More Hopeful Calculations for the Energy Transition

In “The Hard Math of Minerals” (Issues, January 27, 2022), Mark P. Mills writes that “building solar and wind systems requires roughly a tenfold increase in the total tonnage of common materials … to deliver the same quantity of energy compared to building a natural gas or other hydrocarbon-fueled power plant.” This idea is misleading, since the source cited states that it “excluded” the materials related to the fuels used in power plants. Such fuels must be mined forever. With solar and wind, fuel mining is zero, forever. One recent study that accounted for fuel mining plus infrastructure concluded that one gigawatt of wind capacity replacing coal-generated electricity on the Texas grid reduces total mining by 25 million tonnes over 20 years.

In fact, in North America alone, an average of fifty thousand new oil and gas wells are drilled yearly. These are ignored by Mills. The land required for these new wells is 2,500 square kilometers per year. Once a well is depleted, it is abandoned. The United States has 1.3 million active oil and gas wells and 3.2 million abandoned ones. Worldwide, Reuters estimates that about 29 million wells are abandoned.

Research I’ve conducted with colleagues estimates that fossil fuel infrastructure currently takes up about 1.3 % of US land. This is due to wells, coal mines, oil refineries, pipelines, power plants, fueling stations, and storage facilities. In comparison, transitioning the United States for all energy purposes to 100% wind, water, and solar power may take less than 1% of US land. So not only does a transition to renewables reduce material requirements, but it also reduces land use.

Let’s look at a specific materials example. We will need many batteries for electric vehicles and storage. Batteries can now last 15 to 20 years and 15,000 cycles and require only one-time mining, since 95% of their components, including nickel, cobalt, copper, aluminum, lithium, and graphite, could be recycled.

Further, traditional lithium mines are becoming cleaner. In July 2020, a company announced it will use solar photovoltaics (PV) to provide 100% of the electricity required in the annual average for its rare earth and lithium mining project in West Texas.

Environmental damage due to lithium mining can also be averted. Geothermal electricity production in the Salton Sea, California, and the Upper Rhine River, Germany, for example, entails lithium-rich brine being pulled from deep geothermal wells and used for electricity production, then recycled back into the wells. Efforts are underway to extract lithium from the same brine, resulting in no additional mining. Lithium can also be extracted from the same brine that bromine is extracted from, as is being done at a demonstration plant in Arkansas.

Powering mining with renewable electricity is not limited to lithium mining. In April 2021, a gold mine in Mali began using solar PV plus batteries for its electricity. In August 2021, a company in Western Australia announced it would power a nickel mine with PV and another with PV plus batteries. Another company announced it would power an ilmenite mine in Madagascar with PV, wind, and batteries. In September 2021, a potash mining company in Australia announced it would provide two-thirds of its power with a PV-wind-battery microgrid. In sum, while challenges exist, transitioning to clean, renewable electricity and storage for everything will reduce material and land requirements. As my colleagues and I have argued, it will also reduce energy costs by 60%, increase jobs, reduce air pollution deaths and costs, and reduce climate damage. To minimize damage, we need an 80% transition by 2030 and 100% by 2035–2040. We have at least 95% of the technologies needed. As such, we have no excuse not to proceed rapidly.

Mark Z. Jacobson