Unlike traditional pool heat pumps that turn on and off using AC power, an Arctic Inverter Heat Pump turns on and off using DC power. The difference in the two power sources is that AC power goes from 0-60 Hz instantly when it turns on. In other words, 0 to Max instantly. In order to start the motor and get it turning, this start-up requires a lot of extra energy. A starting capacitor is used to store extra energy to deliver this extra power to the motor at start up. Most of us are familiar with this kind of motor when we see the lights temporarily dim when an older AC is turning on. This hard start and stop consumes a lot more energy and puts a lot of extra stress on the more jolting it with extra energy to turn on.