Eucalyptus Magazine / September-October 2012 / Up in the Air

Up in the Air

Energy harvested from the wind

A familiar sight greets motorists on I-580, just east of Livermore: hundreds of wind turbines slice through the air. Built in 1981 on land leased from cattle ranchers, the Altamont wind farm is one of the oldest in the United States and boasts the largest concentration of wind turbines in the world.

Starting in 1974, the U.S. Federal Wind Energy Program developed several wind systems based on differing turbine designs. Altamont’s turbines are an example of an older, less efficient technology. NextEra, the company that owns nearly half of them, is in the process of replacing about 2,000 of the aging turbines, some of which are more than 30 years old. In addition to making Altamont a more efficient energy producer, the replacement project will address one of wind power’s most controversial issues: the deaths of wild birds, particularly golden eagles and red-tailed hawks, who collide with spinning turbines. Newer, taller turbines will be situated out of the flight paths of these raptors and turned off when the birds migrate.

Harvesting the wind is not a new idea. The first windmills were built in Persia some 2,000 years ago. Many innovations in wind power came from early American farms, where windmills were used to grind grain and pump water. In 1888, Charles F. Brush, an American inventor, built the first automatically operated wind turbine that could generate electricity.

Wind power has obvious advantages over fossil fuels. The wind is a clean, abundant, constantly renewable energy source. Wind farms use smaller amounts of land than power plants. And wind power is one of the lowest-priced renewable energy sources. But using the power of the wind for residential energy has serious limitations.

“Most people who buy wind power systems from us are in the Midwest,” says Douglas Arrison, the founder and CEO of Dasolar, a company based in Chevy Chase, Maryland, which installs wind power and solar energy systems across the United States. “They have one to two acres or run a 100-acre farm.”

Wind turbines operate most efficiently in places with wind speeds starting at 10 miles per hour. “The wind must be steady, not gusty or turbulent,” Arrison says. Residential turbines must be high enough (a minimum of 23 feet) to make use of the wind. Commercial wind towers exceed 200 feet. The best sites for wind farms are often far from the cities that need the power. Average setup costs typically run about $20,000, “but there is no ‘average’ system,” Arrison says.

“The first thing people need to look at is cutting their electricity usage. Most customers can cut their consumption by 25 percent without too much trouble. This reduces the size of the installation and the price they end up paying,” Arrison says.

Kyle Gregg of Cal-Power in San Juan Bautista agrees that a wind power system must be cost effective. “No two sites are alike. Trees, nearby houses, and wind speed all affect the feasibility and the price,” he says.

In addition, homeowners and businesses must obtain the proper permits and site approval from local authorities. “Start-up costs are hard to predict,” Gregg says. “Our installations range from $5,000 all the way up to $100,000 for a challenging, hard-to-reach site.”

The most expensive, elaborate system Cal-Power has installed involved two towers on a remote mountaintop. All of the equipment had to be airlifted to the site. “It was completely off-grid,” Gregg says, functioning as a mini power plant that was not connected to the local utility company.

But even for those customers who enjoy the convenience of utility company service, wind power has possibilities. The average home uses between 1,500 and 4,000 kilowatt-hours per month. “We have a 6-kilowatt product called the eddyGT. Depending on a customer’s usage, this product can cut their usage by half,” Gregg says.

Newer wind turbine models, including those that use dual-axis technology, are much quieter than older models, but noise remains an issue for those who decide to put up turbines on their property. Other disadvantages include damage from lightning strikes and power shortages due to low wind periods. But cost remains the biggest issue. Since wind power installations are expensive, it can be years before a consumer begins to reap any financial benefits.

Still, some people choose wind power for the same reason that they drive a Prius. “Our customers value being green,” says Arrison. “They’re willing to invest in something that will pay off in the future. They want energy independence.”

The federal government offers a personal tax credit of 30 percent of the total expenses of installing residential wind and/or solar systems, including materials and labor. In addition, Pacific Gas and Electric Company recently offered its customers a financial incentive to install both on- and off-grid renewable systems.

With constant fluctuations in the oil and gas market, many consumers are lured away from renewable energy every time prices drop. But Arrison says that “relying on foreign oil is just wrong. We in the alternative energy business know that we’re right, especially in the long term.”

Currently, renewable energy sources (wind, solar, geothermal, etc.) make up only 4.7% of the United States’ utility production, in spite of President Obama’s call in 2009 for clean, renewable energy.

“So much of the energy policy in the U.S. is tainted by politics,” says Arrison. “There is still far more investment and research in fossil fuels than in alternatives.” 

Alden Woodrow, Vice President of Corporate Development at Makani Power in Alameda, says his company is taking a different approach to building wind turbines for large-scale energy production, and their innovative design reduces the cost of construction and installation. “Makani’s technology uses the same principles as conventional wind turbines, but eliminates most of the material. Our airborne wind turbine or ‘wing’ flies in large circles while tethered to the ground like a kite. Rotors on the wing spin as the wing flies and generate power, which is sent down through the tether.”

The engineers at Makani Power, Woodrow says, “are focused on the need to produce energy closer to where it is used. Our technology has an even larger advantage offshore, at sea. There are terrawatts of potential wind generation off the California coast alone. Our airborne wind turbines could allow us to harness that energy and deliver it to coastal cities like San Jose, San Francisco, and Los Angeles without having to build polluting power plants on land.”

California has the most aggressive renewable energy laws of all 50 states. By 2020, one-third of the state’s electricity must come from renewable sources, including wind.

Arrison sums it up this way: “Wind power is clean, and clean is better than dirty.”