Going With the Wind
In some parts of the U.S., when we have wind-generated power, we are seeing a significant adverse effect on bird populations, both bird kills and degradation of their flyways and nesting areas. This has led to some activists wanting to ban or move wind generators from some of the prime potential areas for wind-generated power. How does your organization address that issue? — Ken Brown, Mill Creek, Wash.
Bird impacts are very site-specific and are either by collision or migration interruption, rather than habitat or ecosystem impacts and disturbance.
Researchers show that the risk of bird deaths through collision with wind turbines is low. For example, it is estimated that 33,000 birds are killed annually by wind turbines operating in the U.S., an average of 2.2 fatalities for each of the 15,000 turbines. In Spain, a study showed 0.13 dead birds per year per turbine. By comparison, in the U.S., between 100 million and 1 billion birds are estimated to die each year from colliding with vehicles, buildings, power lines, and other structures, with wind power responsible for one out of every 5,000 to 10,000 avian fatalities. Furthermore, one has to take into account the very large number of bird kills from pollution from existing power plants, mainly coal. Worldwide, 99 percent of the threat to bird life is related to human activities.
Careful turbine siting, away from migration routes for example, can virtually prevent fatalities altogether.
Does EWEA support the development of local, decentralized wind-energy production? For example, Buckminster Fuller envisioned that power-gobbling houses could become energy-efficient dwelling machines that not only supplied on-site solar/wind energy to meet the needs of the residents, but also could produce a surplus to power a home business or contribute to the community’s energy needs. Does your association have projects with such goals in mind? — Larry Warnberg, Nahcotta, Wash.
It is a very interesting issue that is catching more and more attention. Generally the idea of all citizens becoming their own power producers is appealing. It would sure democratize electricity generation much in line with the development of the internet. It would dramatically reduce the need to carry electricity from large centralized power stations over long distances.
We, as an association, do not engage in such projects, but there are an increasing number of entrepreneurs, researchers, and great thinkers developing and refining the argument and design of such a future system. Wind power can obviously play a large role in such a future system.
How can small investors, with only a few hundred or a few thousand dollars, best invest in wind energy, helping to avoid an increment of coal-fired pollution, while at the same time making a reasonable return on their investment? — Jeff Schimpff, Madison, Wis.
In many European countries, e.g., Germany and Denmark, the majority of wind turbines are owned by individuals through cooperatives or farmers. A group of people would join forces and invest collectively; usually one turbine share equals the production of 1,000 kilowatt-hours (kWh). This was indeed how half of the 40 megawatt (MW) offshore project, Middelgrunde, outside Copenhagen, Denmark, was financed. Similar possibilities should exist in the U.S. I recommend you contact the American Wind Energy Association for more details on this issue.
Working in Europe, do you find the same indifference and/or hostility toward environmental issues we so often see here in the U.S.? Is it hard to get press for your organization and issues? What is the general public perception of environmental crises in general and wind power in particular? Here in the U.S., it seems to be viewed with mild curiosity, but nothing more. — Name not provided
In Europe, generally, people are concerned about the environment. Of course it differs from country to country, but a good example of the importance is the very strong wording in the Treaty Establishing the European Community. The Treaty, which can be compared to your Constitution, in fact stands over national law. It calls for a “balanced and sustainable development of economic activities” and “a high level of protection and improvement of the quality of the environment” and “the integration of environmental protection requirements in the implementation of Community policies with a view to promote sustainable development” and bases its Community policy on the environment on the principle “that environmental damage should, as a priority, be rectified at source and that the polluter should pay.”
So, legally, at the European Union level, a very high degree of concern for the environment is in place. I do not know the general U.S. opinion on environmental issues as well as you, although I have been there several times and lived in the U.S. for a year. My impression is that there is a general concern for the environment in the U.S. and that Americans are also to a large degree caring about the world they pass on to their children. I am sure that concern will increasingly find its way into the legislative process, simply because it is becoming increasingly clear that it is not only good for the environment but also good economics to act. Cleaning up or reversing environmental degradation is very expensive.
There are some who are concerned about the noise impacts of wind farms, especially low-frequency noise. It seems that some individuals are more sensitive to infrasound than others, but that those who do perceive it are rather dramatically affected. Meanwhile, in the sea, there are increasing levels of concern about general ambient low-frequency noise, which travels quite far underwater. How do you suggest that the wind industry can work to reduce these effects? — Jim Cummings, Santa Fe, N.M.
There are mainly two sources of sound from an operating wind turbine. The mechanical noise from moving components inside the hub and the “swoosh” you hear when the blades rotate. The former is no longer a problem and research is consistently improving the latter. The net effect is that when you are 300 meters away from a modern wind turbine, the sound it creates will not be heard.
Noise was an issue with some early wind-turbine designs, but it has been largely eliminated as a problem through improved engineering and through appropriate use of setbacks from nearby residences. Aerodynamic noise has been reduced by changing the thickness of the blades’ trailing edges and by making machines “upwind” rather than “downwind” so that the wind hits the rotor blades first, then the tower (on downwind designs where the wind hits the tower first, its “shadow” can cause a thumping noise each time a blade passes behind the tower). A small amount of noise is generated by the mechanical components of the turbine.
The issue of low-frequency noise is a little more complicated because knowledge about this issue is somewhat limited, not only in relation to wind turbines, but to many economic activities involving machinery. The Danish Environmental Protection Agency (Miljostyrelsen) in 1997 issued a set of guidelines about low-frequency noise, infrasound, and vibrations. Again, it is not specifically related to wind turbines though. In the guidelines, the agency recommends limits for low-frequency noise and infrasound that ensure that 97 percent of the population cannot hear it. Also, Sweden and Germany have a set of guidelines about low-frequency noise. The levels are about the same as in Denmark.
What have you found to be the most effective argument for increasing the use of wind energy in Europe? Many of the stories about wind that get picked up in the mainstream press in America are about communities rejecting proposed projects for ruining their natural environments. Do you have trouble with the “not in my backyard” attitude about wind energy in Europe? If so, how do you counter it? — Eric Wagner, Collegeville, Pa.
A summary of public opinion surveys carried out in a number of countries, including Spain, the U.K., Denmark, Germany, and Sweden, shows substantial majorities in favor of wind energy, especially when compared with conventional fuel sources. In Germany, for instance, a 2002 poll showed 86 percent in favor of increasing wind’s contribution to the energy mix. The survey also showed that local approval rises once a wind farm starts operating, and is increased with local involvement and good planning guidelines and integration into the landscape.
In some countries, direct involvement of the general public in wind-energy projects has helped to encourage public acceptance. In Denmark, about 150,000 families own wind turbines or shares in wind-turbine cooperatives.
The visual effect of wind farms is a subjective issue. Polls continuously show approval rates in the magnitude of 80 percent for wind power. However, consultation with, and acceptance by, local communities is essential, especially in rural areas where particularly high value is placed on the landscape amenity. Acceptance is more likely where there has been a clear assessment of the impacts of a proposed wind farm, and the mitigation measures have been properly explained. Once sited, however, existing activities such as agriculture can continue operating alongside wind farms.
Has a comprehensive analysis of windmill energy balance (the difference between the energy needed to extract and process the raw materials, manufacture all the elements of wind turbines, install them, and maintain them compared with energy produced) been conducted by a credible independent body, and what are the results? Has such an analysis been conducted separately for offshore wind turbines and onshore wind farms? — Baudouin de Selliers, Bousval, Belgium
Studies (see, for example, “Wind Power Note, No. 16 December 1997″ from the Danish Wind Industry Association) show that it takes a wind turbine between two and three months to produce the amount of energy that is spent on its manufacture, installation, operation, maintenance, and scrapping after its 20-year lifetime. In other words, a 1997 vintage turbine will supply between 80 and 120 times more energy over its 20-year lifetime than the energy used to manufacture, install, operate, maintain, and scrap it. The study used a 600 kilowatt (kW) turbine, typical for that period in time. If a new study were conducted on today’s state-of-the-art turbines (1,500 kW to 2,500 kW), the energy payback time would be even better.
In 1980 a similar study was conducted using that period’s typical wind turbines. Back then the payback period was eight months, i.e., the ratio between energy production and energy use was 1 to 30.
Which countries have the most favorable green energy policies? — Mark B., New York, N.Y.
There is of course a connection between what you refer to as “the most favorable green energy policies” and the actual activity level. Based on current activity levels, Germany and Spain are the undisputed leaders.
The U.S. market was strong in 2003, but due to a stop-go policy in the form of a short-term renewable tax credit, this year will be weaker. If the U.S. tax credit were to be extended for, say, five years, the U.S. market would show a dramatic increase in activity. This would be further strengthened by current high gas prices (gas prices follow the oil prices), making gas-generated electricity expensive.
In Europe, the U.K. framework looks promising but still needs time to develop. We have much hope for France, but there are considerable administrative barriers. Some claim that it is equally difficult to obtain a building permit for a small wind farm as a permit for a new nuclear power station. Italy, the Netherlands, Austria, and Portugal are also showing positive signs due to good framework conditions. The same is true for India, Japan, and Australia.
The global wind-power industry installed 8,133 MW in 2003, bringing the world’s total wind-power generating capacity to 39,294 MW. The new wind-sector investment is worth 8 billion euros, up from 6.8 billion euros in 2002. The total capacity of 39,294 MW provides enough to power the equivalent of 19 million average European households, or 47 million people. Europe and the U.S. dominated the global market in 2003, accounting for 88 percent of the new installations. India added 408 MW (5 percent), the largest single addition outside the European and U.S. markets.
Growth of the wind sector is widely forecast to continue in the double digits into the next decade, even as the industry matures. A survey published by DEWI, the German wind-energy institute in March 2004, reported that the global market could reach 150,000 MW by 2012, worth an additional 130 billion euros.
Do you anticipate further technological improvements in wind-energy gathering (i.e., turbines), or do you think they are more or less as small and effective as they’re going to get? — Name not provided
A modern power-generating wind turbine is designed to generate high-quality, network-frequency electricity, and to operate continuously, unattended, and with low maintenance, for more than 20 years or some 120,000 hours of operation. In comparison, a car engine typically has a design lifetime of 4,000 to 6,000 hours.
Three major trends have dominated the efficiency and economics of grid-connected wind turbines in recent years:
1. In 1980, the standard-size wind turbine was approximately 20 kW. The largest turbines operating on the market today have capacities of 4,500 kW. The average capacity of all turbines installed in Germany and Denmark increased from roughly 200 kW in 1990 to almost 1.5 MW during 2002. In short, the turbines have grown larger, taller, and more efficient.
2. Turbine efficiency has increased. A mixture of taller turbines, improved components, and better siting has resulted in an overall efficiency increase of 2 to 3 percent annually over the last 15 years. Researchers are continuously working on improving efficiency (and thereby reducing costs), e.g., through better aerodynamic and aeroelastic designs, better materials, improved siting, etc.
3. The cost of producing a kWh of wind power has been reduced by some 80 percent over the past two decades and cost reductions are expected to continue in the future by some 3 to 5 percent annually in the coming years. Investment costs have decreased. Today the average cost per kW of installed wind-power capacity varies from 900 euros/kW to 1,100 euros/kW. The turbine comprises about 80 percent of this total cost. One large benefit of wind power is that generation cost per kWh is known at the time of investment because the technology is independent of volatile fuel prices of coal, gas, and oil.
The dramatic increase in size and technological know-how, coupled with economy of scale from fast-growing production volumes, has greatly reduced the costs of wind power to the point where some high-yield onshore wind farms are approaching price competitiveness with the cheapest alternatives — new combined-cycle gas power plants. Competition is further strengthened by the current high oil and gas prices, making other generation technologies more expensive.
A growing market for offshore wind power is now the main driver for the development of large turbines. Wind farms are operating off the coasts of Denmark, Sweden, Ireland, the Netherlands, and the United Kingdom. Although there are still many challenges, including grid connection and foundations, there are major advantages in the higher mean wind speeds (some 40 percent higher energy content in the wind offshore compared to onshore), low turbulence (i.e., longer turbine lifetime), and reduced constraints to be found offshore, and a resource large enough to supply all of Europe’s electricity.
Manufacturers also aim to shrink operation and maintenance costs significantly — O&M costs can account for 20 to 25 percent of total production costs per kilowatt-hour, at some 1.2 euro-cents per kWh on average over the lifetime of the turbine — through the development of new turbine designs requiring fewer regular service visits and, consequently, reduced downtime. Furthermore, the trend toward larger wind turbines reduces O&M costs per kWh produced.
Will the existing system of generation scheduling and transmission-line capacity work without too much difficulty? Will transmission loss be greater than existing because of longer paths like Montana to Florida? — David Cudaback, Berkeley, Calif.
Transmission and system operation is a very important issue. In general, a 20 to 30 percent penetration level of wind power is possible into a power grid without too many complicated alterations. The West-Danish electricity system has 30 percent of annual electricity generated with wind turbines. For Schleswig-Holstein, a region in the northern part of Germany, the figure is approximately 35 percent, and for Navarra in Spain the share of wind power is 43 percent.
Of course some modifications to the grid must be made to accommodate large shares of wind power in the grid, but at the current levels in the U.S. grid there are few transmission and operational problems. The challenge is mostly a change in mentality by grid operators.
Regarding your question on transmission losses, the losses are equally big regardless of whether the electricity is generated by wind power or fossil fuels or nuclear. However, the issue is relevant when discussing how to tap the vast resources in the thinly populated areas of the Great Plains in the U.S.
Texas has been very active in installing wind power in the past five years, following the introduction of a so-called Renewable Portfolio Standard, passed when George W. Bush was governor. Due to this standard, Texas is already way ahead of its renewable electricity target, partly also ignited by higher and volatile gas prices, and the limiting factor in further expansion is more transmission capacity to the large centers of population. Most of Texas development takes place in the western part while the large centers of population are in the eastern part of Texas. Texas is interesting because the grid is more or less an island, with little exchange with neighboring states.
More cooperation and coordination between states on building new transmission lines should be encouraged — not only to accommodate wind power, but also to accommodate other electricity generation. North Dakota alone is theoretically capable (if there were enough transmission capacity) of producing enough wind-generated power to meet more than one-third of U.S. electricity demand. Such a project would require more transmission lines. However, one big benefit of wind power is that it is very flexible compared to large centralized power stations. There is the possibility of centralizing it, e.g., in North Dakota or other windy states, which requires better and more transmission. But you can also use it locally as decentralized generation in areas that are not connected to a large central grid.
Who could a would-be wind-energy worker with a consulting and sales background talk with to find opportunities in the wind-energy field? — Jak Plihal, Oakland, Calif.
People interested in working in wind energy should check out the list of EWEA members on our website. Websites of individual members are listed, as well as their field of expertise, and vacancies are usually advertised on their websites.