| Energy
demand is the rate of kilowatt-hours used over a specified time period.
The demand charge is based on a fifteen-minute interval. For example, twenty
50-watt light bulbs are turned on at the same time and kept on for 15 minutes.
In this case, the energy use would be 0.250 kilowatt-hours and the demand
is 1000 watts or one kilowatt. If the lights are left on for one hour, the
energy use is one kilowatt-hour and the demand is still one kilowatt. Now,
let ten of the lights on for one hour and then have the other ten lights
turned on for one hour. In this example, the energy use is still one kilowatt-hour,
but the demand charge is only 0.5 kilowatts. |
