Wildfire costs related to transmission, distributed solar could provide 30% of electricity need, more

The current benefits of avoided transmission do not include the costs of triggering wildfires. To do so we need to figure out total costs of wildfires, the probability that wildfires occur annually (100%. sigh.), the frequency/ probability with which transmission triggers/ causes said wildfire, and then spreading that cost over transmission that goes through dry-vegetation. Then we’d want to figure out how much of that transmission can be deferred by distributed energy resources.

To reduce the footprint of the grid, which is what is necessary to reduce interaction with vegetation and wildfires, distributed resources need to have two attributes. Save/ produce energy at the right time (evenings per CPUC research), and save/ produce energy at the right place. This is one of the things I hope a new NEM will include. Higher payments for customers to save energy in the evenings and better targeted incentives to install solar and storage at places that allow us to actually defer transmission upgrades. The current one-size fits all NEM at retail rate does neither. (it does include a time of use rate but the differential between on and off peak is minimal and crude)

Sidenote // What have I done to address this issue so far: I spent a fair amount of time thinking through and working on climate adaptation of the energy sector – especially the electric grid – a couple of years ago. An outcome of that were recommendations (through partnership with the Public Advocates and coordination with Berkeley Law Center and CEJA) for utilities to conduct vulnerability assessments of their infrastructure to understand the climate risk of their infrastructure and services. This includes a detailed community assessment. SCE is soliciting public feedback on their community engagement plan (attached) via this survey. I haven’t read through this yet. Here’s a blog on topic last year in case you are interested.

California’s Generation Mix Applied to Calculate Rooftop Solar Benefits

In our calculations to determine what resources rooftop solar replaces and therefore the value of rooftop generation, we applied best estimates (developed by the CPUC) of the mix of resources that are on the margin. This is a mix of gas and solar depending on the location and the time of day. The SMUD report I referenced does the same as well.

  • The CPUC develops values for how and when distributed resources – rooftop solar, storage, efficiency, etc. – actually defer transmission and distribution upgrades and buildouts. This is included in the hourly and locational benefits of distributed resources – called the avoided costs by the CPUC. This isn’t perfect, but a good starting point.
  • To reduce the footprint of the grid, which is what is necessary to reduce interaction with vegetation and wildfires, distributed resources need to have two attributes. Save/ produce energy at the right time (evenings per CPUC research), and save/ produce energy at the right place.
  • This is one of the things I hope a new NEM will include. Higher payments for customers to save energy in the evenings and better targeted incentives to install solar and storage at places that allow us to actually defer transmission upgrades. The current one-size fits all NEM at retail rate does neither. (it does include a time of use rate but the differential between on and off peak is minimal and crude)
  • With the current NEM policy, poor people are paying affluent people’s electricity bills. This reform is about increasing solar access for low-income households, ensuring that solar benefits are equitably distributed, and keeping electric rates affordable for all. Additionally subsidies should help getting rooftop solar at the right places to defer infrastructure build. For each person that NEM helps, it hurts many others. It’s a tough balancing act.

On the MI study:

  • I need to take it in – as is the case with any rigorous scientific study. On initial read, I see that this study estimates US wide numbers on average and (my best guess without a deeper dive) is that a significant benefit of solar in this study is from the positive impacts in deferring coal and gas power production. The grid in CA looks very different than the national grid. No coal and less fossil gas plants running in the middle of the day when solar produces electricity.
  • SMUD did a study and tried to incorporate regional environmental benefits and they came up with a different answer. To be transparent, regulators and researchers that I know thought that this study was fairly conducted and executed. The solar industry did not like this study. Polarizing in an expected way. https://www.smud.org/-/media/Rate-Information/NEM/VOSstudy.ashx

Mohit Chhabra

Senior Scientist

Climate and Clean Energy Program





From: Bill Burke <buseburke@sbcglobal.net>
Sent: Monday, April 19, 2021 9:40 AM
To: Sean Armstrong <seanarmstrongpm@gmail.com>
Cc: Betony Jones <betony@inclusiveecon.com>; Edward Mazria <mazria@architecture2030.org>; Marie Venner <marie@vennerconsulting.com>; Katie Davis <kdavis2468@gmail.com>; Chhabra, Mohit <mchhabra@nrdc.org>; Alice Sung <asung1@gmail.com>; Delforge, Pierre <pdelforge@nrdc.org>; Kelly Knutsen <kknutsen@brightpower.com>; CA Building Decarbonization <ca-building-decarbonization@googlegroups.com>
Subject: Re: [CA-BD] Analysis of (savings or) how microgrids, rooftop solar and storage could help reduce those risks and costs


Many people have been hired over the years by PG&E to do work required by the CPUC to meet regulatory requirements. There are a lot of people on this group who once worked for PG&E or who worked for firms hired to do work by PG&E.

Here are just two examples of some of the that work.

https://h-m-g.com/downloads/Daylighting/schoolc.pdf (I believe Nehemiah worked at HMG at this time.)


I worked at PG&E’S Pacific Energy Center for many years and retired a year ago. In 1999 I invited  Ed Mazria to give a talk at the Energy Center and paid him a modest fee. So Ed has done work for PG&E. Pierre Delforge and Scott Shell spoke at the Energy Center as well, along with many others. I helped get PG&E to financially support the ‘Getting to Zero’ conference held in Oakland by the New Buildings Institute a few years ago. Does that mean NBI is working to undermine decarbonization? If the fact that an individual or a company an individual worked for has ever had PG&E as a client means they should be considered to be actively undermining efforts to decarbonize California and ultimately the world, a lot of people on this list need to be expelled from it. Didn’t we go down this path a few months ago in regard to TRC? 

The CPUC sets regulatory requirements that results in good people being hired by PG&E and the other regulated utilities all the time. A lot of the work those people have done has advanced decarbonization efforts. I’m all for hearing about ways to change the regulatory system to have that work not run through the utilities. But as long as it does, I think it’s a good thing to have many of the people on this group involved.

Your strong, deeply felt and argued efforts to change bad policy and stop corporate interference in advancing California climate goals could not be more appreciated. You are a warrior in that regard. Keep doing that! Your personal path likely wouldn’t permit you to ever do work for a regulated utility. I respect you greatly for that. Your email making the case for why you disagree with Betony is great. However, accusing Betony of advocating for a utility position regarding Net Energy Metering without any evidence other than the fact that the company she works for lists PG&E as a client isn’t helpful. 

Bill Burke

On Apr 19, 2021, at 2:06 AM, Sean Armstrong <seanarmstrongpm@gmail.com> wrote:

And not to put too fine a point on it, but one of your company’s clients is PG&E. Are you working for them right now?  

Image removed by sender.

Sean Armstrong

(he/him for business, but occasionally she/her)

Managing Principal

Redwood Energy

(707) 826-1450


Schedule a meeting with me at: calendly.com/seanarmstrong

Grand Prize Winner of the United Nations World Habitat Awards-2017

Grand Prize Winner of the International PCBC Gold Nugget Awards-2016

Winner of the Sustainability Award of the Building Industry Association of Southern California-2017

Winner of the Department of Energy Innovation Award-2015 and 2020

Awards of Merit from the International PCBC Gold Nugget Awards-2016, 2017, 2018 and 2019

On Mon, Apr 19, 2021 at 1:54 AM Sean Armstrong <seanarmstrongpm@gmail.com> wrote:

Hi Betony,

I’d like to respond to your thoughts:

1. “NEM slows the adoption of distributed storage by providing “free” storage via the grid.” I don’t think a sensible person considers the grid a battery. Batteries provide electricity when the grid is down…so it’s not a battery. Actual batteries need rooftop solar–a 13kWh Tesla Powerwall battery can only last a half a day without rooftop solar.  Most people would sensibly first get solar and then get a battery–solar is the gateway to batteries, not an obstacle or a replacement. Conversely, installing just a battery is crazy expensive, a luxury for the rich–there’s currently no payback, ever, for a battery that’s grid-tied. 

2. “Rate impact of NEM (and other things) will slow electrification by making it more expensive.” As you put it, “other things” are what make the grid expensive. This is evidenced by municipal utilities like SMUD and LADWP, which do a great job for half the price of the for-profit IOUS. Take away NEM, and there’s no path to ever lowering electricity costs in California unless we break up the IOUs and give their assets to the municipal utilities and the CCEs. If that’s what you’re suggesting, I’m right behind you. 🙂 But if you’re only talking about giving the IOUs their wish list of wrecking NEM while keeping their guaranteed 11% profit margin and looking the other way while they kill us with a for-profit strategy of delayed and deliberately falsified maintenance, then I think most Californians would agree that’s a bad deal. 

3. “Expensive electricity is going to make it harder to achieve all of our climate goals (not to mention the equity issues), and everything that is putting upward pressure on rates needs to be re-evaluated.” Yep. Everything needs to be re-evaluated. Yet oddly that didn’t happen when PG&E went bankrupt in 2019–in fact, rates went up. Maybe it will happen when they go bankrupt this year? 

In short, NEM is the only tool Californians have to lower their bills, and it helpfully decreases climate change pollution. We’ve committed more than a billion dollars to install rooftop solar on low-income households in the next 10 years via the SOMAH program, and you’re proposing to cut the benefit to these low-income households in half? Merry Christmas to you too!


.  If the history of places with high residential PV penetration like Australia, Hawaii, California and Arizona has taught us anything, it’s that the incremental value of conventional rooftop solar to the grid declines as more of it is provided.  That stands to reason.  If all of California’s solar were south facing, then at some point, it would furnish more power than the ISO needs at noon on a sunny day, yielding very little marginal value until massive, cheap storage is available.  It’s not, and won’t be for awhile.

So it shouldn’t be controversial to move steadily toward a system that pays homeowners the real time value of the power they’re providing to the grid.  That would increase the desirability of

 opportunistic self consumption with storage (like HPWH’s), east and west facing PV, and stationary energy storage or V2G-capable electric vehicles.  Utilities need be neither heroes or villains in this narrative; they’re simply transacting along with everyone else.

 I’d be less inclined to enshrine indefinitely the lucrative payments made to early, mostly wealthy solar adopters than to true up every 5 years or so to what that generation is actually worth now, under current grid conditions.  That was the lesson from early feed in tariffs in Germany and Spain as well.  Lucrative payments to early adopters helped get the ball rolling, but can’t be continued indefinitely without bankrupting the system.  

NRDC reasonably seeks to enhance equity for low income consumers in the process, and make it easier for them to reap the benefits of future solar installations too.  That’s a good thing.

But pricing should also be a two way street, and electricity prices should get correspondingly very cheap at times of the day when the grid is overloaded with renewable electricity generated at minimal marginal cost.  Those two price signals together would do much to incentivize storage and more diverse renewable portfolios whose peaks in output correlate as closely as possible to peaks in consumer demand.

I also think it’s easy to get overly focused on residential rooftop PV, when utility scale PV is delivering a similar service to society with a higher capacity factor at $1.20/Watt vs $3.80/Watt on average for residential systems.  See LBNL’s 2020 distributed solar report for the specifics.  A dollar spent at utility scale can do about three times as much good as putting it into a residential rooftop system, where partial shading, high customer acquisition costs, minimal economies of scale, and permitting hassles add unavoidably to the expense of making electricity.  Building more utility scale solar plus storage would bring down costs for everyone, improving environmental outcomes and equity in the process.

Chris Calwell

Ecos Research

Sent from my iPhone

On Apr 20, 2021, at 7:50 PM, Sean Armstrong <seanarmstrongpm@gmail.com> wrote:

Very useful citation, both for showing the need for utility scale wind and the benefits of rooftop solar, particularly as we use 50% or more of available roofs. The landscape benefits from less utility PV and more rooftop. With V2B car batteries becoming available, we have enough rooftop space on most houses to power them completely for 2/3rds ofthe year!

Dan Johnson : From this work by E3, it looks like microgrids powered by distributed solar PV can only provide 25-30% of CA’s electricity by 2050. So the bulk of the electricity system would continue to rely on utility lines that create wildfire risk:

Distributed energy resources (DER) can play an important role in reducing the land use impacts of renewable energy development, but large quantities of utility-scale solar and wind are still needed to meet clean energy targets. High rooftop solar scenarios (an additional 9 GW com-pared to baseline 2050 forecast, or a 35% increase) provide multiple benefits: locational value (reduce loads and thus allow deferral of distribution system upgrades), avoided line losses, and land conservation benefits. Results show that about 11–14% of California’s 2050 electricity demand can be met with behind-the-meter (BTM) residential solar PV. Compared to the Base case, the high rooftop solar sensitivity scenarios reduced utility-scale capacity build-out by 3–6%, or 200–445km2. California will still require 95 GW (Full West Base Siting Level) to 132 GW (In-State Siting Level 4) of utility-scale generation capacity, or between 3,800 km2 and 10,700 km2 of land area. 

However, there may be opportunities to increase the DER contribution. The scenarios in this study are limited in assuming development of 25% of technical rooftop PV potential (both residential and commercial) in California, which includes rooftop PV on 90% of homes built after 2020. If 50%of technical potential for BTM PV in California can be realized by 2050 (effectively doubling the high BTM PV assumptions in this study), this would likely reduce electricity demand by another 12-14% percentage points, leaving about 70-75% of total demand that will still need to be met by utility-scale generation. However, these DER adoption assumptions do not include exogenous assumptions about non-rooftop BTM commercial PV (e.g., community solar) or other forms of innovative land-sparing distributed PV systems such as floatovoltaics.

From this E3 study “Power of Place” included in a Docket comment on the 2022 Energy Code CEQA hearing: https://www.scienceforconservation.org/products/power-of-place