SALEM, Ore., Feb. 24, 2014 — The Obama Administration has pushed solar and wind power as the preferred renewable energy replacements for fossil fuel electricity. Will these be adequate for the job?
The administration must think so. It has poured tens of billions of dollars into research, development and deployment of solar and wind energy in large-scale commercial electric power projects.
To show off the administration’s solar power investments to reduce carbon dioxide emissions, U.S. Environmental Protection Agency (EPA) Administrator Gina McCarthy toured the William R. Sinkin Centennial Solar Farms outside San Antonio, Texas on February 12, 2014.
Sinkin is a new state-of-the-art 20 megawatt (MW) solar photovoltaic facility occupying 200 acres of land. McCarthy toured it with San Antonio Mayor Julián Castro and other dignitaries.
Supporting state and local efforts to address the effects of climate change – such as more frequent and severe extreme weather – is an important part of President Obama’s Climate Action Plan
– EPA Press Release, William R. Sinkin solar farm, 2/12/2014
Solar and wind are vital cogs in the President’s Climate Action Plan to reduce U.S. greenhouse gas emissions by 2020. However, according to the U.S. Energy Information Administration (EIA), the United States will consume 4.086 billion megawatt-hours of electricity in 2014. That’s huge, the equivalent of 121,000 Sinkin-sized solar farms.
Can solar and wind power become the mainstay of electricity production in the United States? Even overcoming their other disadvantageous, it’s a question of land area!
Understanding capacity factors is key to understanding electricity production in the United States. It’s crucial when talking about both solar and wind power.
Typically, an electric power plant is described by its generating capacity, usually expressed in megawatts (MW). Sinkin, for example, is described as a 20 MW solar farm.
However, generating capacity isn’t always an accurate measurement of a plant’s true electricity production. No power plant delivers 100 percent of its generating capacity. It delivers less. How much less depends on the energy source.
Nuclear power plants are the most efficient. They run at close to their rated generating capacity 24 hours a day all year long. For example, the Palo Verde Nuclear Generating Station near Phoenix, Arizona operates at 90 percent of its rated capacity.
Palo Verde is the largest electric power plant in the United States. It has 3,875 MW capacity and delivers 30,584 gigawatt-hours (GWh)/year when operating at 2013’s measured 90.1 percent capacity factor.
Solar and wind, on the other hand, both have exceptionally low capacity factors. According to the EIA, solar photovoltaic operated at only 19.4 percent of capacity in 2013. Wind operated at 32.3 percent. Solar thermal operated at just 17.8 percent.
Of course, solar produces only when the sun shines and wind only with a blowing breeze.
The Solar solution
The Sinkin solar photovoltaic (PV) farm requires 10 acres of land area for each megawatt of electric generating capacity. Its 200 acres occupies 0.31 square miles split between two plots.
A Sinkin-like solar PV farm, at a capacity factor of 19.4 percent, would have to have a whopping 18,043 MW of rated capacity to produce the same amount of usable electricity as the Palo Verde nuclear plant.
Palo Verde occupies 6.25 square miles. Sinkin would need 282 square miles of solar panels on a single plot of land to match Palo Verde’s output. That’s about the size of New York City.
To produce all the electricity in the United States with solar photovoltaic panels would require a land area of 37,790 square miles. That is about one third the size of the state of Arizona. Solar thermal would require more.
The Obama Administration has opened up public lands to solar and wind power. Solar PV would require 14 percent of all the BLM managed lands in the continental United States to meet current U.S. electricity needs.
The Wind Solution
Wind power needs even more land than solar for its massive 350 foot tall windmills.
The 845 MW capacity Shepherds Flat Wind Farm on the banks of the Columbia River near Arlington, Oregon was the largest in the world when it opened in late 2012.
It has 338 windmills on two large plots of ranch land occupying 30 square miles in two counties.
Wind has a higher capacity factor than solar, but takes up more space. To match Palo Verde’s usable electric output, Shepherds Flat would need 460 square miles. That’s nearly the size of Los Angeles.
To produce all the electricity in the United States it would take up half the state of Arizona, over 22 percent of all existing public BLM lands in the continental United States.
Solar and wind have numerous important physical limitations:
- Non-scalable. They can’t be turned on or off to adjust to peak electric demand.
- Inefficient. They have exceptionally low capacity factors. They are probably operating near their theoretical limits now.
- Siting. Must be built where conditions are suitable, not necessarily where electricity is needed.
- Land. Require vast land areas to produce significant amounts of electricity.
Land area is a serious obstacle to both solar and wind power. Most people just assume there is enough. There likely isn’t enough suitable land in the continental United States for them to come close to current electric needs, let alone future ones. If electric cars catch on consumption will skyrocket.
Wind and solar provide less than five percent of all electricity in the United States, despite 10s of billions in government subsidies. Subsidies can’t be sustained forever.
The Administration talks the talk of an all-of-the-above energy strategy. Solar and wind economics will soon force government to walk the walk. Solar and wind disadvantageous prevent their adoption as the primary source of electricity in the United States.
EIA data suggest that lower-cost, low emission natural gas and nuclear are the more viable energy solutions for electricity over the next 25+ years.