To reach the worldwide goal of keeping global warming under 1.5 °C, it’s clear we need to increasingly substitute low carbon energy for fossil fuels. This means ramping up production of solar panels, wind turbines, batteries, power lines, electric vehicles for public and private transport, heat pumps, etc. These technologies require many minerals including some “rare earth” elements for their manufacture.
Maybe it’s the name, “rare earth.” Maybe it’s the scary idea of complex technology versus good old-fashioned burning of stuff. But whatever it is, it inspires a lot of negative conjecture: Won’t all the mining destroy the environment? Won’t children be exploited for labor? Surely more energy will be used to mine the minerals than they can create? Won’t all the turbines, panels, and batteries be impossible to dispose of?…
As I always said to my students in answer to these very good questions, we need to think about them rationally and as a matter of scale, two things often missing in emotional debates.
For example, as we discussed in a past column, to produce equal amounts of energy from a coal plant and a wind farm, the coal plant requires extraction of 30 times more material, 40 times as much CO2, and at least ten times more waste (toxic coal ash).
Since the mineral question seems to be gaining momentum among renewable energy nay-sayers, we recently decided to address it here. We started researching details to find a helpful way to make a side-by-side comparison of the life cycle impacts of renewables to those of fossil fuels. In the struggle to find good quantitative data, I happened across an article by energy journalist, David Roberts that was essentially the article I was trying to write. So instead of reinventing the wheel, I will summarize some of his well-researched results. We encourage the reader to read or listen to his entire article*.
A major concern is that renewable technologies are much more mineral intensive than conventional fossil fuel technologies. Critical materials include copper, lithium, cobalt, nickel, chromium, and some of the so-called “rare earth” elements. For example, the powertrain of an electric car requires as much as six times more of these critical minerals than a gasoline-powered car (about 500 lbs compared to 80 lbs.) A wind farm requires nine times the mineral resources of a gas-fired plant with the same output.
But is this the right comparison to make? No: We need to consider the overall impact on the climate of using the technology. If the electric car is powered from carbon-free renewables, over its lifetime the gasoline car will be responsible for more than ten times the greenhouse gas emissions of the electric, even after taking into account the emissions of producing the electric vehicle.
Similarly, while energy to build the gas-fired plant is a tiny fraction of that needed to build the wind farm, over its lifetime the gas plant will produce ten times the CO2 of the wind farm.
In his article, Roberts cites energy researcher Saul Griffiths who offers an illuminating way to compare fossil energy to renewables:
“Assigning all 328 million Americans equal shares of our fossil fuel use, every American burns 1.6 tons of coal, 1.5 tons of natural gas, and 3.1 tons of oil every year. That becomes around 17 tons of carbon dioxide,…all tossed like trash into the atmosphere.
“The same U.S. lifestyle could be achieved with around 110 pounds each of wind turbines, solar modules, and batteries per person per year, except that all of those are quite recyclable…so there is reason to believe it will amount to only 50-100 pounds per year of stuff that winds up as trash.”
That’s a huge difference: 17 tons (34,000 pounds) of waste for our lifestyles the old way, versus 100 pounds the new, electrified way!
So what about the availability of these minerals? It turns out that known reserves of these minerals are many times greater than the anticipated need to achieve carbon neutrality by 2050.
This is not to say that it will be easy! Problems during ramp-up will include the rate of production, supply chain issues, and potential social and geopolitical problems. The biggest problem is how to extract materials without environmental and social upheaval. Some of these minerals are currently being extracted almost exclusively in regions with human-rights issues. These concerns cannot be ignored.
Yes, there are emissions from mineral production, but in a life cycle analysis, clean energy technologies produce far less climate stress–-by the World Bank’s estimate, one-sixteenth of the greenhouse warming effect of fossil fuels through 2050**.
Further, most of these materials have potentially high recycling rates. While the transition will require a significant increase in mining because there will not yet be sufficient recycled material to meet the needs, later–-say around 2050, much of the material will be recycled.
No one’s saying the energy transition is simple, but it’s not impossible. What is impossible is reducing greenhouse gasses sufficiently without the energy transition!
Paul Stancioff, PhD., is professor emeritus of physics at the University of Maine Farmington. Cynthia Stancioff pursues climate action, wild mushrooms, and sanity. Their emails are firstname.lastname@example.org and email@example.com . Previous columns can be found at https ://paulandcynthiaenergymatters.blogspot.com/.
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