Key Issues Around Energy Efficient Lighting
Fluorescent tubes…can last anywhere from 6,000 hours to 15,000 hours, compared to a standard 1,000 hours from a GLS lamp.
Lighting is a major source of electricity consumption. According to the International Energy Agency (IEA), a global switch to efficient lighting systems would shave nearly 10% off the world’s electricity bill.
The IEA estimates that 19% of global electricity generation is used for lighting and to put this into context, the carbon dioxide produced by generating all of this electricity is three times greater than emissions from aviation.
From these figures alone, it is clear that energy efficiency is an important concern when it comes to lighting. However, what exactly is an energy efficient lighting solution? And what does it mean for Facilities Managers?Start of page
More than just a lamp
An energy efficient lighting solution is about more than simply choosing the right lamp. To be fully energy efficient, a lighting solution needs to combine energy saving lamp technology with effective light fittings, control gear and lighting control systems.
Lamps should be primarily selected on the basis of what they are being used for. After choosing the most appropriate type of lamp for the job, the next consideration should be how energy efficient it is. A lamp’s energy efficiency is measured through its efficacy, which is the amount of light emitted in lumens when the lamp has reached full light output. This is calculated using the amount of electricity consumed in Watts. The unit of efficacy is lumens per Watt and the higher the value the better the lamp’s energy efficiency performance. For example a T5 HE lamp is up to 30% more energy efficient than a standard T8 tube.
Ballast units, which are used with discharge lamps, e.g. fluorescent lamps, to control their operation can also increase energy efficiency. Modern ballasts which use electronic circuitry, can operate the lamp at higher frequency resulting in the lamp running more efficiently.
A luminaire will be chosen for a variety of reasons including the application, fixture aesthetics and the type of lamp that is required.
Effective light fittings provide the optical control that ensures the light is directed to where it is required as well as obstructing it from those areas where it is not needed, using reflectors, refractors and/or diffusers.
Luminaires are important from an efficiency point of view because the optical elements can absorb light, meaning that not all of the light from a lamp will be used. The optical efficiency of a luminaire needs to be evaluated depending on its application, and can be calculated by looking at either the Light Output Ratio, the Utilisation Factor (for luminaires providing general illumination from a ceiling array), or for spotlights and similar, illumination performance data.
There are two main types of lighting controls — switches and dimmers — which can be activated manually or automatically by timers, detectors and sensors. Lighting controls are, by their nature, energy efficiency tools, and may be part of a building control system.
User friendly control systems will enable the lighting to react effectively to the use of the building, for example if there are times of the day when it is unused and lighting is not required, then controls can be set to turn lights on and off at specific intervals. Certain areas of a building may only be used intermittently, for example washrooms, and an occupancy detector can ensure that lights are in use only when the area is occupied. Controls can also be used to maximise natural daylight in a building, using artificial light to best complement daylight through the use of a photocell for instance.Start of page
The benefits of choosing energy efficient solutions
There are a number of reasons why it makes sense to choose energy efficient lighting solutions for buildings.
Firstly, picking up on the IEA figures, energy efficient lighting can obviously make substantial savings on electricity bills which is good news for the end users’ bottom line. A report by the Carbon Trust showed that wasted energy cost businesses a huge £570m last summer alone.
In addition to energy bills, since 2001, the Climate Change Levy has meant that the government has subjected all non–domestic users of electricity to an additional energy charge which has increased by about 8% since its introduction.
Energy efficient lamps are also longer lasting than their less green counterparts, reducing the need for replacement. Fluorescent tubes, for example, can last anywhere from 6,000 hours to 15,000 hours, compared to a standard 1,000 hours from a GLS lamp.
A deterrent to opting for an energy efficient lighting solution can be the initial investment that is required. However, financial support is available to organisations investing in low carbon technologies under the climate change levy package. This allows for a 100% first year Enhanced Capital Allowance (ECA) scheme, and a £50m fund for energy efficiency and renewables, which means monies spent on converting lighting to energy efficient products can be claimed back. On the ECG website, www.eca.gov.uk, you can find a list of approved products.Start of page
Complying with legislation
Increased legislation has resulted in a raft of laws intended to shape up the UK’s environmental performance, which organisations must comply with.
The Part L Building Regulations, for example, are geared around increased energy efficiency and state that where practical, lighting controls should maximise natural daylight and avoid lighting areas when they are unoccupied. Part L also demands a minimum of 40 lumens/circuit Watts in office, industrial and storage premises, encouraging the use of high–frequency (HF) control gear and more efficient optical design to generate the maximum light with the minimum Watts.Start of page
The energy strategy for this building [City Hall] enables it to run on a quarter of the energy consumed by a typical high specification office building.
In addition to imposed regulation, more and more organisations are taking it upon themselves to underline their commitment to the green agenda by proactively adopting sustainable solutions. Take, for example, City Hall in London. The energy strategy for this building enables it to run on a quarter of the energy consumed by a typical high specification office building. This is achieved not only through the use of ecologically sound, passive environmental control systems, but also through the shape and alignment of the building. For organisations looking to make a green statement through their building(s), the right lighting solution can play a key role in reducing a building’s overall carbon footprint.Start of page
Performance, reliability and choice
Within any organisation performance and reliability are key factors and the evolution of energy efficient lighting technology means there is no need to compromise on quality. In some cases, energy efficient technology, such as the new T5 fluorescent lamps offer best in class performance with no noticeable drop in performance at end of life.
Over recent years, advances have been made in lamp and optical technology, as well as HF control gear and light fittings increasing options across the board. A number of new products have come to market, for example energy efficient LEDs, with manufacturers dedicating significant resources to new product research and development resulting in a wider choice. Looking to the immediate future, improvements are being made in energy efficient LEDs, to make them brighter and more suitable in a wider range of applications. Advancements in compact CFL technology will allow the lamps to be dimmed and achieve full brightness more quickly.
There is no escaping the fact that energy efficiency will continue to increase in importance in the future. With the ever increasing range of energy efficient lighting available today, the ongoing developments in the sector, the importance of sustainable solutions, the legal obligations and financial benefits of energy saving, it makes complete sense to switch to high efficiency products wherever possible.Start of page