Renewable Energy — page 13 of 18

Renewable Energy terms

1201. Petrocalcic Soil horizon formed when secondary calcium carbonate accumulates in the subsoil and hardens into a hardpan.
1202. Petroglyph A figure or design carved, abraded, or pecked on rock.
1203. Petroleum Any petroleum-based substance composed of a complex blend of hydrocarbons derived from crude oil, including motor fuel, jet oil, lubricants, petroleum…
1204. PETS Proposed, endangered, threatened, or sensitive species.
1205. PFYC See Potential Fossil Yield Classification
1206. pH A measurement for liquids to determine acidity or alkalinity. On a scale of one to 14, seven is considered neutral.
1207. phloem Specialized vascular plant tissue for the transport of assimilates (generally sugars) from the point of synthesis (in the leaf) to other parts of the…
1208. Phosphorous A chemical element used as a dopant in making n-type semiconductor layers. An essential chemical food element that can contribute to the eutrophication of…
1209. photoconversion Conversion of light into other forms of energy by chemical, biological, or physical processes.
1210. Photon A photon is both a wave and a particle. A beam of light is composed of these particles.
1211. Photosynthesis A chemical process by which green plants synthesize organic compounds from carbon dioxide and water in the presence of sunlight.
1212. Photovoltaic A system that converts direct sunlight to electricity using semi-conductor materials.
1213. Photovoltaic (PV) array (PV) An interconnected system of PV modules that function as a single electricity-producing unit.
1214. Photovoltaic (PV) cell (PV) The smallest semiconductor element within a PV module that converts incident sunlight into electrical energy (direct current voltage and current).
1215. Photovoltaic (PV) facility (PV) A solar energy facility that uses photovoltaic cells to produce electricity and that includes all components, such as the PV system, power conditioning…
1216. Photovoltaic (PV) module (PV) An assembly of solar cells (flat-plate type) or receiver(s) and optics (concentrator type) and ancillary parts, such as interconnects and terminals…
1217. Photovoltaic (PV) panel (PV) A collection of modules, either flat-plate or concentrator type, mechanically fastened, electrically interconnected, and designed to provide a…
1218. Photovoltaic (PV) power plant (PV) See Photovoltaic (PV) facility
1219. Photovoltaic (PV) receiver (PV) An assembly of one or more PV cells that accepts concentrated sunlight and incorporates means for thermal and electric energy removal.
1220. Photovoltaic (PV) system (PV) See Photovoltaic (PV) facility
1221. Photovoltaics (PV) (PV) Technologies that utilize semiconducting materials that convert sunlight directly into electricity.
1222. Phreatic vegetation Vegetation supported by groundwater below the land surface.
1223. Phreatophytes Any plant, typically living in the desert, that obtains its water from long taproots that reach the water table.
1224. Physiography The physical geography of an area or the description of its physical features.
1225. Phytoplankton Small, often single-celled plants that live suspended in bodies of water.
1226. Pictograph A design drawn in pigment upon an unprepared or ground rock surface.
1227. Piezometer A nonpumping well, generally of small diameter, for measuring the elevation of a water table.
1228. Piling unmerchantable material (PUM) (PUM) A logging contract requirement to remove and pile unmerchantable woody material of a specified size.
1229. Pilot scale The size of a system between the small laboratory model size (bench scale) and a full-size system.
1230. Pithouse A semi-subterranean dwelling with an excavated floor and earthen superstructure supported by posts and beams.
1231. Placer An alluvial deposit of sand and gravel containing valuable minerals. (nps geo)
1232. Placer mining That form of mining in which the surficial detritus is washed for gold or other valuable minerals.
1233. Placer mining claim Minerals are loose on the ground or in a streambed.
1234. Plains An extensive area that ranges from level to gently sloping or undulating.
1235. Planetary boundary layer turbulence structure In the Earth's atmosphere, the planetary boundary layer is the air layer near the ground that is affected by diurnal heat, moisture, or momentum transfer…
1236. Plankton (planktonic) The aggregate of small plant and animal organisms that float or drift in fresh or salt water.
1237. Plant association A grouping of plant species, or a plant community, that recurs across the landscape.
1238. Playa Flat areas that contain seasonal or year-to-year shallow lakes that often evaporate, leaving minerals behind.
1239. Playa lake Ephemeral lakes formed in the lowest part of a closed (internally drained) basin in an arid region.
1240. Pleistocene The oldest epoch of the Quaternary period, ranging from 2.6 million to 10,000 years ago.
1241. Plot A forest area defined by its condition.
1242. Plume A visible or measurable discharge of a contaminant from a given point of origin.
1243. Plume downwash Downward movement of plumes immediately to the lee of flow obstacles such as buildings, bluffs, or smokestacks, caused by wake turbulence or lee cavity…
1244. Plume model A computer model used to calculate air pollutant concentrations at receptor locations.
1245. Pluton A body of igneous rock that solidified below the Earth's surface.
1246. Plutonic Pertaining to a class of igneous rocks that have solidified far below the Earth's surface.
1247. Pluvial lake A lake formed during episodes of heavy precipitation or glacial melting, such as during the Pleistocene, and may either be extinct or remain as a remnant…
1248. PM10 Particulate that is less than 10 microns in diameter. These particulates are present in the smoke created by burning wood.
1249. PM2.5 Particulate that is less than 2.5 microns in diameter.
1250. Point light source A light source that has no visible surface area, and appears as a point, such as a star.
1251. Point of diversion A specifically named place where water is removed from a body of water. The location of a surface water or groundwater extraction associated with a water…
1252. Point source (emissions) A stationary location or fixed facility from which pollutants are discharged; any single identifiable source of pollution; e.g.
1253. Polishing treatment The final sewage treatment process to further reduce BOD5, suspended solids, and other pollutants.
1254. polymer (PAH-lih-mer) A molecule made up of small identical molecules called monomers. The monomers are joined together in a repeating pattern.
1255. polysaccharide (PAH-lee-SA-kuh-ride) A large carbohydrate molecule. It contains many small sugar molecules that are joined chemically. Also called glycan.
1256. Post-aeration The introduction of oxygen into waste water to further reduce BOD and COD after secondary or advanced treatment.
1257. Potable water Water that is suitable for drinking, as defined by local health officials.
1258. Potential Fossil Yield Classification (PFYC) (PFYC) Initially developed by the U.S. Forest Service and the Region 2 Paleo Initiative in May 1996, the PFYC system provides baseline guidance for assessing the…
1259. Potentially Active Fault See Fault, potentially active
1260. Pound Pound mass (sometimes abbreviated lb(m)). A unit of mass equal to 0.454 kilograms.
1261. Pound force (sometimes abbreviated lb(f)) A force which will accelerate one pound mass at a rate of 32.2 ft/second(2).
1262. Pound of Steam One pound of water in vapor phase; is NOT steam pressure, which is expressed as pounds per square inch (psi).
1263. Power block Portion of the facility at which electrical power is generated.
1264. Power conditioning system (PCS) (PCS) In solar energy facilities, the collection of electrical equipment that converts direct current (DC) from a photovoltaic array to alternating current (AC)…
1265. Power production capacity The amount of power that a facility can produce under ideal operating conditions. See also Battery capacity
1266. Power tower A type of CSP technology composed of many large, sun-tracking mirrors (heliostats) that focus sunlight on a receiver at the top of a centrally located…
1267. Power tower system See Power tower
1268. Power, electrical A unit of electrical energy, usually expressed in watts (W), kilowatts (kW), or megawatts (MW). One watt equals 3.14 Btu per hour.
1269. Precambrian The oldest and largest division of geologic time, between the consolidation of the Earth's crust and the beginning of the Cambrian period.
1270. Precommercial thinning Thinning for timber stand improvement purposes, generally in young, densely stocked stands.
1271. Prehistoric The time period before the appearance of written records. In the New World this generally refers to indigenous, precontact societies.
1272. Prehistoric resources Refers to any material remains, structures, and items used or modified by people before Euro-Americans established a presence in the region.
1273. Prescribed fires Application of fire (by planned or unplanned ignitions) to fuels in either their natural or modified states, under specified conditions, to allow the fire…
1274. Prescription A direction written by the physician to the pharmacist for the preparation and use of a medicine or remedy.
1275. Present value The current value of a future cash flow or series of cash flows discounted at an appropriate interest rate or rates.
1276. Prevention of significant deterioration (PSD) (PSD) Under the Clean Air Act, a planning and management process for air quality when a new source of air pollution is proposed in an area where ambient air…
1277. Prevention of Significant Deterioration (PSD) Program (PSD) A Federal air pollution permitting program intended to ensure that air quality does not diminish in attainment areas which meet national ambient air…
1278. Prey base The assemblage of prey (food) animals available in a given area or habitat to support a predator such as a hawk or cougar.
1279. Prior Appropriation Doctrine A system for allocating water rights used in the western United States under which the first person (or entity) to divert water from a source has a…
1280. process development unit An experimental facility that establishes proof of concept, preliminary process economics, and engineering feasibility for a pilot or demonstration plant.
1281. Process Heat Thermal energy that is used in agricultural and industrial operations.
1282. Producer Gas Low or medium Btu content gas, composed mainly of carbon monoxide, nitrogen(2), and hydrogen(2) made by the gasification of wood or coal.
1283. Productive machine hours That portion of scheduled operating hours during which a machine performs its designated functions, excluding time to transport the machine and…
1284. Programmed timber harvest A timber harvest scheduled by a management plan to occur at a certain rate.
1285. Projectile point Any sharp tip of an arrow, spear, or dart.
1286. Proof A measure of ethanol content. 1-percent ethanol content equals 2 proof.
1287. protein (PRO-teen) A molecule made up of amino acids that are needed for the body to function properly.
1288. Proximate Analysis A commonly used analysis for reporting fuel properties; may be on a dry (moisture free) basis, as "fired", or on an ash and moisture free basis.
1289. PSD increments The maximum increases in ambient pollution concentrations allowed over baseline concentrations for a pollutant while ensuring that an area continues to…
1290. Psi Pounds of pressure per square inch.
1291. Psia Pounds/force per square inch absolute.
1292. Psig Pounds/force per square inch gauge.
1293. Public land Any land and interest in land (outside of Alaska) owned by the United States and administered by the Secretary of the Interior through the Bureau of Land…
1294. Public Land Order (PLO) (PLO) An order affecting, modifying, or cancelling a withdrawal or reservation that has been issued by the Secretary of the Interior pursuant to powers of the…
1295. Public Land Survey System (PLSS) (PLSS) The survey carried out by the BLM and its predecessors for establishing boundaries and subdivisions of public lands of the United States, using the rules…
1296. Public utility commissions State agencies that regulate investor-owned utilities operating in the state.
1297. Public utility district (PUD) (PUD) A publicly owned energy producer or distributor. PUDs operate as special government districts under the authority of elected commissions.
1298. Public Utility Regulatory Policies Act (PURPA) (PURPA) A federal law requiring a utility to buy the power produced by a qualifying facility at a price equal to that which the utility would otherwise pay if it…
1299. Publicly Owned Treatment Works Permit (POTW) (POTW) A permit that regulates discharges to publicly owned sewage treatment plants.
1300. Pueblo The Spanish word for town. A community dwelling with numerous households within, up to five stories high, built of stone or adobe by Indian tribes in the…