Electrofuels are an emerging class of carbon-neutraldrop-in replacement fuels that are made by storing electrical energy from renewable sources in the chemical bonds of liquid or gas fuels. The primary targets are butanol, biodiesel, and hydrogen, but include other alcohols and carbon-containing gasses such as methane and butane. A primary source of funding for research on liquid electrofuels for transportation is the Electrofuels Program of the Advanced Research Projects Agency-Energy, headed by Eric Toone. ARPA-E, created in 2009 under President Obama’s Secretary of EnergySteven Chu, is the Department of Energy’s attempt to duplicate the effectiveness of the Defense Advanced Research Projects Agency, DARPA. Examples of projects funded under this program include OPX Biotechnologies’ biodiesel effort led by Michael Lynch and Derek Lovley’s work on microbial electrosynthesis at the University of Massachusetts Amherst, which reportedly produced the first liquid electrofuel using CO2 as the feedstock. Descriptions of all ARPA-E Electrofuels Program research projects can be found at the ARPA-E Electrofuels Program website. The first Electrofuels Conference, sponsored by the American Institute of Chemical Engineers was held in Providence, RI in November 2011. At that conference, Director Eric Toone stated that "Eighteen months into the program, we know it works. We need to know if we can make it matter." Several groups are beyond proof-of-principle, and are working to scale up cost-effectively. Electrofuels have the potential to be disruptive if carbon-neutral electrofuels can be cheaper than petroleum fuels, and chemical feedstocks produced by electrosynthesis cheaper than those refined from crude oil. Electrofuels also have a great potential to alter the renewable energy landscape, as electrofuels allow renewables from all sources to be stored conveniently as a liquid fuel. , prompted by the fracking boom, ARPA-E's focus has moved from electrical feedstocks to natural-gas based feedstocks, and thus away from electrofuels.
