Originally published at Green Energy Times.
An Old Paradigm
The electricity most of us use comes from a system that was designed mostly over a hundred years ago. It was built around concepts that benefited customers of that time. It started with baseload power plants with transmission lines carrying the electricity to towns and cities where customers lived.
A baseload power plant is designed for efficiency of scale and operation. In those days, that meant it had to be as big as possible. Since any ability to ramp power output up or down quickly would cost a lot extra, the plants were designed to have constant output. With constant output, a baseload plant had be sized to meet a demand that could be counted on always to be there. This is the base load, the lowest load that the grid would ever have over the course of time.
Since the baseload power plant was designed to cover the lowest load, any amount of electricity that would be in excess of that would have to come from other sources, all of which cost much more to run. They were load-following plants and peaker plants.
Baseload power plants were sited based on cost and access to resources they needed. Typically, they went up on inexpensive land at some distance from the market they served. They had to have access to fuel resources, which often meant that they needed their own docks or rail sidings. Also, they were often placed on bodies of water to take care of their cooling needs, which are great, because only about a third of the heat they produce could be used to generate electricity.
Originally, baseload plants mostly burned coal. When nuclear reactors were brought online, starting in mid-century, they fit right in with what was the current paradigm of the time. The difference was that they produced nuclear waste instead of air pollution and carbon dioxide.
We might note for reference here that when the state of Vermont was looking for a contract to replace electricity it had been getting from the Vermont Yankee (VY) nuclear plant, the owner of VY made an offer that they said the state could not refuse. It was the equivalent of 6.5¢ per kilowatt-hour (kWh). The state immediately found cheaper renewable electricity.
A New Paradigm
By contrast, today the least expensive source of renewable power need not be large. Solar panels operate at the same efficiency whether they be in utility-scale arrays or on a residential roof-top. Significant amounts of electricity can be generated by solitary wind turbines.
Of course there is a statement, “The sun doesn’t always shine and the wind doesn’t always blow,” which happens to fall into a range of unintentionally disingenuous to simply deceptive. The amount of electricity coming from a given solar array is really rather predictable and tends to come best in periods of light winds. And wind turbines do best when the sun is not shining brightest, so they compliment each other. But more to the point, while a single wind turbine can be idled in calm weather, the wind never stops blowing over wider geographical areas.
We might ask whether the problem of variable output of wind and solar power is as big as the problem of inability of baseload power to follow loads. The answer to this can be seen in the relative costs of electricity from load following and peaking plants, on the one hand, and batteries, on the other. We could do a detailed analysis of this, but it is really not necessary because the utilities are showing the results of their own analyses.
A number of utilities are replacing plants powered by natural gas, which includes most load-following and peaking plants, with solar arrays and batteries. In one case, Entergy Mississippi is planning to replace older natural gas plants with solar and windpower. In the case of Entergy Arkansas, a combined-cycle (base-load) natural gas plant it had planned will not be built, and the company will build renewable resources instead. (KATV.com)
Comparing Nuclear Power With Solar + Storage
An article in PV Magazine in August compared the cost of two new nuclear reactors with a combination of solar photovoltaics (PVs) and battery storage that would replace them functionally, as dispatchable power sources running full time. The article is titled, “Solar challenging nuclear as potential climate change solution.”
The author, who had some expertise in systems that include solar+storage (S+S), used actual costs for the Vogtle reactors that are being built in Georgia. The two reactors, which have been under construction since 2013, are expected to come online in 2022 and 2023, at a cost of roughly $30 billion, including $3 billion in finance costs. Their capacities will be 1,117 megawatts each.
The PV Magazine article calculates the cost of a solar array big enough to provide the same output as the nuclear reactors in the winter in Georgia. It assumes battery storage to supply the output of the nuclear plants for 16 hours, increased by 10% to be safe.
The author shows that the cost of the S+S system designed to replace the two new Vogtle reactors would cost a little less than $17 billion. That would represent a saving of about $10 billion, not counting…