From Master Resource.
By Mark Krebs
“My major argument: any planned transition to an all-electric renewable energy monoculture is likely to fail, at least in America. That is mainly because peak winter heating requirements can greatly exceed peak summer cooling requirements by as much as 400 to 500 percent in cold climates and because the required minerals are severely limited.”
On August 27, 1997, the Cato Institute published “Renewable Energy: Not Cheap, Not ‘Green’,” written by Robert L. Bradley Jr. (A 58-page PDF of the study is available here and a 25th anniversary review here.) Bradley’s piece focused on the many stark ecological tradeoffs of politically favored renewables, as well as the high cost/low value associated of dilute, intermittent sourcing. This post extends that thinking to the deep decarbonization/all-electrification government program.
Rare earth minerals, on which the forced transition to “clean energy” depends, are critically constrained by many of the same factors as fossil fuels. Supplies of these minerals are dominated by regimes with intent to cultivate and exploit our growing dependency on them. As these raw materials are extracted and the strategic dominance of China increases, prices will have a premium that will impact consumers. Finding and developing supply chain alternatives will also bring increased energy expenditures necessary to secure and process these rare earth minerals. This will decrease ostensible environmental benefits from “green energy.”
One new source of supplies for rare earth minerals and other strategic materials rapidly gaining interest is seabed mining. However, this may lead to a cure that is worse than the supposed disease of anthropogenic global warming (AGW). If so, the claimed “greenhouse gas” (GHG) reductions achievable through the coerced “transition” to “clean (renewable) energy” are, at a minimum, significantly decreased relative to the fossil fuels they aim to supplant.
The purpose of this two-part post is to revisit some of the physical realities associated with raw material acquisition for a centrally planned “clean” energy transition. In short, the prospects are poor. “Betting the farm” on it happening as planned is problematic at best. However, before we get “into the weeds” of these problems, let’s briefly revisit the economics and physics challenging this transition to so-called “clean energy.”
Peak Heating Demand
My major argument: any planned transition to an all-electric renewable energy monoculture is likely to fail, at least in America. That is mainly because peak winter heating requirements can greatly exceed peak summer cooling requirements by as much as 400 to 500 percent in cold climates and because the required minerals are severely limited.
Regional weather differences are pictorially shown by National Centers for Environmental Information maps of Heating and Cooling Degree Days. But energy delivery systems must be sized for worst-case weather scenarios that don’t show up in averages. A prime example of such worst-case scenarios are “polar vortex” events.
To get a basic appreciation of these issues (but not necessarily worst-cases), consider a house with:
- a thermostat set at maintaining 80 deg. F in the summer with a worst-case peak summer temperature of 110 deg. F.
The resulting temperature differences between the inside and the outside are 80 deg F. in the winter and 30 deg. F in the summer. Dividing the temperature differences of 80 (winter) by 30 (summer) yields a ratio of 2.6 (2.6 times more energy for heating relative to cooling). Further increasing the ratio of winter heating loads versus summer are the utility planning needs for adequate safety margins, system redundancy, etc.
Most winter heating requirements in the U.S. are served by the direct use of fossil fuels (mainly natural gas) in furnaces and boilers. The Biden Administration has targeted for elimination these workhorses as part of the overall “transition” to an all-renewables future.
Further consider the complications of serving two-to-three times the electric load with intermittent renewables that are inherently unreliable without some sort of back-up. How much, how long, what kind?
To contractually guarantee availability, renewables may need to be backed-up, either by fossil-fueled generation and/or batteries. At a ratio of 1 kW of fossil-fueled power backup per kW of renewable generation, 2 to 3 times more capacity becomes 4 to 6 times. And this does not consider the additional electric generation requirements needed to simultaneously transition plan from fossil-fueled vehicles to electric, which could increase present electric power needs by at least 100%.
Some claim replacing the present US fleet with electric vehicles will require 2 to 3 times more generation. Also note that batteries for EV’s will likely compete with stationary batteries for wind and solar back-up. Such factors would increase battery costs.
Massive, but geographically dispersed, renewable generation will need equally massive investments in electric transmission and distribution systems. Additionally, such increasingly dispersed and intermittent renewable systems will become exponentially more difficult to manage, especially as traditional, dispatchable power systems decline. (For more information about the complexity of adding renewables to the grid, see FERC orders reliability standards, registration requirements for wind, solar, storage to protect the grid.)
As for deciding what type of back-up, the cheapest form of readily dispatchable fossil-fueled back-up for renewables is typically natural-gas-fueled combustion turbines, coupled with heat recovery steam boilers powering steam turbines (aka., “combined-cycle” systems, abbreviated as NGCC). These are about 66% efficient in the newest applications. In comparison, natural gas-fueled residential furnaces can be 80 to 95% efficient.
However, standing in the way of combined-cycle backup systems is that electric utilities can be among the first curtailed from natural gas supplies during severe cold weather emergencies, simply because ordinary consumers are curtailed last. This problem can be overcome if electric utilities pay to reserve pipeline capacity or if consumers are weaned off the direct use of natural gas. The latter seems the direction that the Biden Administration’s electrification policies are headed. However, some maintain the Administration is aiming to eliminate gas generation as well. If so, the high performing NGCCs have no place at all.
Conversely, we can just chalk-up, as collateral damage in the war against carbon with hundreds of deaths here and there, now and then from freezing due to polar vortex events (like they did in Texas from the February 2021 Winter Storm Uri).
Batteries to the Rescue?
If battery back-up systems are the only type allowed (as environmentalists would like to dictate), consider that:
- Wind droughts can last a week or more.
- Sunlight upon photovoltaic systems can be blocked by snow and ice for as long as it takes for something to physically remove them.
- volcanic eruptions and forest fires can and do limit incoming solar radiation for even longer periods.
How much time should battery back-up systems be needed for worst-case scenarios is equally debatable. Some people maintain a week is adequate, whereas some argue planning for 3 weeks or more of renewable generation downtime. Professor Michaux’s (introduced shortly) is one those arguing for 3 weeks or more.
If the worst-case period is a week, that’s 168 hours. Most battery storage systems are only rated for 4 hours of full load output before they need to be recharged. Thus, getting through just a week of renewable generation down-time with 4-hour rated battery modules indicates a need for 42 kW of batteries per kW of renewables (168/4), at a minimum.
These calculations make a BIG assumption: They assume that wind and/or solar generation has sufficient periods of excess capacity to keep the battery systems fully charged for when you need them. All forms of electric generation have “capacity factors.” Wind and solar capacity factors are in the range of 25% (or less). Given there are 8,760 hours in a year, then you can only count on 2,190 hours (or less) of actual generation. What happens if they don’t have enough time to generate and store their own battery back-up (e.g., reoccurring wind droughts)? You guessed it! You’re still at risk for running out of electricity.
Battery back-up systems also suffer from cold and hot weather extremes. Just read the owner’s manual that came with your cordless drill to verify this. So how to maintain adequate temperatures? Gas heat?
If sufficient technological breakthroughs occur to solve these battery physics problems, there are still major problems with securing the raw materials needed for this “transition.” Not the least of which is that China has largely monopolized most of these strategic materials. This is at least partly due to the over-regulation of mining in the U.S., which China is exploiting. But even China may have problems supplying these strategic materials over the long run, especially if the environmental impact costs are internalized (e.g., carbon import tariffs).
Part II Tomorrow
Mark Krebs, a mechanical engineer and energy policy consultant, has been involved with energy efficiency design and program evaluation for more than thirty years. He has served as an expert witness in dozens of State energy efficiency proceedings, has been an advisor to DOE and has submitted scores of Federal energy-efficiency filings. His many MasterResource posts on natural gas vs. electricity and “Deep Decarbonization” federal policy can be found here. Mark’s first article was in Public Utilities Fortnightly, titled “It’s a War Out There: A Gas Man Questions Electric Efficiency” (December 1996). Recently retired from Spire Inc., Krebs has formed an energy policy consultancy (Gas Analytic & Advocacy Services) with other veteran energy analysts.