80 Plus (trademarked 80 PLUS) is a voluntary certification program intended to promote efficient energy use (PSUs). Launched in 2004 by Ecos Consulting, it certifies products that have more than 80% energy efficiency at 20%, 50% and 100% of rated load, and a power factor of 0.9 or greater at 100% load. Such PSUs waste 20% or less electric energy and the use of PSUs.

Redundancy is typically used in data centers. For the higher certification levels, the requirement of 0.9 or better power factor is 20% and 50% load levels, as well as 100% load. The Platinum level requires 0.95 or better power factor for servers. The Climate Savers Computing Initiative efficiency level targets for workstations for 2007 through 2011, corresponds to the 80 Plus certification levels. From July 2007 through June 2008, basic 80 Plus level (Energy Star 4.0). For the next year, the target is 80 More Silver, then 80 More Silver, then 80 Plus Gold, and finally Platinum.

There have been instances when they have not been certified, and in some cases do not meet the requirements. When a company resells an OEM power supply under the name of the OEM is certified. In some instances, a reseller has claimed a higher wattage than can supply – in which case, the reseller ‘s supply would not meet 80. The 80 Plus web site has a list of all certified supplies, so it is possible to confirm that a supply really meets the requirements. Although there is no such official certification or standard, such as “85 Plus”, there is no such official certification.

The efficiency of a power supply is divided by its input power; the remaining input is converted into heat. For instance, a 600-watt power supply with full load would have 1000 W of the hands and would waste 400 W as heat. On the other hand, a 600-watt power supply with 80% efficiency running at full load would draw 750 W from the hands and would like to waste only 150 W as heat. For a given power supply, efficiency varies depending on how much power is being delivered. Supplies are usually more efficient at one-half and three-quarters load, much less efficient at low load, and somewhat less efficient at maximum load. Older ATX power supplies were typically 60% to 75% efficient. To qualify for 80 Plus, (20%, 50% and 100% of maximum rated power). However, 80 Plus supplies may be less than 80% efficient at lower loads. For instance, an 80 Plus, 520 watt supply could still be 70% or less efficient at 60 watts (a typical idle power for a desktop computer). Thus it is still important to select a source of supply. It is easier to achieve higher power levels, so it is possible to provide a reasonable amount of power for typical machines. Typical computer power supplies may have power factors as low as 0.5 to 0.6. The higher power factor reduces the peak current draw, reducing load on the circuit or on an uninterruptible power supply. Reducing the heat output of the computer helps reduce noise, since fans do not have to spin the fast to the computer. Reduced heat and resulting The testing conditions can lead to an unrealistic expectation of efficiency for heavily loaded, high power (rated much larger than 300 W) supplies. It has a high power output and the power of the energy supply, which is likely to decrease its efficiency. Since they are certified at room temperature, this effect is not taken into account. 80 No longer does it work for low load. For instance, generation of standby power may still be relatively inefficient, and may not meet the requirements of the One Watt Initiative. Testing of 80 More power supplies shows that they vary considerably in standby efficiency. Some power supplies consume half a watt or less, but where do they come from? Inefficiencies in generating standby power are magnified by the amount of time that computers spend turned off.