Milford Haven LNG: Liquefied natural gas terminal expansion plan

Two out of the three LNG ports in the UK are in Milford Haven

One of Europe's largest liquefied natural gas (LNG) terminals has confirmed plans to expand capacity at its site after backing from investors.

South Hook in Milford Haven, Pembrokeshire, processes about 20% of UK current demand for natural gas.

But new research has revealed LNG's environmental costs, and Friends of the Earth Cymru are "very concerned".

The Welsh government said it is developing Wales' pathway to a net zero system.

South Hook has been importing liquefied gas from various parts of the world before turning it into gas and delivering it to homes since 2010.

At the moment, the site can process about 15.6m tonnes of gas per year and can handle 20% of the UK's natural gas demand.

Whether new gas pipelines will be needed from Milford Haven to accommodate South Hook's expansion remains unknown.

• What is LNG and why has it become so important?

• Welsh industry's 23 million tonne carbon problem

LNG is gas cooled into liquid form so it can be sent around the world in ships

Dr Carol Bell, an energy market expert, said Milford Haven is a "vital port" for the UK's import mechanism for gas and a "key conduit" to supply Europe.

Analysis seen by the BBC shows that the production and transport of LNG causes up to 10 times the carbon emissions associated with pipeline gas.

Ms Bell said the alternative for countries like Russia that have cut off the flow of gas to other countries through a pipeline is to burn more coal.

"It's a lot better to be burning gas than coal because gas produces half the amount of carbon dioxide per unit energy compared with coal," she said.

"Anything that stops people burning coal is a good thing, short term of course."

'Move away from fossil fuels'

But Haf Elgar, of Friends of the Earth Cymru, voiced alarm at the expansion plans.

"We're at a time when we need to move rapidly away from fossil fuels and not bring more in and to spend more money on developing that infrastructure in Wales," she said.

Ms Elgar said LNG "has a much larger carbon footprint than even natural gas because of the way it's produced and has to be reduced in temperature and transported across the world".

The Welsh government said it is "scaling up renewable energy generation" and supporting the "just transition" away from using fossil fuels, adding: "We continue to use all the levers at our disposal to achieve those ambitions."

It added: "As a strategic investment for the whole of Great Britain, we need to understand how the UK government intends to guarantee any new investment in fossil fuels ensures the UK remains on the net zero pathway".

The UK government did not comment.

The project is set to be completed by 1 July 2025.