The project is designed to reduce carbon emissions and improve the city's air quality.
Finding a long-term solution for the ageing network, which supplies 3,000 homes, has been controversial.
Average retail prices are peaking at 92% higher than normal due to the war.
Should we embrace air conditioning despite its costs and consequences?
The growth in sales has slowed significantly after a critical government grant programme was cut.
Grantham Meres has replaced its gas boilers with an air source heat pump and 576 solar panels.
The Scottish government says that it intends to wait until 2035 before ramping up the roll-out of the technology.
The government wants more homes to have heat pumps to cut fossil fuel use and drive down energy bills.
The government wants Britons to embrace heat pumps. But will they ever make financial sense for the average user?
