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Letter: Energy comparisons

The “My Turn” article “Power down wind, solar” (Nov. 26) contains many inaccuracies and distortions. Let me address statements about the efficiency of solar and wind energy.

Efficiency is a ratio of useful output compared to input. To calculate energy efficiency, the energy value of fuel consumed is compared to the useful energy produced. A natural gas-fired generation plant with 60 percent efficiency (the number used in the article) wastes 40 percent of the fuel value of the gas.

Cost efficiency can also be measured. For the example gas plant, only 60 percent of the cost of gas used goes for useful gas. End users pay 100 percent of the cost, of course, but 40 percent of that goes for gas that does them no good.

But what does efficiency mean for solar or wind energy? It may be that the solar plant converts only 15 percent of the solar energy that falls on it to electrical energy. It may be that the wind generator converts only 25 percent of the energy in the wind passing through it to electrical energy. But sunshine and wind are free. We cannot measure efficiency of sun and wind in terms of money.

Of course, the cost to build a wind generator or solar farm counts in real life, but the “My Turn” article didn’t count the cost of building or maintaining the gas-fired generator, either.

The above does not even consider the pollution cost of different methods of producing electricity. For the gas plant, 100 percent of the carbon in the fuel becomes carbon dioxide in the atmosphere. We are also learning that the production of natural gas involves leakage of methane into the atmosphere. Methane is a more dangerous greenhouse gas than carbon dioxide.

The “Power down” article compares apples and oranges.



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