The article linked below purports to estimate the land area needed to power the US with electricity generated by solar energy. It makes good use of easy-on-the-eye graphics to communicate information, and I like to see how writers pack as much information as possible into their illustrations. However, some questions go unanswered.
For starters, estimates of US electricity needs often use phrases like “electricity to power 18.6 million American homes.” But how much power does the average American home use? Does that figure, whatever it might be, include heating and air conditioning? Maybe yes. Does it include energy to charge an electric vehicle or two, given the government push to wean us away from vehicles powered by gasoline or diesel? Maybe or maybe not. Does it reflect local attempts to block the use of natural gas for heating and cooking in new or renovated homes, which will force a switch to electric heating and cooking? Maybe not. So we may have a bit of a moving target, which reduces the credibility of projected numbers.
Next, we need to think about how solar generation supports the power grid. The article does not mention energy storage for when the sun is unavailable, nor does it discuss how relying on renewable energy might affect power grid reliability. Over the past 20 years or so, California ratepayers have been subsidizing renewable energy investments (mostly wind and solar) at the expense of other potential electric utility investments, and state government’s hand on the utilities has become heavier and heavier. Meanwhile, the power grid has become less reliable, and brownouts and blackouts come with increasing frequency. Why should ratepayers have to get used to unreliable electricity service?
Last, and probably most speculative, what happens to weather patterns if we replace enough light-colored desert, medium-colored roofs, or green grasslands with black solar panels? The panels convert only a fraction of incoming sunlight to electricity; the rest is mostly radiated as heat back into the atmosphere. In comparison, a rocky desert, colored roof, or grassy field will not radiate as much heat. On a small scale these differences may not amount to much, but if we have a thousand square miles converted from natural surfaces to what amounts to black body radiation, will the increased heat radiated into the air change anything in the weather? Or is this too hypothetical to worry about?
A Cup of Brouhaha 
Great analysis, Jesse. If the politicians were truly interested in green and reliable energy, they would look at nuclear power. But then, that’s not very popular, and what’s not popular doesn’t get votes, and what doesn’t get votes, doesn’t get considered.
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Good point about nuclear, Randy. I may need to do a blog post on that topic. On a related matter, energy conservation, once we insulate our homes, switch to high-efficiency appliances, and switch to LED lighting, I am running out of ideas to reduce our electricity consumption. Seems like we may be reaching a law of diminishing returns…
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All is not lost. For centuries our ancient forefathers transported items too heavy to carry by sliding or rolling them across the ground. Then God, in His mercy, shred the knowledge of the wheel. It’s strange that He has not provided mankind with something to replace the wheel. Obviously, in man’s imperfect, temporal world, the wheel cannot be the perfect answer. Surely, there exists something more efficient than the wheel that God has not shared with us.
I believe in the concept that energy can’t be destroyed, but only converted from one form to another. Maybe we need to work on improving efficiencies and capture of energy conversions. An example is cogeneration plants.
Cogeneration plants generate electrical energy from gas and steam turbines. Catalysts on exhaust stacks could provide more energy through the appropriate chemical conversion of combustion pollutants. Where’s the science that developed catalytic converters on cars or smokestack washers at coal powered plants?
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Law of diminishing returns, or law of diminishing effort and faith in God? How often are our prayers not just for forgiveness of our sinful lives but for scientific research that glorifies God?
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