How Much Land Does Solar Use?

The land use of solar photovoltaic (PV) systems can typically range from 60 to 400 ft2 per Megawatt-Hour (MWh) for new utility-scale installations. To power the average US Household with US generated solar, land use ranges from 863 ft2 in Tuscon, AZ to 2,468 ft2 in Seattle, WA, however most of the United States will require between 1,000 – 1,800 ft2 to power the average US household.

The land use for solar PV for different cities in the world is shown below.

Why Does Solar Land Use Vary so Much?

Solar land use depends on both latitude and how much sun reaches the ground, otherwise known as Solar Radiation. The further away from the equator you want to install solar at, the angle of the sun gets lower and lower in the sky. This means that high latitude solar installations cast longer shadows, like we see during sunrise and sunset. In order for solar PV systems to generate the maximum energy, it’s important that the panels don’t shade each other, and that means that you have to space the solar arrays further apart. Near the equator, changes in latitude have a smaller effect on land use requirements, because the sun is more or less directly above the solar panels. However, at latitudes greater than 30 degrees, small increases in latitude have a larger and larger effect, because the curvature of the earth increases the sun angle at an increasing rate. The relationship between land use and latitude is shown below.

While sun angle is fixed by latitude, solar radiation is not. Take for example, Paris, France (Latitude = 48.73) and Seattle, Washington (Latitude = 47.61). These locations differ by less than 1 degree of latitude, but Seattle requires only 2,468 ft2 compared to Paris, which requires 3,223 ft2. This is 30.1% more land required in Paris, mostly because Seattle receives 32.3% more sun than Paris. However, both of these locations require a high land use for solar because they are both high latitude and receive low sun. Compared to the Almeria desert in Spain (Latitude = 36.83), which requires only 1,161 ft2, Paris requires 2.78 times more land for solar just 820 miles to the north. This is because Almeria is both further south, which has a higher sun angle, and because it receives 71.7% more sun than Paris. If we compare Mexico City, Mexico (Latitude = 19.45) to the equatorial cities of Nairobi, Kenya (Latitude = 1.29), and Bogota, Columbia (Latitude = 4.61), Mexico city requires the least land at 678 ft2 compared to Nairobi (729 ft2) and Bogota (784 ft2). This is because the effect of latitude is lower near the equator, and thus the higher solar radiation in Mexico City compared to Nairobi and Bogota results in less land required.

See the Data and Assumptions Section below for a data table containing all latitudes and solar radiation values for each city.

How Does Solar Land Use Compare to Other Land Uses?

The land use required to power the average US Household electricity for US Solar Energy (1,400 ft2) is similar to Hydro Power (1,200 ft2) and Nuclear Energy (1,200 ft2). Wind Power (120 ft2) uses approximately 10% as much land as Solar Energy. Extracting resources for Natural Gas (2,300 ft2) and Underground Coal (2,300 ft2) require approximately twice as much land as Solar Energy over 100 years. Because the unsustainable resources of Uranium (Nuclear Energy), Natural Gas, and Coal all require continuous mining, their land use requirements grow each year, whereas sustainable renewable energy occupies the same land to produce energy, even if the equipment is replaced. However, Biofuels require over 10 times as much land as Natural Gas and Underground Coal! Even though solar panels only capture 20% of the energy in sunlight, the energy recovered from growing plants is far lower, and therefore so much more land is required. This means we could generate approximately 20 times as much energy on the same land with Solar Energy as we could by growing Corn Biofuels, such as the ethanol that gets mixed in US gasoline.

The land uses discussed above are still less than half of Open Pit Coal (58,000 ft2). Open pit mining creates enormous scars in the land that are not easily converted back into natural lands. However, even Open Pit Coal takes a seat to beef. Eating just 4 ounces of beef a day for one year will require 112,881 ft2, (See the Beef – Carbon Footprint & Environmental Impact Page) and this is only 10 – 15% of the calories you need in a day. Switching from 4 ounces of Beef per day to Chicken (6,379 ft2, See the Chicken – Carbon Footprint & Environmental Impact Page) will save 106,502 ft2 per year, which is equivalent to the Solar Energy land use of 85 average US Households! And for those eco-optimizers out there, switching from 4 ounces of Chicken to a half cup of Soy (2,901 ft2, See the Soy – Carbon Footprint & Environmental Impact Page) will save 3,478 ft2, which is equivalent to the Solar Energy land use of 2.8 average US Households.

So the next time you see a giant field of solar panels, just think about how many more fields it took to grow your food!

Solar Land Use Calculator

If you enjoyed exploring this page, maybe you’ll enjoy exploring how much land solar requires anywhere in the world. All you need to do is go to https://pvwatts.nrel.gov and input a location you’re interested in. You will get the Solar Radiation number (kWh / m2 / day) on the third page of PVWatts, and the webpage can give you the latitude of many locations in the world.

Data and Assumptions

Land Use Calculator Assumptions:

  • Solar land use calculator assumptions are based on Jan van de Ven et al. (2021).
  • Standard assumptions from this study are assumed as default values in the Land Use Calculator.
  • Average solar PV module efficiency of 20% is based on the Jan van de Ven et al. (2021) study, and was validated by the current solar energy marketplace value stated by Energy Sage (2021).
  • The solar land use formula is valid to 66.5 degrees of latitude.


General Assumptions:

  • Solar Radiation values are based on the National Renewable Energy Laboratory (NREL) PVWatts Calcaultor (2021).
  • Average 2020 US Household annual electricity based on EIA (2021).
  • Land use of other energy technologies is based on Fritsche et al. (2017).
 
Reference Latitudes and Solar Radiation Values used for the “Why Does Solar Land Use Vary So Much?” Section are listed below:
 

References

EIA: US Energy Information Administration. (2021). How Much Electricity Does an American Home Use? See Link to Source

Energy Sage. (2021). How Much Energy Does a Solar Panel Produce? Solar Panel Output Explained. See Link to Source

Fritsche, U. R., Berndes, G., Cowie, A. L., Dale, V. H., Kline, K. L., Johnson, F. X., … & Woods, J. (2017). Energy and land use. Work. Pap. Glob. L. Outlook, 14-15.

NREL: National Renewable Energy Laboratory. (2021). PVWatts Calculator. See Link to Source

Van de Ven, D. J., Capellan-Per├ęz, I., Arto, I., Cazcarro, I., de Castro, C., Patel, P., & Gonzalez-Eguino, M. (2021). The potential land requirements and related land use change emissions of solar energy. Scientific reports, 11(1), 1-12.