When oxygen is combined with hydrogen, the products are water and
electricity. Fuel cells exploit this chemical reaction, pulling
oxygen from the air and hydrogen from a fuel source such as natural
gas. Used by NASA for generating power in space, fuel cells are
now being developed for both stationary use and mobile applications
Software-synchronized networks of micropower generators.
Small-scale turbines that generate electricity by spinning a magnet
inside a coil at extremely high speeds. Fueled by a variety of gases.
Less efficient than fuel cells, but cheaper; efficiencies are higher
if microturbine waste heat can also be used on-site (a process called
Also known as solar cells, photovoltaics convert sunlight to electricity.
Costs are high but the fuel is free, and maintenance costs are low.
Refined versions of internal combustion engines provide more efficient
output and lower emissions. Currently lower cost, but higher emissions
and higher maintenance needs than other emerging micropower technologies.
Super-capacitors and flywheels
Short-term storage devices for electricity to smooth transitions
on and off the grid.
Wind turbines are often deployed in large "farm" arrays, but can also
be installed on-site in single-user micropower applications.
See January 2001 fedgazette.
For more information:
Electric Power Research Institute
Energy Efficiency and Renewable Energy, U.S. Department of Energy
Worldwatch Paper #151: Micropower: The Next Electrical Era