Demand Side Management (DSM) is also known simply as “demand management” means changing the way we think about power. Rather than using it as we need it, we can instead use power as it is available.
Electricity cannot easily be stored, so the exact amount consumed generally has to be the same as the amount generated. Until recently, our power supply systems were designed so that the supply side was managed to meet demand; our central-station power plants ramp up and down as electricity demand increases and decreases.
With fluctuating renewables, however, power supply will no longer be able to be adjusted so easily, so demand will have to be managed.
For instance, when there is enough power, refrigerators and freezers could cool down a bit more so they can “ride through” a few hours of lower power production. In this way, peak power demand can be shifted slightly.