technology. Solar and wind power plants with their infrastructure, and extensive corn and rapeseed fields for bioenergy are altering the overall appearance of the landscape. This has diverse consequences for the ecological balance and biodiversity."

A nature reserve holds up green energy

Bremerhaven offers a clear example. The planned construction site for the Offshore-Terminal (OTB) in the mudflats of the Weser River near the fishing harbour includes an industrial park in the protected Luneplate area. There was bound to be oppostion from conservationists. Since early 2015, the marshlands of Luneplate have been part of the biggest nature reserve in the state of Bremen. The site also looms large as a Special Protection Area for Birds of the European Union, giving shelter to 70 water and wading bird species.

The port association "Bremenports" carried out the renaturation of Luneplate in the 1990s by way of compensation for similar port construction projects. The German federal Environmental Agency (Umweltbundesamt") listed the project as a best-practice example in 2013.

Environment measures were also planned to compensate for the new port construction plans. Butt Martin Rode, CEO of BUND Bremen, says they would not offer anything new in the way of nature protection.

Simmering conflicts

Alongside their exceptional interest in protecting the Luneplate region, BUND say their lawsuit is doubly justified in the wake of the latest reform of Germany's pioneering renewable energies legislation. In July, amendments were passed in July, which include a reduction of wind power expansion.

According to Rode, the new offshore terminal servicing port is superfluous. The underlying circumstances no longer justify the por, he says.

However Martin Günthner, Senator for Economy and Ports of the state of Bremen, cannot understand the lawsuit: "The OTB is Bremen's main contribution to the success of the Energiewende. It is simply absurd that an environmental association should stage a lawsuit against a projectthat serves to protect the climate."

Clashes like these are not new to Kathrin Ammermann from the Federal Agency for Nature Conservation: "Simmering conflicts often come to the surface when it comes to getting planning permission for specific wind, solar or hydropower plants."

Location is key

Choosing appropriate sites is the main way to avoid conflicts, says Ammermann.

"Another option is the configuration of the plant. For example, you can incorporate a fish ladder in hydropower plants."

For wind power, she says algorithms have been worked out to turn off the plant when there is little wind and there are bats flying around.

However, taking environmental effects onto account as part of the site selection process requires scientific research. The Federal Agency for Nature Conservation has created a special monitoring project to help make that possible. But it is not always easy to assess all the impacts of renewable technologies on a wider scale.

One example is the red kite:

"Large rapeseed and corn fields for bioenergy are as bad as a sealed area for the red kite. It has to fly longer on its search for food. That increases the risk of coming into contact with wind turbines," says Klenke.

Environment Ministry as mediator

To help resolve conflicts of this kind, Germany's Environment Ministry set up a special "Competence Center for Conservation and the Energiewende" on July 1st. The aim is to pool expert knowledge and practical experience. In the event of a conflict, representatives from both sides will be brought together, with a mediator.

However, these efforts come too late in the case of the Offshore-Terminal Bremerhaven (OTB). The dispute has now moved on to a higher court, where a decision is only expected in the course of next year.