The real cost of lighting and how to control it

By Ian Hambly, Somar International

For a growing number of organisations, the concept of whole-life costing is at the centre of their acquisition decisions. Comparing options and their associated costs over the life of an asset can be particularly productive in relation to lighting, as whole life costs can be substantial. The running costs of a building can be significantly increased if the wrong choice of light sources is made during the design stage of a build or refurbishment project.

The cost of the lamps or light fittings and the energy they use are obvious considerations, but several other factors contribute to the whole-life cost of lighting. The cost of replacing lights, the potential disruption of this process and the health and safety issues of replacing different types of light fittings must be taken into account. Many offices use compact fluorescent lights (CFLs) on their ceilings and replace them all at the same time as they are reaching the end of their useful life. It is generally not an issue if one or two lights go before this mass replacement takes place, as the overall lighting levels are unlikely to be affected. Different workplaces, however, have more complex lighting needs. Ensuring that the workplace has suitable and sufficient lighting – in line with the Workplace (Health, Safety and Welfare) Regulations 1992 – must be a consideration for every business. The Chartered Institution of Building Services Engineers (CIBSE) provides guidance on the level of illuminance required in different working environments. Generally, the amount of light needed depends on how much detail needs to be seen, the age of the worker and how quickly and accurately the task should be carried out. If a workplace has stairs, they must be well lit to avoid shadows. Individual workstations and areas of increased risk must have localised lighting. Lights must not be obscured and regular, efficient maintenance must be carried out.

Lights on stairwells provide a good illustration of how the whole-life costs of lighting can be high. If a light  on a stairwell blows, it must be replaced as soon as possible. Replacing a light that is fitted at height falls within the remit of the Work at Height Regulations 2005 and anyone who is carrying out this work must receive training in working safely at height. Only certain people will be able to carry out this work, which may involve them being taken away from other tasks. This affects other maintenance areas, labour costs and time spent on risk assessment and paperwork. By switching to a light with a longer life span, it needs to be replaced less often. The result? Lower whole-life costs.

With so much focus on providing enough light in the workplace, the risks of over-illumination are often neglected. Over-illumination (the supply of light beyond what is required for safety or functionality) can be just as dangerous as too little light. It is expensive, energy intensive and can result in negative health effects, the most common of which are headaches and blood pressure elevation. In extreme cases, these simple metabolic disturbances can lead to anxiety, stress and immune system disruptions. Workplace over-illumination is also considered to be a chief cause of worker error rate. Studies have shown that giving open plan office workers individual control of lighting can reduce stress and increase job satisfaction. In this increasingly litigious world, all possible steps should be taken to avoid potentially costly legal action.

On an ecological scale, huge amounts of energy are wasted from over-illumination. Typically, this results from an excessively high intensity of light, the unnecessary illumination of areas already lit by natural light, and a failure to exclude unoccupied areas from illumination. Obviously, excessive energy results in high electricity bills. Light pollution also disrupts the world’s ecosystems, by interrupting certain animal migration, interfering with predator/prey relationships and disturbing animal and plant circadian rhythms.

Using energy efficient lighting control solutions is a way to eliminate over-illumination, decrease energy consumption and reduce costs in the workplace, while ensuring that health and safety requirements are met. Control systems range from the most simple of mechanical switches to a highly intelligent automatic control system, which will react to environmental factors and adjust illumination accordingly.

Several companies have addressed the issue of over-illumination as part of their mission to cut costs and increase the energy efficiency of their business. Coca-Cola recently replaced the existing lights in their Edmonton bottling plant with energy efficient high bay luminaries. Not only did this improve the working conditions for the workers – energy costs were cut by a massive £69,516. The new lighting controls enabled environment-reactive dimming and automatic switch-off when light was not required.

Sainsbury’s began its cost cutting, energy saving mission with its huge Corby distribution centre. The entire warehouse lighting system was replaced with 500 energy efficient high bay luminaries. This resulted in a six-figure annual saving on the company’s energy bills, a reduction in carbon emissions of 683 tonnes – and payback took only 16 months.

Seda UK, the specialist food packaging company, took similar steps at their 32,000-square-metre factory in South Wales. Part-funded with a £90,000 interest-free loan from The Carbon Trust, Seda replaced the old lighting with 750 energy efficient high bay luminaries, which will save the company £168,208 and almost 1 megatonne of carbon dioxide per year.

Coca-Cola, Sainsbury’s and Seda are only a few of a growing number of innovative companies who are embracing lighting controls to cut down on overillumination, improve working conditions, reduce electricity consumption and save money. If the increases in energy prices and warnings of electricity shortages are not enough, the looming ‘carbon tax’ alone should motivate other companies to follow suit. In the 2011 Budget, the chancellor announced a ‘floor’ price for carbon – under Europe’s emissions trading scheme – of £16 a tonne in 2013. With this figure estimated to rise to £30 a tonne by 2020, curbing CO2 emissions is a priority for all responsible businesses.

The initial investment in lighting controls guarantees a fast payback; in the case of Coca-Cola, payback was within one year after the Enhanced Capital Allowance. The ECA is a government incentive for businesses to invest in energy efficiency; under the scheme they can claim an ‘enhanced’ 100% capital allowance on qualifying investments in equipment in the first tax year. The cost of the initial investment is therefore no longer a legitimate reason for not making the switch to energy efficient lighting.

Energy efficient lighting control systems can save up to 90% on a company’s lighting energy bill. By combining sophisticated photometric design and advanced sensor control with low energy technology, energy costs are slashed. A lower density of lights are required, so when a standard fluorescent light fitting is replaced with an energy efficient model, savings over 50% can be achieved. A lighting control system exists to meet the needs of every type of working environment. For low-occupancy workplaces, such as warehouses, dimmable lighting controls that are programmed to react intelligently to their surroundings are the perfect choice. High quality ballast systems prompt the light to dim during periods of high levels of natural light. Operational light levels are preserved, but the luminaire output is decreased – increasing cost savings and saving energy. This could be combined with infra-red sensors, which detect the level of activity within certain distances of the light, and automatically turn off or dim lights that are unnecessary. Sainsbury’s have reaped the benefits of this feature in their Corby distribution centre.

The financial and environmental rewards of switching to energy efficient lighting in your workplace cannot be underestimated. By incorporating effective control systems into your lighting, these benefits can be taken to the next level. It all comes back to the whole life costs of the equipment a business needs to operate on a daily basis. Keep costs down by investing in energy saving lights, and protect the workforce and the environment at the same time.