An urgent plan to decarbonize electricity by 2035

We applaud the Biden administration’s goal of completely decarbonizing the U.S. electricity system by 2035. Achieving that, while keeping power affordable and reliable, will be an enormous but feasible undertaking requiring a continuous push for the next 14 years.   

If the 2035 target is to be more than political rhetoric, the administration, Congress, state legislatures and a host of federal and state regulators need to start now to identify, develop and implement strategies to overcome the many impediments that this massive effort will face.

Only a few of these are in the bipartisan Infrastructure Investment and Jobs Act. It has $7.5 billion for electric vehicle chargers, $2.5 billion for new transmission lines, $6 billion to encourage existing nuclear plants to remain operating, $6 billion for battery manufacturing and recycling, and $2.5 billion for zero-emission school busses. While the Democratic budget resolution is still a moving target, even Majority Leader Schumer (N.Y.) estimates that the two bills together would cut emissions by only 45 percent in 2030.

What is really needed?  Start with new generation. Today, only about 40 percent of electricity in the U.S. comes from carbon-free sources. Of that, roughly 20 percent is provided by the aging and shrinking fleet of nuclear reactors, and just over 7 percent by hydropower. Sustaining both will require continuing attention by industry and government. 

Modelers and many power system operators agree that it is possible that renewables can cost-effectively make up roughly 80 percent of electricity generation. The remainder can be storage and gas turbines powered with hydrogen, synfuels, or natural gas with carbon capture. 

Transitioning from the 20 percent of U.S. electricity produced by renewables in 2020 to 80 percent in 2035 will require at least three times the current 285 gigawatts (GW) of renewable power. That means building roughly 55 GW per year. Although the U.S. built 60 GW of natural gas generators per year in 1999 and 2000, it has not built more than 15 GW of renewables in a single year. State Renewable Portfolio Standards targets will add only about 90 GW by 2035.  

Fifty-five GW per year is feasible only if the right policy incentives are created and maintained. The installation of off-shore wind must be accelerated. Land-use constraints will become increasingly binding as more and more renewables are installed. The rapid development of incentives and regulatory attention will be essential. 

Next, consider flexibility. Some of the inherent variability of renewables can be absorbed by flexible demand for electricity. More market and non-market incentives will be needed to increase the present small demand response capability. Storage can also provide flexibility, and continued research, development and demonstration support to lower costs is warranted. While storage can deal with intra-day variability, it will be difficult to cover seasonal changes in wind and sunlight economically with storage while that expensive capital asset sits idle for most of the time. Thus, the 2035 system is likely to need zero-carbon gas turbines. Research, development and demonstration is needed for net-zero fuels such as hydrogen and natural gas with carbon dioxide capture, since storing natural gas or hydrogen is relatively inexpensive.

Finally, consider the wires. While it may be possible to generate a larger fraction of power using distributed resources, almost every serious study has concluded that the country will need more high voltage transmission. For a variety of reasons, but largely due to public opposition, over the past several decades, many proposed new transmission projects have been canceled. When a line does get built, it often takes more than a decade. The Energy Policy Act of 2005 proved that eminent domain is no panacea, and incentives for both transmission owners and land owners are currently inadequate. 

A recent National Academies of Science Engineering and Medicine study called on Congress to establish a national transmission policy and direct the Federal Energy Regulatory Commission to take steps to support regional transmission planning, take on the authority to designate new national interest electric transmission corridors and approve lines in them. It also called on the  Department of Energy to provide funds to states, communities and tribes to enable meaningful participation in regional transmission planning and siting. 

As millions of inverters and smart customer-owned devices are added to the system, the technical and regulatory issues involved in their control will further complicate planning. It is also clear that much greater attention must be directed to assuring the resilience of the power system. That means pursuing strategies that range from micro-grids to system hardening and strategies to assure more rapid system restoration. However, our calculations of transmission project cost estimates combined with 160,000 miles of existing transmission infrastructure shows funding sufficient to add only about 0.5 percent to our existing transmission system is included in the bipartisan bill. 

While additional funding is included in the American Jobs Plan (for example a 5 percent increase in our transmission line miles), it is not all about the money. State and federal regulators should be encouraging transmission companies to consider much greater use of modern power electronics to increase transmission capacity. But even with such technical improvements, multi-state transmission policy will be necessary. 

To achieve the 2035 goal, a high-level coordinating body involving federal and selected state governments and regulators would be very helpful. Congress and state legislatures across the country will need to create both incentives and reduce regulatory constraints. 

We can get to zero by 2035, but doing that will require a significant and coordinated effort that ensures that generators, storage proprietors, transmission owners and customers all get something out of the huge build-out to come. 

Jay Apt is a professor in the Tepper School of Business and in the Department of Engineering and Public Policy at Carnegie Mellon University (apt@cmu.edu). M. Granger Morgan is Hamerschlag University professor in Engineering and Public Policy at Carnegie Mellon University (gm5d@andrew.cmu.edu). Together they co-direct Carnegie Mellon’s Electricity Industry Center. Morgan chaired the recent National Academies study on the future of electric power in the US.