Using Distributed Power Management
The load of your virtual machines is probably not always the same. Sometimes, they need more resources, and sometimes, they need fewer resources. Distributed Power Management (DPM) will use DRS to consolidate virtual machines on fewer ESXi hosts during periods of low resource utilization. The unused ESXi hosts will be powered off. If more resources are needed, DPM will power on ESXi hosts, and DRS will move virtual machines to these hosts. DPM will save you or your company money in power and cooling costs.
Enabling DPM
DPM has two modes: manual and automatic. In manual mode, DPM will give recommendations to evacuate virtual machines from hosts and power off or power on the hosts. You will have to apply the recommendations manually. In automatic mode, DPM will automatically apply DPM recommendations above a certain threshold.
In the following screenshot of the vSphere Web Client, you will see the DPM settings of a cluster with Automation Level set to Manual...