Big Pit National Coal Museum: decarbonising a heritage site

Summary

In 2025, Big Pit National Coal Museum in Blaenafon, Torfaen, embarked on a major decarbonisation project with support from the Energy Service. The initiative focused on replacing outdated gas heating systems with low carbon technologies and improving building insulation across the heritage site. This project is part of a wider commitment to reduce emissions in listed buildings while preserving their historic character, supporting Wales’ ambition for a Net Zero public sector.

Our support

The Energy Service provided expert advice and helped Big Pit secure the Public Sector Low Carbon Heat Grant to fund heat pump installations and building fabric improvements. The Energy Service guided the museum through heritage impact assessments, listed building consent applications, and procurement via the Demand Management and Renewals Framework (DMRF). The team also supported engagement with Crown Commercial Services and coordinated with contractors to ensure compliance and value for money.

Technology solution

• Replacement of multiple natural gas boilers with high-efficiency heat pumps across key areas (shop, cafe, conservation workshop, waiting room, courtyard, and Pit Head Bath).
• Building fabric upgrades, including loft insulation improvements and external lime rendering to enhance thermal efficiency.
• EV charging infrastructure for the museum’s fleet.
• Future-proofing measures to allow integration of additional renewable technologies.

Investment

• Funding was secured through the Public Sector Low Carbon Heat Grant, supplemented by museum resources and framework procurement.
• Through collaboration with local contractors, the project combined strong technical expertise while also driving economic benefits for the community.

Impact

• Significant reduction in carbon emissions across the museum estate.
• Improved thermal performance of heritage buildings without compromising their historic character.
• Creation of local jobs through construction and specialist installation.
• A replicable model for decarbonising listed buildings in Wales.

The buildings, collection items and immersive experience that we deliver at Big Pit certainly appeals to the public. In the past, coal has been produced on this site to an industrial scale but now we’re looking at a future where the total power and heating will be supplied purely by renewable technology.

Brian Lewis, Head of Museum, Museum Wales