A couple of weeks ago (July 29) I had a post titled “A Little Arithmetic: The Cost Of A Solar-Powered Grid Without Fossil Fuel Back-up.” In that post I did some simple calculations based on California’s current electricity usage and output from its existing solar generating facilities to figure out how much they would need in the way of solar panels and batteries to get through a low-output stretch in the winter without any fossil fuel assistance. Since for solar energy the “low-output stretch” is essentially everything from September 21 to March 21, I calculated that they would need roughly something in the range of 54,000 GWH of grid-scale battery storage, which at current prices would run around $10 trillion — assuming that someone could in the meantime invent the grid-scale batteries for this purpose that could store thousands of GWHs of energy for as much as a full year until needed.

In another recent post on the same subject — “California’s Zero Carbon Plans: Can Anybody Here Do Basic Arithmetic?” May 11, 2021 — I did a similar calculation with somewhat different assumptions (this time bringing both wind and solar into the mix), and came up with a rough figure for the cost of the needed additional storage of about $6.7 trillion. As huge as those cost figures may be, neither the May 11 nor the July 29 calculations accounted for the yet additional costs associated with loss of power during storage periods that would be up to a full year in length. Also, neither calculation took into account any margin that would be advisable in case of a year of unusually low sun and/or wind.

Now a reader from California writes to say that he has shown my July 29 post to some business associates who are in the process of developing one of the huge battery complexes that California is just starting to build. The reader reports the response of his battery-developing colleagues as being, in summary, “his arithmetic is correct”; however, “his assessment doesn’t address all the tools in the toolbox.” For supposedly a more full understanding, the battery-developers provide me with a link to the March 15, 2021 Report of several California agencies charged with meeting California’s 2045 zero carbon target, the Report being titled “Achieving 100 Percent Clean Electricity in California: An Initial Assessment.”

Does the California multi-agency Report provide any reason to believe that the California bureaucrats have a good idea as to how to get to a zero-emissions electrical grid? The answer is no. Let me first note that my May 11 post already linked to and discussed that same Report. After studying that document, here was my conclusion, along with my invitation to readers:

The [Report shows] that the California regulators have absolutely no idea what they are doing. Perhaps I am wrong. I invite all readers to check me and see if I am missing something.

Nobody responded with anything that I was missing. The basic “conclusion” of the California regulators’ Report, if you want to call it that, can be found on page 1:

Initial findings suggest that the goals of SB 100 [100% zero carbon electricity by 2045] are achievable, though opportunities remain to reduce overall system costs. This report presents various scenarios to meet the 100 percent clean electricity target with existing technologies, as well as alternative scenarios that explore additional factors. All these scenarios require additional analysis. The preliminary findings are intended to inform state planning and are not intended as a comprehensive nor prescriptive roadmap to 2045. As discussed in Chapter 4, future work will delve deeper into critical topics such as system reliability and land use and further address energy equity and workforce needs.

(Emphasis added.). An awful lot of hedging in that, isn’t there? They essentially admit that they haven’t yet looked much into “system reliability",” which seems to me like the most important aspect of the whole endeavor. Here’s an elaboration on that from page 97 of the Report:

While there is a resource adequacy constraint in the model (a 15 percent planning reserve margin), a full resource adequacy analysis is necessary to determine whether the portfolios produced meet other established reliability planning standards.

Suppose you were tasked with figuring out how to design an electrical grid for California that will have “resource adequacy” without any reliance on fossil fuel resources and principally using intermittent wind and solar generation backed up by batteries. I submit to you that you would quickly realize that there is one fundamental, overriding question that must be the focus of your efforts. That question is: How much grid-scale battery storage — measured in gigawatt hours (GWH) — do we need to get us through the winter, and how much will that cost?

This is the fundamental, overriding question because easily-available weather data would tell you that the sun is low all winter, and the wind also has long periods of calm in the winter. Therefore, if you build sufficient solar and wind generation facilities to produce the same number of GWHs that California consumes in a year, you will have excess in much of the spring through fall, but deficits from some time in the fall all the way through the winter until some time the following spring. To design a grid to survive a year, you need a precise quantification of this seasonality, in order to assess exactly how many GWHs of storage you will need. This is not a difficult calculation. It requires only basic arithmetic, and can be done with a calculator (although a spreadsheet program can help make a detailed calculation quickly). A guy named Roger Andrews, writing at a site called Energy Matters, made just such a calculation back in 2018. I discussed that calculation extensively and linked to it in a post back in November 2018. Andrews was a retired guy and an amateur (he has since died). I am not saying that Andrews’s calculation was perfect, but at least he addressed the relevant question.

Any way you do this calculation, it is going to show you that you need tens of thousands of GWHs of storage. At current prices, the cost is going to be in the multi-trillions, even if you could come up with batteries that could store such huge amounts of power for as much as a year without significant loss.

And here’s the thing I find incredible: the California regulators’ March Report never addresses this question.

Instead, the Report addresses a very different question, which is how much storage will be needed as measured in gigawatts (GW). GW is not a measure of how much energy is stored, but rather is a measure of how fast stored energy can be discharged from batteries to supply the grid. This is also a relevant consideration. However, it is not at all the principal cost driver.

Here is the table from the Report setting forth resources that the bureaucrats have determined are needed to be added to the grid to reach 100% zero carbon power by 2045:

Note that the additional storage resources are given with a measure of GW rather than GWH. Has anybody even troubled to calculate how many GWH of storage may be needed? You won’t find that here.

Further on at page 97 of the Report we find a chart of what passes for the bureaucrats’ analysis of what they call “resource adequacy” of the zero carbon scenarios. Here’s that one:

Once again, storage adequacy is measure only by GW, not GWH. In other words, the assumption is that there is essentially an infinite amount of energy in storage, and the only relevant system constraint is whether the energy can be withdrawn quickly enough to keep all the lights on at peak demand when no other resources are working.

Beginning at page 106, there is a section called “Emerging Technologies and Innovation.” Here is an (almost unbelievable) excerpt:

Energy storage technologies — including batteries, pumped hydro, hydrogen, and other emerging technologies — are expected to play a significant role in helping balance the grid as the state implements SB 100. Storage can help bridge the gap between variable renewable generation and grid energy demands (a role played in large part by natural gas plants today) and provide ancillary services and capacity rapidly to support system stability and reliability. Nearly all newly procured storage by the California utilities, as required by AB 2514, has been four-hour lithium-ion batteries . . . . One key area of innovation is in long-duration storage technologies. While there are 4.5 GW of pumped hydro energy storage in California, new longer-duration energy storage systems (for example, 100 or more hours of energy storage) are in the development phase and may be deployed within the next decade with the right market signals.

(Emphasis added.). Storage technologies for “100 hours or more” are “in the development phase”? Do they have no idea that to make their system work they are going to need storage for tens of thousands of GWH that lasts for as long as a full year, that is, 8760 hours?

I hope I am missing something here, but I don’t think so. If I am, can some reader kindly point it out?

But if I am not missing something, then we are left to ponder whether all these expert bureaucrats in California are either (1) completely unaware of the fundamental and overriding question that is far and away the most important cost driver of this project that they are undertaking, or (2) are very aware of the fundamental question, but intentionally not mentioning it and concealing it from the politicians and the public?

I have to go with (2). In the Soviet Union, if you ever dared mention that the 5 Year Plan could not be achieved, you could expect to lose your job and probably be sent to the Gulag. Thus, all reports always said that the 5 Year Plans could be and were being achieved. Similarly, no bureaucrat in California’s energy agencies dares mention the $5 - 10 trillion elephant in the room.