Information on costs in relation to street lighting (FOI)

Request

I would like to know in relation to street lighting:

A.

Can you confirm only near end of life street lamps are being swapped from sodium lamps to LED lights as there appears to be a significant roll out of LED lighting in the last twelve months.

B.

What research was completed to ensure LED lighting was suitable for Jersey. In particular, LED street lighting is known to impact sleep patterns, is known to significantly impact light pollution / ‘sky glare’ and there are studies that show the significant intensity of the light source is a potentially significant distraction to drivers.

C.

What is the cost (including labour costs) of the TTS LED lamp roll out over 2012 to 2015 and what are expected costs for 2016 to 2018.

D.

Given the costs identified in C, please provide the payback period calculations taking account of cost of purchase plus fitting vs reduced energy consumption within the lifespan of the LED lamps.

E.

Whilst it was noted in a previous FOI response that the light is a higher colour rendering index which should provide better night identification of objects, it appears that whilst the sodium lamps provided a very even and wide illumination of the road surface, the replacement LED lamps have very marked bright spots and very dark gaps due to a narrower illumination angle.

Please confirm if this has been measured and confirm that the replacement lamps provide equal or better uniform lighting of the road surface. Given the differing illumination pattern and spread, have tests been performed to ensure the street lamp distances that exist allow for a comparable uniform and safe lighting of our roads.

Response

A.

Most of TTS sodium lamp street lighting stock is near the end of its working life. 

The lights that were in the worst condition have been replaced with either metal halide lighting or LED.

B.

No specific research has been carried out to ensure LED lighting is suitable for Jersey, because extensive research has been carried out in the UK and Europe on the effects of LED lighting products, the results of which are applicable to the Island’s roads.

The risk of any impact on sleep patterns is extremely low and only to be considered in high lighting levels (more than 30 lux is suggested as being the lower limit for potential problems). 

So for road lighting where the lighting level is normally well below 30 lux, the risk is negligible.

With the recently installed LED lighting, “sky glare” is reduced because lenses direct the light only where it is needed, ie onto the road and footway surfaces and not behind the luminaire or above it.

The effects of discomfort glare and disability glare are lower than alternative outdoor lighting products.

C.

TTS’s LED lamp roll out between 2012 and 2015 has cost £185,000.

Budgets for 2016 to 2018 are not finalised but the annual spend is expected to be similar to 2012 to 2015 spend.

23% of lamps in TTS total lighting stock will have been replaced by the end of 2015.

D.

An example is below. 

Queens Road LED lighting compared with sodium lighting (total 57 lights): 

Extra procurement / installation cost: + £6,000

Saving in running costs: £4,000 / year.

Saving on maintenance: £1,500 / year.

Payback period: 13 months.

Expected lifespan: 25 years.

This example is representative of all other LED lighting replacement projects.

E.

All new lighting schemes are designed in accordance with BS5489 1:2013 (code of practice for the design of road lighting). 

The British Standard requires minimum lighting uniformity percentages which are equalled or improved with the new lighting equipment.

Further improvement to uniformity levels can only be achieved by either increasing the height of the lights or installing additional columns, which is beyond the department’s budgetary restraints.