Solving the aircraft carrier’s energy dilemma

When the Royal Navy’s new aircraft carriers arrived in Portsmouth, the base faced a critical problem: how to find enough electricity.

HMS Queen Elizabeth and HMS Prince of Wales have doubled the base’s power consumption. In fact, the load was so large that it threatened to affect the power supply to the city itself.

To meet the need, they built a new 13 megawatt combined heat and power plant, capable of producing enough electricity to fully power the base, and with the added benefit of also providing heat.

As well as reducing emissions, the plant has saved £4,000,000 a year – money that is reinvested in other green technologies there.

The plant’s financial gains have also provided opportunities to conduct feasibility studies to see what happens next.

“We just completed a feasibility study…taking seawater and breaking it down into oxygen, which becomes a salable product, and hydrogen, which we can then use to mix with our town gas… and these [generators] become not only highly efficient, but also carbon-efficient,” said project engineer Iain Greenlees, Superintendent of Portsmouth Infrastructure.

The power plant is part of a series of initiatives to reduce the base’s carbon footprint and bring it closer to net zero by 2040.

Portsmouth emits 31,000 tonnes of CO2 per year, or around 3% of all defense emissions.

This figure has already been significantly reduced – halved since 2003. At the same time, the base’s energy consumption has been cut in half.

But they want to go further. They are also testing wind power here and building a new logistics building for carriers that will be completely net zero.

The base also has 46 electric vehicles and new solar canopies are being installed on some of the car parks to power the charging stations.

“We’ve had a very good history over the past 10 years of cost-driven reductions in our base energy consumption,” explained Commodore Jeremy ‘JJ’ Bailey, the base commander.

“When I arrived a few years ago I started to change that, so we thought about carbon as part of that dynamic.

“It got us thinking about the kinds of things we could adopt and the technologies we could bring into play,” he added.

Across the water from the dockyard is Whale Island, a former naval artillery school and now home to the headquarters of the Royal Navy.

Here they also go green, encourage the flora and fauna to thrive and build a colony of bees. They even produce their own honey.

“Sustainability has always been at the heart of what we do,” said Rear Admiral Paul Beattie, Director of the Naval Staff.

“The difference now is that it’s core to everything we do and we need to drive that forward and make it an operational advantage.”