Posted by: bmeverett | August 22, 2011

The elusive kilowatt

One of the greatest developments in human history was the harnessing of electricity, which now gives us light and warmth, heats our water, cooks our food and entertains us with television, radio and, more recently, e-books. According to the Energy Information Administration (EIA), Americans paid roughly $350 billion for electricity in 2009, the latest year for which data are available. That amounts to over $3,000 per family per year, partly in our electricity bills and partly in the electricity costs embedded in the goods and services we buy. The investment required over the next 20-30 years to expand and upgrade the power system will be measured not in billions but in trillions of dollars. Unfortunately, many of the critical investment decisions on our future power supply are being made in Washington by people who believe that the cost of power to the American people does not matter.

Wind turbines have been the darling of the green energy crowd for a number of years. Here on Cape Cod (where I am privileged to spend my summers) every town wants a wind turbine, naturally paid for by someone else. Hearts may swell with green price at the sight of these impressive towers, but do they really help our power supply?

Our public officials and the media tend to confuse power production with power capacity. Take, for example, a power plant with a capacity of 1 million kW. If the plant could operate 100%, it would generate 24 X 365 = 8,760 million kilowatt-hours (kWh) of electricity every year. No machine can run continuously without shutting down from time to time for maintenance. You can drive your car at 60 miles per hour, but you need to stop every once in a while for fuel and rest. Modern coal, nuclear and natural gas power plants can operate in excess of 90% of the time, so a 1 million kW power plant can generate close to 8,000 kWh per year. Not so with wind. According to the EIA, wind turbines in the US produce on average only about 2,400 kWh from each one million kilowatts of capacity. In other words, they operate effectively only 27% of the time.

By my calculations, a modern combined cycle natural gas power plant can generate electricity for about 5¢ per kWh, including 2¢ for the plant construction and operation and 3¢ for the fuel. The fuel for a wind turbine is, of course, free, but the plant cost is very high, since it sits idle most of the time. My estimate for wind is 15½¢ per kWh, more than three times as much as natural gas. (I’d be happy to share my calculations with any interested reader.) It’s just silly to call wind power “free”.

Perhaps even more importantly, we have no economically viable way of storing electricity. Electric power companies must have in place sufficient generating capacity to meet demand moment by moment. If you need power, and the wind isn’t blowing, tough luck.

So what does all this mean to consumers? Have a look at an excellent article by Robert Bryce in The National Review entitled “The Wind Energy Myth” which you can find at Bryce looks at the role that wind power has played in meeting the extraordinary power demand in Texas resulting from the extended heat wave they have endured this summer.

According to the EIA, Texas has about 110 million kilowatts (kW) of nameplate electric generating capacity, including about 10 million kW of wind, more than any other state. The rest of Texas’ capacity is mostly natural gas (75 million kW), coal (21 million kW) and nuclear (5 million kW). You might assume that the wind capacity would come in handy when Texans rev up their air conditioners to fight temperatures exceeding 100º F day after day. According to Mr. Bryce, you’d be wrong. Why? Because the wind doesn’t blow much on hot summer days. Wind power tends to come almost entirely at night, when temperatures are lower, businesses and factories are closed and people are asleep. What Texans need is power at the peak of demand in the late afternoon.

According to Mr. Bryce, on the afternoon of August 2, when high air conditioning demand put substantial pressure on the generating system, wind power supplied only 1½ million kW or 15% of its capacity. The chart in Mr. Bryce’s article shows an inverse correlation between when power is needed and when wind energy is available. In essence, wind power supplements, but does not replace other kinds of electricity. When the wind turbines are working during the night, the power company must shut down available natural gas or coal plants. The only cost savings is the fuel. Therefore, wind power at 15½¢ per kWh saves us only 3¢ per kWh in natural gas costs. If a coal plant is shut down, the savings are even less at about 1¢ per kWh.

Not only does wind power not come when we need it, it doesn’t come where we need it. In Texas, for example, most of the wind turbines are in West Texas, where land is cheap and farmers and ranchers are happy to have extra income. Most of the demand, however, is in the big cities of Eastern Texas: Dallas, Fort Worth, Houston, San Antonio, Austin and Corpus Christi. In addition to the $25 billion cost of the Texas wind turbines themselves, Mr. Bryce notes that another $8 billion has been spent on transmission lines to bring the power from west to east.

The bottom line is that all kilowatt-hours are not created equal. A gallon of gasoline is easy to produce, move around and store. Refineries do not have to worry about how many drivers will fill up their cars at 5:00 pm on a hot August afternoon. Kilowatt-hours, on the other hand, must be produced in the right place at the right time. Otherwise, they’re worth very little to consumers.

Like ethanol, wind power is simply a terrible idea. It’s expensive, and its utility is limited. Unfortunately, by the time we ultimately kill these useless programs, we will have spent an enormous amount of money. Good thing the federal government has plenty of cash to spend.


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