An underground pipeline which transfers heat and energy between two hospitals in Oxford has been switched on.
The £14.7m link, which connects the John Radcliffe Hospital and Churchill Hospital, is now in use after building work finished in May.
Digging on the project was delayed when contractors started work without the right permissions last year.
The scheme will save £460,000 each year on bills, Oxford University Hospitals NHS Foundation Trust (OUH) said.
OUH will pay for it over 25 years with money from the annual savings, and said the contractor, Vital Energi, would reimburse if the savings did not amount to £460,000.
The 1.6-mile (2.2km) pipe was laid under several roads in Headington, Oxford.
"There was some disruption, definitely", said Roz Smith, a county councillor for the area.
"They had to cross the London Road and indeed Old Road too, two of the busiest roads we have got in Headington.
"Let's hope this project does do what it says on the tin.