(e.g., algae biofuels). Such fuels are needed to expand options for reducing petroleum use.
Advanced technologies for the production of biomass that provides sustainable yields, minimizes competition with food and feed crops, and offers substantial greenhouse-gas-reduction benefits.
Advanced PV materials and manufacturing methods to improve efficiencies and to lower costs. The deployed efficiency of current PV materials is greater than 10 percent, which is much higher than the field efficiency of plants for biomass. Although biomass is a compact form of chemical energy storage, its production requires a great deal of land and energy and it has to be harvested and processed to make electricity or liquid fuels, whereas the electricity from PV cells can be used directly.
Advanced batteries and fuel cells for LDVs.
Advanced large-scale storage for wind energy and electrical-load management.
Enhanced geothermal power.
Advanced technologies for extracting petroleum from shale and for harvesting natural gas from hydrates.
Alternative fuel cycles that would allow for greater utilization of the energy content of nuclear fuel and the minimization of very-long-lived radioactive waste from nuclear power generation.
Further exploration of geoengineering options.
R&D in other scientific fields that are not addressed in this report will likely provide important support for the development and deployment of new energy-supply and end-use technologies. For example, researchers’ efforts to better understand the interactions between patterns of energy use and climate systems—including, for example, the ecology of microbial systems—could support the development of more effective means to capture, store, and recycle CO2 from energy production. Additionally, social science research on how households and businesses make decisions could lead to more effective measures to encourage energy efficiency.
Finally, attractive technology options will likely emerge from innovation pathways that are essentially unforeseen today—some examples are cited in Part 2 of this report—underscoring the need for a continuing focus on and investments in basic research. Some breakthrough technologies are probably not even on the present horizon; in fact, they may not become apparent until the final time period