LED Case Study Title: MOFFAT DARK SKIES PROJECT Organisation: DUMFRIES & GALLOWAY COUNCIL Dates of Initiative: JAN 2013 - ONGOING Background – general information to set the scene, for example, about the programme and choice of location. What was the existing lighting technology and what led technology replaced it?
The Scottish Government was approached to seek funding for changing the 568 existing lights in Moffat to energy efficient LED lighting. The business case was built around the energy and carbon savings but the changeover to LED lighting also allowed us to apply to the International Dark Skies Association (IDA) to make Moffat a Dark Skies Community. It is hoped that gaining this status will have a positive effect on winter tourism in the town which is an excellent stopping point for coach parties and hill walkers due to its proximity to the M74 and the Southern Upland Way.
The existing lighting in Moffat was a mixture of Low Pressure Sodium (SOX) and High Pressure Sodium (SON) lighting. This type of lighting gives off an orange and golden glow respectively and is not energy efficient. The light given off by the SOX lanterns is not easily directed onto the road due to the size of the lamp and therefore half the light given out is wasted leading to obtrusive light into windows and light pollution of the sky. Both the SON and the SOX lamps last about 3 years before having to be replaced.
The new LED lighting gives out a white light which allows you to reduce the lighting levels, it is energy efficient and does not require the bulbs to be replaced. The lanterns used were Philips Mini Iridium LED and Iridium LED as these were found to have less than 1% upward light ratio at a 5 degree inclination. This was important with respect to our application to the IDA as most lanterns were going onto existing brackets that had a 5 degree inclination.
The total funding for the project was £240,000 pounds which covered the purchase and installation of the lights, design fees and application to the IDA. Over the 20 years lifetime of the lantern it is anticipated to save the council £343,756.41 if the £227,200.00 for the purchase and installation is to be repaid or £570,956.40 if no repayment is required. These figures were worked out using a twenty year average price for electricity, carbon tax and maintenance.
The payback for the changeover is 8 years.
Rationale – why did your Council undertake this?
Dumfries and Galloway Council is committed to reaching the Scottish Governments target of a 20% reduction in CO2 by 2020. It is also under no allusions that the only way energy and maintenance charges are going to go are up. Changing over to LED’s in Moffat will surpass the 2020 target for the town and reduce energy and maintenance by 50%. Process – what led to this good practice? What steps were followed in order to establish and continue this good practice? What are the key elements of this good practice (include different stages, activities undertaken, etc.)? were there any implications on columns or any private wire which need to be addressed before the pilot became fully operational? The process began by approaching the local community to gain public opinion about the changeover. The community were given a presentation showing the difference between the old and new lights. They were very enthusiastic. We then set about researching all available LED lanterns and tried them out on our design software to see which lanterns would light the road to the current BS5489: 2013 standards.
Once a shortlist had been established, the lanterns were reduced down to one main road lantern and one side road lantern. This process involved a series of qualifying test including warranty, colour temperature of the white light, cost, uniformity of output and circuit wattage.
The next step was a site survey to see if there were any obstacles to overcome. It was noticed that some brackets were at 15 degrees that would not be acceptable to the IDA. These would have to be replaced. Any other brackets that were showing signs of fatigue would also have to be replaced as the lanterns have a 20 year lifespan. It was decided to buy 100 brackets that the installation contractor could take to site and replace as necessary. This was proven to be a good idea and was saved time for both parties.
Resources required – what human and financial resources were needed, and who was involved (both in order to set up and continue this activity)?
Throughout the project there has been one person project managing, a consultant who has been helping with the Dark Sky Community Application, a contracting foreman and a sub contracted electrical firm for installation.
All cost involved in the above were paid from the grant sum.
Continuing on from this point the management costs will be absorbed within the lighting budget for the whole of the councils lighting stock.
Facilitating factors – what factors enabled this activity to happen?
The output per Watt ratio of LED’s has nearly doubled within the past 3 years and continues to rise. This means that the cost of getting the correct output has become affordable. At the same time, the price of the LED lanterns has come down by 1/3 and is still falling. Put together this means that the payback for installing LED’s is between 6-8 years compared to 12-14 years a few years ago.
Challenges overcome – what challenges, if any, did you have to overcome?
The biggest challenge was to get the public onside. This was done with the aid of an enthusiastic local councillor and the fact that the consultant for the IDA application is a Moffat resident. The only other major challenge was the timescale to meet the end of year deadline. This was achieved by keeping the pressure on the manufacturers and the installation contractor.
Results observed– what results were observed? This may be at community level, among staff, for the organisation, etc.
The community on the whole have been very impressed by the lighting. To date we have had only two complaints and one of those has since been retracted. We have had some excellent feedback through the community council and a lovely card from a returning resident who had been away on holiday over the changeover. They stated ‘My congratulations and thanks to all – you have enhanced our lives’.
Due to the time of year when the lighting was installed, it is not possible to do the ‘after’ photographs as these are susceptible to late sunsets and early sunrises. The surrounding countryside must also have light levels recorded post changeover for inclusion in the IDA application.
Benefits Gained – could be significant maintenance benefits with LED lighting or better colour rendering which improves CCTV images, environmental benefits etc.
Lessons learned – what worked particularly well? What would you do differently next time? What advice would you give to staff in other organisations wishing to try an LED programme? Did the LED technology deliver the benefits anticipated - what were these? Can they be replicated?
I have been giving feedback through the SCOTS Group for road lighting on my trial. Things of note that I have changed on further installations are that there are better performing lanterns now on the market at 30% less cost. The rate of change in light output to energy consumed is change on a monthly basis so it is best not to jump in and buy thousands of lanterns at a time. Any changeover should take the form of a gradual change possibly over a number of years and be weighed up against rising costs. It is also best practice to tackle the most inefficient first.
There are also other light sources called Cosmopolis that are a white light and are very energy efficient. The lamps are expected to last 6-8 years. It is my opinion that these would be better suited to major traffic routes and town centres at this point in time due to the high output achievable. These can also be readily dimmed as required to save energy during quieter times on the roads.
Next Steps - what are your plans to build on this pilot? How will it affect the roll out of LED lighting in your Local Authority area?
Our council has now adopted a 8 year £7.4 million changeover policy to dimmable LED and other energy efficient white light sources. We have already purchased a further 3000 LED lanterns and are in the process of installation.
Reaction - what was the reaction from the local community? If the reaction was negative, how was this mitigated?
As stated before the community as a whole have been very pleased with the results Additional information– please offer your contact details or other avenue of further information. CALUM EDGAR