Green lights mark runway thresholds at the approach or landing end and are used on some taxiways or for the centerline. Blue lights are used to mark Taxiways.
Yellow lights mark most major airport taxiways.
Red lights mark runway departures and are used mark many runways. White lights are used to define runway edges. Then take 902 kWh's saved per year times 100 lights per airport equals 101,600 kWh's saved per airport. Multiply 101,600 kWh savings times 10,000 airports that equals 1,016,000,000 kWh's saved annually nationwide. The potential savings would be 116,000 kiloWatts or 116 MegaWatts.