Saving more energy with UPS efficiency

The EPA figures 710 million kilowatt-hours consumed annually by UPSs (uninterruptible power supplies) in the U.S. could be saved through better efficiency proscriptions. In that regard, it recently sent out the final draft of the new Energy Star test method for UPS. Plans are to finalize and publish the program specifications by July 15, 2011, and specs will become effective immediately.

The EPA is particularly interested in efficiency at 25% load. It wants UPS makers to share more data, particularly at high power outputs.

EPA's program is based on the IEC Standard 62040-3 method of specifying the performance and test requirements for UPSs. It covers single- and three-phase UPSs for home, small office, and data center use; static and rotary UPSs; ac- and dc-output UPSs; and modular UPSs. Efficiency measurements will be taken at 100%, 75%, 50%, 25%, and 0% load, with optional testing at 10%, 20%, 30%, and 40% load conditions. Power factor limits will also be included in the test procedure.

The EPA recently published a letter summarizing the UPS test results that were added to the Energy Star dataset by manufacturers during Phase 1 of the dataset assembly. Phase 2 has begun, and the EPA is working with manufacturers to coordinate the priorities for Phase 2 testing.

You can access that letter here: http://www.energystar.gov/ia/partners/prod_development/new_specs/downloads/uninterruptible_power_supplies/ES_Stakeholder_Memo_UPS_Test_Results.pdf