New growth factors for wind industry

The wind sector has been growing spectacularly over the past decade. However, to sustain these impressive growth figures over the next twenty years in Europe and North America, business-as-usual will not be enough. In several European countries, the number of remaining onshore sites for building new wind farms is already declining (see interview with François and Benoît Henriet, 'Barriers for wind projects', on this blog). Maintaining current growth will require going off-hore, or at least off the beaten track.

  • Some offshore wind farms are already in operation, but there is still huge potential — if the technology can overcome some of its current teething problems (see blog post 'How fast can we move?').
  • Further expansion of the onshore potential is possible by scaling up existing wind farms in both size and efficiency; radical new design proposals are being put forward.
  • Building-integrated wind turbines have both advocates and sceptics in regards to their potential to open up a completely new market.

Developing offshore wind

Given its target of 20% renewables by 2020, the EU sees offshore wind as a major power source for the future. EU Energy Commissioner Andris Piebalgs declared at the European Wind Energy Conference in March that he is counting on the potential of offshore wind energy to 'ensure that the growth trend in wind energy continues'. He indicated that he would develop an Action Plan by the end of this year outlining the means by which the EU can facilitate the development of offshore wind energy.

Piebalgs also clearly stated that 'a maritime grid infrastructure is needed for the development of offshore wind energy. As this is not yet in place, it must be developed fairly quickly and a central question is how it should be financed.'

In the meantime, the US has yet to see its first offshore wind project even begin construction. Surprisingly enough, it could very well be a group of commercial fishermen and dock operators who will lead the way. I say surprisingly because the commercial fishing industry has almost universally opposed offshore developments as a dual threat to fishing grounds and navigation. The state of New Jersey wants to become the home of the first offshore wind farm in the US and is providing a grant for the best project proposal. One of the leading contenders is the Fishermen’s Energy of New Jersey group. This group has apparently concluded that offshore wind farms are inevitable and that its members will be in a much more powerful position by joining rather than fighting it. If wind turbines are going to limit access to some of their traditional trawling grounds, they want to make sure that they can at least harvest the wind instead.

The active participation of commercial fishermen will enhance the chances of overall success. They are intimately familiar with the local weather, ocean currents, and continental shelf topography. Faced with ever-declining fish stocks worldwide, they are a group of experienced people ready and willing to work offshore. Fishermen’s Energy of New Jersey hopes to install its first pilot of 20 MW by 2011 and to expand it to 320 MW by 2013.

Another group equally well acquainted with working offshore is the Norwegian oil and gas company StatOilHydro. In May of this year, they decided to build the world’s first full scale floating wind turbine. The 2.3 MW wind turbine will be attached to the top of a spar-buoy, a design already being used for some oil and gas production platforms and for various oceanographic instrumentation systems. It will be located approximately 10 kilometres from the coast near the city of Stavanger, Norway. The floating element of this pilot installation will have a draft at some 100 meters below sea level, providing it with the required stability in the often-turbulent North Sea storms.

Floating wind turbines, if they are able to reach technical and economic maturity, have the potential to give a significant boost to the wind sector. It would enable the location of wind farms not only in shallow near-coastal waters, but also at locations with sea depths of 120 to 700 metres, where wind speeds are favourable and the visual impact minimal.

Radical new concepts

The StatOilHydro project combines known technologies in an innovative way. The California-based Selsam Superturbine(TM) company, on the contrary, has developed a radical new concept for offshore floating wind turbines. It consists of a long shaft bending in the wind like a reed and containing several rotors at different heights. The shaft connects to a buoy carrying the generator. The Superturbine website enumerates many potential advantages of this concept:

  • Lower cost by eliminating unnecessary material and components
  • High yield per unit since it contains several rotors at different heights which affect each other favourable
  • Limited visual impact
  • Can be installed in both deep and shallow water without foundations at the sea bottom
  • Can be laid down and even submerged to withstand extreme storms

This is, of course, strictly the current promotional position of the company as they try to sell the concept. The bottom line will be the cost per kWh that this new type of turbine will be able to produce. Moreover, the technology will first have to prove itself in rigorous field tests before it can be regarded as a viable option for the future. In a comment on the Physics Forum, Fred Garvin fears that the rotor dynamics of this concept could be a nightmare.

Probably closer to realisation are the Jet Engine wind turbines by FloDesign, a Massachusetts-based company. The Jet Engine channels the wind into a vortex that spins the small, high speed rotor blades. This makes them at least twice as efficient as traditional rotor blade turbines. Moreover, they are capable of operating both at lower and at higher wind speeds than traditional turbines, enhancing the capacity factor of the unit (see blog post 'The capacity factor of wind power'). FloDesign turbines are easier to install since they have much smaller blades — they fit into a single standard size long haul truck — and are inherently safer. A no less important advantage is that they can be placed closer together on a site, optimising land use. If all those arguments prove out and this technology is cost-efficient, it could boost the yield of onshore wind farms.

Building-integrated wind systems

A new domain for expanding wind energy is building-integrated wind turbines. Like any new idea, it has its sceptics. They point out that wind passing around buildings generally shows a high level of turbulence that can affect the efficiency of the turbines. Nevertheless, proponents can point to the Bahrain World Trade Center in Manama, Bahrain, inaugurated last April, to prove that this barrier can be overcome. It is the first building integrating utility-scale wind turbines into its design. The turbines are mounted on the three bridges that span the gap between two sail-shaped buildings, and not on the rooftop. The architecture of the building shape is designed to funnel wind through the gap between the two buildings to provide the maximum amount of wind passing through the turbines. The turbines have a capacity of 225 kWp each and provide 11 to 15% of the buildings energy needs. They are expected to operate 50% of the time.

Will we all have our own personal wind turbine on our house one day? I have my doubts and, frankly, I hope we will not. Many can still recall the sea of television aerials that once created an urban visual pollution all of it own before the advent of cable. Nevertheless, it appears that residential wind turbines are getting cheaper. The E2D Windmaster of the California-based company Freetricity’s is probably the first affordable roof-mounted residential wind turbine. It is small enough to be used in residential areas and powerful enough to provide 25% to 50% of the electricity needed by the average household. The system connects via an inverter, rather like a photovoltaic system. A unique feature is that it comes with a battery and can be used as a backup system during electrical blackouts. It is probably also an appropriate solution for off-grid houses in remote, windy regions.

References

  • Article 'Brussels to push for development of offshore wind energy' on euobserver.com
  • Article 'Fish Juice: N.J. Fisherman Angling To Develop Offshore Wind' in The Wall Street Journal
  • Article 'StatOilHydro to build first full scale offshore floating wind turbine' on the StatOilHydro Website
  • Article 'Ten Times the Turbine' on PopSci.com
  • Article 'Wind Turbine Concept Inspired by Jet Engines' on Alternative Energy
  • Article 'First Large Building-Integrated Wind Turbines Spin in Bahrain' on the EERE News Website
  • Article 'Inexpensive residential wind turbine' on Environmental News Network

Comments

Anonymous's picture

Wind is more than 5 times more costly than nuclear.

Wind is unavailable for 75% of the time, causing it to be supplemented by conventional power 75% of the time so in the end it cleans little air.

In the US the federal tax subsidy for wind is greater than the total cost of nuclear power (1.9 cents per kwh).

Nuclear is 90% available and if we would build 400 new plants to supplement the 103 already producing we could eliminate much of the 1.1 billion tons of coal burned in the US and have less expensive power instead of the five times more expensive wind energy.

There are many other advantages to nuclear over wind such as not requiring power lines to remote areas, less land usage, 1/3 the capital cost of wind, 33% less manpower required to operate, taxes paid by nuclear plants versus taxes paid to support wind. Nuclear also has a design life of 60 years while a windfarm has less than a twenty year life.

Wind doesn't have the capacity we need, it is far too costly and no electric generation source saves any oil as very little (0.6% in the US) is used for this purpose.

Why on earth are we spending billions on the old failed technology of wind power when we have such a practical and economical source of power that can really clean the air?

(edited by admin)

By Anonymous (not verified) 03/07/2008
Hans De Keulenaer's picture

Reading your comment like this, it appears sheer madness to invest in wind energy. However, a few qualifiers may be appropriate:

1) The true cost of an energy technology is almost impossible to assess, and hence political preferences start to play.

For example, nuclear embeds a hidden subsidy through insuring the risk of nuclear incidents. While generally thought to be very small, the risk can never be zero. But the cost of an incident can be enormous, although the actual cost of incidents has been small, with 3 notable exceptions. The value of this subsidy is therefore the product of a very small number (risk) and the very large number (impact). It is a cost that nuclear energy imposes on society, but we'll probably never agree on the numbers.

2) Regarding lifetime, modern large-scale wind turbines are a relatively new technology, and therefore lifetime is unknown. It may well be longer than 20 years. I could expect rotor blades and the mechanical parts in the nacelle to be weak points, but these can be replaced. Possibly the lifetime of a turbine is determined by its civil engineering - cracks in the tower or foundation will be much less easy to repair. Also in a nuclear power plant, most parts can be replaced. The plant reaches end of life if cracks appear in the reactor vessel which is the only part that cannot be replaced.

By Hans De Keulenaer 04/07/2008
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