Glossary

K

KILOWATT (kW)

1000 watts.

KILOWATT-HOUR

Unit of energy used to perform work (energy and work are equivalent in units, energy being the potential value and work the achieved value). Fuel equivalents: One barrel of crude contains roughly 1700 kWh One ton of coal contains roughly 7500 kWh One gallon of gasoline contains roughly 37 kWh One cubic foot of natural gas contains 0.3 kWh One ton of uranium ore contains 164 million kWh 1.34 horsepower-hours. Thermal Unit: One kWh = 3400 BTU. Can be compared to 860 calories (food value)

L

LOAD

Refers to equipment that is powered by electricity. Usually expressed in terms of amperes or watts. In an electrical circuit, any devise or appliance that uses power (such as a light bulb or water pump).

M

MAXIMUM POWER

The power at the point on the current-voltage characteristic where the product of current and voltage is a maximum (measured in watts).

MODULE

The smallest non divisible, self-contained and environmentally protected physical structure housing interconnected Photovoltaic cells and providing a single DC electrical output.

MULTICRYSTALINE

Material that is solidified at such a rate that many small crystals (crystallites) form. The atoms within a single crystallite are symmetrically arranged, whereas crystallites are jumbled together. These numerous grain boundaries reduce the device efficiency. A material composed of variously oriented, small individual crystals. (Sometimes referred to as polycrystalline or semicrystalline).