During the past 2 years Stoke on Trent City Council have saved over 14 million kWh of energy, through a combination of an LED upgrade and CMS installation programme across the city. With thanks to installation contractor SSE Contracting, and CMS provider Mayflower Smart Control, the council have been able to maximise their energy efficiency and achieve savings of £985,701 per annum.*
Reliable technology for over a decade
The relationship between SSE and Stoke on Trent City Council is longstanding, following the successful award of the Stoke PFI contract back in 2003. At this time, Patrick Mitchell, now Head of Mayflower, was the PFI Partnership Manager for Stoke City Council.
In 2005, Stoke City Council identified three city parks in which they could pilot the capabilities of the Mayflower CMS to improve safety and security for both residents and natural habitats alike. Handley, Burslem and Tunstall parks were all fitted with the then Mayflower cutting-edge technology which is a far cry from Mayflower’s current Node and Sub Master solution. The 315 Nodes installed across the parks enabled the CCTV Control Team to emergency override lighting profiles through a 3rd party interface.
Working alongside SSE, Stoke City Council identified energy efficiency as an area of improvement for their existing SOX and SON lanterns, and requested a business case for conversion to LED lanterns complete with a Central Management System as a key requirement. Following analysis of the business case, it was determined that LED lanterns would be required to be dimmed by a minimum of 20% to achieve the required level of financial savings to progress with the LED upgrade scheme.
The dimming capabilities of Mayflower CMS were demonstrated through on-site evening trials in 2016 led by Mayflower Project Lead, Shawn Blunt and Technical Sales Manager, Steve Green. During the trial, the LED lanterns light output was reduced by 20%, 40% and 60% for comparative purposes. The results of the trial and the flexibility of the system secured the contractual agreement between Stoke City Council and SSE to incorporate Mayflower Smart Control as part of the wider LED solution across the city
The contract between Stoke City Council and SSE began in March 2017, spanning a 2-year installation period in which 28,862 street lights were fitted with the latest Mayflower technology.
The SSE Enterprise Street Lighting team based at the Stoke depot were responsible for the installation of Mayflower Nodes and Sub Masters, following on-site training by the Mayflower Project Lead. System operators were also trained in the Back Office system, enabling them to configure Nodes, view data and export lighting faults for rectification.
The installation period of the Mayflower CMS concluded in March 2019 when the final Nodes were installed and connected successfully to the Back Office System.
SSE currently carry out an Annual Replacement Programme for Stoke, whereby columns requiring update of lanterns or CMS devices are installed as and when required, until the end of the PFI contract.
Mayflower Smart Control provide a Service Level Agreement which includes technical support via telephone, email and when necessary, in-person review meetings.
The current SLA also permits Stoke City Council to make adjustments to lighting regimes which are actioned by the Mayflower Technical Support Team; this enables the council to respond to changes to lighting policy and variable lighting demands.
At present, 28,456 of the total 28,862 lighting units are dimmed by 25% from midnight until 5:30am or a natural light of 18 Lux is achieved. This provides additional scope for further energy and financial savings, should the council wish to implement step dimming throughout the night, either by switching units off or dimming by more than 25%.
Shawn Blunt, Mayflower Field Engineer and Project Lead, commented: “The installation of our Mayflower CMS in Stoke was a very well organised and highly successful project. The scale and geographical nature of Stoke City required detailed planning for the co-ordination of both upgrading lanterns and installing CMS hardware simultaneously. It was a pleasure to work with SSE Enterprise and Stoke City Council throughout the installation process.”
Patrick Mitchell, Head of Mayflower, summarised the project success with: “To achieve savings of over 1 million kWh across the city of Stoke-on-Trent in just two years as a direct result of dimming and trimming lighting regimes, shows how effective and flexible our Mayflower CMS is. The development of our Smart City platform, Mayflower Smart Cities and Places, is nearing completion and we are looking forward to discussing how we can further assist Stoke Council in creating a smarter, greener and more efficient city.”
Sam Peacock, Operation Manager, Stoke on Trent PFI, added, “From conception to completion SSE have received a 1st class service from Mayflower in regards to the delivery and roll out and support for the replacement of 28,862 LED Lighting units with Mayflower CMS Control system across the city, this has seen a reduction in energy cost £985,701 per annum for SSE`s client at Stoke on Trent City Council and the ability to trim lighting levels when traffic routes and footfall are lower throughout the night. The Mayflower CMS system has the ability to produce real time reporting that allows SSE`s admin team to interrogate the system daily for a variety of situations including lighting outages, this enables SSE to respond more proactively and reduce the time taken to rectify lighting faults on site.
*based on a unit rate of 12.956p per kWh