Edge-Defined Film-Fed Growth (EFG) - A method for making sheets of polycrystalline silicon for photovoltaic devices in which molten silicon is drawn upward by capillary action through a mold.

Electric Circuit - The path followed by electrons from a power source (generator or battery), through an electrical system, and returning to the source.

Electric Current - The flow of electrical energy (electricity) in a conductor, measured in amperes.

Electrical grid - An integrated system of electricity distribution, usually covering a large area.

Electricity - Energy resulting from the flow of charge particles, such as electrons or ions.

Electrochemical Cell - A device containing two conducting electrodes, one positive and the other negative, made of dissimilar materials (usually metals) that are immersed in a chemical solution (electrolyte) that transmits positive ions from the negative to the positive electrode and thus forms an electrical charge. One or more cells constitute a battery.

Electrode - A conductor that is brought in conducting contact with a ground.

Electrodeposition - Electrolytic process in which a metal is deposited at the cathode from a solution of its ions.

Electrolyte - A nonmetallic (liquid or solid) conductor that carries current by the movement of ions (instead of electrons) with the liberation of matter at the electrodes of an electrochemical cell.

Electron - An elementary particle of an atom with a negative electrical charge and a mass of 1/1837 of a proton; electrons surround the positively charged nucleus of an atom and determine the chemical properties of an atom. The movement of electrons in an electrical conductor constitutes an electric current.

Electron Volt (eV) - The amount of kinetic energy gained by an electron when accelerated through an electric potential difference of 1 Volt; equivalent to 1.603 x 10^-19; a unit of energy or work.

Energy - The capability of doing work; different forms of energy can be converted to other forms, but the total amount of energy remains the same.

Energy Audit - A survey that shows how much energy used in a home, which helps find ways to use less energy.

Energy Contribution Potential - Recombination occurring in the emitter region of a photovoltaic cell.

Energy Density - The ratio of available energy per pound; usually used to compare storage batteries.

Energy Levels - The energy represented by an electron in the band model of a substance.

Epitaxial Growth - The growth of one crystal on the surface of another crystal. The growth of the deposited crystal is oriented by the lattice structure of the original crystal.

Equalization - The process of restoring all cells in a battery to an equal state-of-charge. Some battery types may require a complete discharge as a part of the equalization process.

Equalization Charge - The process of mixing the electrolyte in batteries by periodically overcharging the batteries for a short time.

Equalizing Charge - A continuation of normal battery charging, at a voltage level slightly higher than the normal end-of-charge voltage, in order to provide cell equalization within a battery.

Equinox - The two times of the year when the sun crosses the equator and night and day are of equal length; usually occurs on March 21st (spring equinox) and September 23 (fall equinox).


Extrinsic Semiconductor - The product of doping a pure semiconductor.