A Johnson thermoelectric energy converter or JTEC is a type of solid-state heat engine that uses the photodecomposition and recombination of hydrogen in a fuel cell via an approximate Ericsson cycle. It is under investigation as a viable alternative to conventional photovoltaic cells. Lonnie Johnson invented it and claims the converter exhibits an energy conversion efficiency of as much as 60% compared to the 30% efficiency typical of the best photovoltaic cells; however, this claim is at a theoretical level based on comparison with a Carnot cycle and assumes a temperature gradient of 600C. It was originally proposed for funding to the Office of Naval Research but was refused. Johnson obtained later funding by framing the engine as a hydrogen fuel cell. Johnson is collaborating with PARC o