1.8.1 Fuel Cell Technology
Use electricity generated and stored during periods of peak supply from renewable sources on demand, utilizing fuel cells.
Supply source of hydrogen (typically hydrogen fuel, PV arrays, or natural gas), fuel reformer, fuel storage, fuel cell.
Hydrogen is fed in to one side of the fuel cell, while oxygen is fed into the other. An electrolyte barrier separating the two creates an oxidation reaction which splits electrons from the hydrogen and creates an electric current. The spent hydrogen combines with the oxygen to create water. Stationary fuel cells can be installed in the basements of buildings, for example, to generate electricity that can be used both for heating and cooling.
The high cost of hydrogen production, low availability of the hydrogen production systems, and the challenge of providing safe production and delivery systems are early penetration barriers. Some states offer tax incentives and/or rebates for fuel cell purchase and installation; see Policies for Stationary Fuel Cells/Power Generation in the State Fuel Cell and Hydrogen Database at www.fuelcells.org/dbs. Natural Gas fuel cells are alternative to pure hydrogen fuel cells targeted for residential projects, as many residential projects have existing natural gas connections. Carbon is stripped from the natural gas, leaving hydrogen fuel.
Using PV arrays as the hydrogen source will deliver clean hydrogen—produced without carbon emissions or air pollutants. Hydrogen fuel production and hydrogen extraction from natural gas both create carbon emissions, however the emissions are lower and efficiency higher than other fossil fuels. Hydrogen-powered fuel cells can have two to three times the efficiency of traditional combustion technologies. Reducing cost and improving durability are the two most significant challenges to fuel cell commercialization.
Hydrogen codes and standards are being developed to provide the information needed to safely build, maintain and operate hydrogen and fuel cell systems and facilities. Educational efforts seek to ensure uniformity of safety requirements and provide local officials and safety inspectors with the information needed to certify hydrogen systems and installations.
1.6.2 Photo voltaic (PV)