How data centres will support renewable power adoption

Author: Carly Weller

By Janne Paananen, Technology Manager, Critical Power Systems, Eaton

Data centres are central to almost everything in people’s increasingly digitally led lives. From managing the transportation we rely on, powering the supply chains that keep our supermarkets stocked, and communicating with our colleagues and loved ones, all is being made simpler, faster, and more efficient by data centre connectivity. This connectivity underpins our digital, social, and professional infrastructures, and as we saw with the COVID-19 pandemic, is robust in even the most challenging of circumstances.

The increasing amount of work being done in data centres also means they are demanding more power than ever. A Swedish study on the global usage of electricity found that data centres and the networks associated with them may lead to information and communications technology (ICT) requiring even up to 21% of our total electricity production by 2030.

While data centre-based solutions may often be more energy efficient than the processes they replace, this growth is still a problem in the context of our urgent need to decarbonise power production to meet climate targets. As a result, there is an ongoing global effort to make data centres greener, doing more work with fewer emissions, and it becomes possible to foresee a world where digital energy demand can be met entirely by renewables, something that many ICT companies are aiming for. Investments into renewable energy and supporting technology have been promoted using industry leading environmental and sustainability targets.

The challenge of renewables

Renewable energy sources bring green electrical energy, but they also bring other issues and engineering challenges. While some renewable energy sources offer predictable production (hydro), we are in fact moving towards a grid dominated by wind and solar. These variable renewable energy (VRE) sources, by nature, fluctuate in their output.

It’s easy to see how this leads to potential problems. An electrical grid system must constantly match consumption with electricity production. This is fundamental to grid and frequency stability. But if VRE has fluctuating output, periods of over- and under-supply seem inevitable.

Also, as VRE is replacing traditional turbine generators, it reduces system inertia i.e. stored energy in rotating mass resulting in faster and larger frequency deviations when mismatches between production and consumption occur.

Grid operators are developing ways to manage that potential mismatch. But consumers can help too. Consumer on-site electrical systems, especially back up power systems, can actually help in grid stabilisation and therefore will enable the successful adoption of renewables on the grid. This help comes in the form of ancillary services that can be delivered ‘back’ to the grid operator.

Rethinking the data centre

On the one hand, we have an increasingly digitalised world requiring more and more power. On the other, we are seeing an enthusiastic uptake of renewable energy which, if we maintain that momentum, will require innovations in how we maintain security of supply.

When thinking about how to build this future, it’s important to remember that these are not independent problems, and that the changes we’re heading towards should be more than a replacement of existing systems; as we transform power systems and digitalise everything from manufacturing to healthcare, we have an opportunity – and responsibility – to not just keep the lights on, but to rethink everything about how these essential services work.

Data centres, of course, cannot afford power instability: by necessity, they are ‘always-on’.

The services we all rely on need data centres with near-constant uptime. To ensure continuous power, data centres are outfitted with uninterruptible power supplies (UPSs) with batteries and backup generators which step in to keep everything running when grid supply fails.

A UPS needs to respond instantly to changes in supply, deliver large amounts of power, and do so with the utmost reliability. In other words, the qualities they need in order to support stable data centre operation also make them perfect for providing ancillary services to the grid, such as quickly adjusting its demand from the grid or feeding in energy. These fast actions can stabilise a grid and contain grid frequency.

Making this a reality requires some work: a data centre UPS will need to be aware of how the grid is operating, while the grid will need to be ready to receive supply from data centres as well as deliver power to them. Eaton’s recent research with Microsoft demonstrates that building the systems to make it work is possible and how data centres can support the grid in real-world testing. As an example, Eaton’s headquarters in Dublin is now home to a new UPS that successfully provides fast frequency response services to the local grid by reducing the building’s demand when grid frequency drops.

This potential shift in how we use our data centre capabilities will mean a complete rethink of the role of power consumers on the grid. Before, electricity transmission was a one-way street from production to consumption; now, we are seeing how it can be bidirectional and interactive, and everyone has their roles to play, from grid operators to consumers. Before, a system like a UPS was an operational necessity and a necessary expense, now we are seeing how it can be a source of revenue when ancillary services are sold back to the grid operator.

As for data centres, we are seeing how their centrality to modern life is more than just digital services. As they begin supporting the renewable energy grid, we may start to see them not just as data centres, but as energy centres helping to decarbonise electricity and creating a digital and sustainable future for all.