On a typical day 1,300 planes take off and land at Heathrow Airport, and keeping that going requires around 20 million litres of jet fuel every day.
That’s the equivalent of filling up your car around 400,000 times.
It’s a massive operation, with fuel piped to the airport direct from refineries and then stored at two facilities know as fuel farms.
“The amount of fuel that passes through Heathrow is enormous. It’s about half of the UK’s jet fuel requirement,” says Matt Prescott, head of carbon strategy at Heathrow.
Heathrow Airport itself does not buy and sell fuel, that’s down to the airlines and their suppliers.
However, it does have to think about the infrastructure, allotting space for storage and pipes, and making sure the airlines and fuel firms have everything they need.
“It’s really about building up the sufficient capacity to ensure that the airport has that resilience built in,” says Mr Prescott.
But, when it comes to fuel, airports around the world are having to have a major rethink.
In the UK, under the government’s Jet Zero plan, by 2040 the UK aviation industry has committed to achieving net zero carbon emissions.
The US aviation industry plans to reach net zero by 2050. The European Union has a similar goal.
What is net zero and how are countries getting there?
These are ambitious targets and to reach them will require alternatives to traditional jet fuel.
Sustainable Aviation Fuel (SAF) – fuel that does not come from fossil fuels – is one option. Airlines are already using it, usually blended with regular jet fuel.
For airports it’s simple to supply SAF – it can be delivered via existing pipes.
But many doubt whether SAF can be produced cheaply enough, or in large enough quantities, to meet the needs of the airline industry.
So, there is much interest in hydrogen, which can store a lot of energy and, when used as fuel, does not produce any CO2.
To be of any use to the aviation industry, hydrogen needs to be in its liquid form, which involves chilling it to minus 253C.
Handling a liquid at that kind of temperature is immensely challenging. Given the chance, liquid hydrogen will “boil-off” and escape as a gas – potentially becoming a hazard.
So tanks, pipes and hoses all have to be extra-insulated to keep the liquid cold.
France’s Air Liquide has a lot of experience in this area. For around 50 years it has been supplying cryogenic hydrogen to the Ariane rockets of the European Space Agency (ESA).
The company produces more than a million tonnes of hydrogen a year and as well as fuelling rockets, its hydrogen is used in trucks and all sorts of industrial processes.
“This gives us a very strong background in technology and industrial knowhow in this field,” says Erwin Penforis, a senior executive at the company’s global hydrogen business.
Over the past three years, in partnership with Airbus and France’s biggest airport operator, Group ADP, Air Liquide has been investigating the potential of hydrogen in the aviation business.
It is also part of the H2Fly consortium which this summer successfully flew an aircraft using liquid hydrogen. For Air Liquide, it was an opportunity to test systems for fuelling a hydrogen aircraft.
Airlines are keen to know if hydrogen planes can be refuelled as quickly as current aircraft, as quick turnaround times are important for the industry.
“Are we able to deliver a few tonnes of liquid hydrogen in a matter of 15 minutes? 20 minutes? We have the technologies for this. We are adapting it – but the answer is yes,” says Mr Penforis.
However, installing the equipment needed to store and distribute hydrogen at airports will not be cheap. The consultancy Bain & Company estimates it could cost as much as a billion dollars per airport.
