by John Lawrence from the San Diego Free Press
This series of articles is based on an excellent book by Tom Rand: "Kick the Fossil Fuel Habit - 10 Clean Technologies to Save Our World." In Part 1 we dealt with all the possibilities for solar power generation. In this article we will consider wind. For centuries wind powered ships and windmills drew water out of the ground. We are now in a position to reconnect with this form of energy and convert it into electricity. How it works is very simple. As the wind blows, enough force is created to spin a turbine which in turn generates electrical energy. These days a single wind turbine can power a decent sized town.
The US Department of Energy has calculated that wind could generate 15 times the total world energy use. That's 15 times all the energy generated by oil, coal and nuclear at the present time. Even oil magnate T. Boone Pickens has called the US the "Saudi Arabia of wind."
Another country with large wind resources is Denmark. Back in the 1970s Denmark decided to become energy independent by developing their wind resources big time. Today a substantial share of the wind turbines in use throughout the world were manufactured in Denmark. Today wind supplies about 30% of Denmark's energy needs, and they intend to increase that to 50% by 2020. As far as storage goes, Denmark has encouraged the use of electric vehicles which are charged primarily by wind power. That power stored in car batteries can be fed back onto the grid at times when wind is not sufficient to generate all the power that is needed. The Danes have thus come up with a clever way to store energy that is wind generated.
Large scale wind power is the fastest growing energy source in the world. Just in 2007, 94 gigawatts of capacity was installed - enough to replace 90 coal-fired plants or power almost 90 million homes. Germany, which is also huge on solar power, leads the world in wind power with over 20,000 turbines up and running which generate more than 7% of the country's electricity.
Clipper, a California company, developed a turbine rated at around 10 megawatts which is enough to supply a decent-sized town. It has a rotor diameter twice the wing span of a jumbo jet. Like a lot of other companies mentioned in Rand's book, Clipper developed financial problems, was acquired by another company which subsequently divested itself. The company is now located in Cedar Rapids, Iowa, is still in business, but limits itself to manufacturing replacement parts. The material in the book is somewhat dated. Although it was copyrighted in 2010, much of the research was done in 2007. Today the largest wind turbine manufacturer is Denmark followed by China, Spain and Germany. GE is the sixth largest and the only US company in the top ten.
Many of the largest operational onshore wind farms are located in the United States and China. For example, the Gansu Wind Farm in China has a capacity of over 5,000 MW of power with a goal of 20,000 MW by 2020. The Alta Wind Energy Center in California is the largest onshore wind farm outside of China, with a capacity of 1,020 MW. As of April 2013, the 1,000 MW London Array in the UK is the largest offshore wind farm in the world. It started producing electricity at the end of October 2012.
This offshore wind farm will reduce annual CO2 emissions by approximately 900,000 tons, which equals the emissions of 300,000 passenger cars. The second phase of the array has been scaled back after concerns were raised by the Royal Society for the Protection of Birds about its effect on a local population of red-throated divers.
Also in the UK is the 504 MW Greater Gabbard wind farm. In the shallow harbor outside Copenhagen sits the Middelgrunden project which is generating enough power for 30,000 homes with turbines standing more than 330 feet tall.
T. Boone Pickens views the American Great Plains as a resource which is ready to exploit, and he's putting his money there to build wind farms all the way from the Texas panhandle to North Dakota. He figures we could generate one-fifth of US electrical production for $1 trillion.
There are also projects being considered for the deep sea where the wind is much more powerful. This is important because almost 80% of the power consumption in the US is by people living along the coasts of the Atlantic, the Pacific and the Great Lakes. Deep sea projects are underway in Norway, Denmark and France and a full scale wind farm is planned for 2013 in the North Sea.
There are also micro wind turbines designed in such a way as to resemble a work of art. Helix Wind located in Poway, CA makes a visually stunning turbine that looks like a pulsating piece of modern art which produces enough energy for several homes. It could fit right into a neighborhood without attracting adverse attention. Helix Wind turbines are completely safe for wildlife because they spin at much lower speeds than horizontal turbines and appear as a solid mass rather than a sharp blurring blade that a bird or bat cannot see or detect.
Wind power systems are also being devised to mine the high altitudes such as the jet stream where the winds are really strong and steady. Sky Windpower has developed giant "spinning kites" designed to fly in the jet stream and send energy back to earth through a tether cable. Sky Windpower reckons that they could generate power at two cents a kilowatt hour - way less than coal. Time magazine named the company's invention as one of the top 50 inventions of 2008.
So what are the problems and pitfalls with wind power? One is the intermittency of the wind. The other is the storage problem. There are various means of storage. One is, as mentioned previously, storage in car batteries connected to the energy internet. Another is using excess wind power to pump water uphill, releasing it to generate hydroelectric power when the wind isn't blowing. Another is a really large interconnected grid so that when the wind isn't blowing in one area, chances are it's blowing in another.
Wind has the potential of supplying 40% of the US energy needs. How fast could we get there? We'd need to install around 1.5 million two-megawatt turbines over the next ten years or so. That's a big job but Lester Brown of the Earth Policy Institute says: "We build 65 million cars every year, so it's not a big deal. We could produce these wind turbines for the entire world simply by opening the closed automobile assembly plants in the United States."
The final question Rand always asks of any technology is: "So what do you get for $1 trillion." You could replace 20% of the US electrical supply (that's almost half of coal-based production), with maybe another $200 billion to get that energy to where it's needed.
Next time: Geothermal
