Not too long ago, we reviewed a report that looked at nuclear energy (and other energy sources) as biodiversity agents. This had to do, in part, with the amount of land a facility needs to function. Nuclear energy and fossil fuel plants use relatively little, wind farms and solar arrays quite a lot of land.
Based on an objective and transparent analysis of our sustainable energy choices, we have come to the evidence-based conclusion that nuclear energy is a good option for biodiversity conservation (and society in general) and that other alternatives to fossil fuels should be subjected to the same cost–benefit analyses (in terms of biodiversity and climate outcomes, as well as sociopolitical imperatives) before accepting or dismissing them.Writer Barry Brook, who collected 75 scientists to endorse his paper, is interested in land use as it impacts flora and fauna. Biodiversity concerns do not get as much play as they might – and, when they do, it annoys many when land is withdrawn due to a specific lizard or weed - but it’s an important factor in siting new buildings of any sort.
But what about land use as an issue in itself? It’s a fair argument that nuclear energy provides a lot of energy in a relatively small amount of space. But how much really? Is it potentially an important issue or just another argument to throw on the pile?
Jesse Jenkins takes a look at land use over at the Energy Collective and concludes, using Brook’s figures:
To fuel one-third of the United States’ 2050 electricity demand with nuclear power would require only 440 sq-km [169 square miles], according to the land use figures compiled by Brook.Solar:
If solar provided one-third of Americans’ electricity in 2050, it would require just 4,000-11,000 sq-km [1500-4250 square miles].That’s – a pretty big range and at least 9 times the space used by a nuclear energy plant.
Wind (also using figures from Brook):
Powering one-third of the country's projected 2050 electricity demand with wind energy could take a land area spanning on the order of 66,000 sq-km… [25,480 square miles]And that’s just gigantic, about the size of West Virginia.
NEI has tried the same exercise recently. Instead of of Jenkins and Brook’s calculation of one-third of American electricity, NEI compares the space needed to supply 1000 megawatts, about the amount of a full-scale reactor. (A nuclear baseline makes sense for NEI, yes?)
NEI also takes into account capacity factor. This refers to the amount of electricity a plant actually puts out against its rated capacity, expressed as a percentage. Nuclear reactors achieve an average capacity factor of 90 percent, largely because they shut down occasionally for refueling. Wind farms, depending on location and other factors, have a capacity factor between 32 and 47 percent, solar arrays between 17 and 28 percent. (See the charts at the link for a more visual comparison.)
Does this give nuclear energy an advantage? You bet it does. Is it fair to consider it? Yes, I think so. Renewable energy advocates often ignore the whole capacity factor thing because it drags numbers down, but that’s the nature of intermittent (solar, wind) versus baseload (nuclear, hydro) energy. If there’s a big jump in battery technology (a big if), wind and solar will improve their capacity factors. Until then, the numbers are what the numbers are. And it will take more land to make up for them.
A 1,000-MW wind farm would require approximately 85,240 acres of land (approximately 133 square miles). Accounting for a range of capacity factors (32-47 percent), between 1,900 MW and 2,800 MW of wind capacity would be required to produce the same amount of electricity as a 1,000-MW nuclear plant in a year. The land needed for wind energy to produce the same amount of electricity in a year as a 1,000-MW nuclear plant is between 260 square miles and 360 square miles. A 1,000-MW solar photovoltaic (PV) facility would require about 8,900 acres (approximately 14 square miles).To be honest, if mischievous, you could make this comparison even better for nuclear energy. Consider that the five reactors now being built in Georgia, South Carolina and Tennessee are at existing facilities. They take up no more land than has already been committed to the facilities. Almost all new wind and solar installations are new builds – of course, mischievous wind and solar folks have distributed energy installations in their camps (roof-top solar and the like). But let’s just call this a minor factor withal – some proposed nuclear reactors could be in newly built facilities.
Accounting for a range of capacity factors (17-28 percent), between 3,300 MW and 5,400 MW of solar PV capacity is required to produce the same amount of electricity as a 1,000-MW nuclear plant in a year. The amount of land needed by solar to produce the same generation as 1,000 MW of nuclear capacity in a year is between 45 and 75 square miles.
The conclusion however you look at it is almost foregone: if you want a lot of cleanly generated electricity in a (relatively) small space, then nuclear energy is the way to go. As Brook points out, this could be determinative in places where land is at a premium or when biodiversity concerns rise in importance. In places like the U.S., it is, or should be, a factor in considering the mix of energy types. These may have started as exercises, but they reveal real issues to consider in energy policy.
EDITOR'S NOTE: The NEI paper, "Land Requirements for Carbon-Free Technologies," is available on NEI's website.