Tag Archives: renewables

What rooftop solar owners understand isn’t mythological

Severin Borenstein wrote another blog attacking rooftop solar (a pet peeve of his at least a decade because these weren’t being installed in “optimal” locations in the state) entitled “Myths that Solar Owners Tell Themselves.” Unfortunately he set up a number of “strawman” arguments that really have little to do with the actual issues being debated right now at the CPUC. Here’s responses to each his “myths”:

Myth #1 – Customers are paid only 4 cents per kWh for exports: He’s right in part, but then he ignores the fact that almost all of the power sent out from rooftop panels are used by their neighbors and never gets to the main part of the grid. The utility is redirecting the power down the block.

Myth #2 – The utility sells the power purchased at retail back to other customers at retail so the net so it’s a wash: Borenstein’s claim ignores the fact that when the NEM program began the utilities were buying power that cost more than the retail rate at the time. During NEM 1.0 the IOUs were paying in excess of 10c/kwh for renewable power (RPS) power purchase agreements (PPAs). Add the 4c/kWh for transmission and that’s more than the average rate of 13c/kWh that prevailed during that time. NEM 2.0 added a correction for TOU pricing (that PG&E muffled by including only the marginal generation cost difference by TOU rather than scaling) and that adjusted the price some. But those NEM customers signed up not knowing what the future retail price would be. That’s the downside of failing to provide a fixed price contract tariff option for solar customers back then. So now the IOUs are bearing the consequences of yet another bad management decision because they were in denial about what was coming.

Myth #3 – Rooftop solar is about disrupting the industry: Here Borenstein appears to be unaware of the Market Street Railway case that states that utilities are not protected from technological change. Protecting companies from the consequences of market forces is corporate socialism. If we’re going to protect shareholders from risk (and its even 100% protection), then the grid should be publicly owned instead. Sam Insull set up the regulatory scam a century ago arguing that income assurance was needed for grid investment, and when the whole scheme collapsed in the Depression, the Public Utility Holding Company Act of 1935 (PUHCA)was passed. Shareholders need to pick their poison—either be exposed to risk or transfer their assets public ownership, but wealthy shareholders should not be protected.

Myth #3A – Utilities made bad investments and should bear the risks: Borenstein is arguing since the utilities have run the con for the last decade and gotten approval from the CPUC, they should be protected. Yet I submitted testimony repeatedly starting in 2010 both PG&E’s and SCE’s GRCs that warned that they had overforecasted load growth. I was correct—statewide retail sales are about the same today as they were in 2006. Grid investment would have been much different if those companies had listened and corrected their forecasts. Further the IOUs know how to manipulate their regulatory filings to ensure that they still get their internally targeted income. Decoupling that ensures that the utility receives its guaranteed income regardless of sales further shields them. From 1994 to 2017, PG&E hit its average allowed rate of return within 0.1%. (More on this later.) A UCB economics graduate student found that the return on equity is up to 4% too high (consistent with analysis I’ve done).

Myth #3B – Time to take away the utility’s monopoly: No, we no longer need to have monopoly electric service. The same was said about telecommunications three decades ago. Now we have multiple entities vying for our dollars. The CPUC conducted a study in 1999 that was included in PG&E’s GRC proposed decision (thanks to the late Richard Bilas) that showed that economies of scale disappeared after several hundred thousand customers (and that threshold is likely lower now.) And microgrids are becoming cost effective, especially as PG&E’s rates look like they will surpass 30 cents per kWh by 2026.

Myth #4 – There aren’t barriers to the poor putting panels on their roofs: First, the barriers are largely regulatory, not financial. The CPUC has erected them to prevent aggregation of low-income customers to be able to buy into larger projects that serve these communities.

Second, there are many market mechanisms today where those with lower income are offered products or services at a higher long term price in return for low or no upfront costs. Are we also going to heavily tax car purchases because car leasing is effectively more expensive? What about house ownership vs. rentals? There are issues to address with equity, but to zero in on one small example while ignoring the much wider prevalence sets  up another strawman argument.

Further, there are better ways to address the inequity in rooftop solar distribution. That inequity isn’t occurring duo to affordability but rather because of split incentives between landlords and tenants.

A much easier and more direct fix would be to modify Public Utilities Code Sections 218 to allow local sales among customers or by landlords or homeowner associations to tenants and 739.5 to allow more flexibility in pricing those sales. But allowing those changes will require that the utilities give up iron-fisted control of electricity production.

Myth #5 – Rooftop solar is the only thing that makes it cost-effective to electrify: Borenstein focuses on the what source of high rates. Rooftop solar might be raising rates, but it probably delivered as much in offsetting savings. At most those customers increased rates by 10%, but utility rates are 70-100% above the direct marginal costs of service. The sources of that difference are manifest. PG&E has filed in its 2023 GRC a projected increase in the average standard residential rate to 38 cents per kWh by 2026, and perhaps over 40 cents once undergrounding to mitigate wildfire is included. The NREL studies on microgrids show that individual home microgrids cost about 34 cents per kWh now and battery storage prices are still dropping. Exiting the grid starts to look a lot more attractive.

Maybe if we look only at the status quo as unchanging and accept all of the utilities’ claims about their “necessary” management decisions and the return required to attract investors, then these arguments might hold water. But none of these factors are true based on the empirical work presented in many forums including at the CPUC over the last decade. These beliefs are not so mythological.

Finally, Borenstein finishes with “(a)nd we all need to be open to changing our minds as a result of changing technology and new data.” Yet he has been particularly unyielding on this issue for years, and has not reexamined his own work on electricity markets from two decades ago. The meeting of open minds requires a two-way street.

A reply: two different ways California can keep the lights on amid climate change

Mike O’Boyle from Energy Innovation wrote an article in the San Francisco Chronicle listing four ways other than building more natural gas plants to maintain reliability in the state. He summarizes a set of solutions for when the electricity grid can get 85% of its supply from renewable sources, presumably in the next decade. He lists four options specifically:

  • Off shore wind
  • Geothermal
  • Demand response and management
  • Out of state imports

The first three make sense, although the amount of geothermal resources is fairly limited relative to the state’s needs. The problem is the fourth one.

California already imports about a fifth of its electric energy. If we want other states to also electrify their homes and cars, we need to allow them to use their own in-state resources. Further, the cost of importing power through transmission lines is much higher than conventional analyses have assumed. California is going to have to meet as much of its demands internally as possible.

Instead, we should be pursuing two other options:

  • Dispersed microgrids with provisions for conveying output among several or many customers who can share the system without utility interaction. Distributed solar has already reduced the state’s demand by 12% to 20% since 2006. This will require that the state modify its laws regulating transactions among customers and act to protect the investments of those customers against utility interests.
  • Replacing natural gas in existing power plants with renewable biogas. A UC Riverside study shows a potential of 68 billion cubic feet which is about 15% of current gas demand for electricity production. Instead of using this for home cooking, it can meet the limited peak day demands of the electricity grid.

Both of these solutions can be implemented much more quickly than an expanded transmission grid and building new resources in other states. They just take political will.

What “Electrify Everything” has wrong about “reduce, reuse, recycle”

Saul Griffith has written a book that highlights the role of electrification in achieving greenhouse gas emission reductions, and I agree with his basic premise. But he misses important aspects about two points. First, the need to reduce, reuse and recycle goes well beyond just energy consumption. And second, we have the ability to meet most if not all of our energy needs with the lowest impact renewable sources.

Reduce, reuse and recycle is not just about energy–it’s also about reducing consumption of natural resources such as minerals and biomass, as well as petroleum and methane used for plastics, and pollution caused by that consumption. In many situations, energy savings are only a byproduct. Even so, almost always the cheapest way to meet an energy need is to first reduce its use. That’s what energy efficiency is about. So we don’t want to just tell consumers to continue along their merry way, just switch it up with electricity. A quarter to a third our global GHG emissions are from resource consumption, not energy use.

In meeting our energy needs, we can largely rely on solar and wind supplemented with biofuels. Griffith asserts that the U.S. would need 2% of its land mass to supply the needed electricity, but his accounting makes three important errors. First, placing renewables doesn’t eliminate other uses of that land, particularly for wind. Acreage devoted to wind in particular can be used also for different types of farming and even open space. In comparison, fossil-fuel and nuclear plants completely displace any other land use. Turbine technology is evolving to limit avian mortality (and even then its tall buildings and household cats that cause most bird deaths). Second most of the solar supply can be met on rooftops and covering parking lots. These locations are cost effective compared to grid scale sources once we account for transmission costs. And third, our energy storage is literally driving down the road–in our new electric vehicles. A 100% EV fleet in California will have enough storage to meet 30 times the current peak load. A car owner will be able to devote less than 5% of their battery capacity to meet their home energy needs. All of this means that the real footprint can be much less than 1%.

Nuclear power has never lived up to its promise and is expensive compared to other low-emission options. While the direct costs of current-technology nuclear power is more than 12 cents a kilowatt-hour when adding transmission, grid-scale renewables are less than half of that, and distributed energy resources are at least comparable with almost no land-use footprint and able to provide better reliability and resilience. In addition, the potential of catastrophic events at nuclear plants adds another 1 to 3 cents per kilowatt-hour. Small modular reactors (SMR) have been promoted as a game changer, but we have been waiting for two decades. Nuclear or green hydrogen may emerge as economically-viable options, but we shouldn’t base our plans on that.

Guidelines For Better Net Metering; Protecting All Electricity Customers And The Climate

Authors Ahmad Faruqui, Richard McCann and Fereidoon Sioshansi[1] respond to Professor Severin Borenstein’s much-debated proposal to reform California’s net energy metering, which was first published as a blog and later in a Los Angeles Times op-ed.

PG&E takes a bold step on enabling EV back up power, but questions remain

PG&E made exciting announcements about partnerships with GM and Ford last week to test using electric vehicles (EVs) for backup power for residential customers. (Ford also announced an initiative to create an open source charging standard.) PG&E also announced an initiative to install circuit breakers that facilitate use of onsite backup power. PG&E is commended for stepping forward to align its corporate strategy with the impending technology wave that could increase consumer energy independence.

I wrote about the promise of EVs in this role (“Electric vehicles as the next smartphone”) when I was struck by Ford’s F-150 Lightning ads last summer and how the consumer segment that buys pickups isn’t what we usually think of as the “EV crowd.” These initiatives could be game changers.

That said, several questions arise about PG&E’s game plan and whether the utility is still planning to hold customers captive:

  • How does PG&E plan to recover the costs for what are “beyond the meter” devices that typically is outside of what’s allowed? And how are the risks in these investments to be shared between shareholders and ratepayers? Will PG&E get an “authorized” rate of return with default assurances of costs being approved for recovery from ratepayers? How will PG&E be given appropriate incentives on making timely investments with appropriate risk, especially given the utility’s poor track record in acquiring renewable resources?
  • What will be the relationships between PG&E and the participating auto manufacturers? Will the manufacturers be required to partner with PG&E going forward? Will the manufacturers be foreclosed from offering products and services that would allow customers to exit PG&E’s system through self generation? Will PG&E close out other manufacturers from participating or set up other access barriers that prevent them from offering alternatives?
  • Delivering PG&E’s “personal microgrid backup power transfer meter device” is a good first step, but it requires disconnecting the solar panels to use, which means that it only support fossil fueled generators and grid-connected batteries. This device needs a switch for the solar panels as well. Further, it appears the device will only be available to customers who participate in PG&E’s Residential Generator and Battery Rebate Program. Can PG&E continue to offer this feature to vendors who offer only fossil-fueled generators? How will PG&E mitigate the local air pollution impacts from using fossil-fueled back up generators (BUGs) for extended periods? (California already has 8,000 megawatts of BUGs.)
  • How will these measures be integrated with the planned system reinforcements in PG&E’s 2022 Wildfire Mitigation Plan Update to reduce the costs of undergrounding lines? Will PG&E allow these back up sources and devices for customers who are interested in extended energy independence, particularly those who want to ride out a PSPS event?
  • How will community choice aggregators (CCAs) or other local governments participate? Will communities be able to independently push these options to achieve their climate action and adaptation plan (CAAP) goals?

A cheaper wildfire mitigation solution: using microgrids instead of undergrounding

PG&E released its 2022 Wildfire Mitigation Plan Update (2022 WMPU) That plan calls for $6 billion of capital investment to move 3,600 miles of underground by 2026. This is just over a third of the initial proposed target of 10,000 miles. Based on PG&E’s proposed ramping up, the utility would reach its target by 2030.

One alternative that could better control costs would be to install community and individual microgrids. Microgrids are likely more cost effective and faster means of reducing wildfire risk and saving lives. I wrote about how to evaluate this choice for relative cost effectiveness based on density of load and customers per mile of line.

Microgrids can mitigate wildfire risk by the utility turning off overhead wire service for extended periods, perhaps weeks at a time, during the highest fire risk periods. The advantage of a periodically-islanded microgrid is 1) that the highest fire risk coincides with the most solar generation so providing enough energy is not a problem and 2) the microgrids also can be used during winter storms to better support the local grid and to ride out shorter outages. Customers’ reliability may degrade because they would not have the grid support, but such systems generally have been quite reliable. In fact, reliability may increase because distribution grid outages are about 15 times more likely than system or regional outages.

The important question is whether microgrids can be built much more quickly than undergrounding lines and in particular whether PG&E has the capacity to manage such a buildout at a faster rate? PG&E has the Community Microgrid Enablement Program. The utility was recently authorized to build several isolated microgrids as an alternative to rebuilding fire-damaged distribution lines to isolated communities. Turning to local governments to manage many different construction projects likely would improve this schedule, like how Caltrans delegates road construction to counties and cities.

Controlling the costs of wildfire mitigation

Based on the current cost of capital this initial undergrounding phase will add $1.6 billion to annual revenue requirements or an additional 8% above today’s level. This would be on top of PG&E request in its 2023 General Rate Case for a 48% increase in distribution rates by 2023 and 78% increase by 2026, and a 31% increase in overall bundled rates by 2023 and 43% by 2026. The 2022 WMPU would take the increase to over 50% by 2026 (and that doesn’t’ include the higher maintenance costs). That means that residential rates would increase from 28.7 cents per kilowatt-hour today (already 21% higher than December 2020) to 36.4 cents in 2026. Building out the full 10,000 miles could lead to another 15% increase on top of all of this.

Turning to the comparison of undergrounding costs to microgrids, these two charts illustrate how to evaluate the opportunities for microgrids to lower these costs. PG&E states the initial cost per mile for undergrounding is $3.75 million, dropping to $2.5 million, or an average of $2.9 million. The first figure looks at community scale microgrids, using National Renewable Energy Laboratory (NREL) estimates. It shows how the cost effectiveness of installing microgrids changes with density of peak loads on a circuit on the vertical axis, cost per kilowatt for a microgrid on the horizontal axis, and each line showing the division where undergrounding is less expensive (above) or microgrids are less expensive (below) based on the cost of undergrounding. As a benchmark, the dotted line shows the average load density in the PG&E system, combined rural and urban. So in average conditions, community microgrids are cheaper regardless of the costs of microgrids or undergrounding.

The second figure looks at individual residential scale microgrids, again using NREL estimates. It shows how the cost effectiveness of installing microgrids changes with customer density on a circuit on the vertical axis, cost per kilowatt for a microgrid on the horizontal axis, and each line showing the division where undergrounding is less expensive (above) or microgrids are less expensive (below). As a benchmark, the dotted line shows the average customer density in the PG&E system, combined rural and urban. Again, residential microgrids are less expensive in most situations, especially as density falls below 75 customers per mile.

A movement towards energy self-sufficiency is growing in California due to a confluence of factors. PG&E’s WMPU should reflect these new choices in manner that can reduce rates for all customers.

(Here’s my testimony on this topic filed by the California Farm Bureau in PG&E’s 2023 General Rate Case on its Wildfire Management Plan Update.)

Has rooftop solar cost California ratepayers more than the alternatives?

The Energy Institute’s blog has an important premise–that solar rooftop customers have imposed costs on other ratepayers with few benefits. This premise runs counter to the empirical evidence.

First, these customers have deferred an enormous amount of utility-scale generation. In 2005 the CEC forecasted the 2020 CAISO peak load would 58,662 MW. The highest peak after 2006 has been 50,116 MW (in 2017–3,000 MW higher than in August 2020). That’s a savings of 8,546 MW. (Note that residential installations are two-thirds of the distributed solar installations.) The correlation of added distributed solar capacity with that peak reduction is 0.938. Even in 2020, the incremental solar DER was 72% of the peak reduction trend. We can calculate the avoided peak capacity investment from 2006 to today using the CEC’s 2011 Cost of Generation model inputs. Combustion turbines cost $1,366/kW (based on a survey of the 20 installed plants–I managed that survey) and the annual fixed charge rate was 15.3% for a cost of $209/kW-year. The total annual savings is $1.8 billion. The total revenue requirements for the three IOUs plus implied generation costs for DA and CCA LSEs in 2021 was $37 billion. So the annual savings that have accrued to ALL customers is 4.9%. Given that NEM customers are about 4% of the customer base, if those customers paid nothing, everyone else’s bill would only go up by 4% or less than what rooftop solar has saved so far.

In addition, the California Independent System Operator (CAISO) calculated in 2018 that at least $2.6 billion in transmission projects had been deferred through installed distributed solar. Using the amount installed in 2017 of 6,785 MW, the avoided costs are $383/kW or $59/kW-year. This translates to an additional $400 million per year or about 1.1% of utility revenues.

The total savings to customers is over $2.2 billion or about 6% of revenue requirements.

Second, rooftop solar isn’t the most expensive power source. My rooftop system installed in 2017 costs 12.6 cents/kWh (financed separately from our mortgage). In comparison, PG&E’s RPS portfolio cost over 12 cents/kWh in 2019 according to the CPUC’s 2020 Padilla Report, plus there’s an increments transmission cost approaching 4 cents/kWh, so we’re looking at a total delivered cost of 16 cents/kwh for existing renewables. (Note that the system costs to integrate solar are largely the same whether they are utility scale or distributed).

Comparing to the average IOU RPS portfolio cost to that of rooftop solar is appropriate from the perspective of a customer. Utility customers see average, not marginal, costs and average cost pricing is widely prevalent in our economy. To achieve 100% renewable power a reasonable customer will look at average utility costs for the same type of power. We use the same principle by posting on energy efficient appliances the expect bill savings based on utility rates–-not on the marginal resource acquisition costs for the utilities.

And customers who would choose to respond to the marginal cost of new utility power instead will never really see those economic savings because the supposed savings created by that decision will be diffused across all customers. In other words, other customers will extract all of the positive rents created by that choice. We could allow for bypass pricing (which industrial customers get if they threaten to leave the service area) but currently we force other customers to bear the costs of this type of pricing, not shareholders as would occur in other industries. Individual customers are currently the decision making point of view for most energy use purposes and they base those on average cost pricing, so why should we have a single carve out for a special case that is quite similar to energy efficiency?

I wrote more about whether a fixed connection cost is appropriate for NEM customers and the complexity of calculating that charge earlier this week.

Understanding core facts before moving forward with NEM reform

There is a general understanding among the most informed participants and observers that California’ net energy metering (NEM) tariff as originally conceived was not intended to be a permanent fixture. The objective of the NEM rate was to get a nascent renewable energy industry off the ground and now California has more than 11,000 megawatts of distributed solar generation. Now that the distributed energy resources industry is in much less of a need for subsidies, but its full value also must be recognized. To this end it is important to understand some key facts that are sometimes overlooked in the debate.

The true underlying reason for high rates–rising utility revenue requirements

In California, retail electricity rates are so high for two reasons, the first being stranded generation costs and the second being a bunch of “public goods charges” that constitute close to half of the distribution cost. PG&E’s rates have risen 57% since 2009. Many, if not most, NEM customers have installed solar panels as one way to avoid these rising rates. The thing is when NEM 1.0 and 2.0 were adopted, the cost of the renewable power purchase agreements (PPA) portfolios were well over $100/MWH—even $120MWH through 2019, and adding in the other T&D costs, this approached the average system rate as late as 2019 for SCE and PG&E before their downward trends reversed course. That the retail rate skyrocketed while renewable PPAs fell dramatically is a subsequent development that too many people have forgotten.

California uses Ramsey pricing principles to allocate these (the CPUC applies “equal percent marginal costs” or EPMC as a derivative measure), but Ramsey pricing was conceived for one-way pricing. I don’t know what Harold Hotelling would think of using his late student’s work for two way transactions. This is probably the fundamental problem in NEM rates—the stranded and public goods costs are incurred by one party on one side of the ledger (the utility) but the other party (the NEM customer) doesn’t have these same cost categories on the other side of the ledger; they might have their own set of costs but they don’t fall into the same categories. So the issue is how to set two way rates given the odd relationships of these costs and between utilities and ratepayers.

This situation argues for setting aside the stranded costs and public goods to be paid for in some manner other than electric rates. The answer can’t be in a form of a shift of consumption charges to a large access charge (e.g., customer charge) because customers will just leave entirely when half of their current bill is rolled into the new access charge.

The largest nonbypassable charge (NBC), now delineated for all customers, is the power cost indifference adjustment (PCIA). The PCIA is the stranded generation asset charge for the portfolio composed of utility-scale generation. Most of this is power purchase agreements (PPAs) signed within the last decade. For PG&E in 2021 according to its 2020 General Rate Case workpapers, this exceeded 4 cents per kilowatt-hour.

Basic facts about the grid

  • The grid is not a static entity in which there are no changes going forward. Yet the cost of service analysis used in the CPUC’s recent NEM proposed decision assumes that posture. Acknowledging that the system will change going forward depending on our configuration decisions is an important key principle that is continually overlooked in these discussions.
  • In California, a customer is about 15 times more likely to experience an outage due to distribution system problems than from generation/transmission issues. That means that a customer who decides to rely on self-provided resources can have a set up that is 15 times less reliable than the system grid and still have better reliability than conventional service. This is even more true for customers who reside in rural areas.
  • Upstream of the individual service connection (which costs about $10 per month for residential customers based on testimony I have submitted in all three utilities’ rate cases), customers share distribution grid capacity with other customers. They are not given shares of the grid to buy and sell with other customers—we leave that task to the utilities who act as dealers in that market place, owning the capacity and selling it to customers. If we are going to have fixed charges for customers which essentially allocated a capacity share to each of them, those customers also should be entitled to buy and sell capacity as they need it. The end result will be a marketplace which will price distribution capacity on either a daily $ per kilowatt or cents per kilowatt-hour basis. That system will look just like our current distribution pricing system but with a bunch of unnecessary complexity.
  • This situation is even more true for transmission. There most certainly is not a fixed share of the transmission grid to be allocated to each customer. Those shares are highly fungible.

What is the objective of utility regulation: just and reasonable rates or revenue assurance?

At the core of this issue is the question of whether utility shareholders are entitled to largely guaranteed revenues to recover their investments. In a market with some level of competitiveness, the producers face a degree of risk under normal functional conditions (more mundane than wildfire risk)—that is not the case with electric utilities, at least in California. (We cataloged the amount of disallowances for California IOUs in the 2020 cost of capital applications and it was less than one one-hundredth of a percent (0.01%) of revenues over the last decade.) When customers reduce or change their consumption patterns in a manner that reduces sales in a normal market, other customers are not required to pick up the slack—shareholders are. This risk is one of the core benefits of a competitive market, no matter what the degree of imperfection. Neither the utilities or the generators who sell to them under contract face these risks.

Why should we bother with “efficient” pricing if we are pushing the entire burden of achieving that efficiency on customers who have little ability to alter utilities’ investment decisions? Bottom line: if economists argue for “efficient” pricing, they need to also include in that how utility shareholders will participate directly in the outcomes of that efficient pricing without simply shifting revenue requirements to other customers.

As to the intent of the utilities, in my 30 year on the ground experience, the management does not make decisions that are based on “doing good” that go against their profit objective. There are examples of each utility choosing to gain profits that they were not entitled to. We entered into testimony in PG&E’s 1999 GRC a speech by a PG&E CEO talking about how PG&E would exploit the transition period during restructuring to maintain market share. That came back to haunt the state as it set up the conditions for ensuing market manipulation.

Each of these issues have been largely ignored in the debate over what to do about solar rooftop policy and investment going forward. It is time to push these to fore.

What to do about Diablo Canyon?

The debate over whether to close Diablo Canyon has resurfaced. The California Public Utilities Commission, which support from the Legislature, decided in 2018 to close Diablo by 2025 rather than proceed to relicensing. PG&E applied in 2016 to retire the plant rather than relicense due to the high costs that would make the energy uneconomic. (I advised the Joint CCAs in this proceeding.)

Now a new study from MIT and Stanford finds potential savings and emission reductions from continuing operation. (MIT in particular has been an advocate for greater use of nuclear power.) Others have written opinion articles on either side of the issue. I wrote the article below in the Davis Enterprise addressing this issue. (It was limited to 900 words so I couldn’t cover everything.)

IT’S OK TO CLOSE DIABLO CANYON NUCLEAR PLANT
A previous column (by John Mott-Smith) asked whether shutting down the Diablo Canyon nuclear plant is risky business if we don’t know what will replace the electricity it produces. John’s friend Richard McCann offered to answer his question. This is a guest column, written by Richard, a universally respected expert on energy, water and environmental economics.

John Mott-Smith asked several questions about the future of nuclear power and the upcoming closure of PG&E’s Diablo Canyon Power Plant in 2025. His main question is how are we going to produce enough reliable power for our economy’s shift to electricity for cars and heating. The answers are apparent, but they have been hidden for a variety of reasons.
I’ve worked on electricity and transportation issues for more than three decades. I began my career evaluating whether to close Sacramento Municipal Utility District’s Rancho Seco Nuclear Generating Station and recently assessed the cost to relicense and continue operations of Diablo after 2025.
Looking first at Diablo Canyon, the question turns almost entirely on economics and cost. When the San Onofre Nuclear Generating Station closed suddenly in 2012, greenhouse gas emissions rose statewide the next year, but then continued a steady downward trend. We will again have time to replace Diablo with renewables.
Some groups focus on the risk of radiation contamination, but that was not a consideration for Diablo’s closure. Instead, it was the cost of compliance with water quality regulations. The power plant currently uses ocean water for cooling. State regulations required changing to a less impactful method that would have cost several billion dollars to install and would have increased operating costs. PG&E’s application to retire the plant showed the costs going forward would be at least 10 to 12 cents per kilowatt-hour.
In contrast, solar and wind power can be purchased for 2 to 10 cents per kilowatt-hour depending on configuration and power transmission. Even if new power transmission costs 4 cents per kilowatt-hour and energy storage adds another 3 cents, solar and wind units cost about 3 cents, which totals at the low end of the cost for Diablo Canyon.
What’s even more exciting is the potential for “distributed” energy resources, where generation and power management occurs locally, even right on the customers’ premises rather than centrally at a power plant. Rooftop solar panels are just one example—we may be able to store renewable power practically for free in our cars and trucks.
Automobiles are parked 95% of the time, which means that an electric vehicle (EV) could store solar power at home or work during the day and for use at night. When we get to a vehicle fleet that is 100% EVs, we will have more than 30 times the power capacity that we need today. This means that any individual car likely will only have to use 10% of its battery capacity to power a house, leaving plenty for driving the next day.
With these opportunities, rooftop and community power projects cost 6 to 10 cents per kilowatt-hour compared with Diablo’s future costs of 10 to 12 cents.
Distributed resources add an important local protection as well. These resources can improve reliability and resilience in the face of increasing hazards created by climate change. Disruptions in the distribution wires are the cause of more than 95% of customer outages. With local generation, storage, and demand management, many of those outages can be avoided, and electricity generated in our own neighborhoods can power our houses during extreme events. The ad that ran during the Olympics for Ford’s F-150 Lightning pick-up illustrates this potential.
Opposition to this new paradigm comes mainly from those with strong economic interests in maintaining the status quo reliance on large centrally located generation. Those interests are the existing utilities, owners, and builders of those large plants plus the utility labor unions. Unfortunately, their policy choices to-date have led to extremely high rates and necessitate even higher rates in the future. PG&E is proposing to increase its rates by another third by 2024 and plans more down the line. PG&E’s past mistakes, including Diablo Canyon, are shown in the “PCIA” exit fee that [CCA] customers pay—it is currently 20% of the rate. Yolo County created VCEA to think and manage differently than PG&E.
There may be room for nuclear generation in the future, but the industry has a poor record. While the cost per kilowatt-hour has gone down for almost all technologies, even fossil-fueled combustion turbines, that is not true for nuclear energy. Several large engineering firms have gone bankrupt due to cost overruns. The global average cost has risen to over 10 cents per kilowatt-hour. Small modular reactors (SMR) may solve this problem, but we have been promised these are just around the corner for two decades now. No SMR is in operation yet.
Another problem is management of radioactive waste disposal and storage over the course of decades, or even millennia. Further, reactors fail on a periodic basis and the cleanup costs are enormous. The Fukuyama accident cost Japan $300 to $750 billion. No other energy technology presents such a degree of catastrophic failure. This liability needs to be addressed head on and not ignored or dismissed if the technology is to be pursued.

Transmission: the hidden cost of generation

The cost of transmission for new generation has become a more salient issue. The CAISO found that distributed generation (DG) had displaced $2.6 billion in transmission investment by 2018. The value of displacing transmission requirements can be determined from the utilities’ filings with FERC and the accounting for new power plant capacity. Using similar methodologies for calculating this cost in California and Kentucky, the incremental cost in both independent system operators (ISO) is $37 per megawatt-hour or 3.7 cents per kilowatt-hour in both areas. This added cost about doubles the cost of utility-scale renewables compared to distributed generation.

When solar rooftop displaces utility generation, particularly during peak load periods, it also displaces the associated transmission that interconnects the plant and transmits that power to the local grid. And because power plants compete with each other for space on the transmission grid, the reduction in bulk power generation opens up that grid to send power from other plants to other customers.

The incremental cost of new transmission is determined by the installation of new generation capacity as transmission delivers power to substations before it is then distributed to customers. This incremental cost represents the long-term value of displaced transmission. This amount should be used to calculate the net benefits for net energy metered (NEM) customers who avoid the need for additional transmission investment by providing local resources rather than remote bulk generation when setting rates for rooftop solar in the NEM tariff.

  • In California, transmission investment additions were collected from the FERC Form 1 filings for 2017 to 2020 for PG&E, SCE and SDG&E. The Wholesale Base Total Revenue Requirements submitted to FERC were collected for the three utilities for the same period. The average fixed charge rate for the Wholesale Base Total Revenue Requirements was 12.1% over that year. That fixed charge rate is applied to the average of the transmission additions to determine the average incremental revenue requirements for new transmission for the period. The plant capacity installed in California for 2017 to 2020 is calculated from the California Energy Commission’s “Annual Generation – Plant Unit”. (This metric is conservative because (1) it includes the entire state while CAISO serves only 80% of the state’s load and the three utilities serve a subset of that, and (2) the list of “new” plants includes a number of repowered natural gas plants at sites with already existing transmission. A more refined analysis would find an even higher incremental transmission cost.)

Based on this analysis, the appropriate marginal transmission cost is $171.17 per kilowatt-year. Applying the average CAISO load factor of 52%, the marginal cost equals $37.54 per megawatt-hour.

  • In Kentucky, Kentucky Power is owned by American Electric Power (AEP) which operates in the PJM ISO. PJM has a market in financial transmission rights (FTR) that values relieving the congestion on the grid in the short term. AEP files network service rates each year with PJM and FERC. The rate more than doubled over 2018 to 2021 at average annual increase of 26%.

Based on the addition of 22,907 megawatts of generation capacity in PJM over that period, the incremental cost of transmission was $196 per kilowatt-year or nearly four times the current AEP transmission rate. This equates to about $37 per megawatt-hour (or 3.7 cents per kilowatt-hour).