So you’re saying it would only take .6 percent of the surface area of the continental United States to power the entire country with renewable solar power? Just 11,200,000 acres to generate 4,000,000 GWh of clean energy?
Well, all right! Problem solved! Let’s just fill that area with solar panels and call it a day… right?
That would be great, but unfortunately the answer isn’t so simple as staking a bunch of panels across 12 million acres and calling it a day. First of all, that 11.2 million acres will expand quickly once things like service roads, operational facilities and transmission lines are incorporated. And then there’s the fact that you can’t just build one massive solar array and walk away. Solar capture areas would have to be distributed over a wide area to avoid the problem of cloudy days or storms or other weather events that would obscure the sun pouring down onto your energy farm.
And just because these energy stations would likely be located in the desert (you know, where the sun lives) doesn’t mean you can just put them anywhere. There are animal habitats and ecological systems that need to be considered, as well as encroachment on Native American tribal lands. According to The United States Department of Energy’s Office of Indian Energy, Indian land contains an estimated 5 percent of all renewable energy resources, which includes 5.1 percent of total potential U.S. solar power, 3.1 percent of its potential wind energy and 5.1 percent of its potential hydropower. And the U.S. government really shouldn’t just charge onto Native American land again and tell them to deal with it or get out.
Then beyond questions of land use, there’s the issue of storage. After all we do not have dual suns that permit us to soak up solar energy 24 hours a day, and there will be inevitable interruptions in power relay due to maintenance or any number of incidents that can befall a power grid. That means we need storage, and really big batteries.
Ryan Carlyle is a Quora user with a Bachelors of Science and Chemical Engineering who works “in the oil industry as an engineer for deepwater well control equipment,” and he frequently writes about energy use topics. In a post about how large a solar array would need to be to power the U.S., Carlyle estimates that if we wanted to build a system that could provide four-days worth of emergency or backup energy for the entire United States we would need a combined battery storage capacity of 45.5 TWh. That is terawatt hours, or a unit power equal to one trillion watts.
The largest battery storage facility in the world is the Nishi-Sendai Substation Battery Energy Storage System Project in Japan, and its capacity is 40,000 KWh. According to the Clean Energy Authority that’s the same amount of power produced by about 10 automobile engines. Put another way, that is a tiny fraction of the 45.5 TWh required to supply backup power for the whole country. For comparison, one of the biggest battery centers in the United States is in Fairbanks, Alaska and it has a capacity of 27,000 KWh. It also cost $35 million to build. We won’t get into the weeds with the math of what building on the scale of terawatts would cost, but you can imagine it’s an extreme amount of money.
So, yeah. It’s not so simple as just throwing down 12 million acres of solar panels and hitting the on switch. But no one ever said ditching fossil fuel completely would be cheap or easy. And if the return on this investment is literally saving the word, we think it’s worthwhile.
by Gabriel Reilich & Jordan Crucchiola / Good.Is / April 22, 2016