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Precautionary Principle

Ed Reid's picture
Vice President, Marketing (Retired) / Executive Director (Retired) / President (Retired) Columbia Gas Distribution Companies / American Gas Cooling Center / Fire to Ice, Inc.

Industry Participation: Natural Gas Industry Research, Development and Demonstration Initiative Chair, Cooling Committee (1996-1999)   American Gas Association Marketing Section...

  • Member since 2003
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  • Jun 1, 2022

The Precautionary Principle is frequently cited as the justification for actions to halt or retard climate change. This commentary will question the application of the principle to the design of a renewable plus storage electric grid.

The application of the principle to the current US electric grid has centered on the maintenance of a 20% (+/-) capacity reserve margin relative to peak demand. This reserve capacity plus scheduling of generator maintenance during off-peak periods have been very successful in avoiding grid failure. Utility customers with critical loads frequently install standby generators to compensate for distribution or transmission outages caused by adverse weather and accidents.

In recent years, the introduction of intermittent renewable generation and the retirement of conventional generation has tended to reduce capacity reserve margins, as electricity generated by the intermittent renewable generators has displaced electricity generated by conventional sources when the intermittent renewable generators operate. This issue has surfaced in California, which no longer maintains sufficient conventional generation capacity to completely replace the output of intermittent generators when they are unable to generate because of time-of-day or weather conditions. This has resulted in the application of demand-side management programs and in the use of rolling blackouts to avoid grid failure. California also routinely relies on imports of electricity from neighboring states to meet demand.

The critical differences in a renewable plus storage grid with no conventional, dispatchable generation are the very limited availability or complete unavailability of generation sources which are not weather dependent and the unavailability of fossil-fueled standby generators for use in the event of distribution or transmission outages, or worse a grid failure. The unavailability of fossil-fueled standby generators is a particular issue for users with critical loads, such as hospitals.

In a renewable plus storage grid, the dispatchable element is storage. Therefore the Precautionary Principle would appear to require that there be sufficient charged storage capacity with sufficient deliverability to replace the output of the renewable generators over whatever time period the renewable generation is unable to perform or perform at capacity; and, that there be sufficient additional renewable generating capacity to rapidly recharge storage depleted during a renewable generation hiatus in anticipation of the next renewable generation hiatus.

The Precautionary Principle would also appear to require that conventional generating capacity be maintained until sufficient storage capacity and deliverability are installed and operational to replace the conventional generation and sufficient additional renewable generating capacity is available to recharge storage. Renewable generating capacity alone is insufficient to replace dispatchable generation capacity, though it can displace the output of the conventional generation, as is the case today.

While a renewable plus storage grid would require additional capacity to recharge storage, it might not require the type of capacity reserve margin typically used in grids with conventional generation. The individual renewable generators would be much more numerous and of much lower capacity than conventional generators and therefore failure of an individual generator would have far less impact on grid generating capacity.

It would seem that the Precautionary Principle would require that the initial renewable plus storage grid buildout consist of significantly more generating and storage capacity relative to peak demand than the conventional grid it replaces. Experience gained during the early operation of the renewable plus storage grid would help determine the appropriate level of generating and storage capacity and deliverability to be added and maintained as the conversion to an all-electric energy economy proceeds.

Rick Engebretson's picture
Rick Engebretson on Jun 2, 2022

All the generalities being discussed regarding "energy" technology rarely, if ever, discuss simple, specific, useful solutions.

For example, when was the last time you saw a discussion of agricultural opportunity amid vastly excessive global atmospheric CO2, and amid serious concerns for global food supply?? On farm, crude biofuels must be managed by including quality distributed electrical power generation for export.

I'm not sure the various "energy" conceptual ruts are helpful solving the technical, economic, environments we face.

Ed Reid's picture
Ed Reid on Jun 3, 2022

I am not sure that "simple, specific, useful solutions" exist, nor that they will in the foreseeable future. I do believe that suggested "solutions" should be rigorously tested to assess their validity.

I do not understand your assertion of "vastly excessive global atmospheric CO2" when the globe continues to "green", largely as the result of increased atmospheric CO2, and agricultural production globally continues to increase, in part because of increased atmospheric CO2.

"Everything should be made as simple as possible, but not simpler.", Albert Einstein

Rick Engebretson's picture
Rick Engebretson on Jun 4, 2022

In the "simplest, most specific, less useful" case, certainly applicable technology already exists in great abundance. The corn ethanol derived as a waste product of complex nutrient bio-molecules produced from sugar is highly proven. And the nominal order of magnitude electrical power produced to run a typical car equals the power consumed by a family home. An entire chain of stored chemical energy, electric power production, and modern electrical power usage is already everywhere apparent.

We really need to focus on preventing these ridiculous forest fires. Don't try so hard to see so little.

Ed Reid's picture
Ed Reid on Jun 4, 2022

Corn grown for ethanol production (40% of US crop) competes with corn and other crops grown for food. Ethanol production from waste products is not yet commercially feasible.

There are twice as many cars and light trucks in the US as there are family dwelling units. Electric vehicle charging would therefore require roughly triple the electricity currently consumed by family dwelling units.

The electric power production infrastructure is being displaced, but not replaced, by intermittent renewable generation. However, the storage required for a stable and reliable grid is not currently available.

The government / electric industry push for "all-electric everything" would require 3-4 times expansion of electric generation, transmission and distribution infrastructure.

Too many US forest fires are the result of careless human activity and arson. Some are the result of poor utility right-of-way management. The rest are largely caused by lightning. The intensity of these fires is increased by poor forestry management.

Rick Engebretson's picture
Rick Engebretson on Jun 4, 2022

I'm not jumping into any of your "conceptual ruts." Corn "yogurt" derived ethanol certainly does not displace food production. But it certainly challenges "sustainability" in many ways.

And I'm not talking about "electric cars." I'm saying that driving a normal car using headlights, climate control, and entertainment (besides running the car) is already both a power generation source and electronics model that rivals home electric power usage.

Ed Reid's picture
Ed Reid on Jun 4, 2022

Please provide a link to information on corn "yogurt" derived ethanol production.

Rick Engebretson's picture
Rick Engebretson on Jun 7, 2022

Wikipedia ( ) mentions; "The remaining stillage is processed into a highly nutritious livestock feed known as distiller's dried grains and solubles (DDGS).[12] "

Ed Reid's picture
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