Hertfordshire, UK

Welwyn Garden City

Working with Welwyn Garden City to meet the requirements for their conservation area

In January 2019, Welwyn Garden City (WGC) embarked on upgrading the street lighting in the residential area to far more energy-efficient LEDs, whilst reducing maintenance visits to replace lamps and finally improving the overall carbon footprint for WGC and Hertfordshire County Council (HCC). As most of the luminaires in WGC are classified as conservation areas, this meant any change to the luminaires had to be very carefully considered and to meet the approval of WGC Local Councillors. As well as offering energy cost savings Ringway Infrastructure Services (RIS) on behalf of HCC were looking for a supplier that would meet all the operational requirements whilst improving efficiencies through innovation, service, and distribution capabilities.


  1. Approximately 2000 streetlights located in the conservation area of WGC required replacement.
  2. RIS on behalf of HCC and were tasked in collaboration with WGC councillors providing an LED low energy solution that was in keeping with the existing street lighting via a competitive tender process.
  3. The lighting design criteria stipulated by HCC was that the lumen output and performance on the road was equal or better than the existing lighting, whilst maintaining the aesthetics of the luminaires.
  4. RIS & HCC required the supplier to provide the best ‘long term value’ in consideration of; • combined capital, energy, and carbon costs over ten years • technical, commercial and logistics requirements • quality and warranty offers
  5. The project had a small window in terms of timescale. CU Phosco as the successful tenderer was appointed in July 2019 and the project was required to be completed by November 2019, in preparation for the Centenary celebrations of WGC in 2020.

Developing a bespoke solution

During the tender process CU Phosco created a bespoke LED version of their P107 Post Top luminaire. The P107 was originally used in some areas of WGC using previous HID technology. CU Phosco specifically developed the LED version for this project to meet all current lighting standards with the compatibility to the Telensa CMS system used by HCC. Throughout the process, CU Phosco worked closely in collaboration with RIS working on behalf of HCC to ensure the best ‘long term value’ was met.

The development of the product incorporated a trial scheme to establish approval through combined involvement with local residents, WGC Councilors, HCC Highways Engineers and RIS to ensure all parties were satisfied with the product both aesthetically and performance-wise.

The specification was to provide an LED light engine delivering an equal lumen output to the existing streetlights. Initially, a clear bowl was specified however CU Phosco technical engineers also presented an opalized version. The opalized version was well-received by all parties and a decision was made to use opal bowls in keeping with the existing luminaire appearance whilst delivering exceptional lumen output and energy efficiencies.

As CU Phosco is located within Hertfordshire, site visits, technical development and the final delivery enhanced the carbon offset requirements stipulated in the tender.

As part of Hertfordshire’s drive to LED and CMS Ringway sought to replace the existing post top lighting in residential areas of Welwyn Garden City. This style of lighting is unique in Hertfordshire and required careful consideration to satisfy all the stakeholders. These issues included the appearance, lighting level, glare and opacity, value for money, maintenance, compatibility with the central management system and energy costs. As if that is not enough the lighting is in conservation areas, highly esteemed by the residents. The lighting is an integral part of that and we consulted with councillors, planners and local preservation groups to ensure the solution met expectations. After an initial tender process, we awarded the contract to supply the lanterns to CU Phosco who were flexible enough in our needs and were able to meet the demands put upon them.

The whole scheme was completed on time and within budget. The products look good in place and to date the residents and public officers are happy. Thank you to CU Phosco for a job well done.

Jonathan Watt,

LED replacement project manager

Energy Savings

A 70% average saving in energy over the previous luminaires installed within the WGC Conservation areas has been achieved. The luminaire energy calculations are based on LED full power when in light and do not include any dimming regime which can be adopted by HCC via their Telensa CMS.