The Department of Energy announced September 13 that it would spend up to $10 million in a bid to settle the question of whether low-energy nuclear reactions (LENR)—historically known as “cold fusion”—could ever become a carbon-free energy source. The funding is part of an Advanced Research Projects Agency–Energy (ARPA-E) LENR Exploratory Topic designed to “encourage the submission of the most innovative and unconventional ideas in energy technology.”