The push to power more of the modern world with electricity—and to get those electrons without burning fossil fuels—isn’t entirely green.
Vows to steer down a path to “net zero” carbon emissions around the middle of this century have become a centerpiece of climate policies for companies, states and entire countries. Such moves are considered critical if the world is going to keep temperature increases well below 2°C, a threshold commonly cited as a point when the effects of global warming become severe.
But kicking the fossil fuel addiction comes with an environmental price of its own, especially if we want to hang onto the cell phones, plane trips, car commutes and 24/7 easy electricity that are hallmarks of modern life in the developed world. Copper, aluminum, lithium and rare earth metals, to name a few, need to be mined. And then there’s the question of where to put all those solar panels, wind turbines and switchgrass fields.
Now, a group of scientists working in the western U.S. have crafted a road map for getting the region to net zero while minimizing the environmental footprint. The upshot: It’s going to take a lot of land blanketed with solar panels and wind turbines. But careful planning could shrink the footprint on sensitive habitats and valuable farmland by half.
Grace Wu, a University of California, Santa Barbara environmental scientist who helped lead the research, summed up her view of the likelihood of western states reaching net zero this way: “It’s going to be hard, but it’s not impossible.”
Reconfiguring an entire energy system is no easy task. The North American electrical grid alone has been described as the world’s largest machine. Add in all the ways energy today is produced (wind, solar, geothermal, nuclear, gas, coal, oil, etc.) and used (transportation, manufacturing, server farms, watching Netflix, writing this story, etc.). The number of variables is staggering.
Wu was part of a team of scientists with expertise in all things energy who joined forces to try to come up with detailed, realistic scenarios for how the 11 states in the western U.S., which are joined together by electrical transmission lines, could shift their energy systems to net zero carbon emissions by 2050. They also wanted to see what the footprint would be on land and in the ocean. Members included people from a handful of California universities, consulting firms, energy companies and the environmental group The Nature Conservancy.
To find answers, the group embarked on a binge of data-crunching and computer modeling. They used environmental and land-use data to map where power generators such as wind farms could be built. They modeled routes and costs for power lines to get electricity from where it’s made to where it’s used. They plugged all of this into a program called RIO, designed to create different scenarios that would meet future energy needs. They then calculated how these results overlaid on the region’s farmland, important wildlife habitat and relatively undamaged landscapes.
The magnitude of the impact is boggling. By 2050, turning the western U.S. into a highly electrified net zero mecca run largely on renewable energy would take as much as 4.5 times more total electricity than a system built without worrying about carbon emissions. That’s largely because of the shift from fossil-fuel burning devices (cars, stoves, furnaces) to ones running on electricity. Demand for transmission systems to move that electricity would be as much as 65% greater. And the amount of land and ocean space dedicated to energy could be as much as 11 times greater than if carbon weren’t a concern. All told, the region’s energy footprint would be between 70,000 and 143,000 square kilometers bigger with the net zero push, the scientists reported this month in the Proceedings of the National Academy of Sciences. The larger number represents enough solar panels, power lines, wind turbines and bioenergy crops to cover nearly half the state of New Mexico.
“The scale, pace, and land use requirements of the energy infrastructure build-out required to achieve net-zero economy-wide emissions are unprecedented,” the researchers wrote. “Yet, if this transition is adequately planned, it is technically feasible, affordable, and environmentally sustainable.”
The final footprint, however, depends on the details. Shifting more quickly to electricity would reduce the amount of land used, because it would mean less reliance on producing liquid biofuel from crops, the most land-intensive part of this energy equation. Likewise, adopting measures to steer power production away from more ecologically or agriculturally valuable land would shift power production to less land-intensive uses, the scientists found. For example, more conservation-minded policies would translate into a 25% increase in solar farms, while wind farms would shrink by 26%.
Emphasizing land conservation does add a 3% cost to overall energy production, which amounts to $7.8 billion in annual costs in 2050, the study showed.
While these scenarios help clarify the tradeoffs of choosing different paths forward, they illustrate how daunting it will be to make good on the net zero promises. It also raises questions about whether society and governments are ready for it. Between now and 2050, construction of low-carbon energy infrastructure would need to advance at two to three times current rates.
The biggest roadblocks could come with some of the least glamorous hardware: transmission lines. It can take a decade to build high-voltage transmission lines to ferry electricity across multiple states – for example from Wyoming windfarms to California, said Wu. That’s in part due to the challenges of getting permits for such projects. The study found that even with more strict land conservation policies, getting to net zero would take more than 10,000 kilometers of new high-voltage lines. “I worry more about actually permitting transmission than I do about permitting wind and solar farms,” she said
Wu, et. al. “Minimizing habitat conflicts in meeting net-zero energy targets in the western United States.” Jan. 19, 2023. Proceedings of the National Academy of Sciences.
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