Tag Archives: Diablo Canyon

Status of Desalination Plants in California

Peter Lobner

1. Introduction

This article is an update to a similar article I wrote in mid-2015. At that time, California was experiencing a persistent drought and surface water resources and aquifers were being strained by high demand. At that time, there were only five desalination plants operating in California:  

  • Diablo Canyon NPP (seawater) desalination plant in San Luis Obispo county
  • Cambria Community Services District (brackish water) desalination plant in San Luis Obispo county
  • Sand City Coastal (brackish seawater) Desalination Plant in Monterey County 
  • WRD Robert W. Goldsworthy Desalter in Torrance
  • Southern California Edison (seawater) desalination plant on Catalina Island

At that time, several other desalination plants in California were in various stages of development, ranging from construction to reactivation to planning / permitting. This article provides a brief overview of the status of these Caliifornia plants, and more recent desalination projects in the planning stage in late-2023.

2. California desalination plants in operation in mid-2015

Diablo Canyon nuclear power plant (NPP) desalination plant

In a 9 June 2015 article, Forbes reported on the Diablo Canyon NPP, located on the Pacific coast near San Luis Obispo, CA, and noted that the plant could meet 100% of its own fresh water needs with an onsite reverse osmosis (RO) + ultrafiltration desalination plant that draws seawater from the ocean. At that time, this was the largest desalinization plant operating on the U.S. West coast. The plant has a maximum fresh water production capacity of 1,500,000 gallons/day (1,681 acre-feet/year).

Diablo Canyon NPP. Source: PGE

Desalination plant at Diablo Canyon NPP. Source: PGE

The Forbes article suggested that the Diablo Canyon NPP would be able to help nearby communities that currently were experiencing water shortages during a persistent drought. With additional modular RO units and a pipeline to connect to the public water system, up to 825,000 gallons/day (925 acre-feet/year) fresh water could be delivered for public consumption.

For more information on the Diablo Canyon NPP desalination plant:

Cambria Community Services District desalination plant 

Also in San Luis Obispo county, this desalination plant began operating in early 2015, providing 223,000 gallons/day (250 acre-feet/year), about 35% of the town’s fresh water needs. The process itself runs a brackish water (mix of freshwater, estuary water, and highly treated sewage wastewater) through three stages of osmosis, eventually injecting treated water into the San Simeon and Santa Rosa Creek aquifers to supply the community with additional potable water. This project makes Cambria one of the first communities in California to recycle sewage wastewater into an eventual drinking-water source.

For more information on the Cambria Community Services District desalination plant:

Sand City Coastal desalination plant

Sand City Coastal Desalination Plant in Monterey County was the first full-scale brackish seawater desalination facility in the state of California.  It became operational in May 2010 and can produce 268,000 gallons/day (300 acre-feet/year).

For more information on the Sand City Coastal desalination plant:

WRD Robert W. Goldsworthy Desalter in Torrance

The Goldsworthy Desalter (https://www.wrd.org/wrd-robert-w-goldsworthy-desalter) is a reverse osmosis system commissioned in 2001, and expanded in 2018, to treat 5,000,000 gallons per day of brackish water drawn from the West Coast Groundwater Basin under the City of Torrance and produce potable water for the city water system. The Desalter produces about 30% of the fresh water used by Torrance residents and businesses. The plant is owned by the Water Replenishment District (WRD) and operated by the City of Torrance. 

For more information on the Goldsworthy Desalter:

Southern California Edison (SCE) desalination plant on Catalina Island

SCE’s seawater desalination plant on Catalina Island has operated since the 1990s. It can produce 200,000 gallons/day (224 acre-feet/year). During winter months, the water produced by this desalination plant is enough to meet Avalon’s needs. During the summer, the water demand increases to 400,000-500,000 gallons a day, and up to 800,000 gallons a day on peak weekend days.

A second desalination unit, built in partnership with the city of Avalon and Los Angeles County, became operational on December 2015. The new desalination unit is connected to SCE’s original desalination plant and can produce an additional 150,000 gallons of water a day (168 acre-feet/year). 

For more information on the SCE desalination plant on Catalina Island:

3. New desalination capacity in California since 2015

Since mid-2015, two additional desalination plants have been placed in operation in California:

  • Poseidon Resources Corp. Claude “Bud” Lewis desalination plant, Carlsbad, CA
  • City of Santa Barbara’s Charles E. Meyer desalination plant

Poseidon Resources Corp. Claude “Bud” Lewis desalination plant, Carlsbad, CA

The Poseidon Resources Corp. seawater desalination plant in Carlsbad, CA, (http://carlsbaddesal.com) was completed in November 2015. It was officially dedicated and renamed in honor of former Carlsbad Mayor, Claude “Bud” Lewis, on 14 December 2015, in a public ceremony attended by more than 600 elected officials, community leaders and project partners. A 30-year Water Purchase Agreement is in place between the San Diego County Water Authority and Poseidon Water for the entire output of the plant, which has a design capacity of 50,000,000 gallons/day (56,050 acre-feet/year).  This plant is providing about 10% of San Diego county’s fresh water needs. It currently is the largest sea water desalination plant in the western hemisphere. 

Claude “Bud” Lewis desalination plant in Carlsbad, CA.  Source: screenshot from Dudek video, 2021

For more information on the Claude “Bud” Lewis desalination plant, Carlsbad, CA

City of Santa Barbara’s Charles E. Meyer desalination plant

The city-owned Charles E. Meyer desalination plant in Santa Barbara (https://www.countyofsb.org/2401/Desalination) was completed in 1992 and then mothballed after a short test period. In July 2015, the City Council voted unanimously to reactivate this plant, which has a licensed capacity is 6,691,0000 gallons/day (7,500 acre-feet/year) and can meet about 30% of the city’s fresh water needs. In May 2017, the startup testing at the plant was completed and the City started distributing desalinated water into the City’s water system. 

Charles E. Meyer Desalination Plant in Santa Barbara, 2019. Source: Florence Low / California Department of Water Resources

For more information on the Charles E. Meyer desalination plant:

4. Other desalination projects planned in California in mid-2015

In mid-2015, several other desalination projects were in the planning stage, including:

  • Doheny Ocean desalination project in south Orange County
  • California American Water (Cal-Am) desalination project in Marina, CA
  • Poseidon Resources Corp. desalination project in Huntington Beach
  • Deepwater Desal project at Moss Landing

Since then, some have advanced while others have been withdrawn.  Here’s a brief summary of their current status.

Doheny Ocean Desalination Project in south Orange County – approved, under construction

This coastal seawater desalination plant has a design capacity of 15,000,000 gallons/day (16,816 acre-feet/year). The project was unanimously approved by the California Coastal Commission in September 2022. The completion date has slipped from 2020 (original estimate in 2015) to late 2028 or early 2029. 

Artist’s rendering of the desalination plant proposed for Doheny Beach. Source: South Coast Water District

For more information on the Doheny Ocean Desalination Project

California American Water (Cal-Am) desalination project in Marina, CA – approved, pre-construction

This seawater distillation plant project was approved by the California Coastal Commission on 17 November 2022 at a capacity of 4,800,000 gallons/day (5,380 acre-feet/year). Cal-Am (https://www.amwater.com/caaw/) plans to have the plant operating by the end of 2027. 

For more information on the Cal-Am Marina desalination project:

Poseidon Resources Corp. seawater desalination project, Huntington Beach, CA – withdrawn

This project was in the final phase of permitting and originally was expected to be completed in 2018, with a capacity of 50,000,000 gallons/day. The project was withdrawn in February 2023.

For more information on the Huntington Beach desalination project:

DeepWater Desal project at Moss Landing – withdrawn

DeepWater Desal (https://www.deepwaterdesal.com) originally proposed to build a 8,922,000 gallons/day (10,000 acre-feet/year) seawater desalination plant that would draw water from the Pacific Ocean through an existing underwater pipeline that, in the 1940s,  was used to move diesel oil from offshore ships to what is now the gas-fired Dynegy Power Plant.  The pipeline has been unused for decades. On 4 June 2021, the National Oceanographic and Atmospheric Administration (NOAA) announced that it was terminating the NEPA process and closing the Project’s permit application because the permit applicant (DeepWater Desal) notified NOAA in May 2020 that the primary scope of the Project changed from desalination to land-based aquaculture.

For more information on the DeepWater Desal project:

The People’s Moss Landing Desalination Project – no significant progress

In 2013, the Moss Landing Commercial Business park, LLC proposed to build a 11,950,0000 gallons/day (13,400 acre-feet/year) saltwater desalination plant using an existing subsurface harbor water intake and pumping station built by Henry Kaiser in the 1950s. A Notice of Preparation of a Draft EIR was filed in June 2015. However, in 2023, it appears that the project is not moving forward.

For more information on the People’s Moss Landing Desal project:

Armstrong Ranch brackish water desalination plant, Marina Coast, CA – no significant progress

Seawater intrusion into the aquifer underlying the Marina Coast area is aggravated by extensive groundwater pumping for local agriculture and residents in marina and Fort Ord. The Armstrong Ranch property, which occupies both sides of Highway 1, sits atop aquifers that are impacted by seawater intrusion. A deep aquifer of clean fresh water underlying the area also is being heavily pumped.

A brackish water desalination plant was proposed for Armstrong Ranch, with a design capacity of 2,409,000 gallons/day (2,700 acre-feet/year). One proposal suggested that 150 acres of the Armstrong Ranch parcel could host enough solar panels to both power the desalination plant and sell back surplus power to the grid.

It appears that there has been no significant action in developing this desalination plant.

For more information on the Armstrong Ranch / Marina Coast desal project:

5. More recent desalination projects planned in California 

In April 2023, California Department of Water Resources announced that the following three projects has been selected under the Water Grant Desalination Program for funding:

  • Water Replenishment District (WRD) of Southern California Construction Project: In Los Angeles County, a project in the City of Torrance will construct a conveyance pipeline to connect an existing well to the existing WRD Robert W. Goldsworthy Desalter system and install a self-cleaning auto-strainer. The project will reduce the community’s reliance on imported water, provide a sustainable local potable water supply, and increase desalinated water production by 1,070,667 gallons/day (1,120-acre feet per year) or approximately enough water for 2,200 households. 
  • Westlands Water District Design Pilot Project: In Fresno County, the project will desalinate brackish groundwater from the westside upper aquifer and use salt-tolerant plants to remove salts from the brine. The project will provide cost-effective, reliable and high-quality water to the district and the communities of Coalinga, Huron and Avenal.
  • City of Fort Bragg Design Pilot Project: Near the City of Fort Bragg, the project will install an innovative, wave-powered, seawater desalination iceberg buoy to provide potable water to residents. The project will diversify the city’s water supply portfolio, create a locally controlled, sustainable, and carbon-free potable water supply, produce water without grid electricity, and strengthen water resiliency during future droughts.

The NRC will allow the Diablo Canyon 1 & 2 nuclear power plants to continue operating while considering their belated license renewal applications

Peter Lobner

This is good news for all Californians and California businesses that depend on the State’s rather fragile electrical grid as their primary source of electric power! 

On 2 March 2023, the U.S. Nuclear Regulatory Commission (NRC) granted an exemption to Pacific Gas & Electric Co. (PG&E) that would allow the Diablo Canyon 1 & 2 nuclear power plants to continue operating while the NRC considers its license renewal application. The NRC press release stated:

“The exemption granted today will allow those licenses to remain in effect provided PG&E submits a sufficient license renewal application for the reactors by Dec. 31, 2023. The NRC will continue its normal inspection and oversight of the facility throughout the review to ensure continued safe operation. If granted, the license renewal would authorize continued operation for up to 20 years.”

Diablo Canyon Nuclear Power Plant. 
Source: Pacific Gas & Electric Company

You can read the full NRC press release here: https://www.nrc.gov/cdn/doc-collection-news/2023/23-015.pdf

You can track the status of the Diablo Canyon license renewal process on the Nuclear Regulatory Commission website here: https://www.nrc.gov/reactors/operating/licensing/renewal/applications/diablo-canyon.html

You may recall that, in 2016, many environmental groups and state legislators claimed victory in getting the commitment from PG&E to close the Diablo Canyon nuclear power plant early.  Here’s just one example of that sentiment at the time:

“In a major victory for environmentalists, California is going nuclear-free, ending atomic energy’s more than half-century history in the state. On Tuesday, one of the state’s largest utilities agreed to a proposal endorsed by environmental groups and labor unions to shutter California’s last operating nuclear power plant, Diablo Canyon, by 2025.” (Source: Democracy Now, 22 June 2016).

In my 2016 post, “The Nuclear Renaissance is Over in the U.S.,” I noted: 

“On 21 June 2016, PGE issued a press release announcing that they will withdraw their application to the NRC for a 20-year license extension for the Diablo Canyon 1 & 2 nuclear power plants and will close these plants by 2025 when their current operating licenses expire.  PGE will walk away from about 41 GW-years of carbon-free electric power generation.”

Almost seven years ago, it was quite apparent to many that the early closure of Diablo Canyon would not be good for California or the environment.  It took that long for the state government to understand the situation and support the current effort to get the Diablo Canyon operating licenses extended.  Better late than never.  However, in their shortsighted view, the state government seems to be supporting a license extension only through 2030. If the legislators have their way, California will reclaim only a small portion of the carbon-free electric power generation that would be available from the 20 year operating license extensions that the NRC may grant.

I’d like see the California legislature and the associated complex web of state agencies that have a stake in this matter unanimously acknowledge that nuclear power is an important contributor toward energy de-carbonization.  In addition, I’d like to see that same group acknowledge that nuclear power plants are important for delivering reliable 24/7 generating capacity to the CALISO grid, and thereby helping maintain stability on a grid with a large fraction of variable-output, renewable generators.  If those factors are important to California’s government, then perhaps there is a future for nuclear power in the state, including the new generation of small, modular reactors (SMRs). California state support for nuclear power generation would open many exciting options for modernizing and decarbonizing electric power generation, transmission and distribution throughout the state, while ensuring that reliable electric power is available to all residents and business, many of which are seeking to decarbonize their activities by replacing their fossil fuel use with electricity that is available as needed, 24/7.

You can call that my California dream.

For more information:

Hey, PG&E! Energy Storage is Not the Same as Energy Generation!!

Peter Lobner, updated 20 February 2022

The two-unit Diablo Canyon nuclear power plant, which is owned and operated by Pacific Gas & Electric (PG&E), is the last operating nuclear power station in California. In the five year period from 2016 – 2020, the average annual load factor performance of these power plants was as follows:

  • Diablo Canyon 1:  1,138 MWe net @ 91.56% = 1.042 Gigawatt-years (GW-years) generated per year
  • Diablo Canyon 2:  1,118 MWe net @ 85.64% = 0.957 GW-years generated per year

Over that five year period, the average annual amount of electricity delivered to the California electrical grid by the two-unit Diablo Canyon nuclear power plant was about 2.0 GW-years (2,000 Megawatt-years or 17,520,000 Megawatt-hours). On a daily basis, that’s an average of about 48,000 MW-hours. This electricity was generated reliably, 24/7 (except during planned outages), with zero carbon emissions.

The Diablo Canyon nuclear plant in Avila Beach, CA. 
Source: Joe Johnston / San Luis Obispo Tribune via LA Times (2018)

In 2016, I reported (https://lynceans.org/all-posts/the-nuclear-renaissance-is-over-in-the-u-s/):

“On 21 June 2016, PG&E issued a press release announcing that they will withdraw their application to the NRC for a 20-year license extension for the Diablo Canyon 1 & 2 nuclear power plants and will close these plants by 2025 when their current operating licenses expire.  PGE will walk away from about 41 GW-years of carbon-free electric power generation.”

The shutdown plan was approved by the California Public Utilities Commission in January 2018.

In 2019, PG&E reported that their mix of generation sources (owned and purchased from a third-party) looked like this:

Source: PG&E (2019)

A few interesting points about this PG&E generation source chart:

  • Nuclear power generation is the biggest piece of the pie chart. Shutdown of Diablo Canyon by 2025 will eliminate this piece.
  • Renewables include wind, solar, small hydro, geothermal and biomass / waste.  Batteries are not included because they are energy storage devices, not energy generation sources.  The energy stored in a grid-scale battery comes from a generator, or simply, from the grid.
  • Large hydro depends on the associated reservoirs having enough water in them. The Edward Hyatt hydroelectric power plant at Lake Oroville (California’s second-largest reservoir) was shut down in August 2021 for the first time since it opened in 1967 because of low water levels during the persistent drought affecting the US West. Power production at Oroville resumed in January 2022 with only a single hydroelectric generator, after heavy winter precipitation increased lake water level. If the drought continues, the large hydro piece of the pie chart will shrink.

Another point is that the PG&E generation source mix is quite different from the California state-wide generation source mix reported by the California Energy Commission in 2020 and shown in the following pie chart.  Not all of the generation sources represented in this chart are physically located in California (more on that later).

Source: Data from California Energy Commission (2020)

Diablo Canyon has a disproportionate impact on the PG&E  generation mix because they own the nuclear power plant and they take credit for its entire net generation.  State-wide, nuclear power makes up only 9.33% of the state generation mix in a much larger electric power market.

When Diablo Canyon is shut down in 2025, I would think that the PG&E energy generation mix will look a lot more like the California state-wide generation mix, with most of the nuclear power generation share being replaced, at least in the short term, by fossil fuel-powered generators.

In January 2022, PG&E announced that they have a plan: “PG&E Corp. said it has reached agreements to install nine new battery energy storage projects as part of a push to replace a retiring nuclear power plant and help decarbonize California’s power grid.”

So, let me see if I’ve got this right.  PG&E is going to use grid-scale storage batteries that produces zero carbon emissions during their operation to partially replace a nuclear power generating station that produces zero carbon emissions during 24/7 operation. Where will the power come from to charge those batteries?  It’ll come from the California Independent System Operator (CAISO) grid, which has the California state-wide generation source mix shown above, with almost 40% coming from fossil fuel-powered generators in 2020, and likely to increase after Diablo Canyon’s retirement. So, one charge-discharge cycle of a grid-scale battery isn’t carbon-free.

PG&E further announced, “The proposed projects would have a total capacity of about 1,600 megawatts, which would bring its total battery energy storage capacity to more than 3,300 gigawatts by 2024…”

On the surface, that sounds like an impressive amount of battery capacity, but let’s put it in perspective.

The former Moss Landing fossil power station on Monterey Bay was decommissioned and transformed into a grid-scale energy storage facility. In August 2021, after completing Phase II of the transformation, the facility was operating with a capacity of 400 MW / 1,600 MW-hours, making it the world’s largest grid-storage project. The facility’s owner, Vistra Energy, said the Moss Landing facility could be expanded to a capacity of up to 1,600 MW / 6,000 MWh.

At its current discharge capacity of 400 MW, the Moss Landing batteries could discharge their full energy storage capacity of 1,600 MW-hours in about four hours.  Then the battery is “empty” and needs to be recharged from the CAISO grid (as we discussed, that’s about 40% from fossil-powered generation sources in 2020). Of course, a grid-storage facility wouldn’t be operated regularly on such a stressful cycle. But my point is that the world’s largest grid-storage project is be capable of delivering no more than 3.3% of the 48,000 MW-hours of electricity delivered daily, 24/7, with zero carbon emissions, by the Diablo Canyon nuclear power plant.

California has a huge, and growing, energy problem of its own making. With Diablo Canyon and several fossil-powered generators scheduled for retirement in the next few years, the state needs new generating capacity.  However, the development time scale for a new large generating facility in California, especially considering the state’s challenging regulatory environment, might have to be measured in decades.

One of California’s solutions to its shortfall of electrical generating capacity is to import electric power from other states and nations.  The U.S. Energy Information Administration (EIA) reported that California was the largest net electricity importer, by a wide margin, of any state in 2019. Its net electricity imports were 70.8 million MW-hours, or 25% of the state’s total electricity usage. California utilities partly own and import power from several power plants in Arizona and Utah. In addition, California’s electricity imports include hydroelectric power from the Pacific Northwest and power from fossil and wind generators in Mexico.

Source: EIA

Grid-scale battery storage is not going to solve the state’s shortfall of electrical generating capacity. Rather, the batteries are a means to mitigate short-term demand peaks and help stabilize the grid as generators attempt to match energy supply with demand.

Another mitigating measure used by CAISO is a “flex alert,” which asks consumers to cut back on electricity usage and move their electricity usage to off-peak hours, typically after 9 pm.  CAISO issued five flex alerts in 2020 and eight in 2021. When a grid-scale battery is discharged during a flex alert, recharging it would add a large load on an already strained grid; probably not a good idea.

California is throwing away valuable 24/7 generating capacity and replacing it with intermittent renewable generators, with grid-scale energy storage facilities to provide short-term mitigation that doesn’t address the real underlying problem.  There is no substitute for adequate generating capacity, sized to meet the current and future demands of businesses and individuals as we try to move together into a more electrified future.

Failing that, I can see increasing electric power rates, more flex alerts, and in California, I wouldn’t be surprised to see some form of legislated energy rationing coupled with higher energy use taxation. So much for that vision of a more electrified future.

Don’t sell you gasoline or diesel-powered car yet.  You may need it during the next flex alert.

20 February 2022 update: Moss Landing battery fires

Since becoming operational, Vistra Energy’s Moss Landing battery storage facility on Monterey Bay experienced two damaging fire events in lithium-ion battery packs. A fire on 4 September 2021 set off fire suppression system sprinklers that damaged about 7,000 batteries. Vistra Energy reported corrective actions following this fire on 21 January 2022.  Another fire on 13 February 2022 resulted in 10 melted lithium-ion battery packs. The latest fire event was contained by the facility’s fire suppression system. Vistra reported that it was looking further into the latest incident, while the Moss Landing facility remains offline during the investigation.

For more information