With rapidly rising energy costs and government legislation to reduce carbon emissions the incentives to install energy efficient lighting in applications such as schools, hospitals, commercial, retail, industrial and logistics applications are extremely powerful. Whilst many private companies and public institutions have a strong desire to replace their lighting the process can often be daunting with wide number of factors involved. The top 10 points for consideration are listed below to help in this process.
1 Any return on investment calculation will be dependent on the operating cost of the existing installation. It is important to understand the unit cost paid for electricity, the operating hours per annum of the installation and the energy consumption of the existing luminaires. Only then can a comparison be made with the proposed replacement allowing a return on investment to be calculated and a conclusion drawn if the replacement can be justified.
2 It is easy to focus on the capital cost of the replacement luminaires only, however the installation cost can also have a significant impact on the return on investment. The critical factor to consider is whether luminaires will be replaced on a one for one basis therefore minimising any need for changes to wiring and the costs associated with this, or whether with improvements in luminaire efficiency and optical design the luminaire positions can be changed allowing fewer luminaires to be used and therefore energy savings to be increased. Finding the optimum point where luminaire capital cost, installation cost and energy consumption are minimal is essential to gaining the maximum return on investment from your installation.
3 The installation of presence detection sensors is a common method for improving return on investment. In many applications these bring significant benefits both by reducing energy cost and reducing maintenance by ensuring that luminaires only operate the minimum amount of time required. Although there is additional cost involved in the installation of presence detection sensors the savings offered often significantly outweigh this and more than justify the investment. It is however important to consider the application and ensure that their use is viable. In areas where footfall is very high or where there is machinery and equipment in motion that will activate the sensors continuously their use may not be practical.
4 Daylight regulation sensors can offer similar benefits to those listed under presence detection sensors above, however consideration must also be made for the application to ensure that there is a sufficient contribution of natural daylight to justify the investment. For optimum payback sensors offering both daylight regulation and presence detection combined should be installed.
5 As LED technology has developed costs have reduced and output and efficiency has improved. As a result this has now become a viable light source for the majority of applications and offers significant benefits over traditional sources such as fluorescent and HID. Despite a slightly higher initial capital investment the full life time savings often justify the additional cost associated with LED, as well as offering significantly reduced maintenance costs. Where budgets allow LED should be considered as the first choice of source.
6 Whilst the focus of return on investment is often on energy saving other aspects of cost reduction should not be overlooked. Maintenance costs can form a significant part of the cost of operating any lighting installation, especially where luminaires are mounted in high level areas, difficult to access areas (ie above machinery) or where the costs associated with shutting down an area to carry out maintenance are high. The benefits of LED lighting or long life fluorescent products are significant in such applications. Other associated costs can also be considered at this point, for example when lighting industrial freezers and chillers the low energy consumption of LED and sensor controlled products can also give a significant reduction in refrigeration costs as the luminaires contribute significantly less heat into the environment. It is important to consider all aspects of the installation and environment above and beyond energy consumption when calculating your return on investment.
7 When installing any sensor controlled luminaires or a DALI installation it is important to remember that programming and commissioning will be required to ensure that the installation is optimised for the environment and savings are maximised. More complex DALI systems will often require commissioning by a DALI engineer, usually at a cost in excess of £500 per day. This can add significantly to the overall installation cost and reduce return on investment. In the event of a luminaire fault or change in use of an area it is often necessary to have this recommissioned again at similar cost, therefore such costs can be ongoing for the lifetime of the installation. Where possible use a simple system with integral sensor controls that can be programmed by non expert personnel allowing you to adjust the function of your installation as you please without incurring cost.
8 When choosing a luminaire type ensure that the design of the luminaire has been considered to allow for rapid installation to minimise installation cost and maximise return on investment. Consider factors such as ease of access for wiring and suitability for existing mounting and suspension points to ensure that the infrastructure requires as little modification as possible.
9 Always ensure that the luminaire specified is suitable for the application with consideration for the environment it is to be installed in and the legal requirements for health and safety, light levels, uniformity, colour temperature and rendering. Replacement of the installation due to a lack of suitability will be extremely costly and eliminate any saving that would have been gained.
10 Always ensure that the product chosen is manufactured by a reputable and established company that you can be confident will offer a quality product and support for the lifetime of the installation. The LED market in particular has been inundated by manufacturers jumping on the LED bandwagon and as a result the quality of LED luminaires and companies supplying them differ greatly. Always challenge your luminaire manufacturer to support their offer with technical data, photometric files, full luminaire specification including energy consumption, lumen output, light output ratio, product design life and warranty and certificates of conformity. Many of the less scrupulous manufacturers do not have the facilities or capability to carry out the required testing on such products. Ensure that the components used within the luminaires are manufactured by established and reputable companies. It is important to remember that although a low cost product may initially offer a tempting return on investment, in the medium to long term premature product failures with lack of support from the manufacturer will be extremely costly and have associated costs with down time for replacement and potential health and safety issues that may eliminate any potential savings.
