Digital Realty and Enel X 

Turning data centre backup power into grid support

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Climate-related energy risk: Grid instability, renewable intermittency, constrained grid capacity, and barriers to growth 
Solution pathway: Grid-interactive UPS systems and dynamic frequency balancing 

Business type: Large corporate 
Sector: Data centres and digital infrastructure 
Geography: Ireland / Europe 

In Practice

Data centres depend on extremely reliable electricity. Even short outages can be highly disruptive for customers, digital services, and the wider economy. Digital Realty’s Dublin Metro data centres are designed to deliver 99.999% availability and are equipped with uninterruptible power supply systems, or UPS, to provide backup power if the grid fails. 

Through an award-winning collaboration with Enel X, Digital Realty has turned this backup infrastructure into an active grid-support asset. Under normal conditions, UPS batteries usually sit on standby. In this project, the batteries remain fully available to protect Digital Realty’s customers but can also respond almost instantly to signals from Ireland’s electricity grid operator, EirGrid. If grid frequency drops below 50Hz, the data centres can safely draw some power from their batteries rather than taking the full amount from the grid. This reduces pressure on the grid and helps restore frequency balance. 

The system uses dynamic control technology developed by EpiSensor in collaboration with Enel X. It tracks grid frequency variations in real time and adjusts battery output during moments of instability. Digital Realty has initially integrated 6MW of UPS capacity into the programme, providing critical frequency-balancing support to Ireland’s electricity grid. 

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The result is a model where energy-intensive businesses can contribute to the resilience of the electricity system they depend on. Enel X estimates that each 1MW added to a dynamic frequency programme can save around 4,000 tonnes of CO₂ per year. With 6MW of UPS capacity integrated, the project is helping avoid more than 24,000 tonnes of CO₂ annually, depending on customer load. Further available capacity is planned. 

This is especially relevant for data centre operators in Ireland, where electricity grid constraints have contributed to delayed or blocked data centre developments. By showing that data centres can provide flexibility and grid services, Digital Realty and Enel X demonstrate how large electricity users can move from being seen only as grid demand to becoming part of the solution. 

Why this example was selected

This case study was selected because it is a specific, award-winning business action that addresses a real energy resilience challenge. The Digital Realty and Enel X DS3 Dynamic Frequency Project won Data Centre Power Project of the Year and Sustainable Project of the Year at the 2024 ER & DCR Excellence Awards. It also won IT Project of the Year (Private Sector) at the 2024 Tech Excellence Awards. It shows how businesses can use existing energy assets more intelligently, improving their own resilience while supporting wider grid stability and renewable energy integration. 

Key Lesson

Businesses that depend on reliable electricity can improve resilience by turning backup energy assets into flexible grid-support systems that protect their own operations and strengthen the wider energy system they rely on. 

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