Riello UPS’s Leo Craig talks everything datacentre design in the latest edition of DCS UK magazine.
When UPS was first introduced to the market, energy efficiency didn’t matter as much as it does now.
What did matter was making sure connected loads were protected against the common power problems associated with raw mains energy – for example, voltage spikes, reductions in input voltage and blackouts.
UPS systems have evolved greatly over the past decade. It’s an evolution that has been driven by the rise of the data centre, in which the need to use power more effectively and to control lifetime costs of equipment is as important as the need for mission-critical power protection.
Power Density Driving Datacentre Design
In the modern datacentre, space is now a key consideration because of greater demands on infrastructure through the explosion of cloud-based services.
From this, a trend for higher power density is clearly emerging. This ultimately means being able to pack more capacity into a smaller space.
But with this trend comes a number of challenges. Squeezing more resources into a smaller area requires improved cooling facilities. It also needs the appropriate power distribution and backup infrastructure to support it.
With floor space a premium concern, managers must think carefully about how the datacentre is designed, particularly with regard to future expansion plans. At the outset of any datacentre design and build project, it is prudent to fall back to the 5Ps adage: “perfect planning prevents poor performance”.
Changing Face Of Data Centre Design
Most datacentres will have an 18-month rolling expansion plan. For rapidly expanding cloud-based service providers, this can be as little as three months.
The expansion plan will allow for the take up of free floor space to house additional servers and extra associated power and cooling services, if required.
For a micro datacentre, expansion may simply mean installing additional servers in the existing server cabinet. For a large datacentre, it can be the addition of one or more server cabinet rows.
Over recent years, changes to data centre infrastructure, for example, virtualisation and advances in servers that have made them smaller in size but just as power hungry (if not more so), have made it more difficult to predict datacentre power demand when future proofing.
Although virtualisation actually reduces the power demand of the servers and enables them to work more efficiently, it also frees up more space in the datacentre which allows for expansion of the server estate. This often results in a greater demand for power than before.
Such factors should be considered early on in the design of the data centre power structure. This means future expansion plans can be incorporated and the best UPS can be identified at the outset.
Historically, UPS systems have been oversized to meet the needs of tomorrow, today. But this scenario is wholly unacceptable in today’s efficiency-conscious data centres. Systems should be right-sized and expanded incrementally by adding new units one at a time.
Everything In Modulation
It is new modular technology which has allowed for flexibility and ease for expansion in datacentres ranging in size from micro to large scale.
According to global research body Frost & Sullivan, the market for modular UPS is expected to grow to £260 million (US $400 million) by 2017.
Whilst only representing less than 10% of the overall UPS market, it demonstrates a growing acceptance of the modular component UPS. This is driven in part by the growing development of small to medium-sized data centres and their need to rapidly expand to meet the demand for cloud-type services.
Modular offers the maximum in availability, scalability, reliability, and serviceability. In addition, it also offers high efficiency, low cost of ownership, and a high power density. Space is always a premium in the modern datacentre.
Key highlights include:
- Floor space flexibility: Modular component UPS systems can be expanded vertically provided there is room within the existing cabinet. Alternatively, a modular component UPS system can expand horizontally with the addition of a further UPS cabinet.
- Operating efficiency: This is achieved by right-sizing the UPS to the load size. This is because maximum efficiency is typically achieved when operating at 80-100% of the design capacity.
- Ease of use: Modular component UPS systems are slightly easier to service and repair in situ because a failed UPS module can be ‘hot-swapped’. The failure or suspect module is then returned to a service centre for investigation. To return a standalone UPS system to active service may require a board swap.
- Single points of failure: Standalone systems operate as a single UPS with no shared components other than a communications cable. Failure of the cable or accidental disconnection is accommodated in firmware algorithms within each UPS to ensure that the entire system continues to function and support the load.
Modular Versus Standalone
In terms of resilience, both modular and standalone UPS approaches can be configured to provide similar levels of availability.
Modular component UPS systems have a premium price compared to standalone UPS. However, when the space saved and the total cost of ownership is considered, the overall the price is comparable.
Resilience is a major factor when selecting a modular solution. Close attention should be paid to any single points of failure such as a common controller. Should this fail, the whole system will fail in spite of any redundant module.
Due diligence is always recommended when selecting the right modular solution.
Energy Efficient Technology In The Data Centre
With efficiency a key driver, there is a shift towards energy generated from renewable power sources, such as solar panels.
Consequently, UPS manufacturers are developing products that are Smart Grid-ready so that they can be integrated with alternative renewable power sources and facilitate switching between the grid and solar while allowing export back to the grid.
The introduction of lithium-ion (Li-ion) batteries has made it more feasible to utilise UPS batteries as energy accumulators.
Again, this allows the export of power back to the grid. But it can also enable the data centre to operate in island mode when a generator is present. This effectively takes the datacentre off the grid for a short period of time.
For operators, this not only helps to manage energy costs but also creates an additional revenue stream. In addition, it offers an opportunity to test the resilience in real time with minimal operational risk.
The Data Centre Of The Future
With a continued reliance on the internet and vast amounts of data out there, it is clear that there will be more demand placed on datacentres.
Technology is continually advancing and approaches like modular should, therefore, be embraced to continue to raise the bar in datacentre efficiency.
UPS will continue to play a vital role in the power chain. But the role will go beyond simply back up power and focus on the additional benefits to businesses.
This article first appeared in the February 2015 edition of DCS UK magazine
