Riello UPS data centre efficiency expert Chris Cutler weighs up whether operators should maintain an ageing uninterruptible power supply (UPS) or take the plunge and invest in a completely new system.
It’s a dilemma every data centre operator or IT manager will face at some point. Your UPS has provided sterling service for several years, but it’s definitely seen better days.
Do you maintain it, even give it a bit of an overhaul so it can carry on doing the job for a while yet? Or do you bite the bullet and replace it with a new system delivering the efficiency and performance enhancements provided by the latest technologies?
A classic quandary: stick or twist? Will the long-term gains make up for the short-term pain of the disruption and additional capital expenditure?
Of course, there are certain circumstances where you won’t have this choice. Perhaps support from the Original Equipment Manufacturer (OEM) has finished. This tends to happen when a model’s been phased out of production for a few years. In that case, spare parts are hard to find, making maintenance prohibitively expensive, if not practically impossible.
It could be the firmware isn’t compatible with current security protocols, meaning your UPS is vulnerable to communications problems or even cyber-attacks. Or maybe your uninterruptible power supply simply isn’t capable of meeting your present and future load requirements. Basically, it’s not fit for purpose anymore.
In any of these situations you’ll need to replace your UPS with a new system. But assuming your UPS isn’t coming to the end of its useful service life, what factors will influence your choice of whether to overhaul or upgrade?
Planning for the future
It’s important to assess the state of play with your whole IT infrastructure, not just your UPS. If your facility is nearing capacity or full of ageing equipment, it could be that outsourcing to a colocation could prove to be a more cost-effective solution. That’ll see the vendor take responsibility for managing the UPS system.
Likewise, think about your load requirements. If you’re running at near full load and expecting your power demands to carry on increasing, then you’re going to need a larger capacity. Can this be achieved by adding to your current system? Or are you limited by how many modules or units can work together in parallel?
Alternatively, what if your current UPS is lightly loaded and your future plans are unlikely to see that situation change too drastically – is downsizing practical?
Replacing an uninterruptible power supply doesn’t always mean ‘bigger is better’. Downscaling to smaller units is likely to enhance overall efficiency, reduce the number of batteries you need, and cut maintenance costs.
Maintaining the status quo
Choosing to continue running a legacy UPS gives you a couple of options. You can ‘run to fail’, which is slightly misleading as UPS maintenance and regular servicing are still undertaken. It’s just that there’s no significant investment to improve system performance.
However, this approach increases the risk of sudden system failure. This sort of reactive ‘time and material’ maintenance also becomes incredibly expensive once a unit is around 10 years old. It’s a short-term option if you plan on consolidating to the cloud or Colo, but it’s ill-advised for mission-critical environments.
The alternative is to upgrade or overhaul your UPS. In essence, this aims to prolong the unit’s lifespan by proactively swapping critical components such as fans and capacitors ahead of their typical end-of-service life.
Overhauls reduce the risk of serious system failure and help optimise performance. But they aren’t a silver bullet. Many components simply aren’t cost-effective to replace, and in effect, an overhaul simply delays the inevitable. Whether it’s sooner or later, the UPS will need replacing.
Investing for the long-term
Replacing a legacy UPS with a new unit inevitably involves a significant up-front capital investment, while there’s also a heightened short-term operating risk during the changeover period. But these drawbacks are balanced by several advantages.
Firstly, UPS technology has evolved massively in recent years. If your UPS is 7-10 years old, it’s likely to be a transformer-based static tower that needs masses of expensive air conditioning to keep it running safely. These old-style systems only offer peak operating efficiency of 85-92% – they’re even less efficient at low loads – resulting in significant losses.
Modern UPS power supplies manufactured using transformerless technology can achieve anywhere from 94-99% efficiency and are capable of such performance even running low loads, meaning less wasted electricity. Cooling costs are cut considerably too because they generate less heat.
Another energy-saving aspect of new UPS systems is that it’s far easier to right-size them at initial installation. The advent of modular UPS, in particular, means a new system can be rated far closer to the actual load profile, without losing out on redundancy.
They’re scalable too, so when the time comes to expand, this can be achieved either by adding in extra power modules (with modular configurations) or paralleling extra units (for non-modular systems). Such ‘pay as you grow’ flexibility gives far greater control over the total cost of ownership (TCO).
Small improvements in efficiency – even just 1% – can produce sizeable savings. Look at the impact replacing a legacy UPS with a modular system such as our Multi Power (MPW) can have.
These figures don’t even factor in air conditioning costs, which would be considerably higher in the legacy installation.
Compared to old-style massive monoblock systems, modern UPS take up less space and are far lighter, making transportation and installation easier and more cost-effective.
For comparison, a legacy 800 kVA UPS (minus any batteries) weighs nearly four tonnes (3,950kg) and requires 3.2m2 floorspace. If such a unit was replaced with a Multi Power (MPW) modular solution, the three necessary cabinets combined would only need 1.89m2 and even when populated with power modules would only weigh 1,760kg – less than half the weight and just over half the footprint.
The freed up floor space is available to install lucrative server racks or additional batteries that could be deployed for energy storage schemes such as demand side response (DSR) – either way, that’s additional revenue streams to explore.
Add in the fact that newer systems incorporate user-friendly touchscreen communications and offer cloud-based remote monitoring capabilities too, which give operators greater control and help to bring day-to-day operating costs down.
A final point to remember is that many of today’s most efficient UPS systems feature on the government’s Energy Technology List (ETL). This is part of the Enhanced Capital Allowance (ECAs) tax scheme and allows companies to offset buying new equipment against their profits. Basically, an incentive to tempt firms to take a long-term view by investing in more energy efficient equipment. In this case, it could reduce the cost of buying a new UPS.
Economic and environmental gains
Replacing an ageing UPS with new might make a short-term dent in your finances, but the longer term benefits pay for itself many times over. Improved performance, enhanced efficiency, reduced energy bills, and greater control over the total cost of ownership. For many data centre operators contemplating the next move with their critical power protection systems, these advantages should make a compelling case.