1. Improved energy storage systems: The sun and the wind are incredible energy sources. Finding ways to store that energy to use after the sun sets and the wind stops blowing is a big challenge we need to solve. We do have ways to store energy for a matter of hours—like lithium ion batteries—that are becoming cheaper every year.
2. Carbon capture and storage and nuclear: I often hear that lower cost solar and wind power along with the emerging breakthroughs in energy storage mean that these sources will be enough to get us to a carbon-free power grid. But because the world must balance the need to eliminate carbon emissions with economic growth, we should also consider what solutions would be most affordable. A recent study from researchers at MIT found that supporting renewable energy with a mix of clean energy solutions—including nuclear and carbon capture and storage (CCS)—would make carbon-free electricity up to 62 percent cheaper than using renewables alone.
3. High-voltage, long-distance transmission lines: Renewable power resources like wind and solar are often located far from the cities or industrial areas where energy demand is the greatest. Connecting our renewable energy supply with demand will require us to build transmission lines that can handle large amounts of power over very long distances. High-voltage direct current (HVDC) transmission technology—as opposed to the alternating current power lines most electric grids in the U.S. use today for transmission—would help us integrate renewable energy into our world’s power supply. Expanding HVDC lines, however, will not only require new investments in our power grids, but also supportive national and local policies to support their construction. Research and development at U.S. Department of Energy national laboratories like the Pacific Northwest National Laboratory and the National Renewable Energy Laboratory is helping lay the groundwork for how we can design, build, and operate a 21st-century grid.