The funding for a range of measures, including an electrically powered heating and hot water system, is part of the latest round of the Public Sector Decarbonisation Scheme.
Mike Parkhill, group chief estates and facilities officer at Lincolnshire Community and Hospitals NHS Group, said: ‘Achieving the national green agenda begins with action at a local level.
‘This funding brings us closer to achieving our net-zero target by 2040, while also reinforcing our commitment to provide modern and more energy efficient environments for our patients and staff.
‘By significantly reducing carbon emissions and lowering our reliance on fossil fuels, we're investing in a more sustainable future for Boston. We are also working on future bids for our other hospital sites across Lincolnshire.'
The scheme is delivered by Salix on behalf of the Department for Energy Security and Net Zero.
Salix director of public sector decarbonisation, Ian Rodger, said: ‘We have no time to stand still when talking about climate change and reducing our carbon emissions is key.
‘This funding will not only help the hospital site achieve its net zero ambitions, but it will make the buildings better and more comfortable for the patients, staff and everyone who uses them.'