Heathrow Airport: Energy Use and the Case for Onsite Generation

Heathrow operates one of the UK’s largest private electrical networks, managing its own substations, internal distribution, and backup systems. While not a true microgrid, it has many of the features of one — but remains dependent on the national grid for normal operations.

In 2023, Heathrow consumed around 271 GWh of electricity. Based on an average electricity rate of 30p per kWh, that equates to an estimated £81 million annual spend on electricity.

Breaking that down:

• £222,800 per day

• £18,567 per hour (assuming 12 hours of peak operations)

At that price, Heathrow’s average electricity demand is around 62 MW, with peak demand likely reaching 100 MW or more.

To partially offset this with onsite clean energy, a feasible approach could include:

• 150 MWp of solar PV

  • Estimated to generate 135 GWh annually, covering about 50% of Heathrow’s total energy use

• 600 MWh battery storage

  • Capable of supplying 62 MW for 9.7 hours or 100 MW for 6 hours

• Diesel generator backup

  • To ensure full reliability during extended shortfalls or emergencies

This mix would not make Heathrow fully energy independent, but it could substantially reduce grid reliance, cut carbon emissions, and strengthen energy resilience.

Sources: Heathrow Sustainability Investment Report 2023, UK solar capacity factors (National Grid ESO), business electricity pricing from Ofgem, and UK battery storage data from industry reports.

This type of hybrid setup — large-scale solar, grid-scale battery, and flexible backup — is increasingly viable for major infrastructure sites and aligns well with net zero strategies.

Source: Heathrow Sustainability Report 2023 page 18