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Photovoltaic & Storage for Fall 2021, Part 3, States, Megafactory

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John Benson's picture
Senior Consultant, Microgrid Labs

PROFESSIONAL EXPERIENCE: Microgrid Labs, Inc. Advisor: 2014 to Present Developed product plans, conceptual and preliminary designs for projects, performed industry surveys and developed...

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  • Sep 28, 2021

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This is Part 3 of a Three-Part Series photovoltaic (PV) and battery energy storage system (BESS) projects in the U.S. The first two parts are described below and linked in the post’s Introduction.

Part 1: This is First-Part of a Three-Part Series of posts. It started out as a single post, but quickly grew to twice my preferred length for a post. Then I discovered an amazing (and huge) report on the future of Solar Energy.

This report is based on a conclusion that I have held for several years: Solar Energy’s amazing development and rapidly exploding deployments can only lead me to believe that it will accept a lion’s share of renewable energy’s displacement of greenhouse gas (GHG) emitting electric energy sources.

This post is a summary of DOE’s “Solar Futures Study,” the report described above.

Part 2: This is the second post in the three part series. My last post on this subject was in mid-June, and it was a real chore.

Section 2 will be for the U.S. utility scale BESS and storage market in general. Each of the following sections is for the major projects and other information for a single state and these sections are in alphabetical order by state, up through Florida.

Section 2, below is some late-breaking news on Tesla’s first Megafactory, each of the following sections is for the major projects and other information for a single state and these sections are in alphabetical order by state, from Indiana through Wisconsin.

Bob Meinetz's picture
Bob Meinetz on Sep 28, 2021

"Utilities building solar and wind farms are increasingly pairing these with large batteries to store excess energy to discharge to the grid later."

John, that many developers are building battery storage in proximity to solar or wind farms does not mean they share an electrical connection, or that exclusively clean energy will be stored.

To my knowledge none are configured that way, and there would be no financial reason to do so. They're storing electricity from a grid mix, and increasing its emissions by anywhere from 104 - 407 kg/MWh in the process.

They are effectively arbitraging energy - buying it whenever it's cheapest, and selling it when it's most expensive. It may result in a reduction in emissions sometimes, but it will always waste energy, and could very well result in a net increase in emissions.

"Pairing" wind and solar farms with storage is a non-solution, a visual artifice designed to capitalize on the naïveté of renewables advocates - fruit that's always ripe for the picking.

John Benson's picture
John Benson on Sep 29, 2021

Hi Bob:

You are right, at least for now.

Go through the link below to an older post, starting at section 2.4.1, is a thorough description of all of the methods used to integrate (or not) storage with PV.

Looking at the diagrams, most developers of PV with storage projects, or those choosing to add storage to existing PV Projects. seem to favor "...independent PV plus storage system" or "...AC coupled..." designs. This is so they can use the BESS for multiple applications. There is a high degree of uncertainty in the California market, and more-so in other markets, so I expect this is a risk mitigation strategy. 

However, for now, and the immediate future, I expect most developers with a combined PV + Storage project will still end up bidding most of its capacity as a combined-firm generation unit, especially for the highest priced peak demand period.

On the other hand, the most efficient configuration will be one of the DC-coupled designs, but these also have limited functionality. Still, some developers might have off-takers (under a long-term PPA) that that are only interested in an integrated resource so they will choose this.

See section 2 of part 2 of this series (Photovoltaic & Storage for Fall 2021) for more information on current trends.


Bob Meinetz's picture
Bob Meinetz on Sep 30, 2021

Thanks John, this issue has urgency with respect to Diablo Canyon.

The California Public Utilities Commission recently issued a proposed Integrated Resource Plan that claims grid-scale storage will be used to replace clean electricity lost by shutdown of the plant. Unless the electricity is 100% clean, however, it's not only a lie, it's illegal (SB 1090 requires only carbon-free electricity can be used to replace generation lost from Diablo Canyon's closure).

Environmental Progress, Californians for Green Nuclear Power, Mothers for Nuclear, and other groups are planning litigation to reverse approval for the shutdown if the commission continues to operate under the assumption battery storage, in California, is 100% carbon-free. It isn't, and never will be.

If the dispute ends up in court, the original renewables lie - that intermittency is merely an inconvenience, that it can be mitigated with batteries, that there is a possible future workaround, that it doesn't make 100% carbon-free energy impossible - will be called out, and the implications couldn't be bigger for climate.

Charles Botsford, PE's picture
Charles Botsford, PE on Oct 4, 2021

Hi Bob,

John is right regarding DC-coupled energy storage with PV. It's a fully integrated system that is more efficient and cost-competitive. The downside is that this configuration is also less flexible relative to market trading (e.i., using the ESS for other purposes). The other issue is that DC-coupling requires a bit more sophisticated power electronics and controls on the high voltage DC bus prior to the system inverter.

Bob Meinetz's picture
Bob Meinetz on Oct 5, 2021

"DC-coupled energy storage with PV. It's a fully integrated system that is more efficient..."

I understand that, Charles. But there's little incentive for "paired" solar + storage developers to pay more for sophisticated power electronics and controls, so that gathering electricity from the sun might be more efficient for a few hours on sunny days.
And there's a huge incentive to claim everything coming out of their batteries is clean - to lie. Why? Selling "renewable energy certificates" is big business, and having engineeers verify every "paired" solar + storage facility in the state is storing exclusively renewable energy is a practical impossibility.
Putting absolute faith in free-market capitalism when the environment is on the line is a loser. Always has been.

John Benson's picture
John Benson on Oct 5, 2021

Hi Bob:

Just saw this response. 

As I've said before, I would support keeping Diablo open, but from everything I've seen I just don't think it will happen. 

CPUC / CAISO does a yearly forecast in conjunction with their Resource Adequacy Process. This normally looks 3-5 years into the future (I believe). This is a hugely complex process, made even more complex by the changes resulting from renewable implementation and the community choice aggregators assuming responsibility for this function. It should be interesting to see whether there are concerns when the Diablo shutdown starts entering fully into this planning window. 

There is also a major source of surprises: the weather changes being thrown at us by climate change.


Bob Meinetz's picture
Bob Meinetz on Oct 6, 2021

John, there are several obstacles standing in the way of a premature Diablo Canyon shutdown:

  1.  CPUC's Preferred Procurement proposal claims California can rely on imports, deliberately hidden under the obscure label of "unspecified sources of energy", to provide system reliability. But any generation that isn't submitted to the California Energy Commission for meeting RPS mandates will be cheap fossil power - especially, when PacifiCorp is in the process of building a transmission line capable of exporting 5 GW of coal-fired power from Wyoming to California.
  2. Several groups, determined to force San Luis Obispo County to include impacts of climate change in its mandatory Environmental Impact Review, have committed to litigation if necessary. Litigation of EIRs can take years - time that PG&E and decommissioning firm Holtec don't have.
  3. Clean Air Task Force, in association with Stanford, MIT, and other universities, is preparing a report showing why decommissioning Diablo Canyon will will be impossible without increasing carbon emissions (under the terms of SB 1090, replacing Diablo Canyon with any sources that emit carbon is illegal). The report was expected in September, but CATF is busy sewing up loose ends and will be in Sacramento by year-end to make its case.
Joe Deely's picture
Joe Deely on Sep 29, 2021

Good stuff John.


I mostly track the Western States... Right now, I see signed contracts for about 10,000 MW/35,000 MWh of storage out West over next few years.  I'm guessing that number will increase to at least 50,000 MWh by end of 2025.


Eventually, most of the existing solar plants will have battery storage added on site. Standard size will be same as max interconnection at the location and for now duration standard is 4 hours.  So, for existing 100 MW solar plant - a 100 MW/400 MWh battery will be added.


Here is a recent example of proposed battery project being added to existing 250 MW solar installation - Silver State South - in Nevada. 


Note: there is about 20,000 MW of Utility scale solar capacity in Western states currently.

Michael Keller's picture
Michael Keller on Oct 4, 2021

Tough to get accurate information on the impact on energy costs for these installations. Not too surprised, as the that is not much of a consideration for democratic politicians.

Is relatively easy to figure out, as basic parameters are net installed cost ($kW) and capacity factor of battery/solar energy facility. That net energy cost is clearly higher than a solar facility by itself. A simple cycle gas turbine with battery facility very likely has a much lower energy cost. Combined-cycle and battery, probably lower, but that depends on the capacity factor for the combined-cycle unit.

I think Bob is right, however. Basically a means for investors to rake in cash with basically zero risk because the government subsidizes the scheme.

John Benson's picture
John Benson on Oct 4, 2021

Hi Michael:

In response to your last agreement with Bob, I also basically agree, assuming you are a "me too" developer. Pioneers are the guys with arrows in their back.

Of course there are plenty of ways to screw up a big project even for the "me too" crowd. I've been through several major projects where the latter has happened, and my company (generally when I worked for Siemens) had to bail out, because the risk became unacceptable.


Michael Keller's picture
Michael Keller on Oct 6, 2021

Not really a “me too” developer. More of a pragmatic engineer with financial expertise, but am pioneering advanced energy approaches that we have patented.

Have observed that to successfully deploy major projects, you need the technical skills and financial assets of large companies. Such firms tend to shy away from pioneering projects because the financial risks are too high in the context of corporate profitability goals. Coming in to salvage a project is, however, a low-risk proposition because the Owners are more or less desperate.

John Benson's picture
John Benson on Oct 7, 2021

My "you" was intended to be general sense, not to you specifically.

In addition to Siemens, I've worked Landis & Gyr (pre-Siemens acquisition) and GE (Nuclear). Even though all of those have deep-pockets, they also were very reluctant to take significant risk, for the reasons you state.

I've had a few instances of clients with failed projects (before my company took them on), and they were indeed, very reasonable to work with.


John Benson's picture
Thank John for the Post!
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