Rows of concert seats were softly lit and two musicians on harp and oboe serenaded from a stage as conference delegates filed in quietly and solemnly to a Brussels music theatre, Ancienne Belgique. The audience lights dimmed completely for the opening address as a spotlight aimed onto the vice president of the European Wind Energy Association (EWEA), Jos Beurskens. "I've never experienced such a sacred opening of a wind conference," Beurskens said. "I'd expect more roughneck offshore types here."
But by the closing session on the third day of the EWEA Special Topic Conference on Offshore Wind Energy last month, an energetic rock band might as well have been playing. After years of research the event showed that things are finally starting to move. Over the next two or three years, hundreds of turbines are expected to go up off the coasts of Denmark, Belgium, the Netherlands, Ireland and the UK, with hopes still high to move forward in Germany by 2003 and France and Spain too. The question now is not whether offshore wind can be done, but whether it can be done cheaply. Issues of environmental impact and grid access also loom large -- though while both were mentioned in presentations, grid access was not given serious attention.
Five hundred delegates from 29 countries attended the event -- 200 more than expected -- and nearly every one of the sessions was well attended. The North and Baltic seas were a definite focus. Not only is all the serious activity happening here, but the area lends itself beautifully to offshore wind, as several speakers made clear. The two seas surround densely populated countries and boast good wind and relatively shallow waters -- the North Sea alone has 150,000 square kilometres at less than 35 metres depth. "Offshore wind is a local market," says Andrew Garrad of British wind power consultancy Garrad Hassan.
The cost issue was like a whale that surfaced for air in nearly every session, from technology to financing to legal issues. Repeated from previous conferences was the necessity to build very large wind farms so that economies of scale can kick in for many areas. "To make this work properly we need a huge canvas," said Garrad. "I think we must be looking at wind farms in the gigawatt size, not megawatt. The coming 160 MW Danish project is not big enough to merit the investment," he said, referring to the Vestas turbines under development at Horns Rev.
Everything is more expensive at sea, from the beginning research stage to maintenance of a working turbine. Of capital costs, onshore turbines take 70% of the total, whereas offshore turbines use only half. Just installing and running an anemometer mast offshore can cost EUR 500,000, compared with EUR 20,000 on land, Garrad pointed out, adding quickly that once a measurement is in-house, one can be sure that it covers a broad area, since there is no landscape to influence it.
Garrad said a main challenge is availability of offshore turbines. "I don't believe we've grappled with this at all yet." The technology challenge lies in accessibility, which will be "the single most important aspect determining revenue," he said.
His comments were amplified by Gerard van Bussel of Dutch Delft University of Technology, who said that due to accessibility issues at sea, attention needs to be paid to improving the most vulnerable components, including gear box, control system, electrical system and blade pitch system. Of experience so far, accessibility of site by vessel has not had promising results, continued Van Bussel. Even in the best weather of summer months, the Horns Rev site in the North Sea, 14-20 kilometres from shore, has an accessibility by boat of only 80%. Van Bussel stressed that since offshore turbines are merely adapted from onshore models, the industry should be anticipating a higher failure rate at sea and lower reliability in these early stages of development -- and access for operation and maintenance (O&M) must be dealt with.
Maintenance costs are still relatively unknown offshore, stressed Theo Verbruggen of the Dutch national laboratory, ECN. Previous relatively benign issues like configuration control are going to prove crucial, he said.
Probably the most notable discussions revolved around environmental issues of offshore wind farms. In its haste to build, the wind industry is lacking some vital information and common strategy surrounding wildlife and ecological issues like birds, marine life and even coastal impact. "I'm not yet fully convinced of the colour of green energy," commented Eric Stienen from the Belgian Institute for Nature Conservation (INC), who is studying the marine environment and sea birds.
Wind farms will soon be a common phenomenon along the North and Baltic sea coasts, he said, and the first generation will be located in shallow coastal waters. These locations have a high ornithological value as important feeding and migrating pathways for sea birds. "I will not plea against offshore wind farms. I will plea for the sound choice of location based on good scientific knowledge."
The three potential effects wind turbines have on birds are habitat loss, mortality and barriers to migration, requiring knowledge on such things as distribution patterns of sea birds, flight patterns and collision risk. Through ten years of monitoring birds in the Belgian territorial waters, the INC put together thousands of distribution maps, finding that seven seabird species -- four of them threatened -- will be put at risk by the first generation of Belgian offshore wind farms. Little data exists yet on migration routes and patterns, however, since these are difficult to track. Many questions remain, such as whether seabirds tend to fly higher or lower than wind turbines, or the extent to which they migrate at night -- most collisions happen at night or in poor visibility. "With seabirds, a small change in their survival can have disastrous effects on the whole population," Stienen stressed. "And keep in mind that a change in the population in Belgium can effect the bird population in Norway."
Lars Kjeld Hansen of Danish research agency Energi & Miljø Undersøgelser, EMU-SPOK, presented the results of a review of environmental impact, social acceptance and politics. Birds and visual impact are the two most important issues. He repeated what became a mantra for the conference (admittedly one with lots of work hungry researchers): "More studies are needed."
Importantly, Hansen said that different species react differently to wind turbines, depending on distance to shore, time of day or year, weather, noise and layout of a wind farm. Thus, while eider ducks have been observed to fly around the Utgrunden wind farm in Sweden, the same cannot be expected for all species of birds.
Underwater effects also need to be studied more, as well as the impact of noise vibrations from the turbines or maintenance vessels on birds, sea mammals and fish. Hansen said that during construction of one offshore site recently he saw fish lay on the surface of water like they were dead. A while later, they swam off again. "It's important to avoid sensitive periods for wildlife. This will prove to be a potential conflict, because sensitive periods are in the summertime, when most offshore wind farms will be built," Hansen said. The second Danish 150 MW offshore demonstration project, to be built at Rødsand, will be located a few kilometres away from an important seal preserve, bird migration route and a protected area. Hansen says it will give a great opportunity for more studies.
Among several other mentions of environment and the yet unknown impact of offshore wind farms, Jos Beurskens made a plea to delegates: "A lot of monitoring is still necessary, and we must share experiences," he said. "This is not a competitive arena. It's information we all need for developing our projects."
A topic mentioned in passing several times revolved around grid integration and particularly transmission. With so much offshore production expected to come on-line in the next few decades, there is as yet nowhere near enough hardware -- or software, as one speaker said -- to transmit it into the grids of Europe that need it most. Bart Boesmans of Belgian Tractable Energy Engineering said the most promising immediate step is to increase the accuracy and reliability of wind forecasting techniques. Much more research is needed into potential solutions to the imbalance of electricity production and consumption, such as demand side management, energy storage and increasing the control in wind farm output, Boesmans said.
Meanwhile, an EWEA task force is working on a strategic European paper, linking offshore and onshore wind power production to security of supply and calling for a trans-national transmission network, along with a common policy. "This is heavy, strategic stuff," Beurskens said. "It needs a lot of collaborative efforts."
QUANTUM LEAP IN DESIGN
In the technology discussion, Andrew Garrad envisioned the development of "real offshore turbines," which might look significantly different than onshore units. "The technology is still quite young. We shouldn't close our minds to some quantum leap in design," he said.
"Onshore design parameters are not technical at all," he added. "They are based in environmental or social aspects -- you can't have large machines dominating a village or running too fast and noisily." Parameters are different offshore. Gone are the factors of visual impact, noise or dominance on a landscape. These are replaced by factors of construction and turbine technologies. "For an engineer, this is a very important step. You're moving from what was dominated by social constraints to a market constrained only by technology."
There arose some discussion, however, as to how far one had to go from land before a farm was truly "offshore." Visual impact from the shore would not seem to be a problem beyond, say, 10-15 kilometres, but Ruud de Bruijne of Dutch Novem said he had visited the Swedish Utgrunden site. "It was beautiful weather that day, and you could see it from a distance of 30 kilometres."
Garrad also noted that the wind and offshore industries are used to approaching projects differently, with the result they are experiencing a "clash of cultures" as they start to collaborate. "Wind is used to developing a high volume product at low cost onshore -- and on budget. Offshore sector is used to doing low volume at a high cost," he said.
There is no doubt, however, that serious collaboration has begun among wind people, offshore people and offshore O&M people, he said. And Detlef Matthiessen of the German wind industry association, Fördergesselschaft Windenergie, noted that wind made a fine showing at a recent German offshore industry conference and exhibition, InWaterTec. Practically, Garrad noted that it was necessary to be careful in the use of offshore terminology when hiring contractors. "At the moment, you'll probably want coastal engineers," he advised, adding that "offshore engineers," who typically work far out at sea in deep waters, cost about ten times more.
With all the discussion at the conference, it could easily be forgotten that offshore wind power is still in its infancy, with only a handful of projects on-line. But speakers were positive that they would still be getting together in ten years to hold a conference for what will then be a steadily growing offshore wind sector. "Just look at the past ten years. No technology field has grown so spectacularly as the wind industry," Beurskens said. "None of these things are difficult to do -- it's easy to go to an offshore contractor. But it's difficult to do it cheaply.
"If you come back in 2010, you might find two industries -- an offshore wind industry and an onshore one," he said, adding that the wind sector now must be careful not to overexpose offshore and forget about the huge amounts of onshore wind, 100,000 MW, targeted to be installed in Europe by 2020. "That's still a huge leap. We must not think that all problems installing wind turbines on land have been resolved."
Ruud de Bruijne of Dutch Novem summed it up like this: "If we succeed, the sky's the limit. If not, it's going to be tough to convince financiers. It's all or nothing."