Can Data Centres Use Solar Power?

Why data centres are interested in solar

Electricity is one of the biggest running costs for most data centres. Servers, cooling systems, ventilation equipment, security infrastructure and backup systems operate continuously, often every hour of the year.

At the same time, electricity prices have become more volatile and grid capacity is becoming a growing concern in some parts of the UK. Large power users are therefore looking more closely at ways to reduce dependence on expensive daytime electricity and improve long-term energy planning.

Solar power is attractive because it produces electricity during business hours when energy demand and electricity prices are often highest. Large roof areas on industrial or commercial buildings can also make solar installations practical from a space point of view.

Some operators are also under pressure from customers, investors or corporate policies to reduce carbon emissions and improve environmental performance.

Can solar run an entire data centre?

In most cases, no. A data centre normally requires a constant and highly reliable electricity supply that solar alone cannot provide consistently.

There is more information about this on the Prudent Power website.

Solar generation changes throughout the day and falls sharply during winter evenings and poor weather. A data centre, however, still needs stable power whether the sun is shining or not.

For this reason, solar is generally used to offset part of the electricity demand rather than replace the grid entirely. The site may still rely on grid imports, standby generators, UPS systems and battery storage to maintain reliability.

Some very large operators use solar farms or long-term renewable energy agreements to balance a greater proportion of their annual electricity consumption, but this is different from relying purely on rooftop panels.

Where solar can work particularly well

Solar can be especially useful where a data centre has:

• Large unobstructed roof areas
• High daytime electricity demand
• Expensive peak electricity tariffs
• Cooling systems operating heavily during sunny weather
• Good on-site electricity consumption during solar generation hours
• Battery storage or load management systems

Some facilities also benefit because cooling demand often increases on hotter, brighter days, which can coincide with stronger solar generation.

Industrial estates, edge data centres and commercial server facilities may therefore find solar more useful than many people expect.

What usually limits solar on data centres?

The biggest limitations are often roof space, electrical infrastructure and grid connection constraints.

Even a large roof may only support a solar system capable of supplying a fraction of the site's total demand. Data centres often consume far more electricity than a typical commercial building of similar size.

Electrical integration can also be more complicated because critical systems require stable and carefully managed power arrangements. Backup generators, UPS equipment and resilience planning must all work together safely.

In some areas, export restrictions or limited grid capacity may affect the type of solar system that can be installed. Some sites therefore add battery storage to improve flexibility and reduce peak demand rather than maximise export.

Weight loading, rooftop plant, cooling equipment and future expansion plans can also affect the usable roof area.

Is battery storage important?

Battery storage is becoming increasingly important for some data centre projects, although it is not always essential.

Batteries may help store excess daytime generation, reduce peak demand charges, improve resilience and support better use of on-site solar electricity. In some situations they may also help reduce strain on the grid connection.

However, batteries add cost and complexity. They need to be designed around the site's actual load profile, operational priorities and resilience requirements rather than added automatically.

For some facilities, the most practical approach may simply be using solar to reduce daytime grid imports while retaining conventional backup arrangements.

What should operators consider before installing solar?

Before considering solar, it is important to understand how and when the facility uses electricity. Half-hourly electricity data, cooling demand patterns, backup arrangements and future expansion plans all matter.

Operators should also review roof condition, structural suitability, available space, export limitations and the relationship between solar generation and actual site demand.

Useful UK resources include government solar PV information, Ofgem, the Climate Change Committee and techUK.

The most effective projects are usually the ones designed around the operational realities of the data centre itself, rather than simply installing the largest possible number of panels.