July 26, 2011

Efficiency in UPSes - Part 2

Continuing from last post on Efficiency...

Besides Power Factory Efficiency, the other type of Efficiency is Topology Efficiency.

This type of Efficiency is more related to energy savings, but honestly more gimmicky as manufacturers tout their green credentials.

Simply put, Topology Efficiency is the amount of energy used to operate the UPS.  Lets recall Topology... Its is the method of providing backup power.  Online Topology, is simply that its allways online.. allways giving you clean power.  Line Interactive Topology uses a 'switch' to turn on the UPS power if something in the line goes bad.  Obviously, Online - since its always on - will use more energy than a line interactive that just turns on when needed.


So line interactive UPSes are more efficient than online types can ever be.   Within the Line Interactive model mix, there are a few super efficient models.  The APC 5th generation units, (like the 200v) dont switch over to the energy intensive UPS power, unless its really necessary.  Some sort of magic corrects alot of the minor power problems without energizing those line interactive transformers.  Older units, didnt really care, and just switched over - saying to hell with a few watts.

And thats the problem... this super efficient line interactive UPS like the 5th gen APC save so little power, thats its kind of stupid.  The idea that saving of 5 kWh ($1) a month when your server room is set at 60 degrees and you are running 10,000 watts of servers is pointless.  Its like ordering a Diet Coke with a Bacon Double Big Mac, Fries, Milkshake and a bucket of lard.

Bottomline, the Topology of the UPS dictates its efficiency by determining how often the unit runs.