Average rated life is a unit expressing the rate of flow of electric current.

Ballast (electronic) is an electronic device that converts electrical current to the optimal voltage, current and waveform required to start and operate a fluorescent lamp.

Dispersion is the separation of visible light into a spectrum, may be accomplished by means of a prism or a diffraction grating. Each different wavelength or frequency of visible light corresponds to a different color, so that the spectrum appears as a band of colors ranging from violet at the short-wave length (high-frequency) end of the spectrum through indigo, blue, green, yellow, and orange, to red at the long-wavelength (low-frequency) end of the spectrum.

Energy is the ability or capacity to do work.

Energy efficiency is the most work derived from the least amount of energy resources.

Energy resources are discovered to be hydro, solar, wind, biomass, geothermal, coal, crude oil, natural gas, and ocean-wave motion and are used to produce power.

Environmental Stewardship is the wisest use of both finite and reusable energy resources to produce the most work guided by a principle of causing the least known harm to the environment and driven by a desire to aid in the restoration of a healthier environment.

Generators are machines that convert fossil and nuclear fuel, or hydro, wind, and solar energy into electricity.

Illuminance is the light on a surface expressed in lumens per the defined area. 1 lumen per square foot equals 1 foot-candle.

Kelvin is the color temperature of light source. Lamps having a low correlated color temperature (2700K to 3400K) are said to be “warm” in color. Lamps having a high color temperature (4100K to 6500K) are said to be “cool” in color.

Lamp is a manufactured light producing light source.

LED is a Light Emitting Diode. The longest lasting and most efficient light source available today.

Lumen is a measure of overall light output produced by a lamp.

Photovoltaic power comes from harnessing solar energy with non-mechanical semiconductors that convert sunlight to direct current energy.

Power is the rate at which energy is taken from an electrical system usually expressed in watts. Power generated by a utility is usually expressed in volt/amperes.

Solar energy is any form of energy radiated by the Sun, including light, radio waves, and x-rays. Solar energy is needed by green plants for the process of photosynthesis, which is the ultimate source of most food. The energy in fossil fuels (e.g., coal and petroleum) and other organic fuels (e.g., wood) is derived from solar energy.

Spectrum is an arrangement or display of light or other forms of electromagnetic radiation separated according to wavelength, frequency, or energy.

Sun is the intensely hot, self-luminous body of gas (mainly hydrogen and helium) at the center of the solar system. The Sun is a medium-size main-sequence star. Its mean distance from Earth is about 865,400 miles (1,392,000 km) its volume is about 1,300,000 times, and it’s mass 332,000 times, that of the Earth. At its center, the Sun has a density over 100 times that of water and a temperature of about 15,000,000 degrees Kelvin. This temperature is high enough for the occurrence of nuclear reactions, which are assumed to be the source of the Sun's energy. The bright surface of the Sun is called the photosphere; its temperature is about 6000 degrees Kelvin.
Lighting intensity is a measure of the quantity of light, usually defined in lux or lumens. These terms were first defined before modern bulbs. A lumen is the amount of light that falls on a square foot of surface area that is located equidistant from a candle, 1 foot away. The lux is one lumen falling perpendicular to a square meter. (This has to be one of the few metric measurements defined using English measurement terms!) For reference, the intensity of sunlight on a sunny day at noon is approximately 130,000 lux (12,000 lumens).
Lighting is defined in terms of duration, intensity and spectrum.

The power grid is the entire interconnected system of power transmission lines that extends throughout the United States and into Canada and Mexico. The grid is divided into three "interconnections" that serve all of the consumers in each region. Smaller distribution points within these interconnections make the supply more manageable as it makes its way to consumers.

Rolling blackouts are controlled power outages designed to lessen the threat of an overload or crashing of major transmission systems brought on by short supply and high demand for power. Rolling blackouts are scheduled for predetermined sectors of the transmission grid at timed intervals. This spreads the burden of power shortages across the entire region for short, manageable time periods (usually no more than a few hours) rather than allowing unplanned blackouts to hit and jeopardize public safety and sensitive equipment.

British Thermal Unit (Btu) is defined as the quantity of heat energy necessary to raise one pound of water by one degree Fahrenheit.

Kilowatt-hour (kWh) is a measure used to express a quantity of electric energy. It is equal to the draw of one Watt over 1,000 hours. Said another way, it equals 10-100 Watt light bulbs operated for 10 hours. One kWh produces 3,413 Btu's of heat.
R-value is a numbering system used to express the resistance to heat flow through a material such as insulation products. The larger the number, the slower that heat passes through.

SEER or Seasonal Energy Efficiency Ratio is used as a rating for air-conditioning equipment. The larger the number, the more efficient the unit will operate. For example, an air-conditioning unit with a SEER rating of 13.6 will move approximately 4 times as many Btu's as it consumes of electrical energy.