Every business is feeling the pinch of increased electricity costs. The recently announced Energy Business Discount Scheme (EBDS), set to replace the current Energy Business Relief Scheme (EBRS) which runs to the end of March 2023, may not have sufficient positive impact to address the growing concern for businesses across the UK.
Data centres using technical equipment such as UPS, which require significant amounts of electricity to run, now seriously need to consider how they can control consumption, and therefore costs, better.
Calculate and monitor losses
Firstly consider inefficient systems. The main culprits are air conditioning, lighting and UPS solutions. Even the most modern, efficient UPS will produce a 2.5 – 3% loss, flat lining across a load range, consistently. At 20p/kWh, a 1 MW system is likely to cost in excess of £50,000 (at full load) to run per year in electricity alone. This is using the very latest technology. Imagine an inefficient legacy system which is undersized, perhaps incurring up to 20% losses. It’s important to be aware of, and to monitor, losses in this objective way and work out where savings can be made.
Will replacement help?
A review of existing UPS equipment is useful. We find that replacement of inefficient legacy UPS will usually pay for itself in five years and in some situations as little as 2.5 years. This is based on current electricity prices, and these are set to continue to rise.
When evaluating a new UPS purchase, taking time to select the best technology which is the most efficient is also key. Buying the cheapest – which will definitely not be the most efficient – will not provide the best outcome over the long term.
But there are easy things that can be addressed quickly. For example, Feng Shui the space! It doesn’t cost much to install a stud wall to separate heat sources from equipment that needs environmental control, immediately saving energy. Similarly, evidence shows that running a data centre slightly hotter is more efficient and it saves on air conditioning too. Consideration could be given to using Li-ion batteries which can run optimally at much higher temperatures.
Right sizing
One of the most effective ways to reduce power consumption is to right size the UPS. Appreciating that the load profile will change over the next five to 10 years means selecting a solution which can react and maintain the efficiency of its sweet spot.
When we review and assess a new site to help data centre clients achieve optimal performance of their UPS systems, it is common to see UPS oversized and underutilised. Generally, this relates to large standalone systems, but it can also occur with modular systems too. Regardless of the topology, if a system isn’t designed based on actual load, organisations are likely to be paying more than they need for running costs, not to mention maintenance contracts and remedials.
If a UPS system is oversized, it doesn’t automatically mean it has to be replaced; there are other things that can be done to hit the sweet spot of efficiency. For example: there may be multiple UPS supporting a much smaller load than initially intended – switching off the UPS that are not required will have a positive effect on efficiency. As long as the required resilience level is maintained, there is no issue with this approach.
Maximising modes
Some UPS will offer an economy (eco) mode. In the right circumstances, switching to eco mode can increase the efficiency to 99%, even on the most efficient technology that can reduce losses by 2%. With legacy systems with efficiencies as low as 85%, the savings would be much greater. Again, there is no risk with this approach: if the mains goes out of tolerance, the transfer back to the inverter is instantaneous and seamless. This is a good option for data centres with a minimum resilience level of N+N.
A true modular UPS designed with intelligent technology that uses as many modules as needed to match the load demand is an option for data centres looking to maximise efficiency with a new solution. A UPS with Maximum Efficiency Management (MEM) mode will look for the most optimised energy efficient point of the overall system and use active-sleep modules to ensure it is always operating at its maximum efficiency, automatically. As the load decreases modules hibernate, and when the load increases the modules become instantly available, maintaining the required resilience.
Battery management
I believe the new frontier of battery management will be achieved through peak shaving. This means at peak times reducing the amount of power taken from the grid and combining this with some battery energy to deliver the load at peak times. Batteries can be re-charged during off-peak times. Because this approach requires many battery cycles, Li-ion batteries are better suited than traditional VRLA units which have limited cycling ability.
Active UPS management
There are numerous ways to make an immediate impact on reducing power usage. However, the key to maximising efficiency within data centres over the long term is increased customer understanding of their UPS solution. Understanding load profiles and the UPS’ data means live real-time information can be used to make tweaks and changes to optimise efficiency. We encourage our customers to get involved in the training we offer so they can react quicker to any changes and take ownership and more control of running costs.
UPS manufacturers can also help by working with data centres to assist them in planning how to maximise efficiency. The information is readily available about the true performance of any UPS and experienced manufacturers can use this to help clients to optimise their UPS systems.
It also costs nothing to have a full review of existing technology and to make the appropriate calculations to see what improvements can be made. Our experienced team at Centiel offers clients access and assists them to understand the data so they can make informed decisions to help control consumption costs over the long term.
