Offshore Wind Energy – Consistent with Nature

Wind energy is green energy - good for our climate and the environment. Most people do agree on that today. With the exception of anti-wind groups who are not shy to point out potential dangers again and again like birds and bats dying in rotor blades or ramming for the installation of offshore wind farms destroying ocean wildlife e.g. driving away whales.

No experience

And offshore wind farms even bear more imponderabilites. Many aspects of the versatile ocean wildlife are still unknown even to scientists.

There was no or very little experience with influences on nature when the first offshore wind farms were built. Collecting data on the impacts is still command to science nowadays.

Most countries in the world are still trying to adopt their environmental laws to the needs of ocean fauna, tightening restrictions and laws. Germany and Denmark for example are known to have quite strict laws concerning underwater noise as it frightens sensitive animals like porpoises.

Research made some progress though in the last years. Methods to reduce construction noise have increased. But studies have also shown that the noise is not as damaging as first thought.

Study of the German Federal Maritime and Hydrographic Agency (BSH)

Germany's BSH last year published their long-term study conducted at the offshore testing site Alpha Ventus. Scientists came to a surprising conclusion: Offshore wind farms have positive influences on the oceanic environment. Though construction noise does actually drive away fish and whales at first, but said porpoises do return to their natural habitat very quickly after silence has come back.

Studies from other countries back these results. But there are still a lot of open questions showing research hasn't reached its end. Bob Rumes of the Belgium MUMM (The Management Unit of the North Sea Mathematical Models) shared some insight at the EWEA Offshore last year: “So we do know porpoises will return after construction is finished, but what happens to animals unable to swim as great a distance as to get away from the noise in the first place?” The effects on such populations are still mostly unknown.

Growing biodiversity

Numerous results of the studies are surprisingly positive: Because fishing is forbidden inside an offshore farm e.g. these areas give strained fish stock the possibility to recover. Even new fish like mackerel and seebull settle here. Birds are drawn to wind farms because of the possibility to rest on top of the turbines and to hunt for fish. Furthermore the foundations of the turbines act as 'natural riffs' where sea stars, shells and anemones settle. Biodiversity in an offshore wind farm rises significantly.

Scientists were astonished to learn migratory birds are not disturbed by the farms as much as they thought. The BSH study shows there are close to no collisions at all between birds and turbines if the weather is good, because the birds travel in higher air spaces. Georg Nehls of German-based 'Bio Consult SH' commented on that topic at the EWEA Offshore: “Problems occur only if the weather gets bad. Then birds fly in lower air spaces making a collision with a turbine much more likely.”

Radar systems can put things right

To help avoiding collisions in bad weather companies like DeTect from Florida specializing in remote sensing technologies for environmental survey developed an advanced radar system to detect flocks of birds and bats before they get close to the blades, making it possible to shut down the turbine for the time the birds pass.

In offering pre-screening of migratory animals in the area companies like DeTect also provide help before the construction of a farm begins. The inserted technologies were originally invented for the NASA and American Air Force, but now engineers, scientists and ornithologists work together to make wind farms operational even in difficult environments.

Furthermore they share collected data for more research. DeTect claims to have built the biggest database worldwide collecting data about migratory birds and bats in the US – even the size of their flocks.

Stricter Laws

In Europe offshore wind parks get in the focus of the law because of the huge technical developments in the years to come. Administrations and officials react to studies from the environmental sector tightening the laws and restrictions for wind farms. Before the construction of a wind farm will be given permit a survey on bird migration in the area must be submitted. Problem is that the laws only apply to one country at a time. In Germany and the US there are even different formalities in each federal state.

Fine for dead birds

In the US the case of 'Duke Energy Renewables' gained public interest late last year. The company accepted a fine for causing the deaths of 14 golden eagles. The birds died colliding with turbines of the two Duke Energy wind farms in Casper, Wyoming. The payment of 1 million dollar will be divided between several environmental and wildlife foundations. Duke Energy claimed afterwards construction of the two farms was underway in the years 2007 – 2009. That is some time before environmental damage came into focus.

The American government has been issueing 'eagle take permits' since 2009 allowing wind park owners to stay exempt from punishment for dead birds for 30 years. But up to this day not a single company had obtained a permit which is the reason why Duke Energy took the fine: They wanted to get the attention of the public eye and sensitize fellow companies for the topic.

Wind energy instead of climate change

Wind energy and nature protection are not contrarious – even the most strict environmental groups and foundations agree on that. The European Wind Energy Association (EWEA) states in one of their papers: “Birdlife, WWF, Greenpeace, Friends of the Earth and others support wind energy. Birdlife recently stated that climate change was the single largest threat to birds and wind and renewables were a clear solution to climate change.”