Optimising energy for UK data centres: grid, hybrid, and microgrid approaches

Understanding Data Centre Energy Challenges

As data centres scale to meet accelerating AI and cloud demand, one of the earliest and most consequential decisions is how they connect to the energy system. 

I used Gridcog to model some alternative approaches for supplying energy to a hypothetical 100MW data centre located in Slough in the UK.

Option 1: Fully grid-supplied energy

A fully grid-supplied approach, modelled at £1.9 billion over 15 years, is simpler operationally but often difficult in practice. A shortage of available grid capacity, long lead times for connection approvals and high upfront costs require operators to consider alternatives that reduce dependence on the grid.

Option 2: Smaller grid connection with onsite thermal generation

Adding on-site firm generation for energy supply and not just for back-up power is gaining significant traction. Here we’ve modelled a hybrid configuration combining a reduced grid supply with a 50 MW gas genset. This reduces lifetime costs to £1.79 billion, whilst also easing pressure on the grid. 

Although gensets carry carbon and fuel-price risks, they provide a practical buffer where grid reinforcements are slow, expensive, or uncertain, helping operators secure power earlier and with more control over delivery timelines.

Option 3: Smaller grid connection with onsite renewables, battery storage and thermal generation

A more transformative option is the microgrid-style portfolio of solar, wind, battery storage, grid import, and genset capacity. This integrated configuration reduces whole-life cost to £795 million and mitigates grid-connection exposure by supplying a large proportion of energy onsite. 

The final asset sizes are BIG and definitely won’t be everyone’s cup of team, with 124 MW of solar, 259 MW of wind, and 70 MW of storage, but it illustrates how diversified generation can both decarbonise and materially reduce reliance on grid upgrades. 

Why Data Centres Must Rethink Energy Strategy

Data centres are no longer simply buying power, they’re required to actively participate in addressing grid-connection concerns, either by reducing their reliance on the grid or by offering significant flex during “system stress” events. 

If you’re a data centre developer, or a renewables project developer looking to secure offtakes from DC owners, and need some help understanding your options then hit up the Gridcog team.