An uninterruptible power supply (UPS) is business-critical for data centres – a sector where even the slightest fluctuation in, or loss of, power can have serious operational, financial and reputational consequences.

he issues are even more pressing in the current geopolitical climate, as we face the full impacts of an energy trilemma: balancing the competing demands of affordable, sustainable and secure power.  

While the UK is in the top five, globally, on the World Energy Trilemma Index, the recent report flags up serious issues relating to the UK’s position for energy security and equity – reflecting concerns about the lack of energy storage capacity and the high cost of electricity. Clearly, this is a global problem, but there are obvious signs from the UK government that the trilemma is a pressing problem for the country.  In late May, Business and Energy Secretary, Kwasi Kwarteng, wrote to the National Grid ESO, requesting that they explore options to boost energy security for this winter.

There is no easy solution to the current energy crisis. Cost and security of supply will be volatile for the foreseeable future. This is more complex than a quick switch to renewables, with a need for careful balancing – and the nature of the trilemma means there are competing agendas at play. Waiting for a stable and affordable energy supply from the Grid, one that meets the net zero demands of current legislation, is a risky option. Perhaps now, more than ever before, the climate demands that businesses – and data centres are a clear case in point – mitigate against geopolitical and financial risks by taking control of their energy supply.

New solutions

As power disruption is one of the most significant risks to data centre operations, the sector has traditionally relied upon uninterruptible power supply (UPS) to protect critical equipment and prevent the loss of vital data in the event of disruption. These older UPS systems usually rely on lead-acid battery technology which, while covering the basic and critical requirement of preventing disruption to supply from affecting sensitive equipment, have significant drawbacks – impacting on affordability, sustainability, as well as being potentially insecure. In the context of the energy trilemma, a traditional UPS looks increasingly untenable as a long-term solution.

Modern UPS technology involves the combination of a control system and sophisticated battery energy storage (BESS). This offers ultra-fast switching to connect the battery to the site supply in less than 10ms, protecting all equipment on site in the case of any power disruption. Critically, and additionally, power management software offers the capability to forecast and manage multiple power loads, as well as any on-site power generation to help achieve the cheapest, most sustainable, and stable electrical supply.

With energy costs spiralling, the storage element inherent in a BESS solution can offer significant benefits when factored into data centre energy management infrastructure – helping to address the affordability arm of the energy trilemma. Energy can be purchased when prices are at their lowest and retained, to be used when needed. Renewable firming offers the built-in capacity to store energy generated on-site, which can then be stored and used when needed or sold back to the Grid. It is this opportunity for a new revenue stream that can be most compelling.

A BESS solution allows businesses to capitalise on the National Grid’s Demand Side Response (DSR) opportunities. Balancing services are used by the Grid to even out demand across the UK’s power supply and, as inflexible renewables are increasingly important within the country’s energy mix, balancing services show continued growth. Companies who have the storage capacity and the technology to engage in balancing services receive a guaranteed income if they can be flexible.

This is one of the greatest assets of a BESS, which can rapidly draw down electricity from the Grid or release it back again, to be available at times of peak demand, meaning that the company can fulfil their contractual obligations and introduce a new revenue stream – a far more positive option than the sunk costs of older UPS.

A balancing act

The issue of affordability is intertwined with that of sustainability, where traditional UPS solutions are concerned. By its very nature, a typical UPS consumes significant amounts of energy, as it constantly switches between AC and DC, remaining powered up on standby, with losses of between 10 and 15%. This compares to a BESS and smart microgrid solution which has typical losses of around 1%. For a 1MW UPS system, that means wasted consumption of about £200,000 of electricity each year. 

Compared to a BESS, which will consume approximately 95% less power, the cost savings are reflected in the reduction in carbon emissions. The reputational impact is evident, worldwide, as highlighted by the United Nations Sustainable Development Goal Strategy, which identifies net zero data centres as a cornerstone of clean energy infrastructure.  

Customers and the supply chain are ever more aware of the need to act on legally binding targets for net zero and are making business decisions based on sustainability. Where data centres’ key client bases are increasingly focused on their own net zero strategies – with the NHS, public sector bodies, the financial sector and large corporates as obvious examples – being able to demonstrate clear steps towards decarbonisation in your own company will be reputationally critical.

Maintaining supply

The third arm of the energy trilemma – security of supply – is most pressing and critical for data centres. As with the reputational issues highlighted above, any loss of data due to power disruption carries with it significant reputational and financial risk. 

A study by the British Chamber of Commerce found that 93% of businesses suffering data loss for more than 10 days file for bankruptcy within 12 months, while another recent report found that data loss costs UK companies an average of £71 for each individual record lost.  

While a traditional UPS generally offers sufficient protection for individual pieces of equipment, there is no way to monitor the state of charge of a battery, meaning that without proper maintenance – an additional cost – there will always be some risk of failure. Factoring this issue of security of supply into data centre energy management makes the case for embracing new technology ever more compelling.  

Future-proofing is critical, to provide the resilience the data centre sector needs, as the world becomes increasingly digitalised, and as the energy trilemma becomes more pressing. Fortunately, for forward-thinking companies, there is technology to help address each of the issues. Modern UPS and smart microgrid solutions can offer site-wide protection, can help investment in on-site power generation to achieve a better return, and can even provide new revenue streams.  

Investment in behind-the-meter generation and energy storage helps reduce the impact of Grid fluctuations, making companies less vulnerable while bolstering brand reputation, demonstrating a clear commitment to working towards net zero.