Does alternative energy actually replace fossil fuel consumption?

It is the stated policy of the federal government, and some state governments, to replace use of fossil fuels with alternative energy, especially in the production of electricity. The stated rationale for this policy is to reduce carbon dioxide emissions and lessen our dependency on imported fossil fuels. Several states (including Arizona) have laws which mandate that a certain (increasing) percentage of electricity be produced with the usually much more expensive alternative energy sources such as solar and wind generation. How well is that working?

A study published earlier this year asked: “Do alternative energy sources displace fossil fuels?” The answer is “not much.”

Richard York of the University of Oregon studied the use of alternative energy in 130 countries to assess the contribution of various forms of non-fossil fuels. The study showed “that the average pattern across most nations of the world over the past fifty years is one where each unit of total national energy use from non-fossil-fuel sources displaced less than one-quarter of a unit of fossil-fuel energy use and, focusing specifically on electricity, each unit of electricity generated by non-fossil-fuel sources displaced less than one-tenth of a unit of fossil-fuel-generated electricity.”

Nuclear and hydro generation were the best of the alternatives to fossil fuels. Each kilowatt-hour (kwh) of nuclear generation of electricity displaced about 0.2 kwh of fossil fuel generation; hydro displaced about 0.1 kwh. Wind and solar generation did not displace any fossil fuel generation.

There are two reasons for that last result. First, wind and solar generation, while increasing, still represent a very small part of the generation capacity compared to consumption. But the main reason for lack of impact of solar and wind generation is that they are unreliable, intermittent sources that require backup generation, and that is usually by fossil fuels. Furthermore, because the fossil fuel backup generation must be on-call, it cannot run efficiently and therefore it actually uses more fuel than it would had it been the primary source. And incidentally, the backup generation also produces more carbon dioxide emissions than it would have had it been run efficiently as primary generation.

York concludes: “These results challenge conventional thinking in that they indicate that suppressing the use of fossil fuel will require changes other than simply technical ones such as expanding non-fossil-fuel energy production.”

See also:

The scale problem for solar and wind generation of electricity

Renewable energy mandates raise electricity costs

Renewables receive bulk of tax preference subsidies

Electricity generated by wind power may raise temperatures and costs

Wind farms raise local and regional temperatures

Blowing in the Wind, a look at green jobs

EIA says Clean Energy program will increase electricity costs 29%