Last month entrepreneurs, investors, corporate executives, and government officials gathered for the third annual ARPA-E Energy Innovation Summit to discuss the future of energy technology. ARPA-E (which stands for Advanced Research Projects Agency – Energy) is a new agency within the Department of Energy which funds potentially game changing energy technologies. Among the list of very distinguished speakers at the summit was Bill Gates.

During his remarks Gates spoke to the challenge of innovation in energy: “The problem with using IT and telecommunications as models for innovating in clean energy is that people underestimate the difficulty of the scientific work needed and how much time is needed for innovations to become adopted.”

What kind of breakthrough technologies are Bill Gates and ARPA-E funding? What other game changing energy technologies are on the horizon? There are five energy technology that show tremendous promise for the coming decades including nuclear power from nuclear waste; fuels made from carbon dioxide, water, and sunlight; plants engineered to produce gasoline; batteries that recharge in the air, and solar in space.


Bill Gates is betting his money on a fourth generation nuclear technology called TerraPower which uses spent fuel from existing nuclear plants to generate electricity. This technology would offer a zero-emission, proliferation-resistant nuclear power that would solve the challenge of waste from traditional nuclear reactors while generating power. According to Gates: "A cheaper reactor design that can burn waste and doesn't run into fuel limitations would be a big thing."



ARPA-E is investing in two potentially game changing technologies in the liquid fuel arena. The first is called Electrofuels which harness micro-organisms to create liquid transportation fuels in a new way that could be up to 10 times more efficient than current biofuel production. Rather than relying on plants — which require resources, such as water, fertilizer, and large areas of land to grow crops — the micro-organisms used for Electrofuels can directly use energy from electricity (which could be generated by solar power) and hydrogen (from water) to convert carbon dioxide into liquid fuels.

Plants Engineered to Replace Oil

The other ARPA-E program is called PETRO — plants engineered to replace oil — and its aim is to develop non-food crops (like pine trees, tobacco, sugarcane, and sorghum) that directly produce transportation fuel. These genetically engineer plants would produce molecules already found in petroleum-based fuels that could be dropped directly into the tanks of existing vehicles.


A breakthrough technology in the battery arena seeks to address the major restriction of electric vehicles having to plug in and recharge. Lithium-air batteries would change all this. The Berkeley-based company PolyPlus is being funded by ARAP-E to develop the world’s first commercially available Li-Air battery that could use air from the atmosphere to recharge. The other advantage of Li-Air batteries is that they store nearly 700% more energy than traditional batteries.

Space-Based Solar

A final technology that holds great potential in the longer term is space-based solar. The idea is that solar panels would be launched into the earth’s orbit and could transmit power back to the earth’s surface at a variety of locations. The appeal of solar in space comes in the ability to attain much higher efficiency. Space based panels are unaffected by the filtering effects of the ozone layer and can collect rays 24 hours a day so it is estimated they would produce 144% more power than the maximum attainable on earth. The most obvious downside, of course, is the huge expense of space launches and the construction of a delivery infrastructure. Although this may sound closer to science fiction, in 2009, Solaren, a California startup, signed an agreement with Pacific Gas & Electric, to buy 200 MW of space based solar power.