Glossary of Terms - J & K

• Jet Fuel - Kerosene-type; high-quality kerosene product used primarily as fuel for commercial turbojet and turboprop aircraft engines.
• Joist - A structural, load-carrying building member with an open web system that supports floors and roofs utilizing wood or specific steels and is designed as a simple span member.
• Joule - A metric unit of energy or work; the energy produced by a force of one Newton operating through a distance of one meter; 1 Joule per second equals 1 Watt or 0.737 foot-pounds; 1 Btu equals 1,055 Joules.
• Joule's Law - The rate of heat production by a steady current in any part of an electrical circuit that is proportional to the resistance and to the square of the current, or, the internal energy of an ideal gas depends only on its temperature.
• Junction - A region of transition between semiconductor layers, such as a p/n junction, which goes from a region that has a high concentration of acceptors (p-type) to one that has a high concentration of donors (n-type).
• Junction Box - A PV generator junction box is an enclosure on the module where PV strings are electrically connected and where protection devices can be located, if necessary.
• Jurisdictional - utilities, ratepayers and regulators (and impacts on those parties) that are subject to state regulation in a state considering restructuring.
• Kaplan Turbine - A type of turbine that that has two blades whose pitch is adjustable. The turbine may have gates to control the angle of the fluid flow into the blades.
• Kerosene - A type of heating fuel derived by refining crude oil that has a boiling range at atmospheric pressure from 400 degrees to 550 degrees F.
• Kilovolt-Ampere (kVa) - A unit of apparent power, equal to 1,000 volt-amperes; the mathematical product of the volts and amperes in an electrical circuit.
• Kilowatt (kW) - A standard unit of electrical power equal to one thousand watts, or to the energy consumption at a rate of 1000 Joules per second. On thousand watts.
• Kilowatt-hour - The basic unit of electric energy equal to one kilowatt of power supplied to or taken from an electric circuit for one hour. A unit or measure of electricity supply or consumption of 1,000 Watts over the period of one hour; equivalent to 3,412 Btu. The kWh is a unit of energy. 1 kWh=3600 kJ.
• Kinetic Energy - Energy available as a result of motion that varies directly in proportion to an object's mass and the square of its velocity.