BLOG: Power Perspectives

[#1]

In today's datacenter industry we hear much about going "Green". Experts often expound on the benefits of alternative energy, new battery designs, more effective ways of designing a datacenter, gaining LEED certification, etc... The questions I have to ask is, after all is said and done, how much does all this "improvement" cost related to the savings?

It is no secret that most people today do not stay in the same job for 20 years. Hence, we are seeing more and more decisions being made for the short term. What is going to make the bottom line look good this year, this quarter, this month?

I'd like to hear from others in the industry on this topic. What are you seeing in the way of investment in "green" technologies and designs? Post your thoughts below.

Message Edited by Siggy62 on 12-10-2009 02:23 PM

[#2]

I personaly dont know of ANY...

[#3]

Recently conmpleted a data center in Peoria, Illinois. back-up with (2) C32 1MW units. Very difficult to go green in a data center because of the high density of the load. We used 10yr VRLC cabinetized batteries; owner did not want to deal with wet cells which I believe are greener. The cabinetized batteries are replaced about every 6-7 years at best. Not sure where they go or if recycled. There are options but at a very high cost.

We did use dry coolers for free cooling in the winter. This will save substantially over three large chillers when the weather is right. Some people are even using outside air when the conditions are right. There are a lot of problems associated with that.

I would certainly like to use greener batteries if available at a reasonable cost. Some clients are willing to pay a little more to minimize waste and polution.

[#4]

Isn't that the usual story; self appointed "leaders" (AlGore etc.) demanding that hard working people and business' spend inordanate sums of money on unproven or high cost technolgy of unknown benifit to the "earth". If we stopped improving say  todays  automobile's efficency and emissions and wait for the older cars to retire we would be in a very good position as far as pollution and oil consumption go, but that is not enough for the true believers: endless regulations as far as the eye can see. KDM

[#5]

Minimizing waste and polution can actually have benifits beyond costs. Many of the "earth saving technologies" are actuallymore efficient and a better value. Initial cost for true value engineering can be higher. I don't see data center efficiency being driven by regulations. Many of the technologies are proven and the benifits well understood.

[#6]

The greenest batteries are no batteries!  If you're building a data center and you've got generators, look into battery-free UPS systems (I believe Caterpillar markets them too). They are physically smaller, don't require you to dispose of toxic batteries, and more energy-efficient then traditional battery-based UPS systems.  A clear win.

[#7]

battery option is not really a green option so far as datacentre is concerned.there other issues about the batteries like toxic materials used  etc which make it impossible to dispose off safely ,besides there are technical reliability issues.considering pros and cons,DG set with heavy flywheel (and kept running at no load) was used as UPS for citibank,bahrain project

[#8]

With my background, I must look at what Caterpillar has done to make things a little greener. Some time ago, Cat introduced the battery-free UPS system. The total system seems a little pricey at first, but when battery maintenance (and replacement) is figured into the whole equation, it would appear that the rotary UPS has some benefits. And, there is no concern about disposal of battery materials when replacement time rolls around.

Recently, Cat extended the recommended oil change intervals for standby generator sets. That means the user must dispose of less used oil than in previous years. 

The current generator sets produce much less exhaust pollution and have a higher usable power output per unit of fuel than the previous ones. That results in less polluting materials in our ecosystem, and more efficient use of the fuel being burned.

All the things mentioned above spell "greener" to me, and they are mostly concerned with a long term investment rather than a quick ROI.

At the user level, I have seen an increase in interest about heat loss recouperating systems in recent times. There is no doubt that producing energy is costly. But, if more of that fuel heat content is actually used, the total energy system (with a Cat generator set as the basis) can become a little greener and can help to recoup much of the initial cost on a long term basis.

[#9]

The term "Green" and Static UPS should not be used in the same sentence.  Static UPS are not "Green".  The Valve Regulated Lead Acid (VRLA) batteries are made of lead plates suspended in an immobilized sulphuric acid solution.  Not very good for the environment and are considered a controlled waste substance.  Basic VRLA battery technology has not changed in the last 20 years.  It is not the best technology on the market, however, it is cheap. 

Some people talk about 10 year batteries, but in my experience, these are basically the same batteries with replacement cost built-in up front.

The best way to minimize the impact of the batteries on the environment, is to maintain them in an optimum environment.  For every 10 degrees (Celsius) above 25 degrees, you will half the life of the batteries.  You also should check the impedance and "State of Charge", every year or so.  If one battery is going weak, you will want to change it.  One weak battery will bring down the whole string.  You also need to check all the connections and make sure they are properly tightened, to the suggested torque.

If you can make sure the batteries are never used, is also a great way to extend the life of a battery.  Unlike Generators, batteries have a defined duty cycle.  A standard UPS battery has on average, only 200 FULL discharges before it fails.

Lead is one of the most recyclable products in world.  When replacing the batteries, we need to make sure that the old ones are recycled.

Another area of concern with Online Static UPS is the basic design.  An Online UPS converts the voltage to DC, floats the voltage over the batteries, and then converts the voltage back to AC.  The power on the input and output are independent of each other.  There will always be losses in this process.  Even the most efficient Online UPS are only 90 to 94% efficient, and even this is only at a high percentage of load.  At partial load the efficiency will dramatically decrease.  We need to ask the effeciency at our load, not at 100%.  I have seen UPS at 50% load with a 65% efficiency.

Recenlty, some UPS have come out with an ECO mode.  The idea is to turn the rectifier and inverter to standby mode and run the UPS as a line-interactive type of UPS.  The efficiency will now be 99%.  The mode defeats the whole purpose of having an online UPS.  You will no longer have any harmonic mitigation or power protection, and when the power goes off, the UPS will switch to battery.  Some sensitive loads may go down during the 2 to 4 milliseconds it takes for the batteries to come on line.

Most static UPS today will offer current harmonic cancellation.  For this reason, we need to make sure the UPS is as close to the load as possible.  I have seen many installations where the UPS was 3 to 4 floors away from the load.  First, this is not a good idea for power quality reasons, but by having the UPS at the load, we will decrease the I squared R losses. 

I think people are getting "Green" crazy.  they need to remember what the main purpose of the product is and pick the best solution to match their needs.

Just look at hybid cars and compact fluorescent light bulbs.  People are buying these products because they are "Green", however when you do the math, in some cases, more conventional products may be "Greener" overall in the end for their application.

The best way to make a UPS "Green", is with paint.  Which also is not good for the environment.

[#10]

I have had the opportunity to be factory trained by Liebert on their CRAC's and 610 series UPS's in Ohio. i have been a journey level electrician for over 30 years, HVAC tech for 20, and moonlight for electrical testing firms for the last 22 years. I have worked on most of the large data centers here in northern California, and have also built 2 data centers here for my current employer. I hate to say it, but greening data centers has got to start with getting rid of the 25% data center ac loads. I believe liquid cooling is the best answer at this stage of their development. So far, the best I've seen is the iceotope servers built in the UK, ram rodded by a smarty named Steve Starbuck. The potential for using this heat taken from the servers in liquid form is limitless. Greenhouses in colder climates, heating buildings, melting icy roads, etc. and no AC's, just a pump, maybe with a pump backup. And I agree with getting rid rid of the batteries, use the flywheels, and keep on top of your gen-sets.