A Free-Market Energy Blog

California Grid Frailty: Imported Power/Solar at Issue

By -- May 5, 2021

Ed note: Power shortages in California in 2020 and Texas in 2021 have exposed the limits to renewable energy for a reliable grid. The post below complements prior analysis here and here.

“The apparent difference between SDG&E [no blackouts] and PG&E [blackouts] can be attributed to the greater proportion of decentralized green power cooperatives in PG&E’s service area that relied on a greater percentage of green power.”

The anti-energy environmental lobby concluded that natural gas-fired power plants failed during California’s blackouts last summer and should be phased out. But empirical investigation reaches an opposite conclusion, questioning the future of dilute, intermittent energies.

Earthjustice, the Sierra Club and the California Environmental Justice Alliance in the article “Gas Is Failing in California: Time to Move On” (Utility Dive: April 16, 2021) accuse the Wall Street Journal and gas “industry voices” of fear-mongering about renewable’s role in the state’s blackouts during the region’s southwest summer heat wave of 2020.

They rely on a report by the California Independent System Operator (Cal-ISO) to conclude that climate change and delayed implementation of a fully renewable energy grid resulted in the blackouts. (Note: Cal-ISO is not independent but totally controlled by one-party political appointees.)

Instead of looking inward, the above enviro-lobbyists blamed “a perfect storm of software errors that caused California to export power during the blackouts, gas plant failures, and unprecedented heat that left demand vastly outstripping supply in California.”

Los Angeles or Arizona Blackouts Avoided (think gas, coal by wire)

Data from the U.S. Energy Information Agency (EIA) does not support the lobbyist’s claims for Los Angeles, which escaped rolling blackouts due to the availability of imported natural gas and coal power.

The Los Angeles Department of Water and Power (LADWP) reports that normally it relies on:

  • Natural gas – 34% (three gas power plants in Los Angeles)
  • Green power – 33% (wind farm-Tehachapi, CA; solar power, Kern County)
  • Coal power – 19% (from Utah and Arizona)
  • Nuclear power – 9% (from Arizona)
  • Hydropower – 5% (Hoover Dam, Castaic Lake)

Additionally, Jill Hanks of APS stated (“Insight into how Arizona Power Company Avoids Blackouts as California Remains on Flex Alert,”) that the key to their avoiding blackouts in Arizona was a diverse energy mix, including 50 percent natural gas power, 18 percent coal power and a mere 10 percent solar power in their power portfolio. 

What is revealing in the data shown below is that APS relies on 50 percent natural gas power, compared to 29 percent for SDG&E, and 0–17 percent for PG&E (where the blackouts occurred). 

Blackouts Were Mainly PG&E

As indicated in the data table below, the 2020 California power shortfall had a geographic location: mainly in PG&E territory in Northern and Central California. There were 99 power outages in PG&E’s customer service area on August 18 at 7:15 pm, equating to one outage for every 51,515 customers. But San Diego Gas and Electric (SDG&E) had only 3 outages.  No data was available from Southern California Edison, which had multiple outages but does not provide data or location of the number of outages online.

Snapshot – Power Outages August 18 – 7:15 pm

 SDG&E San Diego CountyPG&E North & Central CaliforniaArizona Public Service Urban AZMarin Clean Energy Marin County, CA
EntityPublic Utility
Public Utility (CPUC)Public Utility
(Az. PUC)
Energy buying co-operative
No. Customers1.4 million meters5.1 million electric customers1.2 million customers470,000 customers
No. Power Outages on Aug.18- 7:15pm3992Not disclosed
Outage to Customer Ratio1 outage per 466,6671 outage per 51,5151 outage per 600,000Not stated
No. Community Choice Power Co-Operatives02101
Percent Green Power43%39%10% hydro + solar61% solar 13% hydro 74% total
Percent Nuclear Power0%34%22%0%
Coal Power0%0%18%0%
Natural Gas29%0 to 17%50%0%
Other – imports or RECS28%6%0%26%

Solarization Power Shortages in Nearby States

What happened in the 2020 California blackouts is that the ISO Energy Balancing Market could not find enough alternative sources of imported power to serve PG&E during the heat wave because other nearby states had also shifted to using intermittent solar power and needed their reserves for their own customers. 

SDG&E, however, relied on 43 percent green power but avoided widespread blackouts while PG&E with 39 percent green power did not. Marin Green Power, located in PG&E’s service area and dependent on its transmission/distribution line system, for example, depended on 74 percent of its power from solar and hydropower, both of which were in short supply during the heat wave.

The apparent difference between SDG&E and PG&E can be attributed to the greater proportion of decentralized green power cooperatives (confusingly called Community Choice Aggregators or CCA’s) in PG&E’s service area that relied on a greater percentage of green power. 

Preceding the blackouts, CCA’s had refused to comply with the ISO orders to buy more reliable gas power.  Stephen Berberich, then President of the Independent System Operator (Cal-ISO) was critical of CCA’s not complying with orders from the California Public Utilities Commission (CPUC) to buy more adequate reliable power:

The CPUC’s order for utilities and other “load-serving entities”, such as community-choice aggregators, to procure 3,300 megawatts of resource adequacy has so far been met with contracts to build battery systems to store solar power for injection into the grid in the evening.

However, later Berberich contradicted himself, saying green power was not the culprit behind the heat wave power shortage.  Berberich could not say otherwise because he created the ISO’s Western Energy Imbalancing Market that mis-assumed that backup imported power would always be available during heat waves. So, California’s explanations for the blackouts suffer from a case of selective perception.

The ISO asserted it was not grid congestion or downed power lines from wildfires, but a true lack of available power plants to come online when other plants failed, causing the shortage.  I obtained PG&E’s power logs from days when blackouts occurred, and it was mainly a loss of 1,000 megawatts of wind power and the unplanned shut down of natural gas power plants that precipitated the in-state problem. 

Contributing to the blackouts was California’s 25-percent dependence on imported power from other states especially during sunset (Duck Curve), mainly hydropower to reduce smog in air basins. But the entire southwest was hot, leaving little surplus power available anywhere.

The crux of the power shortage resulting in blackouts in the summer of 2020 was a withholding of imported backup power from the market due to expansion of solar power in nearby states. Contrary to the eco-lobbyists, it is green power, not natural gas power plants, that will be environmentally and economically obsolete in the near future.


Wayne Lusvardi, recently relocated from California to central Texas, worked for for the largest urban water district in California. His previous post, “California’s Energy Vampire: Solar at Night,” also deals with California blackouts in 2020.


  1. John W. Garrett  


    Thank you !


  2. Gregory Rehmke  

    The renewables planners have rocks in their head!

    That is, they may be thinking of deploying the new Danish technology: “A Danish consortium is seeking to store electricity from large scale renewable energy plants in the form of thermal energy in big tanks containing crushed, pea-sized stones made of basalt.”



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