This blog (and others) use enough acronyms and terms of art that it is important to have a ready reference for people who wonder what the conversation is about. I have decided to keep my own glossary (which is likely to contain pointers to outside resources) to make this a bit easier. Suggestions for the glossary are welcome.
eat and P
ower. This is the additional production of electricity from processes which otherwise produce only space heat or domestic hot water (DHW); this is also known as cogeneration
Direct Carbon Fuel Cell
: This is a variant of the MCFC
which takes its fuel as solid carbon (graphite, charcoal or coke) rather than as a gas at the anode. The DCFC may be able to reach 80% efficiency.
: The additional production of electricity from processes which would otherwise yield only some other product. Most cogeneration systems make space heat, but it is feasible to extract electricity from systems making medium-pressure steam for industrial process heat. Should it become feasible to extract useful energy from e.g. strongly exothermic chemical reactions in industrial processes, this would probably also fall under the definition of cogeneration.
: The adjustment of the power balance of the electrical grid by controlling loads (e.g. turning electric water heaters on and off) instead of adjusting generation.
ehicle, aka plug-in hybrid
. This is a hybrid-electric vehicle which has enough battery capacity to travel distances of several miles without starting its engine and can recharge from the electrical grid. As long as the user plugs in and does not need to drive long distances, gasoline is completely optional.
, Institute for Analysis of Global Security
ycle. This is a
process where a fuel (usually coal, but sometimes coke or bitumen) is partially
burned in an oxygen-deficient environment to convert it to a "syngas". The syngas is filtered to remove particulates and scrubbed of pollutants such as sulfur, then it is burned in a gas turbine to make power. The hot gas output of the gas turbine is fed to a heat recovery steam generator (HRSG); the steam
from the HSRG runs a turbine which makes more power. IGCC plants burning coal are substantially more efficient than powdered-coal combustion (PCC) steam-cycle powerplants (~40% vs. ~33%) and have much lower emissions of sulfur, nitrogen oxides and particulates.
Molten Carbonate Fuel Cell
: This is a fuel cell which uses a molten bath of carbonate salts as its electrolyte. At the cathode, it combines oxygen, electrons and carbon dioxide to make carbonate (CO32-
) ions; at the anode, the carbonate is combined with carbon and/or hydrogen to make CO2
, water and free electrons. The electrons complete the circuit outside the fuel cell. A further refinement is the direct carbon fuel cell (DCFC
aste. All the stuff that you put into the can to be thrown "out", from coffee grounds to 40-year-old insecticide powder.
Proton Exchange Membrane
: This is an element of the most common type of hydrogen fuel cell (as well as some electrolyzers), which allows protons to pass but blocks electricity. Current PEMs have short lifespans and are difficult to fabricate into working cells, which is part of the high expense of hydrogen fuel cells.
ehicle. Synonymous with GO-HEV
. Appears to have replaced PIH and GO-HEV as the favored term (13-Apr-2006).
ybrid. Synonym for GO-HEV
. May be falling out of favor.
oltaic. A technology for converting photons (light) to electricity. Historically, PV cells used semiconductor materials such as silicon or cadmium indium sulfide but they are increasingly moving to common materials such as titanium dioxide and plastics.
ell. A fuel cell which uses an oxide ceramic, typically zirconia, as its electrolyte. The charge carriers
are oxygen ions (O2-
), which has useful properties in certain circumstances. SOFC's require high operating temperatures to allow ions to move within the ceramic and permit current to flow; the lowest operating temperatures
are now around 800° C.
olymerization. A process owned by Changing World
Technologies which uses conditions of high temperature, pressure and anoxia to convert mixtures of carbonaceous material and water to light hydrocarbons, combustible gas and carbon solids. This process appears great in the lab, but the pilot plant has severe odor emissions of an undisclosed nature.