How much electricity and money can be saved?
Typical energy consumption of a computer can be reduced by over 30%. See Energy Consumption Chart for a comparison.
Benefits of a 80 Plus Computer Power Supply
- Lower energy consumption for the life of the 80 Plus computer
- Save money from energy efficiency for the life of the 80 Plus computer
- Lower heat created from the computer for the life of the 80 Plus computer
- Less building air conditioning capacity needed for the 80 Plus computers
- Lower cooling running costs for the 80 Plus computer
- Improved computer reliability with less heat related issues and less fan noise
- Better power factor values reduces energy costs by avoiding unbalanced loading charges by the electricity supplier.
When do I need 80 Plus?
When buying a new computer look for the 80 Plus logo and an Energy Star 4 or 5 logo.
When building a computer look for efficient processors and 80 Plus logo power supplies. Enable Computer Power Management in the BIOS and the Operating System.
What does Computer Power Management CPM achieve?
CPM turn off sections of the computer after periods of inactivity to save power. E.g.
- Turn off screen after 15 minutes of inactivity
- Turn off hard drives after 15 minutes of inactivity
- Put the computer in Sleep mode or Hibernation after 30 minutes of inactivity
- Energy Star 4 computers have CPM turned on at purchase
- Assume CPM will save up to an extra 38% in energy consumption.
Energy Consumption Chart
|Power Supply Efficiency (Percent)||50||55||60||65||70||75||80||85||90||95|
|Example Power used by computer (watts)||200||200||200||200||200||200||200||200||200||200|
|Energy needed by power supply (watts)||400||364||333||308||286||267||250||235||222||211|
|Potential cooling capacity needed for computer (Watts)||120||109||100||92||86||80||75||71||67||63|
|Yearly Power Consumption at 45 hrs/week (kWh)||936||851||780||720||669||624||585||551||520||493|
|Yearly electrical cost at $0.20 / kWh ($)||187||170||117||156||133||125||117||110||104||99|
|If Computer Power Management is enabled|
|Yearly Power Consumption at 45 hrs/week (kWh)||580||528||484||446||415||387||363||341||322||305|
|Yearly electrical cost at $0.20 / kWh ($)||116||106||97||89||83||77||73||68||64||61|
80 Plus Details
|Specification Level||Efficiency at 50% load||Minimum Power Factor|
|80 PLUS Bronze level||87%||0.9|
|80 PLUS Silver level||89%||0.9|
|80 PLUS Gold level||92%||0.9|
Efficiency is tested at 10%, 20%, 50% and 100%. Efficiency from 20% to 100% load must be over 80%.
There are over 1000 80 Plus computer power supply models available.
Energy Efficient Computing Conclusion
The use of 80 Plus power supplies has a good return on investment.
The small extra cost of purchase would be returned in the first year.
Another benefit is reduced cooling capacity needed and reduced cooling running costs.
Enabling Computer Power Management is also a good way to save electricity on all computers possible.