A promising LED lighting project that didn’t quite make the grade …

Organisation involved:

Oxford City Council

Overview:

It wasn’t always the case, but as prices have reduced LED lighting is increasingly recognised as a “no brain-er” for energy efficiency. It isn’t always so clear cut, as this project demonstrates …

Background:

St Aldates Chambers is Oxford City Council’s flagship office building in the centre of Oxford. Originally a telephone exchange built in the 1930s, the offices underwent a comprehensive refurbishment in 2012 in which:

  • boilers were replaced with high efficiency gas condensing models,
  • cavity wall insulation was installed,
  • high efficiency T5 lighting and controls were installed.

LED technologies at the time of the refurbishment were not as technically developed and commercially viable so were not pursued during the 2012 refurbishment works.

The Energy and Natural Resources team at the Council have however been initiating the roll out of LED lighting and controls upgrades on a number of buildings across its estate since 2012; prices and technical performance have improved year on year for LEDs with a range of main stream manufactures now providing this type of lighting.

Solution: 

Prices and performance of LEDs have improved year on year and the team has observed the improvements as it continued to consider LED lighting and controls for roll out across the estate.

This wide spread roll out across the estate led to positive experiences, so the team revisited the scope for LED lighting as a replacement for the existing T5 lights St Aldates Chambers.

A comprehensive audit of existing lighting (developing a full inventory of existing lighting and savings potential) made the technical and environmental case for upgrade:

  • savings of 30,680 kWh/year equivalent to a reduction of carbon emissions by 15tCO2 per year; and,
  • financial savings of ca £3700/year are possible.

The council has a SALIX revolving loan fund for energy efficiency projects which could have contributed around £18500  based on these savings.

This upgrade, however, is not straight-forward however as the existing suspended luminaires in the open plan offices would need to be retained.

The cost of replacement per luminaire is approximately £200 at present meaning that the Salix contribution only meets about a quarter of the cost of the replacement.

Outcomes and benefits delivered:

Not yet!

Lessons learned/conclusion: 

An on-going programme of energy efficiency improvements across the estate allows the council to assess and reassess business cases as the technical and economic potential of a given solution evolves. This maintains improvements without compromising value for money.

LED lighting would deliver improved maintenance (reduced number of lighting replacements) and flexibility on control. However the paybacks are of the order of 19 years meaning that unfortunately whilst technically possible the economic case does not quite meet the mark at present.

The team continue to explore other areas in the building where LED lighting may be possible such as stairwells, meeting rooms and amenity rooms where controls could be improved significantly with LED technologies.

Link for further info:

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