LED street lights – spend and process

1) The LED lamps should, and I’m sure, will use less energy, but what is the anticipated payback time i.e. how long for the energy cost saving to cover the cost of converting all the streetlights across the region?

It is expected that the payback time will be less than about 9 years for the latest investment that is being made, but this time period will decrease with any inflationary increase in electricity prices.

2) What warranty, if any, is given on the LED lamps? From my own experience, LED lamps have often failed to give the life span suggested by the manufacturer. Obviously, you will not be wanting the cost of having to replace lamps again, if they are still in the process of paying for themselves, by the energy cost saving. 

Devon County Council have specified high quality LED luminaires supplied from a leading manufacturer. The contractor is required to maintain them for the duration of this contract to cover any failures at their cost and in addition the supplier warranties for the current contract are:

• Luminaire (body/shell): 18 years
• LED Modules: 50,000 hours
• Driver: 10 years
• Photo-cells: 12 years

3) Looking at it from a more environmental perspective, what is the environmental cost / carbon generated by producing 79,000 new lights, recycling or disposal of the 79,000 old lights, plus all the carbon emitted by contractors vehicles etc in the process of replacing all the lights across the region? Bear in mind that it would be a fair assumption that the majority of these lights will still be actually working ok.

We do not hold information available to be able to respond to this level of detailed question. However it should be noted that the existing lanterns contained lamps that need regular lamp replacement of between 3-5 years, which the LED’s will not. Also outages that are currently being reported will have the complete lantern replaced to an LED, thus saving on any repeat attendances.

4) How many actual street light posts will need to be replaced to accommodate the LED lights, and how much carbon is it anticipated this will produce?

The street lighting columns will not need to be replaced as a consequence of the LED installation work, they will however continue to be replaced pending natural deterioration, age profile and failed structural inspection. The LED lanterns are generally lighter than the existing lanterns and have slimmer profiles therefore offering less wind resistance and reducing stresses onto the column.

5) What is the intention with the number of hours the lights will be operational? Is the intention to keep them on all night, because they consume less energy, or to continue to keep them off during the early hours?

The lanterns will continue to be turned off for 5 hours in mainly residential areas, the Part Night Lighting will not change. DCC have however implemented a stepped dimming profile for lanterns on main roads to allow for additional energy savings to be made.

6) With the road network being in quite a pretty terrible condition across the region, and the associated vehicle damage claims, how is spending a huge amount of money on replacing working lights, a higher priority than improving the condition of the road, which also puts cyclists and motorcyclists at risk of serious injury or death, in addition to the risk of damage it presents to vehicles?

We note your opinions and we do not consider this to be a request for information or data.  We are therefore not obliged to respond to this question pursuant to s. 1 of the Freedom of Information Act.  Please feel free to seek information from this authority.