Regenerative Fuel Cells (RFC)

The Regenerative Fuel Cell (RFC) is a system that can operate in a closed loop and could serve as the basis of a hydrogen economy operating on renewable energy. Fuel cells generating electricity, heat, and water from hydrogen and oxygen would be used throughout the economy, powering factories, vehicles, and houses. The hydrogen would be generated from the electrolysis of water, splitting it into its constituent components of hydrogen and oxygen, using renewable energy sources such as wind, solar, or geothermal.

Such a system would not require any specific type of fuel cell, but would need an infrastructure to deliver hydrogen to the many fuel cells in use. Little to no new technology is required to implement a renewable-based system. However, there currently does not exist the infrastructure for hydrogen delivery. Also, the cost of electricity would be high, but will decrease as costs decrease for each of the components: fuel cells, hydrogen storage, and delivery, renewable energy collection, etc.

Currently, there is a project led by NASA to develop an efficient and lightweight regenerative fuel cell system for use on board an airplane called the Helios that can fly at altitudes near 100,000 feet. The predecessor aircraft was powered by photovoltaic solar cells. The goal is to incorporate both photovoltaic solar cells and a regenerative fuel cell on board. The solar cells will power the aircraft during the day and generate a supply of hydrogen that would be stored for use by the fuel cell overnight. Such a system would then be capable of flights lasting many days.