March 24, 2012
Letters, Oklahoma

Wind and solar energies need backup power 24 March 2012

Roger B. Rensvold (Your Views, March 20) argues in favor of wind and solar energy to replace fossil fuels. Problem is, due to the intermittent nature of these sources, backup is required. Only quick-starting backup is feasible, such as open-cycle gas turbines, which have a much lower efficiency than conventional steam power plants. Thus, most if not all of the savings when the wind blows are lost when backup comes on.

To generate more power than just when the wind blows, storage (such as hydraulic storage) is required. If the wind blows 30 percent of the time and we want all the power to come from wind, over three times the capacity of wind power capacity is required, with the excess used to pump water to reservoirs. This water flows through water turbines when the wind stops. The losses in the storage system are such that about five times the wind power generation is required rather than the three-plus if the storage efficiency were 100 percent. Allowing for the pumping and water turbines, about 10 times as much electrical equipment is needed as for a normal power plant. Immense reservoirs are required to store the water. As a result of these considerations, wind and solar aren’t viable except on a small scale where there’s a “free” backup from the existing system.

The Germans, Spaniards and others are beginning to realize this and are cutting subsidies, with consequent financial problems in their wind/solar industries. The quicker we realize that wind and solar aren’t magic bullets, the better. Huge amounts of money are being wasted.

Ted Rado, Oklahoma City

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