Hydrogen
Hydrogen is an energy carrier
The production of hydrogen fuel requires energy. For this reason, hydrogen is often described as an energy carrier.
Hydrogen can be produced using excess electricity from renewable resources. For example, the wind may be blowing through a wind farm in the middle of the night, when demand for electricity is low. If the electricity production in the middle of the night is greater than the need for electricity, the extra energy can be used to produce hydrogen.
The hydrogen can be stored and used later, when electricity demand is at its peak.
Or, the stored hydrogen can be used as a transportation fuel.
Where does hydrogen come from?
Hydrogen gas, the "fuel" for fuel cells, does not exist in nature for very long in its pure form (H2). Instead, hydrogen is usually found combined with other elements, such as:
- with oxygen in water (H2O)
- with carbon in "hydrocarbons" (methane: CH4; propane: C3H8; and numerous other carbon-hydrogen chains and rings found in gasoline and diesel)
- with carbon and oxygen in alcohols (methanol: CH3OH; ethanol: C2H5OH)
Hydrogen from water
The hydrogen in water can be separated from the oxygen in a process called hydrolysis. The amount of energy required for the hydrolysis process is more than is ultimately produced by the fuel cell.
However, if renewable energy sources (solar, wind, biomass, etc.) are used for the hydrolysis process, it's a way to convert available energy from these sources (sunlight, wind, etc.) into a fuel (hydrogen) that can be stored for later use.
Hydrogen from hydrocarbons and alcohol fuels
Hydrogen can be separated from the carbon in hydrocarbons, and carbon and oxygen in alcohol fuels, through a device called a "reformer." Several companies are developing reformers that will use liquid fuels, such as gasoline, alcohol, or gasoline-alcohol combinations, to produce hydrogen for use in fuel cells.
Reports and Links
- Nurturing a Clean Energy Future in Hawaii: Assessing the Feasibility of the Large-Scale Utilization of Hydrogen and Fuel Cells in Hawaii - Report prepared for DBEDT in 2002 by the Hawaii Natural Energy Institute and Sentech (pdf file; 3,302 kb)
- General Electric - geglobalresearch.com - Hydrogen energy is included on GE's website under "core technologies"
- Hawaii Natural Energy Institute - www.hnei.hawaii.edu/hydrogen.asp - includes information on Hawaii hydrogen and fuel cell activities and partnerships
- International Energy Agency - www.ieahia.org - includes links to renewable-hydrogen case studies and demonstrations
- National Renewable Energy Laboratory - www.nrel.gov/hydrogen/ - hydrogen research
- Renewable Energy Analysis Studies Network (REASN) - www.nrel.gov/reasn - studies
- Renewable Energy Annual - www.eia.doe.gov - current information on renewable energy from the U.S. Energy Information Administration
- Renewable Energy Alliance - www.realliance.org - encouraging the expansion of renewable power markets
- Renewable Energy for Development - www.sei.se/red - newsletter on Third World energy utilization and technologies
- Renewable Energy Education Module - solstice.crest.org/renewables/re-kiosk/index.shtml - online renewable energy education
- Renewable Energy Policy Project - www.repp.org - articles "strive to be understandable, without glossing over technical issues crucial to well-crafted renewable energy policy"
- State Renewable Energy News - www.nrel.gov/analysis/emaa/projects/sren - news from across the U.S.
- Union of Concerned Scientists - www.ucsusa.org - "working for a healthier environment and a safer world."
- U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy - http://www.eere.energy.gov/