The Impossibility Of Bridging The "Last 10%" On The Way To "100% Clean Electricity"

December 10, 2022 Francis Menton @ Manhattan Contrarian

As my last post reported, the Official Party Line from our government holds that we have this “100% Clean Electricity” thing about 90% solved. As the government-funded NREL put it in their August 30, 2022 press release, “[a] growing body of research has demonstrated that cost-effective high-renewable power systems are possible.” But then they admit that that statement does not cover what they call the "last 10% challenge” — providing for the worst seasonal droughts of sun and wind, that result in periods when there is no renewable power to meet around 10% of annual electricity demand. That last 10%, says NREL, will require one or more “technologies that have not yet been deployed at scale.”

But hey, we’ve got 90% of this renewable transition thing solved. How hard could figuring out that last 10% really be?

And on that basis the government has embarked upon forcing the closure of large numbers of power plants that use fossil fuels like coal and natural gas, as well as on suppressing exploration for fossil fuels and other things like pipelines and refineries. After all, if we’re transitioning at least 90% to renewables, we won’t need 90% of the fossil fuel infrastructure any more, will we?

Actually, that’s completely wrong. Until the full solution to the so-called “last 10% challenge” is in place, we need 100% of our fossil fuel backup infrastructure to remain in place, fully maintained, and ready to step in when the wind and sun fail.

Let’s take a brief look at what bridging the last piece of the renewable transition actually looks like.

NREL’s August 2022 Report titled “Examining Supply-Side Options to Achieve 100% Clean Electricity by 2035” lays out several scenarios for supposedly achieving that goal. For all the scenarios, the most important piece is the same: building and deploying lots more wind turbines and solar panels. (The scenarios differ in the degree of deployment of other elements like transmission lines, battery storage, carbon capture technology, and additional nuclear.). As foreseen by NREL, by 2035, total electricity generation capacity in the U.S. has more than tripled, with the large majority of the additions being wind and solar. There is substantial overbuilding of the wind and solar facilities, presumably to provide enough electricity on days of light wind or some clouds, while having large surpluses to discard on days of full wind and sun. Some storage has been provided, but mostly “diurnal” (intra-day) and not seasonal.

Here is a chart from the Report (page x) illustrating the addition of facilities in the four scenarios by 2035. In this chart, the left-most column depicts current (2020) conditions, and the right-most four columns depict the four proposed scenarios for 2035:...........To Read More....