The oddly named Virginia Clean Economy Act or VCEA mandates the phaseout of fossil fueled power generation by 2045, with deadlines all along the way. Dominion Energy, Virginia’s primary electric utility, recently filed what is called an Integrated Resource Plan. In their recent IRP, Dominion’s Alternative Plan C is designed to comply with the VCEA.

This design is not sufficient to maintain reliability. The inevitable result will be price spikes and blackouts.

The basic problem with the Plan C design is that there is not nearly enough storage to adequately backup the intermittency of the planned solar and wind generating capacity.

Under VCEA the Virginia grid is mandated to transition to all solar and wind power. This entails that power from these intermittent sources be reliably available around the clock, day after day. During much of this time the solar and wind generators will be producing very little power, so a great deal of storage is required. In today’s world this means batteries, lots of them.

The Dominion IRP actually points to this problem. Dominion argues that they cannot backup their solar and wind generators using imported power, because other utilities will be facing the same backup need. Here is a telling quote. In particular note the reference to solar generation and extended cloudy winter periods.

There is a good bit of jargon but that can be ignored for our purposes. THE SCC is Virginia’s State Corporation Commission, which oversees Dominion’s electric power monopoly. PJM is the Mid Atlantic power coordinator. The DOM Zone is basically Dominion’s territory.

Dominion says this:

The SCC directed the Company to consider market purchases during the winter from the PJM wholesale market or from merchant generators located in the DOM Zone.The Company is concerned that over-reliance on the market for purchases could present issues if other states within PJM build significant amounts of solar generation and those zones expect the market to provide energy at the same time the Company is expecting that energy (e.g., extended cloudy winter periods). If that were to become reality, either energy shortages or extreme price spikes would occur. Concerning purchases from merchant generators located within the DOM Zone, those generators would likely be needed to meet the non-DOM LSE load within the DOM Zone, which is also winter peaking.” (Emphasis added)

The point is that without enough storage, extended cloudy winter periods can cause energy shortages (including protracted blackouts) and extreme price spikes. As we shall show, Dominion’s Plan C does not provide nearly enough storage to prevent such catastrophic results.

Here we use the results of my simple, but somewhat technical, generic reliability assessment. I explain that generic reliability analysis in my recent article “Unreliability makes solar power impossibly expensive”. See https://www.cfact.org/2022/01/19/unreliability-makes-solar-power-impossibly-expensive/.

The focus of Dominion’s VCEA IRP is the period 2021-2036. During that time they build about 14,000 MW of new solar generating capacity. They also retire around 3,000 MW of CO2 emitting generation, including power plants that burn coal, oil and biomass.

The solar build sounds like a lot, more than enough to cover the retirements, but it is not. According to our generic analysis, it take at least 6,000 MW of solar capacity to reliably produce just 1,000 MW of electricity.

The reason you need so much is pretty simple.

First it takes 1,000 MW of capacity to generate 1,000 MW during the 8 hour production period on a sunny day.

Second it takes 2,000 MW or more of capacity to generate, during that same period, the electricity needed to charge the batteries that will then produce 1,000 MW all night long.

Third, we need to recharge a lot of other batteries that get us through four dark cloudy days. This takes another 3,000 MW, assuming we have four sunny days to do it in. In reality we may need a lot more than this. See the generic explanation for some discussion on this issue.

Working with our 6,000 MW number it turns out that the 14,000 MW of solar generating capacity only provides about 2,300 MW of continuous power. This does not cover the 3,000 MW of retired capacity. However, that is not the big problem, because Plan C also calls for building 1,600 MW of nuclear generating capacity. Given the projected growth of the need for Dominion power this combination of solar and nuclear generation just about covers that need.

Two tangential points need to be made here. First, the projected growth does not include the massive switch to electric cars and trucks that is also supposed to happen during thus period. Second, Plan C also includes over 5,000 MW of wind capacity but this is irrelevant to our case, because the wind need not blow hard during the four cloudy days we are building for. Power systems must handle relatively extreme events. That is what reliability means.

Now we come to the really big problem, the one that makes Plan C a total failure in reliability. Our generic analysis says that, in order for the 6,000 MW solar capacity to reliably produce 1,000 MW of electricity, it needs at least 120,000 MWh of batteries. (It may need 200,000 but we ignore that for now.)

Given the need for 120,000 MWh of batteries for each 1,000 MW, Plan C’s 2,300 MW requires an enormous 276,000 MWh of batteries.

Plan C appears to only provide a minuscule 16,000 MWh or so. In fact the IRP never says what the storage capacity of the added batteries is. It just gives their discharge rate, at about 4,000 MW. But the standard grid scale battery provides 4 MWh for every MW, which gives us the 16,000 MWh.

So we are short an enormous 260,000 MWh, as far as reliability goes. In the generic analysis we use the EIA standard battery cost estimate of $250 per MWh. Multiplying this by 260,000 gives an added cost of $65 billion.

The huge added cost of these batteries, to make solar work through 2036, is more than Dominion’s estimate for the entire cost of Plan C, which is around $50 billion. The solar batteries more than double the cost of Plan C.

But it get worse, much worse in fact. Between 2037 and 2045, Plan C retires all the rest of Dominion’s CO2 producing generation. The IRP does not give the amount but it is a lot more than the roughly 3,000 MW retired by 2036, perhaps three times more. This could add another $200 billion or so to the cost of Plan C, for a total add on of something like $265 billion.

Plus, as alluded to above, there are several reasons why this huge cost could in fact be much greater. These factors include things like electrification of transportation and gas heat, the need for a reserve capacity, the fact that batteries cannot be used to 100% of their capacity, etc.

It is obvious from this analysis that Plan C is completely unreliable. The amount of battery storage is almost nothing when compared to that needed for reliability under VCEA. This unreliability could begin to show up as soon as winter 2024-25, when the first big capacity retirements take effect.

Dominion needs to go back to the drawing board and present a Plan that maintains reliability in the face of VCEA’s drastic requirements. Only then will we know what VCEA really costs. That cost will be astronomical.