Acronyms and Unit Abbreviations

Acronymns

BOS balance of system CB conduction band CHP combined heat and power COP coefficient of performance CPV concentrated photovoltaic dc direct current DNI direct normal irradiation DOE U.S. Department of Energy EFG edge-defined film-fed growth EIA Energy Information Administration EPV electrochemical photovoltaic HCPV high-concentration photovoltaic HHV higher heating value IPCC Intergovernmental Panel on Climate Change IR infrared ITO Indium Tin Oxide LH1/LH2 light-harvesting pigment/protein complexes MBE molecular beam epitaxy MEG multiple exciton generation MESP minimum ethanol selling price MOCVD metalorganic chemical vapor deposition NAE National Academy of Engineering NHE normal hydrogen electrode NRC National Research Council OEC oxygen-evolving complex OLED organic light emitting diode OPV organic photovoltaic (solar cell) PCET proton-coupled electron transfer PCM phase change storage material PEC photoelectrochemical PEM proton exchange membrane PRD priority research directions PV photovoltaic R&D research and development RC reaction center TCO transparent conducting oxide TMS theoretical modeling and simulation TPV thermophotovoltaic U.S. United States UV ultraviolet XAFS X-ray absorption fine-structure (spectroscopy) ZT thermoelectric figure of merit

ACRONYMS	Meaning
a-Si:H	hydrogenated amorphous silicon

Units

°C degree(s) Celsius $/kW dollar(s) per kilowatt μm micrometer(s) μs microsecond(s) Å angstrom(s) amp ampere(s) Bbl billion barrels cm centimeter(s) cm/min centimeter(s) per minute eV electron volt(s) fs femtosecond(s) gal gallon(s) Gha gigahectare(s) GJ gigajoule(s) Gtons gigatons (109 tons = 1 billion tons) GW gigawatt(s) (109 W = 1 billion watts) kg kilogram(s) kWh kilowatt hour(s) kWth kilowatt(s) (thermal) K Kelvin L liter(s) MHz megahertz mm millimeter(s) MW megawatt(s) (106 W = 1 million watts) MWe megawatt(s) (electric) MWth megawatt(s) (thermal) MW/yr megawatt(s) per year nm nanometer(s) nm/s nanometer(s) per second ps picosecond(s) psi pound(s) per square inch s second(s) TW terawatt(s) (1012 W = 1 trillion watts) W watt(s) Wp peak watt(s) yr year(s)