The annual gathering organised by the European Wind Energy Association (EWEA) is traditionally a time to reflect on past events and look forward to new opportunities. Both feelings were reflected at this year's bash in Brussels, Europe's political capital, and the place where the 2020 targets driving wind power and other renewable energy sources were forged.
The wider visibility of this year's EWEA event, which attracted more than 9,000 participants, was overshadowed by the tragedy unfolding in tsunami-stricken Japan. But beyond the inevitable debate sparked by the Fukushima nuclear plant crisis, the wind industry's battle to overcome the hurdles that are standing in its way dominated the conference agenda.
In the policy sessions, concern emerged over the perceived lack of ambition displayed by the current European Commission - the bloc's executive body - compared with its previous incarnations. Portugal's energy minister Carlos Zorrinho recalled how, under his country's presidency of the EU in 2007, an "ambitious environmental vision" was launched. Europe needs to fight climate change with an innovative approach that allows European countries to be leaders - not followers - he said.
A characteristically combative Claude Turmes, a member of the European Parliament and shepherd of the 2009 renewable energy directive, slammed the EU's emphasis on low-carbon rather than renewable technologies in its 2050 climate roadmap. But in an aside to the press, climate-change commissioner Connie Hedegaard clarified that, for electricity, the EU's vision was for 100% renewables by 2050.
Preparing for the future
Wind energy will obviously represent a very large part of that vision. But many questions remain unanswered on the types of regulatory frameworks, permitting regimes, infrastructure networks and financing models needed for the sector to thrive. Meanwhile, the industry continues to work hard to improve its performance, introduce product innovations and - most importantly - further drive down the cost of energy.
Judging from the products on display at the event, the relative lull of the past couple of years was used to come up with new solutions and prepare for the next swell in orders, which some in the industry expect to start in the latter part of this year.
Rotor diameters have seized the spotlight from nameplate capacity. For both existing and new wind turbines, a major trend emerging on the exhibition floor was the dramatically increased rotor size for a given power rating. This development aims to boost energy yield at lowand medium-speed wind sites, thereby driving down wind power generation costs.
Super class
In the larger power-rating category, Gamesa's first G128-4.5MW prototype with a 128-metre rotor diameter, which was erected in Spain two years ago, is expected to get a GL-type certificate in August. The company has recently added a sister version featuring a record 136-metre rotor diameter, aimed at locations with low to medium wind speeds. According to marketing director Juan Diego Diaz Vega, series production is expected to start by the end of 2011.
Gamesa has plans for offshore too. "Our 5MW offshore concept is technically based on the 4.5MW onshore turbine, with 128-metre rotor blades made in one piece. The second 6-7MW offshore turbine will be developed by our Scottish team, with a design focus on optimising the balance between the cost of energy and reliability," Diaz Vega said. Because wind energy competes with combined-cycle gas-fired power plants, it needs to demonstrate that it can get "more energy from the same amount of copper and steel".
At the upcoming industry fair in Hanover, Germany, Nordex will introduce a new 6MW direct-drive turbine with a record 150-metre rotor diameter. Alstom of France is also working on a 6MW direct-drive offshore turbine, for which its partner LM Wind Power claims to have developed the world's longest rotor blades. These are based on LM's latest-generation slender-shape GloBlade design blades, which are said to generate 4-5% more energy annually than standard equivalents. Details on blade size are not yet known.
For offshore turbines, the industry seems to be temporarily settling for the 6MW-plus range, with or without large rotor size. Repower already makes a 6.15MW turbine, while Bard has completed the installation of two 6.5MW prototypes. Nordex, for its 6MW model, is talking about a third-generation offshore turbine with top head mass of about 300 tonnes. GE was a notable exception in Brussels, with the introduction of its smaller 4.1MW offshore turbine.
Aiming high
A second strategy to boost energy production - and thus capacity factor - at lowand medium-speed wind sites is to put turbines on a high tower. Because the wind at greater height tends to be stronger and more stable, due to reduced turbulence, the operational lifespan of wind turbines can be improved as a result. At EWEA 2011 Repower introduced a 3.2MW wind turbine featuring a 114-metre rotor diameter and a concrete-steel hybrid tower with a record 143-metre hub height.
A higher capacity factor reduces copper cable use for electricity distribution. Considering current concerns about copper scarcity within the next two or three decades, the future expansion of renewable energy sources, including wind power, is dependent on such technical developments. Worries over the future availability of rare-earth elements, as well as copper, have also sparked some innovative thinking.
Estonia-based Goliath Wind has developed a 3MW direct-drive generator with a 12-metre diameter, based on an original design by Professor Edward Spooner of Durham University. The layout aims to drastically cut the use of electrically and magnetically active material such as copper wire coils, stator iron laminations and magnets. It is claimed that, for a similar power output and rotational speed, a doubling of the diameter approximately halves the quantity of active materials needed. A unique feature of the Goliath generator, aimed at minimising weight, is the positioning of spokes between the inner bearing housing and the outer rotor ring that contains the permanent magnets.
Winergy of Germany displayed its new compact 3MW medium-speed drive system for offshore application, named Hybrid Drive. It comprises a two-stage gearbox integrated with a permanent-magnet generator and can be made available for the 6-7MW class too. Winergy spokesman Tobias Hang said the Hybrid Drive requires only 20% of the rare-earth elements normally used by a direct-drive generator of the same power rating. Earlier products with similar functionality are The Switch's Fusion Drive and GE Transportation's Integra Drive.
Austrian firm Sustainable Energy Technologies presented an electro-mechanical differential system that is functionally comparable to solutions such as Voith's Win Drive. This system makes it possible to operate the turbine with variable rotor speed in combination with a fixed-speed generator that is directly connected to the grid, eliminating the need for a power converter.
The wind industry's continuous drive to improve its reliability, efficiency and cost-effectiveness is vital to its future success, all industry players agreed. On the exhibition floor, which occupied three halls hosting nearly 500 exhibitors, there was some discontent about the conference's technical sessions. A senior officer with one major supplier said: "We have decided not to send our engineers any more to EWEA conferences as they learn nothing." Experts who had been impressed with the quality of the technology panel were dissatisfied this year with a perceived lack of depth and detail.
While favourable policy in the shape of generous support systems has allowed wind power to prosper, what a relatively mature market like Europe needs now is a stable environment with visibility beyond the ten-year horizon provided by the 2020 targets on the one hand, and significant technological progress delivering better cost-effectiveness on the other.
Investors at EWEA 2011 forecast a rough patch ahead for a few more years, due to European governments' budgetary constraints and other hurdles such as permitting rules and transmission networks. But in five years from now, they said they expected to see a surge in offshore wind and a brighter future for the whole sector.
Controversy wages over nuclear - Catherine Early reports on reactions to the Japanese disaster
The wider political and environmental benefits of renewable energy globally were put in sharp focus at this year's European Wind Energy Association conference by the panic over possible nuclear meltdown in Japan. The world was cruelly reminded that nuclear power - wind's long-time rival in debates over costs and grid access - was not inherently safe.
"We need to take lessons from Japan and realise that this happened in the most well-prepared country to deal with this scale of disaster," said Anni Podimata, vice-chair of the European Parliament's industry, research and energy committee. "If the Japanese couldn't do it, it means there is no absolute security in nuclear power."
The crisis shows why nuclear power should not share the same platform as renewable energy in policy debate, Claude Turmes, Green Party member of the European Parliament, pointed out. "Nuclear is a very risky technology, not just during the lifetime of the plants, but for years afterwards, he said."
"Around the world now there will be a lot of reflection over energy strategies in countries either where they have nuclear power or had had thoughts of having it," said EU climate-change commissioner Connie Hedegaard.
Surge of protestors
One such country is Germany, where anti-nuclear sentiment had already been stirred up by the government's decision last autumn to keep nuclear reactors running for longer. Previously planned demonstrations have been boosted by a surge in support, with thousands of protestors on the streets of several towns and cities (see page 17).
Dania Ropke, a policy officer at the German Wind Energy Association, said it remains to be seen how the government's decision to take seven nuclear reactors offline for three months will affect the wind sector. "It may be a delaying tactic until people calm down," she added.
Hedegaard agreed that it was too early to draw conclusions: "The events are still unfolding. But one thing is for sure - the tailwind in nuclear is gone, no matter what comes out of the next few days."
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