Electric companies have a responsibility to maintain a steady flow of electricity to domestic and commercial customers. The end users expect energy to be available whenever they raise the thermostat, turn on the oven, need hot water, dry laundry, and, in the case of manufacturers, start their high-consumption equipment. Customers generally don't know what goes on 'behind the scenes', and aren't aware how complicated production and transmission can be.
Heating and cooling requirements vary with the weather, which varies constantly. In order to operate both economically and dependably, a utility must consider weather when projecting demand. Temperature is the most critical element in heating and cooling requirements. The electric company can make a reasonably accurate demand projection based on the 24-hour average temperature alone. But demand varies with the level of domestic activity at different times of day and with times of high and low temperatures. Peak demands can be especially critical between 6:00 a.m. and 9:00 a.m. when the low temperature usually occurs, and again late in the afternoon with the high temperature. The company must be prepared to meet these peaks. When severe heat waves and cold waves strike, peak demand can become unmanageable and require curtailing service to high-volume industrial users.
Forecasts are also needed in scheduling generating capacity, energy transactions, fuel deliveries, facility maintenance and personnel.
There is only one way to manage demand projection, and that is with a dependable forecast that provides hourly temperatures for projecting overall daily demand and to help identify the time and magnitude of peaks. These temperature forecasts should be enhanced with projections of cloud cover (more fuel needed on a cloudy day), and wind speed (more fuel needed on a windy day). Some idea of the general weather would also be helpful, especially in scheduling and advising outdoor crews when snow and ice threaten. The forecasts should be provided at least twice a day based on the latest available weather observations, forecaster expertise and computer guidance, and should be provided in a format that the industry can use quickly and efficiently in projecting demand. Skywatch can provide the forecasts that do this and more. Daily forecasts for each day usually include maximum, minimum and average temperatures, average wind speed and direction, relative humidity range, precipitation details and cloud cover. Delivery is available via fax, computer-to-computer, dial-up and the Internet. Text format can also be accompanied by a data stream suitable for direct input to load forecast models.
Of course, the electric power industry is particularly sensitive to weather features that could damage above-ground transmission networks, cause high power demand or affect ground transportation. Air Science keeps a utility fully informed, across its entire service area, of conditions such as wind gusts above the customer's threshold, thunderstorms with cloud-to-ground lightning, heavy wet snow, freezing rain/drizzle, large damaging hail, hurricanes and tornadoes, heat and cold waves, and blizzards. Alerts are issued 12 to 30 hours in advance, briefly describing the nature of the threat and its approximate timing. Warnings are issued two to four hours in advance, with a more detailed description of the threat and its timing. Updates, as necessary, are issued until the threat passes.
As always, authorized decision makers can call, toll-free, for consultations and special updates. Speaking directly with the forecaster can be the final factor in important decisions, and can be especially critical during strong cooling and warming trends, and during extended periods of extreme temperatures.Three- to five-day forecasts are standard. Skywatch can also provide seven-day, 10-day, monthly and seasonal outlooks.