Small embedded data centers in Wisconsin

Small embedded data centers (SEDCs) are one of the fastest growing end uses of electrical energy in commercial buildings and are estimated to account for nearly one percent of the total electricity use in the U.S. By some accounts, as much as one third of this usage is unnecessary, but this premise has not been addressed by Focus on Energy programs or by most device manufacturers.

A major barrier to realizing the energy savings opportunities in SEDCs is the difficulty in effectively reaching out to a diverse and dispersed customer base. The principal objective of SEDC system administrators is to provide sufficient server availability and capacity to satisfy their business operations and needs. Energy use considerations are not only secondary to IT services but are typically ignored by SEDC system administrators.

To address the opportunities in this market, Slipstream provided Focus on Energy with a better understanding of the number, type, and efficiency level of SEDCs in Wisconsin. We further developed program recommendations including a set of energy efficiency measures with the highest potential and least barriers for adoption.

Key observations

There are approximately 1,600 commercial buildings in Wisconsin with SEDCs.

There are approximately 14,300 servers in Wisconsin SEDCs. This equipment consumes approximately 98 GWh annually at a cost to Wisconsin businesses of $10.7 million.

Over half (52%) of servers in Wisconsin SEDCs are in offices and 14% in education facilities.

Only one-quarter (26%) of Wisconsin SEDC serve businesses with 24/7 occupancy. This means there is an opportunity for reducing server usage during unoccupied hours in the majority of Wisconsin SEDCs.

Almost half (46%) of survey respondents plan to upgrade their servers in the next year and a half.

IT measures

The following recommended IT measures have the most potential to achieve substantial savings, increasing the likelihood of implementation.

1. Increase UPS utilization to 75-80% through UPS consolidation.

2. Identify dormant (comatose) servers and turn them off if access to those servers are no longer required.

3. Reduce the number of physical hosts by employing server virtualization.

4. Reduce the servers by moving those IT services to the cloud (typically email, file, and database servers).

5. Purchase ENERGY STAR-certified IT equipment when refreshing.

6. Move storage to cloud services.

7. Archive unused storage onto tape drives and power down unneeded disk drives.

8. Perform Live Migration or DPM on virtualized servers and place unused physical hosts on standby.

9. Power down network switches, ports, and/or PoE during non-work hours, such as nights, weekends, and holidays.

Cooling measures

For SEDCs that have dedicated mechanical systems, two primary measures can be performed:

  1. Improving air flow management through:
    1. Cold aisle/hot aisle containment by delivering the conditioned air to the front of the server racks (cold aisle) and exhausting the heated air from the back of the server racks (hot aisle);
    2. Installing blanking panels; and
    3. Performing cable management best practices.
  2. Raising the set point temperature in the SEDC to deliver 75°F inlet temperatures at the server racks.


The project was funded by the Environmental & Economic Research and Development (EERD) Program under Focus on Energy, the Wisconsin statewide energy efficiency and renewable resource program funded by Wisconsin ratepayers.

Lester Shen and Chris Plum of the Center for Energy and Environment ( were instrumental to this project. Other Slipstream staff who contributed to this project include Melanie Lord, Scott Hackel, Peggy Heisch, Anna Svensson, and Sarah Huston.

Thank you to all who participated.