Cold fusion implies a nuclear reaction taking place at low temperatures to produce energy. In the past, energy output has been relatively low due to the low temperature, but now an Italian inventor says his design could be a boon for world energy production: "Andrea Rossi is an Italian inventor that claims to have produced the world's first commercial ready 'cold fusion' reactor. For 20 years or longer scientists have been producing nuclear reactions at low temperatures in small reactors that cost a fraction of what is used to produce 'hot fusion.'"