Case Study: Frimley Health NHS Foundation Trust achieves £700,000+ annual energy savings and 1,621 tonnes CO2 reduction with Ameresco’s CHP energy infrastructure upgrade

Frimley Health NHS Foundation Trust And Ameresco Announce Energy Savings Project

Frimley Health NHS Foundation Trust faced aging 1960s steam boilers and an unreliable heat and hot water system at Wexham Park Hospital that threatened service continuity and limited expansion. To address this, the Trust engaged Ameresco under a £7.5 million energy infrastructure and maintenance contract, using an energy savings performance contract (ESPC) and Salix financing to upgrade the hospital’s energy systems.

Ameresco installed a high‑efficiency 1.5 MWe CHP plant, three 2.5 MWth dual‑fuel low temperature hot water boilers, and an LTHW distribution network connecting over 30 plantrooms, completing works within 12 months and commissioning in December 2018. Ameresco’s solution — backed by a 15‑year O&M agreement — delivers around £700,000 in annual energy savings, displaces 90% of grid electricity, supplies 75% of the hospital’s heat, and reduces carbon emissions by 1,621 tonnes CO2 per year.

Frimley Health NHS Foundation Trust

Colin Mapperley

Director of Estates & Facilities