The clean energy success story of the 21st century is the astonishing rate at which solar photovoltaic (PV) and wind power have gotten cheaper and expanded around the globe, becoming mainstream sources of carbon-free electricity. In the United States, solar PV and wind have grown from a negligible share of electricity generation two decades ago to 2 percent and 7 percent, respectively, of electricity generation today.
Yet, this progress marks the beginning rather than the end of the renewables revolution. The International Energy Agency’s (IEA) Sustainable Development Scenario (SDS), in which global warming is limited to 2 degrees Celsius, envisions renewables—a grouping that stretches well beyond solar PV and wind—as the bedrock of the low-carbon economy, providing clean power, heat, transportation, and other vital services. By 2030 in IEA’s scenario, a mere decade away, the share of the world’s electricity drawn from renewable resources will have doubled. By 2040, it will be 72 percent.
There is no doubt that achieving such ambitious objectives will require aggressive and immediate deployment of mature renewable energy technologies. But a strategy limited to deployment would be shortsighted. Despite impressive improvements, renewables face constraints around affordability, availability, and reliability. If clean energy is to fully supplant unabated fossil fuels, especially in the developing world, these constraints must be overcome.
The possibilities are exciting. Thin, flexible solar panels could be manufactured at low cost and integrated into the architecture of dense, urban environments. Floating platforms could support massive wind turbines in deep waters far off the coasts. Geothermal reservoirs that are built, rather than discovered, could draw always-on power from the hot rock deep beneath the Earth’s surface. These are just a few examples. Innovation can turn many of these possibilities into realities, unlocking massive decarbonization opportunities and complementing deployment of today’s state-of-the-art technologies.
That state of the art owes a great debt to federal investments in innovation going back decades. All advanced nations, including the United States through its Congress and Department of Energy (DOE), should now build on that legacy and drive forward an ambitious renewables innovation agenda. DOE has already laid the groundwork in studies such as Wind Vision, Hydropower Vision, and GeoVision. This body of work provides ample reason to believe that innovation in advanced renewable energy technologies can catalyze a massive clean energy buildout and help draw down global emissions.
This report puts forward an innovation agenda for solar, wind, geothermal, and water power. It organizes the key technologies into two categories: those that supply variable energy, which is only produced as a resource is available, and those that supply firm energy, which is available as needed. The technologies in each category have common roles, challenges, and opportunities. They also complement one another: Firm renewables enable very cheap variable renewables to provide more energy than they otherwise would. Within the two categories, each subsection summarizes the current status of a technology, describes its potential to contribute to decarbonization, and identifies opportunities for the federal government to accelerate innovation.
The report offers several overarching recommendations:
- Congress should significantly increase DOE’s funding for renewable energy research, development, and demonstration (RD&D), consistent with Information Technology and Information Foundation (ITIF) proposals for the entire federal portfolio.
- Congress and DOE should ensure wind and solar PV, the two major variable renewable technologies, can fulfill their promise to provide the bulk of new low-carbon energy capacity by driving RD&D to improve the efficiency of generating devices and promoting their integration into the electric grid.
- Congress and DOE should support the improvement of firm renewable power technologies—such as geothermal energy, concentrating solar power (CSP), hydropower, and marine power—that would offer reliability and other benefits for a grid dominated by variable renewables, by ensuring they can be deployed in diverse locations at low cost.
Advanced renewable energy technologies are not magic bullets for climate and clean energy. Getting to zero emissions will require advances in grid technologies, solutions for hard-to-decarbonize sectors such as shipping and chemical manufacturing, and likely negative emissions technologies as well. Other electricity generation technologies, such as nuclear power and fossil fuels with carbon capture and storage (CCS), might also play valuable roles and should continue to be pursued.
Advanced renewables are, however, indispensable. They will be the conduits linking the planet’s inexhaustible natural resources to clean energy a thriving global society can depend on.