Renewable Energy terms starting with P

142 terms

Paleontological resources Fossilized remains, imprints, and traces of plants and animals preserved in rocks and sediments since some past geologic time.
Paleozoic An era of geologic time, from the end of the Precambrian to the beginning of the Mesozoic, spanning the time between 542 and 251 million years ago.
Palm oasis (1) A desert habitat with permanent water or a water table near the surface that supports a canopy of palm trees.
Palustrine wetlands Shallow freshwater wetlands that often support plant communities of trees, shrubs, emergent plants, mosses, or lichens.
Pan evaporation A measurement that combines or integrates the effects of several climate elements: temperature, humidity, solar radiation, and wind.
Parabolic solar collector trough See Parabolic trough
Parabolic Trough A solar energy conversion device that uses a trough covered with a highly reflective surface to focus sunlight onto a linear absorber containing a working…
Parabolic trough system See Parabolic trough
Partial cut A harvest method in which portions of a stand of timber are cut during a number of entries over time. Compare precommercial thinning.
Particulate A small, discrete mass of solid or liquid matter that remains individually dispersed in gas or liquid emissions.
Particulate emissions Fine liquid or solid particles discharged with exhaust gases. Usually measured as grains per cubic foot or pounds per million Btu input.
Particulate matter Fine solid or liquid particles such as dust, smoke, mist, fumes, or smog, found in air or emissions.
Particulates The fine liquid or solid particles contained in combustion gases. The quantity and size of particulates emitted by cars, power and industrial plants, wood…
Passerine Birds of the order Passeriformes, which includes perching birds and songbirds such as the jays, blackbirds, finches, warblers, and sparrows.
Passive solar energy system Solar heating or cooling that uses natural energy flows to transfer heat.
Patterned-body anthropomorphs Object or drawing having a human shape with a pattern or design. See also Anthropomorphic; Anthropomorphism
PCB´s Polychlorinated biphenyls. A group of organic compounds. PCB´s are highly toxic to aquatic life.
Peak flow The highest flow of water attained during a particular flood for a given stream or river.
Peak horizontal acceleration See Acceleration
Peanut-body anthropomorphs Object or drawing having a human-like shape resembling that of a peanut. See also Anthropomorphic; Anthropomorphism
Pediment 1. The triangular space forming the gable end of a roof above the horizontal cornice. 2. An ornamental gable, usually triangular, above a door or window.
Per capita income The average income per person in a given group.
Percolation The filtering of a liquid passed through a medium with many fine spaces.
Perennial allotment A BLM grazing allotment that consistently produces enough perennial forage to support a year round livestock operation.
Perennial streams Streams that flow continuously because they lie at or below the groundwater table, which constantly replenishes them.
Perennial surface water features Surface water features that contain water at all times throughout the year.
Perennial yield (groundwater) The amount of groundwater that can be withdrawn from a groundwater basin over a period of time without exceeding the long-term recharge of the basin or…
Perennial/safe/sustainable yield A specified rate of groundwater pumping that can be sustained for an indefinite period of time without impairing hydrogeologic and ecologic processes…
Perfluorocarbon (PFC) Compounds consisting of carbon and fluorine. They do not deplete the stratospheric ozone but are very strong greenhouse gases with long lifetimes in the…
Permeability The rate at which liquids pass through soil or other materials in a specified direction.
Permissible Exposure Limit (PPL) The maximum amount or concentration of a chemical that a worker may be exposed to under OSHA regulations.
Permit Any permit other than a Notice to Proceed issued by the Landmarks Preservation Commission in accordance with the Landmarks Law: (a) "PMW shall mean Permit…
Permitted use The forage allocated by, or under the guidance of, an applicable land use plan for livestock grazing in an allotment under a permit or lease; expressed in…
Permittee An individual who holds either a BLM grazing permit or grazing lease that authorizes grazing use of the public lands issued under authority of Section 3…
Personal Protective Equipment (PPE) Clothing or devices worn to help isolate or shield a person from direct exposure to a hazardous material or situation.
Pesticide (PES-tih-side) Any substance that is used to kill insects and other pests.
Pestle An elongated, often cylindrical stone used to pulverize food products and other cultural products in a mortar. See also Mortar
Petrocalcic Soil horizon formed when secondary calcium carbonate accumulates in the subsoil and hardens into a hardpan.
Petroglyph A figure or design carved, abraded, or pecked on rock.
Petroleum Any petroleum-based substance composed of a complex blend of hydrocarbons derived from crude oil, including motor fuel, jet oil, lubricants, petroleum…
PETS Proposed, endangered, threatened, or sensitive species.
PFYC See Potential Fossil Yield Classification
pH A measurement for liquids to determine acidity or alkalinity. On a scale of one to 14, seven is considered neutral.
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…
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…
photoconversion Conversion of light into other forms of energy by chemical, biological, or physical processes.
Photon A photon is both a wave and a particle. A beam of light is composed of these particles.
Photosynthesis A chemical process by which green plants synthesize organic compounds from carbon dioxide and water in the presence of sunlight.
Photovoltaic A system that converts direct sunlight to electricity using semi-conductor materials.
Photovoltaic (PV) array An interconnected system of PV modules that function as a single electricity-producing unit.
Photovoltaic (PV) cell The smallest semiconductor element within a PV module that converts incident sunlight into electrical energy (direct current voltage and current).
Photovoltaic (PV) facility A solar energy facility that uses photovoltaic cells to produce electricity and that includes all components, such as the PV system, power conditioning…
Photovoltaic (PV) module An assembly of solar cells (flat-plate type) or receiver(s) and optics (concentrator type) and ancillary parts, such as interconnects and terminals…
Photovoltaic (PV) panel A collection of modules, either flat-plate or concentrator type, mechanically fastened, electrically interconnected, and designed to provide a…
Photovoltaic (PV) power plant See Photovoltaic (PV) facility
Photovoltaic (PV) receiver An assembly of one or more PV cells that accepts concentrated sunlight and incorporates means for thermal and electric energy removal.
Photovoltaic (PV) system See Photovoltaic (PV) facility
Photovoltaics (PV) Technologies that utilize semiconducting materials that convert sunlight directly into electricity.
Phreatic vegetation Vegetation supported by groundwater below the land surface.
Phreatophytes Any plant, typically living in the desert, that obtains its water from long taproots that reach the water table.
Physiography The physical geography of an area or the description of its physical features.
Phytoplankton Small, often single-celled plants that live suspended in bodies of water.
Pictograph A design drawn in pigment upon an unprepared or ground rock surface.
Piezometer A nonpumping well, generally of small diameter, for measuring the elevation of a water table.
Piling unmerchantable material (PUM) A logging contract requirement to remove and pile unmerchantable woody material of a specified size.
Pilot scale The size of a system between the small laboratory model size (bench scale) and a full-size system.
Pithouse A semi-subterranean dwelling with an excavated floor and earthen superstructure supported by posts and beams.
Placer An alluvial deposit of sand and gravel containing valuable minerals. (nps geo)
Placer mining That form of mining in which the surficial detritus is washed for gold or other valuable minerals.
Placer mining claim Minerals are loose on the ground or in a streambed.
Plains An extensive area that ranges from level to gently sloping or undulating.
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…
Plankton (planktonic) The aggregate of small plant and animal organisms that float or drift in fresh or salt water.
Plant association A grouping of plant species, or a plant community, that recurs across the landscape.
Playa Flat areas that contain seasonal or year-to-year shallow lakes that often evaporate, leaving minerals behind.
Playa lake Ephemeral lakes formed in the lowest part of a closed (internally drained) basin in an arid region.
Pleistocene The oldest epoch of the Quaternary period, ranging from 2.6 million to 10,000 years ago.
Plot A forest area defined by its condition.
Plume A visible or measurable discharge of a contaminant from a given point of origin.
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…
Plume model A computer model used to calculate air pollutant concentrations at receptor locations.
Pluton A body of igneous rock that solidified below the Earth's surface.
Plutonic Pertaining to a class of igneous rocks that have solidified far below the Earth's surface.
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…
PM10 Particulate that is less than 10 microns in diameter. These particulates are present in the smoke created by burning wood.
PM2.5 Particulate that is less than 2.5 microns in diameter.
Point light source A light source that has no visible surface area, and appears as a point, such as a star.
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…
Point source (emissions) A stationary location or fixed facility from which pollutants are discharged; any single identifiable source of pollution; e.g.
Polishing treatment The final sewage treatment process to further reduce BOD5, suspended solids, and other pollutants.
polymer (PAH-lih-mer) A molecule made up of small identical molecules called monomers. The monomers are joined together in a repeating pattern.
polysaccharide (PAH-lee-SA-kuh-ride) A large carbohydrate molecule. It contains many small sugar molecules that are joined chemically. Also called glycan.
Post-aeration The introduction of oxygen into waste water to further reduce BOD and COD after secondary or advanced treatment.
Potable water Water that is suitable for drinking, as defined by local health officials.
Potential Fossil Yield Classification (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…
Potentially Active Fault See Fault, potentially active
Pound Pound mass (sometimes abbreviated lb(m)). A unit of mass equal to 0.454 kilograms.
Pound force (sometimes abbreviated lb(f)) A force which will accelerate one pound mass at a rate of 32.2 ft/second(2).
Pound of Steam One pound of water in vapor phase; is NOT steam pressure, which is expressed as pounds per square inch (psi).
Power block Portion of the facility at which electrical power is generated.