The group had installed gliricidia wood burning biomass gasifiers to run boilers at Heritance Tea Factory in Sri Lanka's hill country and Heritance Kandalama in the island's central province, which the group said was the first by any hotel in the country.
The boilers made hot water for the hotel room and steam for the laundry.
Aitken Spence says the gliricidia wood was saving 300,000 litres of diesel a year. The farmers who grew the plant were earning 100,000 US dollars a year or 13 million Sri Lankan rupees.
"We are very enthusiastic in continuing in this trend and playing our part in reaching the United Nations goal of achieving sustainable energy for all by 2030…," Rohitha Rajaratne, vice president, engineering at Aitken Spence Hotels said in a statement.
Another hotel in the chain, Heritance Ayurveda Maha Gedara had struck a net metering agreement with Sri Lanka's power grid to produce and sell excess solar power.
Aitken Spence had installed a 3.5kiloWatt solar array which had resulted in savings of 4,639 kiloWatt hours a year, the firm said.