Guest post by David Middleton
The Strata group at Utah State University recently published a study on the “footprint of energy.” For each energy source, the calculated the full-cycle land use required to generate 1 MW of electricity from each source of energy. Despite the fact that they included the land required to drill and mine for natural gas and coal, all of the processing and transportation requirements, as well as power plant footprints, fossil fuels and nuclear power were the clear winners, by a long-shot.
Modern society requires a tremendous amount of electricity to function, and one of this generation’s greatest challenges is generating and distributing energy efficiently. Electricity generation is energy intensive, and each source leaves its own environmental and ecological footprint. Although many studies have considered how electricity generation impacts other aspects of the environment, few have looked specifically at how much land different energy sources require.
This report considers the various direct and indirect land requirements for coal, natural gas, nuclear, hydro, wind, and solar electricity generation in the United States in 2015. For each source, it approximates the land used during resource production, by energy plants, for transport and transmission, and to store waste materials. Both one-time and continuous land-use requirements are considered. Land is measured in acres and the final assessment is given in acres per megawatt.
Specifically, this report finds that coal, natural gas, and nuclear power all feature the smallest physical footprint of about 12 acres per megawatt produced. Solar and wind are much more land intensive technologies using 43.5 and 70.6 acres per megawatt, respectively. Hydroelectricity generated by large dams has a significantly larger footprint than any other generation technology using 315.2 acres per megawatt.
While this report does not attempt to comprehensively quantify land requirements across the entire production and distribution chain, it does cover major land components and offers a valuable starting point to further compare various energy sources and facilitates a deeper conversation surrounding the necessary trade-offs when crafting energy policy.
|Chart 1: Land Use by Electricity Source in Acres/MW Produced|
|Electricity Source Acres per Megawatt Produced|
Strata receives at least some funding from those great Americans: The Koch Brothers. They are also very up-front about their economic philosophy:
I just couldn’t resist taking their results and seeing if I could make renewables look even worse… And it was easy.
The U.S. currently has 274 GW of coal-fired generating capacity (274,000 megawatts). Using the capacity factors in the EIA’s most recent LCOE analysis, I calculated how many MW of each source would be required to replace 274 GW of coal and then used Strata’s per MW footprint to calculate the footprint required by each source, if it completely replaced coal.
|MW||ac/MW||Total Footprint (ac)||Sq. Miles||Capacity Factor|
|Capacity-Adjusted MW||ac/MW||Total Footprint (ac)||Sq. Miles||Capacity Factor|
Then I related the footprint of each source to U.S. States.
For hydroelectric, I used the total areas of California and Texas. Otherwise, I just used land areas.
Some may say, “That’s silly! No single power source is expected to replace coal.” This is true, however some people think that wind, solar and hydroelectric can provide 100% of our electricity. In which case we would need a Georgia-sized wind farm, a Washington-sized solar farm and a hydroelectric capacity (including the rivers) almost as big as Texas.
Or, we could just roll with three Connecticut-sized footprints: Coal, natural gas and nuclear.
LCOE: Levelized cost of electricity.
GW: Gigawatt = 1,000 MW
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