The Long-term Cost of a Fully Solar Grid

By: Corey Henderson  |  Our Voice Contributor

Why does power cost money? The root of the answer is because it took work to generate it. But what if it didn’t take work to generate that electricity? Or, more specifically, what if the work was done so long ago that it already has been paid for many times over?


Imagine a future where there are solar arrays on every roof. No need to set aside land for solar power, there’s enough collective area on roofing of homes and buildings to cover more than that which is required to cover our energy needs. In a future where solar cells are so cheap, and replaced so infrequently, the equilibrium of the production and recycling of them is somewhat akin to painting buildings; a tiny labor force that shows up, works for a day, and then you never see them again.

Power would be bursting from our eyeballs. During the day, even a cloudy day, there would be so much power available it would be like the nitrogen in the air your breathe; everywhere! And it’s not something you ever hear or think about unless it’s your job to understand it.

During the day, so much energy hits the earth that you literally could say we are being blasted by a cosmic superpower. The energy of the sun is no joke. In this future, solar power would be such a pervasive commodity, it would cost next to nothing, if anything at all.

Now, a fully solar grid has the obvious problem of the sun not shining at night. This is where we have to ask the question again; why does power cost money? In a fully solar grid, power isn’t being constantly slapped in our face when the sun is down. This is where power starts to cost money, because it takes work to create it.

So in this fully solar future, what work creates the power at night? Currently, we burn coal or gas. You know what coal and gas are? They’re energy storage, it’s just not a kind that’s renewable. In-fact, they were created by sun energy, millions of years ago. But, you burn it, and it’s gone, and we’ll eventually run out. Renewable energy storage comes in many different forms; batteries, water splitting, molten salt, dam+reservoirs, rail-car-on-a-hill, etc. Each have their pros and cons. The closest form of renewable energy storage to gas and coal is water splitting, and it’s probably the least efficient form of energy storage that I listed.

So we put our excess power into energy storage, and boy would we have excess power, and use that power at night. But that energy storage has to work at night to generate the power, whereas the solar arrays didn’t have to work to generate it. So, that is where the cost is. Nighttime power.

This is where you ask, how much power do we truly need at night? That’s where the free market gets to decide. We do need power at night, of course; but those who use it will have to pay for it. If something is free during the day, and not-free during those short periods before and after you are typically asleep, it’ll mostly get used when it’s free. Our behavior as a society will adjust to the new cost pattern.

We’ve seen this sort of behavior happen before. Remember when cell phone rate plans charged less (or nothing) on nights and weekends? Lots of people made the effort to switch the time of their communication, or at the very least, keep short the conversations during peak rate hours. We even already have this behavior in some energy markets where electricity is more expensive at peak hours. They just so happen to be peaking in price be during the day. A fully solar grid would be the other way around.

The biggest necessary use of energy at night is creating heat. But we already have this, and just do not realize it, because our heater is often gas powered, and the cost is on a separate bill than electric. They’re essentially the same thing, though; the transmission and use of energy.

There are, of course, many other uses of energy at night. Hospitals need to run life savings equipment. Certain long running industrial processes can’t be interrupted. Light is needed to see in buildings and on the road. I could go on. But these are things that we already pay for, the price simply adjusts to the economics of a fully solar grid, which drops the price overall.

I’m not saying that our electricity bills in this future would be zero. Those solar arrays do cost money. The power transmission lines and substations will still need to be maintained like they do now. We will have to pay for the availability of the energy storage, even if we personally don’t use it much. I’m simply saying that, as a whole, energy will cost much less than it does now in a fully solar grid.

Coal/gas power plants explode. Mines collapse. Pipes burst. Dams ruin local ecology. Turbines get ripped apart by strong winds. Nuclear power plants melt down. Moving parts are tricky… This is why I’m a nut for solar. A ‘sun spill’ is called a nice day! And what a nice future it would be if the grid were entirely powered by solar.

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