AC power uses a LOT of extra energy to go from 0-60 Hz instantly when it turns on (in other words, 0 to max). In order to start the motor and get it turning, a starting capacitor is used to store extra energy that delivers 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 appliance is turning on. This hard start and stop consumes a lot more energy and puts a lot of extra stress on the mechanical parts with this extra jolt of energy to turn on.
Using DC power, an inverter motor is much more energy efficient. Unlike AC power, a DC motor can modulate the amount of energy from 0-60 + Hz. What does this mean? It means when we start the compressor, we gently turn up the speed as we start until we reach the optimal required speed with no starting capacitor used. This results in ultra-quiet start up with no extra torque on the compressor motor, and we reach peak efficiency with no wasted energy and maintain it with max energy savings.