Sabien founder Alan O’Brien saw the value of his 50 per cent stake in the company rise by £3.25 million after penning the contracts.
The company’s M2G product increases the efficiency of commercial boilers by up to 25 per cent.
The company, which made a £497,000 pre-tax loss in the last half-year, already works with RBS, Aviva, Virgin Media, O2 and Vodafone to help them cut their carbon footprints.
Alan O'Brien, founder and chief executive, said the company was in talks with all the other major utility companies about selling the technology, which can be retro-fitted to old boilers to provide cost-savings within two years.
Mr O’Brien said: “The potential could be huge or the uptake could be small. We won't know until the deal starts delivering contracts.”