Does a Big Economy Need Big Power Plants? Amory B. Lovins says, no:
Thermal power stations burn fuel or fission atoms to boil water to turn turbines that spin generators, making 92 percent of U.S. electricity. Over a century, local combined-heat-and-power plants serving neighborhoods evolved into huge, remote, electricity-only generators serving whole regions. Electrons were dispatched hundreds of miles from central stations to dispersed users through a grid that the National Academy of Engineering ranked as its profession’s greatest achievement of the 20th century.This evolution made sense at first, because power stations were costlier and less reliable than the grid, so by backing each other up through the grid and melding customers’ diverse loads, they could save capacity and achieve reliability. But these assumptions have reversed: central thermal power plants now cost less than the grid, and are so reliable that about 98 percent to 99 percent of all power failures originate in the grid. Thus the original architecture is raising, not lowering, costs and failure rates: cheap and reliable power must now be made at or near customers.
If central thermal power plants are so efficient and so reliable because they’re big and centralized, then numerous small plants might not help the situation. Rod Adams, publisher of Atomic Insights, makes this point — and others:
He talks about how most power failures occur in the grid, not the power plant, and then advises that a microgrid of small, distributed units can be more reliable than our current model. The problem with that statement is that central station power plant reliability is partially a result of careful engineering, redundancy and professionally trained operators that would not exist if units are too small. Microgrids also have many of the same vulnerabilities of the existing grid, but they will be less carefully engineered and less carefully maintained.Lovins likes to use the evolution of computers as an analogy, but anyone who is commenting here who has paid close attention to the computer revolution knows that reliability has not been its strongest measure of effectiveness.
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As William Tucker pointed out, Lovins is not totally wrong — there are some significant advantages to right sized power plants that can be manufactured in a factory rather than stick built and that can be delivered in far less time than is typically assumed for a large central station power plant of any kind. There are at least three companies who have publicly announced plans to build nuclear power plants in unit sizes of less than 50 MWe (150 MW thermal). They are Toshiba, which has designed a 10 MWe unit that can run for 30 years without new fuel; Hyperion, which has designed a 70 MW thermal heat source useful for assisting in enhanced oil recovery, district heating and which can be connected to a 27 MWe steam turbine for power production; and NuScale, which has designed a 45 MWe power plant that can be delivered as a single 300 ton unit to a site that has water or rail access.For my money, those smaller nuclear plants have a huge advantage over the types of systems that Lovins advocates — they produce reliable power without producing any polluting emissions at all. They also need very little in the way of fuel delivery infrastructure. In a world powered by Lovins microgrids, there will be a large demand for diesel fuel and natural gas to fuel the generators that must back-up intermittent wind and solar power. That vision also includes a whole lot of excess capacity that must sit idle for much of its existence.