In a given electrical circuit, the amount of current in amperes (i) is equal to the pressure in volts (V) divided by the resistance, in ohms (R).

The replacement of a non-functional or ineffective lamp with a new, more efficient lamp.

Those privately or publicly owned establishments that generate, transmit, distribute, or sell electricity.

A lamp where the light beam is focused 2 inches ahead of the lamp reducing the amount of light trapped in the fixture.

These lights use an electrically heated filament to produce light in a vacuum or inert gas-filled bulb.

The electrical power that oscillates between the magnetic field of an inductor and the electrical field of a capacitor. Reactive power is never converted to non-electrical power. Calculated as the square root of the difference between the square of the ki ...

A device used to measure total incident solar radiation (direct beam, diffuse, and reflected radiation) per unit time per unit area.

The products of all combustion processes formed by the combination of nitrogen and oxygen.

Thermosyphon systems use a separate storage tank located above the collector. Liquid warmed in the collector rises naturally above the collector, where it is kept until it is needed. The liquid can be either water or a glycol solution. If the fluid is wat ...

The amount of time required for positive cash flows to equal the total investment costs.

A measure of the effective cooling capacity of a refrigerator, expressed in Btu per hour or in tons, where one (1) ton of capacity is equal to the heat required to melt 2,000 pounds of ice in 24 hours or 12,000 Btu per hour.

Materials with various qualities that are applied to glass windows before installation. These coatings reduce radiant heat transfer through the window and also reflects outside heat and a portion of the incoming solar energy, thus reducing heat gain. The ...

The thermal energy used in an industrial process.

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.

A solar water or space-heating system in which solar energy is collected, and/or moved by natural convection without using pumps or fans. Passive systems are typically integral collector/storage (ICS; or batch collectors) or thermosyphon systems. The majo ...

A gas that does not react with other substances; e.g. argon or krypton; sealed between two sheets of glazing to decrease the U-value (increase the R-Value) of windows.

The value of a personal portfolio, product, or investment after depreciation and interest on debt capital are subtracted from operating income. It can also be thought of as the equivalent worth of all cash flows relative to a base point called the present ...

A device that transfers heat by the continuous evaporation and condensation of an internal fluid.

The maximum value of natural solar insolation.

The process of implementing measures to reduce peak power demands on a system.