According to the U.S. Department of Energy, Widespread use of LED lighting has the greatest potential impact on energy savings in the United States. By 2027, widespread use of LEDs could save about 348 TWh (compared to no LED use) of electricity: This is the equivalent annual electrical output of 44 large electric power plants (1000 megawatts each), and a total savings of more than $30 billion at today’s electricity prices.
Beam Angle: The angular dimension of the cone of light from reflectorized lamps encompassing the central part of the beam out to the angle where intensity is 50% of maximum. Categories from narrow angle to wider angle are Spot, Flood, Narrow Flood, and Wide Flood.
Color Rendering Index (CRI): A measure of the correspondence between the color of an object and its appearance under a light source. CRI>60 or >70 = not good, CRI >80 = very good, CRI >90 = excellent. CRI=100 is equivalent to natural sunlight!
Correlated Color Temperature (CCT): A specification of the color appearance of a lamp, measured in degrees Kelvin (K). For example: