A devise composed of cells constructed in a parabolic shape with a specular finish. This shape provides better light control, thus reducing glare and light pollution.
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 fluid that can be used for medium temperature space or process heat or to operate a steam turbine for power or electricity generation.
Parallax
A distortion or incorrect interpretation of what is seen when objects are located on in front of the other, and apparently looks as though it is one thing, when in fact it is another, such a an indicator being read from the side rather than from the front.
Parallel
Similar property. Properties that are side by side but do not meet.
Parallel application
Drywall (wallboard) installation with the long edge running in the direction of the framing rather than perpendicular to it, as it is normally.
Parallel circuit
Electrical circuit with the loads connected across the power source instead having the power source pass through each load in the series, keeping unbroken continuity of the circuit, so that if one fails, the other do not.
Parallel clamps
Two sets of hand screws, on a set of clamp jaws, adjustable to hold objects at different angles.
Parallel connection
A way of joining photovoltaic cells or modules by connecting positive leads together and negative leads together; such a configuration increases the current, but not the voltage.
Parallel lines
Lines that are the same distance apart along a straight length.
Parallel system
Two or more identical size heaters piped with water connections, that is, cold water travels equal distance into the inlets of the heaters from a "T" connection and hot water travels equal distance from the outlet of the heaters to a "T" connection.
