Data centers, as major customers of energy providers can significantly contribute to reduce peak loads in the electricity grid or help out if there is a surplus of renewable energy available. Data centers provide numerous methods to adapt power consumption. Some of the methods allow for storing energy when the availability of renewable energy is high. Other methods use the spatial and temporal relocation of services in order to adapt the load in the data center to the actual situation of the electricity grid.
Adaption of power consumption by storing energy
The main idea of the energy storage approach is to store energy in the data center when in the grid more energy could be produced than consumed (power surplus). The stored energy can be used in times of peak load to reduce the power consumption from the electricity grid. Data centers offer following possibilities to store energy:
- In times of peak the UPS can be used to provide a part of the energy that is needed which will result in a lower power consumption of the data centre (from the grid perspective)
- Air-conditioner approach
- When there is more energy produced in the grid than consumed (power surplus), the air conditioner can transform electricity into cold by cooling down the data centre and use the temperature as a “battery”
- In times of peak load on the grid the air-conditioner can be turned off for a certain time period so that the temperature in the data centre increases to a certain, non-critical level. If the data centre was cooled down at a time of power surplus, the air-conditioner can be turned off for a longer time period.
Adaption power consumption by spatial and temporal relocation of services
The main idea of the spatial and temporal service relocation approach is to reduce or increase the data center power consumption by the relocation of services. Such relocation can be spatial or temporal:
Spatial service relocation
- In times of peak, services are consolidated on a subset of powered-on servers whereas unused servers are powered off.
If renewable energy is available, consolidated services can be “deconsolidated” by relocating the services to unused servers.
- Temporal service relocation
- In times of peaks, some of the services are delayed. The delayed services are executed when there is a surplus of energy in the electricity grid.