Digital Realty Grid interactive UPS Case Study

The global drive to replace fossil fuel electricity generation with renewable sources presents challenges for electricity grids. Because renewable sources are intermittent and non-programmable, national grids need to find alternative sources of energy flexibility to guarantee a constant balance between supply and demand, while avoiding grid inefficiencies and outages.

At the same time, data centres must maintain high levels of availability, as downtime can be devastating for businesses – and the digital economies that rely on them. To avoid outages, data centres are equipped with uninterruptible power supplies (UPSs), which provide power conditioning and backup electricity for the facility in the event of a grid failure.

Data centre UPSs are built to respond quickly, providing backup power in less than half a second in the event of a grid failure. While this is essential for uninterrupted operation, it also gives data centre battery backup systems the potential to contribute to grid balancing through demand-side response programmes.

One such programme is EirGrid’s Delivering a Secure, Sustainable Electricity System (DS3) program, introduced by the Irish transmission system operator to help balance supply and demand in the Irish transmission network. DS3 works by balancing the frequency of the grid as it fluctuates in response to customer demand, and variations in increasingly renewable energy generation. It depends on standby energy assets capable of stepping in to maintain the grid frequency at 50Hz, thus preventing damage to grid hardware during times of stress.

Enel X is working with Digital Realty, the largest global provider of cloud and carrier-neutral data centre, colocation and interconnection solutions, to help balance the EirGrid network through the DS3 programme.

"Our work with Enel X is helping Digital Realty give back to, and support, Ireland’s grid, through dynamic frequency-balancing services."

— Evan Barker, manager facilities engineering, Digital Realty

Under normal conditions, Digital Realty’s nine highly connected data centres demand a constant amount of energy from the grid. But when the grid frequency drops below 50Hz, the data centre can safely draw some power from its batteries, reducing the demand on the grid and helping balance the frequency. The process happens almost instantaneously, turning an idle asset into an active supporter of electricity grid stability.