In July, Leeds City Council announced a project to convert nearly all its lanterns with LED bulbs, requiring changes to a pre-existing PFI deal with Tay Valley Lighting - for which the equity holders are energy company SSE and the Royal Bank of Scotland - which is responsible for the maintenance and replacement of street lights in the area over the 25- year period from summer 2006 to 2031. -> THE LOST BILLIONS - an interactive look into the increasing cost of PFI dealsConstruction took place between 2006 and 2012, and data obtained by JPIMedia Investigations shows that the estimated cost of the PFI as of 2017 was £326m, compared to its capital value of £94.6m. However, since 2013 more than 3,700 street lights have been turned off between midnight and 5.30am, saving the council around £136,000 per annum, according to local authority documents. In its announcement this summer, when the council confirmed Tay Valley Lighting would carry out the new work following contract changes, the authority said it currently spends around £4.8m a year on electricity to run around 92,000 street lights, with 6,000 already earmarked to be converted to greener LEDs - and the new programme will convert the remaining 86,000. It said the project would generate savings of £3.4m a year at current energy prices, once the work is complete, and reduce the street lighting energy consumption in the city by around 62 per cent and contribute towards the city becoming carbon neutral by 2030. This followed a public consultation from November 2017 to January 2018, which received 2,000 responses, more than 80 per cent of which backed the upgrade of lights. A council report in October last year also stated that the firm wanted to "resolve a number of unrelated contractual disputes" ahead of contract changes confirming the LED project. RBS' own chairman, Sir Howard Davies, last year described PFI as "fraud on the people" and has admitted there may not be a full £45bn payback after the bank was bailed out by the Government in 2008. A Leeds City Council spokesman said: “In December 2018, we approved as a council an ambitious plan to upgrade all street lights in the city to make them more energy efficient, following a wide-ranging public consultation. “In converting approximately 92,000 street lights to LEDs, it is estimated that when completed, this will provide savings of approximately £3.4m a year and help reduce street lighting energy consumption in Leeds by around 62 per cent and deliver around 7,050 tonnes of carbon savings. The new LED Lanterns are also fully recyclable, and their increased efficiency will mean that less maintenance visits need to be undertaken and therefore result in less emissions from service vehicles. The introduction of our street lights conversion programme also provides another meaningful step in our wide-ranging work to make Leeds carbon neutral by 2030.” The spokesman confirmed that "virtually all" of the lanterns installed under PFI will be replaced, along with an existing 5,500 lanterns not previously renewed. SSE and the Royal Bank of Scotland have been approached for comment.