A new study from the Brookings Institution, a Washington think tank, argues that using solar and wind energy may be the most expensive alternatives to carbon-based electricity generation, even though they require no expenditures for fuel.
The paper, by economist Charles Frank, compares the benefits and costs of renewable energy. The benefits range from the lack of emissions to the savings in expenditures for fuels. The costs include the construction and maintenance of these plants, and the drop in power generated when winds are calm or the Sun doesn't shine.
Frank's conclusion: Wind and solar power cost far more than anyone expected.
The paper examined four kinds of carbon-free energy – solar, wind, hydroelectric and nuclear – as well as low-carbon gas generation, and compared them with generators that burn fossil fuels. It also posited a value of $50 per metric ton of reduced carbon emissions and $16 per million BTUs of gas.
Frank calculated that electricity generated by a combination of nuclear, hydro and natural gas have much greater benefits than either wind or solar energy because wind and solar generators cost more to operate even though they require no fuel.
For example, nuclear plants run at about 90 percent of capacity compared with wind turbines, which are only about 25 percent efficient, and solar plants with only 15 percent efficiency. As a result, Frank wrote, nuclear plants avoid almost four times as much CO2 per unit of capacity as wind turbines, and six times as much as solar generators.
Specifically, this means nuclear power offers a savings of more than $400,000 worth of carbon emissions per megawatt of capacity. Solar saves only $69,000 and wind saves $107,000.
Still, Frank conceded, nuclear power plants are costly to build. As an example, he cited a new plant at Hinkley Point in southwestern England, which is expected to cost $27 billion by the time it's finished. Its operating costs rise because, like all nuclear plants, it can't be covered by commercial insurance.
But like all nuclear plants, it will run 24 hours a day and so, Frank calculates, it will be only 75 percent more expensive per megawatt of energy to build and operate than a solar generator.
Into this equation, Frank included the generators powered by fossil fuels that will be needed to take up the slack for the inevitable idle periods for wind farms and solar generators. He calls them "avoided capacity costs" that wouldn't exist if the alternative energy plants hadn't been built in the first place.
Therefore, Frank wrote, it would take four wind farms or seven solar generators to replace one coal-fired plant generating similar output. Solar generation costs $189,000 to match 1 megawatt per year generated by coal, and wind power is nearly as expensive. Hydropower, he said, provides a net savings, but only a small one.
Frank's paper concluded that the winner in this comparison of zero-emission power generation is nuclear power because, despite initial costs, it is greatly efficient and operates non-stop.