Weather $ Calculator Use this application to see the impact of weather on the wholesale price of electricity. The price will change when you adjust the outdoor temperature or indoor thermostat settings. When you adjust the temperature, these changes are representative of the entire PJM region. As the demand for electricity increases, PJM calls on increasingly expensive generators to run until the system load reaches the daily peak – the maximum amount of electricity use on that day. To learn more about how electricity use changes throughout the day, check out The Ups and Downs of Load Curves. The megawatts of total system load and energy prices shown in this application are representative, not actual. Click the question mark button for help, and then click each highlighted segment to learn more.