What a rapid transition from fossil fuels to carbon-free energy alternatives looks like
If the COVID-19 pandemic has taught us anything it is that an early, science-based response to a rapidly unfolding disaster is critical. In recent years we have witnessed the mounting effects of climate change in the form of droughts, worsening storms, more frequent floods and record wildfires. Many of these burdens fall inequitably on citizens with lower incomes. Although we need to address the many causes of greenhouse gas (GHG) emissions, three-quarters of U.S. emissions come from burning fossil fuels. Thus, the most important thing we must do to halt climate change is rapidly transition from fossil fuels to carbon-free energy alternatives.
Fortunately, the solutions at hand have improved markedly in the last 10 years. The costs of electricity from solar and wind energy have declined dramatically and are now the cheapest sources of electricity in much of the U.S. — about one-quarter the cost of new nuclear power. There is growing agreement on a course of action for addressing climate change:
1. Maximize energy efficiency.
2. Deploy low-cost solar and wind electricity as rapidly as possible. A clean electricity standard (CES) that requires 100 percent of electricity to be carbon-free by 2035 is the best tool to get there, and Congress needs to act.
3. Electrify as many of our energy uses as possible to take advantage of this carbon-free energy.
4. Continue to develop carbon-free and carbon-neutral fuels for those limited applications that are difficult or very expensive to electrify.
How can we have a reliable grid with largely weather-dependent generation? There are a variety of ways we can address this. For almost a decade, NREL and others have developed best practices to integrate variable renewables into the grid at least cost. Options include expanding balancing areas to minimize variability, using advanced weather forecasting and shortening grid dispatch times, adding transmission and storage, utilizing demand flexibility in buildings and many others.
Many analysts see a clear path to achieving an 80 or 90 percent renewable electricity grid. Addressing that last 10 or 20 percent will also likely require long-term storage as well as grid modernization including improved market design. Although some observers have called for a massive R&D effort to develop innovative solutions to the climate crisis, the truth is that we already have the technologies we need to solve most of the problem, and our chief focus must be on enabling and deploying them.
That’s not to imply this will be easy. 2020 was a record year for new U.S. wind and solar electric capacity additions, at about 33,000 megawatts. To achieve a carbon-free grid by 2035, we will have to install an average of roughly two to three times that amount every year over the next 15 years. The actual amount needed will depend on factors such as how quickly we electrify transportation, buildings, and industry.
How can we make that goal more achievable? First, the more efficient we make our transportation, buildings, and industrial sectors, the less additional electricity we will need. Another important step is to keep our existing nuclear reactor fleet running for as long as we can safely do so. We can also electrify in stages starting with those energy uses that provide the biggest immediate climate change benefits. Cars and trucks account for over 80 percent of our transportation-related GHG emissions, and battery electric vehicles use energy much more efficiently than internal combustion engines, so electrifying that segment is a priority.
Following vehicle electrification, using heat pumps to electrify heating in buildings and low-temperature industrial processes is next. Electrifying new buildings avoids the capital investment and long-term commitment in natural gas equipment and piping. (It will take somewhat more effort to economically electrify existing buildings.) Electrifying higher-temperature industrial processes can wait until the grid is sufficiently carbon-free.
What about uses that are hard to electrify like long-distance aviation and ocean-going cargo ships? Biofuels can play a role here, although they face challenges in land use, biodiversity tradeoffs, biomass transportation costs and net carbon impacts. There is increasing interest — and debate — regarding the role of hydrogen (and ammonia produced from hydrogen). Renewable electricity can produce “green” hydrogen from water via electrolysis. But there are inefficiencies and expenses associated with producing, storing, transporting and utilizing the hydrogen. Hydrogen can also be combined with carbon (captured from biomass, industrial processes or — most expensively — from the air) to produce synthetic “drop-in” hydrocarbon fuels, which are easier to use but even more expensive to produce. Fortunately, the applications that might need these fuels are responsible for only a small percentage of greenhouse gases.
The Biden administration is setting an example for the rest of the world by targeting 2050 for a net-zero carbon economy. In this context “net-zero” generally means we are removing as much carbon dioxide from the atmosphere as we are adding. After the important step of stopping deforestation, there are a variety of ways we can remove carbon dioxide, all of which have their tradeoffs. But the most cost-effective thing we must do is to not emit CO2 in the first place. Thus, any efforts to remove CO2 from the air must not detract from efforts to rapidly replace fossil fuels with zero-carbon energy.
We already have the technologies we need to solve most of the problem, and we have a variety of options for getting the rest of the way there. The biggest challenges are not technological but rather political and sociological. Strong policies are needed, and to realize them, we must rise above our divisive politics. Fossil fuels are cheap, partly because of continuing subsidies, and these must be removed. Putting a price on carbon that reflects its social cost will help. But a new focus that follows science, together with the prospects for a strong post-pandemic economic expansion and the many opportunities it offers, make this the ideal time to finally address the climate change crisis. The COVID-19 pandemic was devastating for people and economies around the world — a future with unabated climate change would be far worse.
Charles Kutscher is a fellow of the Renewable and Sustainable Energy Institute (RASEI) at the University of Colorado Boulder. He was previously a researcher and manager at the National Renewable Energy Laboratory (NREL). Follow him on Twitter: @ChuckKutscher
Jeffrey Logan is associate director of RASEI and held previous positions at the International Energy Agency, World Resources Institute and the Congressional Research Service.
The authors recently published “Accelerating the US Clean Energy Transformation: Challenges and Solutions by Sector.”