Solar Energy — page 8 of 11

Solar Energy terms

701. Palm oasis (1) A desert habitat with permanent water or a water table near the surface that supports a canopy of palm trees.
702. Palustrine wetlands Shallow freshwater wetlands that often support plant communities of trees, shrubs, emergent plants, mosses, or lichens.
703. Pan evaporation A measurement that combines or integrates the effects of several climate elements: temperature, humidity, solar radiation, and wind.
704. Parabolic solar collector trough See Parabolic trough
705. 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…
706. Parabolic trough system See Parabolic trough
707. Particulate matter Fine solid or liquid particles such as dust, smoke, mist, fumes, or smog, found in air or emissions.
708. Passerine Birds of the order Passeriformes, which includes perching birds and songbirds such as the jays, blackbirds, finches, warblers, and sparrows.
709. Patterned-body anthropomorphs Object or drawing having a human shape with a pattern or design. See also Anthropomorphic; Anthropomorphism
710. Peak horizontal acceleration See Acceleration
711. Peanut-body anthropomorphs Object or drawing having a human-like shape resembling that of a peanut. See also Anthropomorphic; Anthropomorphism
712. 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.
713. Per capita income The average income per person in a given group.
714. Perennial allotment A BLM grazing allotment that consistently produces enough perennial forage to support a year round livestock operation.
715. Perennial streams Streams that flow continuously because they lie at or below the groundwater table, which constantly replenishes them.
716. Perennial surface water features Surface water features that contain water at all times throughout the year.
717. Perennial yield (groundwater) The amount of groundwater that can be withdrawn from a groundwater basin over a period of time without exceeding the long-term recharge of the basin or…
718. 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…
719. Perfluorocarbon (PFC) (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…
720. Permeability The rate at which liquids pass through soil or other materials in a specified direction.
721. Permissible Exposure Limit (PPL) (PPL) The maximum amount or concentration of a chemical that a worker may be exposed to under OSHA regulations.
722. 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…
723. 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…
724. 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…
725. Personal Protective Equipment (PPE) (PPE) Clothing or devices worn to help isolate or shield a person from direct exposure to a hazardous material or situation.
726. Pesticide (PES-tih-side) Any substance that is used to kill insects and other pests.
727. Pestle An elongated, often cylindrical stone used to pulverize food products and other cultural products in a mortar. See also Mortar
728. Petrocalcic Soil horizon formed when secondary calcium carbonate accumulates in the subsoil and hardens into a hardpan.
729. Petroglyph A figure or design carved, abraded, or pecked on rock.
730. PFYC See Potential Fossil Yield Classification
731. 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…
732. Photon A photon is both a wave and a particle. A beam of light is composed of these particles.
733. Photosynthesis A chemical process by which green plants synthesize organic compounds from carbon dioxide and water in the presence of sunlight.
734. Photovoltaic (PV) array (PV) An interconnected system of PV modules that function as a single electricity-producing unit.
735. Photovoltaic (PV) cell (PV) The smallest semiconductor element within a PV module that converts incident sunlight into electrical energy (direct current voltage and current).
736. 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…
737. 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…
738. Photovoltaic (PV) panel (PV) A collection of modules, either flat-plate or concentrator type, mechanically fastened, electrically interconnected, and designed to provide a…
739. Photovoltaic (PV) power plant (PV) See Photovoltaic (PV) facility
740. 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.
741. Photovoltaic (PV) system (PV) See Photovoltaic (PV) facility
742. Photovoltaics (PV) (PV) Technologies that utilize semiconducting materials that convert sunlight directly into electricity.
743. Phreatic vegetation Vegetation supported by groundwater below the land surface.
744. Phreatophytes Any plant, typically living in the desert, that obtains its water from long taproots that reach the water table.
745. Physiography The physical geography of an area or the description of its physical features.
746. Phytoplankton Small, often single-celled plants that live suspended in bodies of water.
747. Pictograph A design drawn in pigment upon an unprepared or ground rock surface.
748. Piezometer A nonpumping well, generally of small diameter, for measuring the elevation of a water table.
749. Pithouse A semi-subterranean dwelling with an excavated floor and earthen superstructure supported by posts and beams.
750. Placer An alluvial deposit of sand and gravel containing valuable minerals. (nps geo)
751. Placer mining That form of mining in which the surficial detritus is washed for gold or other valuable minerals.
752. Placer mining claim Minerals are loose on the ground or in a streambed.
753. Plains An extensive area that ranges from level to gently sloping or undulating.
754. 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…
755. Plankton (planktonic) The aggregate of small plant and animal organisms that float or drift in fresh or salt water.
756. Playa Flat areas that contain seasonal or year-to-year shallow lakes that often evaporate, leaving minerals behind.
757. Playa lake Ephemeral lakes formed in the lowest part of a closed (internally drained) basin in an arid region.
758. Pleistocene The oldest epoch of the Quaternary period, ranging from 2.6 million to 10,000 years ago.
759. Plume A visible or measurable discharge of a contaminant from a given point of origin.
760. 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…
761. Plume model A computer model used to calculate air pollutant concentrations at receptor locations.
762. Pluton A body of igneous rock that solidified below the Earth's surface.
763. Plutonic Pertaining to a class of igneous rocks that have solidified far below the Earth's surface.
764. 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…
765. PM10 Particulate that is less than 10 microns in diameter. These particulates are present in the smoke created by burning wood.
766. PM2.5 Particulate that is less than 2.5 microns in diameter.
767. Point light source A light source that has no visible surface area, and appears as a point, such as a star.
768. 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…
769. Point source (emissions) A stationary location or fixed facility from which pollutants are discharged; any single identifiable source of pollution; e.g.
770. Potable water Water that is suitable for drinking, as defined by local health officials.
771. 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…
772. Potentially Active Fault See Fault, potentially active
773. Power block Portion of the facility at which electrical power is generated.
774. 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)…
775. Power production capacity The amount of power that a facility can produce under ideal operating conditions. See also Battery capacity
776. 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…
777. Power tower system See Power tower
778. 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.
779. Precambrian The oldest and largest division of geologic time, between the consolidation of the Earth's crust and the beginning of the Cambrian period.
780. Prehistoric The time period before the appearance of written records. In the New World this generally refers to indigenous, precontact societies.
781. Prehistoric resources Refers to any material remains, structures, and items used or modified by people before Euro-Americans established a presence in the region.
782. 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…
783. 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…
784. 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.
785. 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…
786. Projectile point Any sharp tip of an arrow, spear, or dart.
787. PSD increments The maximum increases in ambient pollution concentrations allowed over baseline concentrations for a pollutant while ensuring that an area continues to…
788. 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…
789. 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…
790. 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…
791. 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…
792. Pueblo rights A water right possessed by a municipality which, as a successor of a Spanish or Mexican pueblo, entitled to the beneficial use of all needed…
793. Pyroclastic flow High-speed avalanches of hot ash, rock fragments, and gas that move down the sides of a volcano during explosive eruptions or when the steep edge of a…
794. Pyroclastic surge Similar to a pyroclastic flow, but contains a higher proportion of gas to rock and is more turbulent and faster moving.
795. Quad-level occurrence The recorded occurrence of a species in the area represented by a specific, named U.S. Geological Survey 7.5-minute topographic quadrangle map (quad map).
796. Quartzite A hard, metamorphic rock that was originally sandstone.
797. Quaternary The present period, forming the latter part of the Cenozoic Era, originating about 1 million years ago and including the Recent and Pleistocene epochs.
798. Rain shadow effect The region on the lee (sheltered) side of a mountain or mountain range where the precipitation is noticeably less than on the windward side, because the…
799. Rangeland Land on which the native vegetation, climax, or natural potential consists predominately of grasses, grasslike plants, forbs, or shrubs.
800. Rankine steam cycle The thermodynamic cycle of temperature and pressure changes of water as it is converted from a liquid to a gaseous state by heating, and returns back to…