Background

With a large proportion of its 93,000 street lights reaching the end of their natural life, Nottinghamshire County Council took the decision to use this as an opportunity to upgrade its lighting stock to LED whilst completing one of its scheduled maintenance programmes, which take place every several years. The Council’s focus was on reducing energy usage and costs whilst also being mindful of the needs of the Council’s residents. Lucy Zodion worked with the Council to develop a new photocell that met their energy saving and product application needs. The new ZCELLLED 20:20 photocell from Lucy Zodion will be fitted in 40,000 lanterns in residential areas across the county as part of the Council’s five-year street lighting upgrade project.

 The Project

 Nottinghamshire County Council’s Electrical, Environment and Operations Team had investigated upgrading to LED lanterns five years ago. However, LED technology in street lighting was relatively untested at that time and the cost per lantern was high compared to today’s prices, meaning return on investment for SALIX funding was not sufficient to fund the project. Five years on things have now changed.

 LED lantern costs have lowered considerably over the last three years and LED technology is now proven and widely accepted across the industry. Importantly, other forward thinking manufacturers have confirmed their commitment to LED by bringing a range of unique products to market. One such solution is Lucy Zodion’s revolutionary ZCELLLED photocell.

 This ultra low power NEMA ZCELLLED photocell – the unit has its own UMSUG code – has been developed to minimise maintenance, provide a life span of more than 15 years and consume 60% less energy than traditional photocells. It offers the lowest power consumption (less than 100mW), highest power factor and highest ingress protection rating of any photocell currently on the market. With an immediate switch on capability of LED lanterns due to zero warm time; this combination makes the ZCELLLED the most energy and operationally efficient photocell on the market.

 Lucy Zodion produced a bespoke, 20:20 lux version of its ZCELLLED photocell for Nottinghamshire County Council that is perfectly suited to LED switching regimes and efficiencies. The 20:20 lux feature reflects the zero warm up time and immunity to switching of LED lanterns.

 Nottinghamshire County Council undertook an initial three-month trial of LED lanterns fitted with the ZCELLLED photocell – the Council’s chosen lantern was the Vmax lantern from Holophane - to assess the solutions feasibility. This was conducted in a residential area and feedback from the public was invited during and after the trial period. Not only was the feedback from residents overwhelmingly positive, the significant cost savings offered by the system led to the Council taking the decision to role out the solution across its 40,000 strong residential street lighting estate.

 The Results

The feasibility trial highlighted the considerable reduction in energy usage, and costs, that the new LED lanterns combined with the ZCELLLED photocell would provide. While previously each street light would use £30 average worth of energy per annum, this new solution would reduce this cost to £7.50 average per year per street light. Therefore, based on the solution being installed in 40,000 street lights, the potential average annual energy-cost saving for Nottinghamshire County Council on completion of the project will equate to a massive £900,000 per annum

 Clare Murden, Lighting, Management and Energy Savings Project Manager at Nottinghamshire County Council, said:

 “The ZCELLLED photocell is now the standard cell for all our LED installations in Nottinghamshire.  If local authorities are carrying out a bulk change from SOX to LED’s then it would be wise to build in the cost for changing the cell whilst there.  The 20/20 lux feature will save them additional burning time each day which will soon add up in terms of additional energy savings.”