August 9, 2016
I have been thinking a lot about the possible technological, ecological and social consequences of a really robust investment in solar energy production. Much of what will follow is not based on specifics – I am not an engineer, and I don’t have easy access to the numbers, but I will refer to many existing technologies and the extrapolations are not outrageously unlikely.
To begin, let’s assume that you can generate a lot of electricity via a solar power installation. There are a few ways to do this – photovolaics are very commonly seen these days, but you can get better efficiency out of mirror-based, thermal plants. These plants are really neat, in that they use salt to absorb the focussed heat of the sun, and use that molten salt to drive steam turbines all night, so that a solar plant can generate electricity around the clock. There is a lot of maintenance in any power plant, but this maintenance is the only ongoing expense in a solar plant – no fuel needed and no waste to dispose of. This part isn’t fiction – these plants exist, and they are generating power right now.
Here’s where my thoughts diverge from what people are doing with solar power right now. Right now, people are mostly generating power with solar plants – power which competes in the same market with nuclear, wind, hydro and combustion power plants. This creates the opportunity for the incumbent players in the power generation market to manipulate that market, by supplying power more cheaply to discourage an outsized investment in surplus solar power generation. Here’s where I think investment in solar power can diverge from the problem of contributing to a power grid that must be balanced across the loads of half a continent. If your goal is to generate as much power as possible, perhaps with many plants clustered together, what is possible with unlimited free electricity – not truly free of course, but not defined in price based on the rest of the grid.
The answer, to my mind, is carbon. Specifically, carbon nanotubes and nanowires. These are materials with amazing properties, but they are scarce because they are difficult to make. They are microscopically fine filaments that are incredibly strong and, when combined, incredibly tough. They are an ideal product to produce with a surplus of solar energy – because their scarcity can demand a higher price per watt than exporting the electricity. There is another cool side effect – the carbon feedstock for this process can come from the air. Sandia National Labs has demonstrated a process that captures atmospheric carbon on a cobalt-iron ceramic element. There is a significant challenge to industrialize the process to convert atmospheric carbon to high-quality carbon nanotubes and nanowires, but for the rest of this series, I’m am going to take it as a given.
As an aside, the process demonstrated at Sandia National Labs used the carbon captured to create synthetic fuels that are carbon-neutral, because the carbon they release when burned has already been removed from the atmosphere. This is another secondary benefit of a solar-based energy surplus.
Part 2 of this series extrapolates from the above and discusses what might be done with carbon products if they were available in industrial quantities.
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