Peter Panfil, Vice President of Global Power Sales at Vertiv, explores the ins and outs of data center power utilization and ways to avoid excess capacity and cut down on costs while driving up revenue.
Excess power capacity drags down operating efficiency and inflates operational expenditures (opex), and there are two main reasons this condition exists: a sub-optimal specifying process and the natural human desire for a security blanket.
As a leader in data center infrastructure, it’s not uncommon for Vertiv professionals to visit with large, respected organizations with power system utilization below 20%. Clearly, there is room for improvement, and that improvement can bring significant opex savings.
I participated in a series of consultants’ master classes recently and did an impromptu survey of a full room. Only one participant of those attendees indicated they targeted 100% or higher redline utilization. When I asked folks why they did not target 100% or higher, it was a mix of not wanting to operate at the equipment rating and the conservative approach of their clients.
For colocation providers, this can represent a lost revenue opportunity. If we can help them recover, say 360 kilowatts (kW) of capacity in a prime location, how much would that be worth? It’s not that hard to figure out. If that capacity could be sold for $1,000 per kW (to make the math easy), that’s $360,000. That is certainly worth your time and effort to examine.
The most forward-thinking data centers, especially the biggest of the big, are increasingly interested in realizing these savings. And there are two ways to change the low power utilization equation:
- Change from the bottom up by adding IT load. We have seen some colocations sell more capacity than they originally planned in order to increase power utilization.
- Change from the top down by right-sizing the power infrastructure. As an infrastructure provider, the biggest opportunity we can address is right-sizing the power infrastructure at the front end.
Here are three main ideas for right-sized power infrastructure that will deliver the most bang for the buck:
1. Size Your Power Train Precisely: Optimize UPS Ratings
Purchasing organizations are well intended but tend to subscribe to a common practice that hurts utilization: buying based on lowest common denominator versus buying based on optimal kW sizes. For example, specifying an 800 kW uninterruptible power supply (UPS) system costs less per kW upfront than a 750 kW system. Since the breakers in the gear are the same (750-800 kW), if a 750 kW is selected, organizations are leaving 50 kW on the table and increasing system cost per kW.
Increasingly, customers are evaluating power infrastructure based on cost per kW. I’m not shy about telling customers when they are stranding capacity and increasing their cost per kW.
The UPS is just the most obvious element, but there are opportunities to rescue stranded capacity at every step in the power chain. Matching capacities across the chain — input board, output board, static transfer switch, UPS — brings you maximum utilization. Anything else strands capacity.
If you can take this step to precisely size your power train, you could save approximately 7-8% in power system operating costs.
2. Bust the Buffer Myth: Drive to 100% Redline Utilization
Most UPS system redlines or the “not-to-exceed capacities” are set to less than 100%. Vertiv encourages using our UPS systems to 100%, and in some cases, the UPS is specified to more than that based on a given temperature.
So why not use that capacity?
There are extremely IT-dependent, world-class companies that set their UPS redline at 100 percent or higher, and more are likely headed in that direction based on the conversations we are having.
Setting the redline at less than 100% made sense five or 10 years ago when managing your IT load to 80% maximum UPS capacity was the norm. Loads were lagging and needed more kilovolt-amperes (kVA) than kW. But in our transformer-free world where one degree of variability is taken out of the equation, that’s no longer the case. The power system is more precise, and you can operate closer to the UPS power rating rather than the kVA.
Be sure to work with an experienced infrastructure provider as you explore ways to both reduce your operating costs and maintain your service level agreements.
There are lots of reasons that prevent organizations from moving redlines to 100 percent: lack of real-time consumption data, inconsistent full load capacity from vendors, and fear of oversubscribing. If you can align the stars, though, this can cut costs by 5-10%.
3. Reduce Battery Runtimes
Most organizations have at least five minutes of battery runtime, and that’s largely because valve-regulated lead-acid (VRLA) battery manufacturers historically wouldn’t provide warranties on batteries with less calculated runtime.
With greater adoption of lithium-ion battery technology and alternative smart-energy backup sources, this is changing. What’s truly needed is exactly the runtime it takes for generators to kick in and support the load. If your operations team can repeatedly prove that two minutes is what it takes, then two minutes is what should be prescribed.
If you cut back your battery capacity to exactly what’s needed to bridge to backup power, you could save another 17-24% in power operating costs.
If Saving Is This Black and White, Why Isn’t Everyone Doing It?
But even if you take just these three steps, you can save more than a third of your power system operating cost and free up significant capacity. So why isn’t everyone doing this?
There’s a simple reason. It takes guts. It’s easier and more comfortable to leave yourself extensive wiggle room. However, with razor thin margins and multiple ways to achieve five nines of availability (especially in colocation facilities), rescuing capacity should become a priority. Be sure to work with an experienced infrastructure provider as you explore ways to both reduce your operating costs and maintain your service level agreements.
Peter Panfil is Vice President of Global Power Sales for the Vertiv AC Power business.