Wind energy: more farms, bigger machines

Wind energy: more farms, bigger machines

By Jeff Havens, Staff Writer

Expect taller wind machines with larger turbines that turn slower as wind farms spread across Europe to the United States and beyond. The Feb. 24 edition of Chemical and Engineering News featured a cover story on wind energy, which said that although growth of wind energy capacity has accelerated worldwide, especially in Europe, the United States can expect no more than 3 percent of its energy needs to be met by wind power over the next 20 years.

The article also indicates that the bulk of future research and development will be focused on improving turbine blades to allow them to be lighter and stronger. Improved blades will allow them to be longer, which has dropped the rotor revolutions per minute (rpm) from 50 rpm in 0.75 megawatts (MW) machines to 15 rpm in 3.6 MW machines.

As the blades have become longer (up to 50 meters or 165 feet) and revolutions per minute have dropped, tip speed of the blade has remained the same at 70 to 80 meters per second (about 157 to 179 miles per hour).

This is good news for birds that have sometimes been killed by turning blades. Also, blades that turn slower are more quiet. Older wind machines have been targeted by critics as being noisy, bird killing eyesores.

Blade researchers hope the next generation of wind machines will use carbon epoxies rather than epoxy glass used in today’s machines. Use of carbon epoxy technology should allow for the stronger, lighter, quieter and longer turbine blades.

There are many differing sized wind machines that range in size and energy output from 10 kilowatts (kW) to 10 MW. However, most wind machines are eligible for state and federal tax credits.

The federal production tax credit gives wind energy producers a tax credit of about 1.7 cents per kilowatt-hour for the first 10 years of a turbine’s use. This credit has helped catalyze the recent proliferation of wind energy capacity in the U.S., according to the article. Illinois has similar renewable energy incentives.

Here is a list of resources to assist putting together a wind energy system:

1. American Wind Energy Association. – Answers many frequently asked questions.

2. Illinois Department of Commerce and Community Affairs.—Provides information about Illinois renewable energy grants and rebates.

3. Environmental Law and Policy Center.—Provides information on Illinois net metering programs.

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