Last week, surrounded by wind turbines and solar panels, President Joe Biden stressed the need to attain a carbon-free power sector by 2035. “We can do that, we can do all of this in a way that creates good jobs, lowers costs to consumers and businesses and makes us global leaders,” the president said.
The crown jewel of the administration’s clean energy plan seems to be the Department of Energy’s new Solar Futures study. The report provides a blueprint for how the U.S. could get 40% of its electricity needs met with solar energy by 2035 without raising electricity prices.
“The study illuminates the fact that solar, our cheapest and fastest-growing source of clean energy, could produce enough electricity to power all of the homes in the U.S. by 2035 and employ as many as 1.5 million people in the process,” said Secretary of Energy and renewables champion Jennifer Granholm. “Achieving this bright future requires a massive and equitable deployment of renewable energy and strong decarbonization policies – exactly what is laid out in the bipartisan Infrastructure Investment and Jobs Act and President Biden’s Build Back Better agenda.”
The contents of the Solar Futures study, however, should give us pause.
The plan’s proposals are immense in size and scope. It calls for the U.S. to quadruple its annual solar installations to reach 1,000 gigawatts of capacity by 2035 – 40% more than the total amount of solar worldwide as of 2020. To accommodate the expansion of solar and wind, the study finds that transmission will need to expand by at least 33% over the same time period and up to 90% by 2050. Reaching the study’s target of 1,600 gigawatts of installed solar would require an estimated 244 million metric tons of materials, according to a forthcoming report from the Center of the American Experiment. And to deal with the massive throughput necessary to replace these solar installations every 30 years (though industry reports on solar degradation suggest that 30 years is an optimistic estimate), it proposes closed-loop recycling, which is prohibitively expensive.
There are plenty of reasons to doubt we will achieve the targets laid out in the Solar Futures study. Rebuilding the American economy to be carbon-free within this century would likely require significant feats of infrastructure and manufacturing, but let’s assume for the sake of argument that we could do it. The study calls for 40% of U.S. power generation to come from solar by 2035. The study factors wind into its modeling at 36%, bringing the combined total to 76%. What would it take to make this work?
The primary hurdle to overcome is assuring grid reliability. The challenges posed by a renewables-dominant grid were described in a MISO presentation on a recent four-year reliability study. “Growing renewables are driving localized reliability risks now,” the presentation states. “[The reliability report] finds these challenges will become footprint-wide beyond 30% system-wide renewable penetration.” In fact, increasing the ratio of renewables in our energy portfolios is already creating massive problems for multiple regions around the country.
California, which gets about a third of its electricity from renewables, has announced that it will build five new natural gas plants to stave off blackouts like the ones the state experienced last year. Grid operator CAISO has resorted to sending out “flex alerts” that discourage people from using electricity from 4 to 9 p.m. Texas, which gets about 20% of its electricity from renewables, has seen similar problems. Its $66 billion fleet of wind turbines hardly produced any electricity during its winter blackouts in February, and the state was almost caught off-guard by a typical summer heatwave.
The authors of the study acknowledge reliability problems associated with a grid dominated by weather-dependent energy sources. One of their prescriptions for maintaining grid integrity is the expansion of energy storage. They model a 70-fold increase in energy storage of 12 hours or less between now and 2050. But as we witnessed with the crisis in Texas, poor weather can last for days and even weeks.
Beyond speculating that technological advances will create cheaper batteries with longer-duration storage, the report’s authors describe how renewable-energy combustion turbines (RE-CTs) can guarantee resource adequacy. Unlike solar and wind, RE-CTs use stored fuel to provide generation when it’s needed; this means that when the sun is down or the wind isn’t blowing, RE-CTs can fill in the gap. The study predicts that RE-CTs will run at similar outputs as natural gas turbines do now.
What exactly are RE-CTs? According to the Solar Futures study, they are “essentially conventional gas turbines with modifications enabling them to burn liquid or gas fuels from renewable resources.” These fuels could include biofuels and biogas, synthetic hydrocarbons, and hydrogen – gas, in other words, but clean. The reference model in the Solar Futures study projects natural gas capacity increasing nearly 75% by 2050. Its two other models, however, show natural gas capacity at zero by this time. The study anticipates that natural gas will be replaced by more than 400 GWs of RE-CT capacity, which it acknowledges that hydrogen fuel will power.
The study doesn’t provide an explanation of how RE-CTs come to replace coal and natural gas generation, but it assumes that all fossil fuels will disappear. If RE-CTs are to replace fossil fuel plants, how will they compete with the natural gas industry? The U.S. is awash in easily accessible natural gas. And despite recent jumps in price, American gas is still relatively cheap. Given the nascency of renewable fuels, gas would need either to be banned outright or become prohibitively expensive to make room for alternatives to become widespread and cost-effective.
The Democrats appear to be making headway on this problem. The Committee on Natural Resources is pushing to get an addition to the budget resolution for 2022 that would freeze domestic expansion of fossil fuel energy. Biden’s American Jobs Plan includes provisions for decarbonized hydrogen production along with a new production tax credit to bolster the fledgling industry.
However, the decarbonized hydrogen industry would still have to increase more than five-thousand-fold to hit the desired amounts that Solar Futures envisions. If America commits to a bold renewables buildout (Solar Futures assumes a hefty expansion in wind energy as well), it could outstrip the national ability to back up renewables and thus stabilize the grid. That the study assumes no substantial green hydrogen backups until 2050 reinforces this potential.
From our vantage point, it seems unlikely that Solar Futures will come to fruition. The Biden administration has just come under fire from environmentalists for allowing 78 million acres of the Gulf of Mexico to be open for fossil fuel exploration. There are tensions within the Democratic Party over how to balance climate ambitions with energy necessities.
Regardless, what could pursuing this ambitious renewables plan mean? After all, the Energy and Commerce Committee’s provisions for the Build Back Better Act showcase the Democrats’ commitment to a large renewables buildout. If we look across the Atlantic to Europe we can catch a glimpse of what might be in store. Renewable-heavy countries have avoided crises in the past because they could rely on natural gas or coal (if they have it). Now, gas is expensive and their stores for winter are thin heading into winter — when demand spikes, daylight hours shrink, and consistent wind isn’t guaranteed. European governments, markets, and grid operators are panicking and for good reason. Unless blessed with a mild winter it’s likely they will see brownouts (perhaps even blackouts), energy rationing, and a massive uptick in public discontent to say nothing of the potential economic effects.
Two paths diverge toward the horizon into Biden’s solar future: a surrender of energy sovereignty through imports of fossil fuel from allies, or energy austerity like we’re already seeing in states with flourishing renewables portfolios. The two paths converge, however, at the same point: a sunset on American prosperity.