I’ve received several questions about the feasibility of powering our entire country with renewables, like solar or wind. It’s definitely possible — all we’d need to do is install 1200 GW of solar panels or wind turbines. So the short answer is “yes” but as is almost always the case, the long answer winds through several related topics.
The map shows how much land is currently allocated for solar and wind, and how much would be required to power the entire country. Solar includes both large-scale solar farms, as well as rooftop or ground-mounted panels for residential and commercial structures. I put the wind farm in Texas, which has 25% of the nations wind power capacity and plenty of wide-open flat land. Plus, that land can still be used for ranching and grazing — cattle don’t seem to mind the swooshing sound of turbine blades.
I put the solar farm in sunny Nevada, with 79% clear skies. Arizona is higher with 85%, but Nevada has more open space on federal lands (87,500 square miles) that’s not being used for much of anything these days. Notice that the blue rectangles are smaller than their green counterparts. That’s because you can pack solar panels a lot closer than you can wind turbines. Generally, turbines need to be spaced 5–10 rotor-diameters apart to avoid downstream turbulence interference.
The size of the rectangles were calculated from widely available data:
https://todayshomeowner.com/eco-friendly/guides/how-much-space-does-a-wind-turbine-need/
https://greenbusinessbarbados.com/how-much-power-can-a-solar-farm-produce-per-acre.html
Wind currently provides 160 GW. Wind farms average around 23 MW per square mile. That means 21,000 square miles of wind farm could power the entire country. Solar currently provides 130 GW. Solar farms average around 64 MW per square mile (because of their higher packing density). That means “only” 7500 square miles of solar farm could power the entire country.
It’s important to note that the US already uses a good amount of renewable energy. Solar, wind, tidal, hydro, and geothermal produce 220 GW of the current 470 GW average continuous demand. That 1200 GW figure is for peak demand, so most of the time some of the generating capacity is offline. But the capacity needs to be there for the inevitable periods of higher demand.
The main graphic is just to convey a sense of scale. I’m not suggesting putting all our renewable energy production in one place is a practical solution. That would require the construction of high voltage transmission lines to connect them to outside points on the electrical grid. Those lines are largely non-existent and expensive to build. There’s a strong argument for more distributed power generation, like putting solar panels of the roof of every home and business, as well as building more solar farms of the size currently deployed around the country. But just to show you what can be done …
The largest solar farm on the planet is in China’s Gansu Province. The Gansu Dunhuang Solar Park covers and area of 1400 square miles and produces 5 GW of electricity. The photo shows only the east edge of it. If it were added to the map graphic, it would be a tiny blip just 3.8% the size of the small blue rectangle:
The largest wind farm on the planet is also located in Gansu Province. The Gansu Guazhou Wind Farm covers an area of 1600 square miles, and produces 20 GW of electricity. Again, the photo only captures a small part of the entire farm. If added to the map graphic, it would be 12.5% the size of the small green rectangle — definitely noticeable:
So big projects are being built, but at nowhere near the size proposed in this post. That would be a project on the scale of the Apollo Program, the Manhattan Project, or the Interstate Highway System. But we could make it happen if, as a nation, we committed to it. Burning fossil fuels doesn’t make sense given the many green alternatives we can tap into.
The data used in my analysis are admittedly uncertain. Estimates of realizable wind generation rates per square mile range from 0.8 MW/mi2 – 122 MW/mi2, and for solar 26 MW/mi2 – 312 MW/mi2. The numbers I used are on the low end of those ranges, but valid for comparison proposes. Further uncertainty is added by the continued increase in hardware efficiency: state-of-the-art wind turbines generate electricity with an efficiency of 40%, the best solar panels are at 25%.
So the bottom line is “yes.” We could indeed power the entire country with renewable energy, but the implementation would be complex. Still, as a proof of concept, I’ve shown how it could be done.
Next Week in Sky Lights ⇒ Laser Weaponry