In 2018 Central Bedfordshire Council contacted Solar Illuminations to inquire about the feasibility of supplying and installing solar powered car park lighting at Houghton Hall Park near Dunstable. The client had specific criteria in mind. These included 4M columns and LED lighting that would automatically illuminate at full power from dusk for 4 hours and then again 2 hours before dawn. Between these times the requirement was that the lighting be automatically dimmed to about 33% brightness and that PIR/motion detectors be interfaced with the lighting systems to provide full power upon activity being detected in proximity. While the criteria may sound complex it actually forms part of a list of options that are available to clients when we design our lighting systems. We are yet to be presented with a set of criteria that we have been unable to meet!

It’s common knowledge that the solar radiation levels (insolation) are much lower in the UK in the winter months than most of our southern neighbouring countries. Bearing in mind that the longest night of the year in the UK (December 21st) can stretch to almost 17 hours! So, on the basis of providing a reliable, efficient and trouble-free system which is fully operable all year round, no matter the weather, the LED power consumption was a major consideration. Using highly efficient (high lumens per watt) Philips Luxeon LED luminaires of 10W and 20W we were able to provide the Lux levels across the site that would prove acceptable. The 6 hour illumination time at full power coupled with the 1/3rd power and motion sensor features enabled these higher wattage luminaires to be proposed.

As a matter of course, we attended the site, conducted a survey and risk assessment etc. We then determined the LED power and quantity of lighting columns necessary, and produced a photometric rendering of the site. In doing so we are able to fine tune the column spacing and ensure that the Lux levels and distribution patterns are perfectly arranged. Particular attention was paid to the eastern side of the property line where there are multiple tall trees that could pose shading issues. All the column locations were plotted to provide optimum lighting coverage as well as keeping any light pollution and overspill to the natural areas to an absolute minimum.

Solar Illuminations submitted a detailed tender and was awarded the contract in the summer of 2018. In total, 9 car park lighting systems were installed at the site which took two days to complete (including commissioning) in August 2018. 7 were installed in the main car park area. These were a combination of Type II and III 20W LED luminaires. A further two lighting columns were installed specifically for illuminating the footpaths and entrance area to the building. These used 10W LED luminaires with Type II and III optics. All in all, we successfully achieved an average of 5 Lux (0.5fc) across the entire site.

It’s standard practice for Solar Illuminations to calculate and size the solar panel wattage and battery capacities for every project. In this instance we allowed for 3 days of autonomy (back-up/reserve power). We use calculations made in a ‘worst case scenario’ e.g. longest night of the year with the worst weather conditions. We provided heavy duty 89mm OD root mounted column, solar panels configured in pairs, top quality AGM batteries and high performance GJD PIR/motion detectors. Super-efficient MPPT charge controllers with Bluetooth and smart phone connectivity were used and are standard with most of our lighting systems. Because the site is open to the public, to reduce the risk of theft and vandalism the solar panel was installed at the top of the column and the metal lockable battery enclosure was installed just below the luminaire arm so that everything is very much out of easy reach.

The combination of quality, proven reliable components that we integrate into our solar car park lights along with our technical expertise and professional installation team, forms a complete package that is second to none.