Peter Haseler from the Siemens Building Technologies division argues that a more strategic approach to controlling lighting requirements for buildings and public spaces can deliver real benefits in terms of energy cost reductions and operational effectiveness.

As the business community continues to seek ways to reduce costs and improve efficiencies they will often look at obvious areas of operation such as personnel, processes or purchasing.  However, a key area is often overlooked which could have significant impact for all types of companies, organisations or bodies charged with controlling interior or exterior space.  That area is the control and use of lighting.

Light, or access to it, is taken for granted. We depend on natural light in many cases to support our everyday activities; while technological innovation over the past century has provided the means to generate artificial light to sustain the life of a building, as well as help illuminate open public spaces when natural daylight is not feasible or available.  Light underpins the human experience and helps to provide a safer, more secure environment in which society can function.

However, the delivery of artificial lighting also comes at a cost – an energy and environmental cost

With soaring energy bills over recent years, and predictions that high energy costs are set to stay, taking a more strategic approach to lighting and its control to support requirements of public safety, security and comfort, as well as ultimate energy costs, could assist businesses and other organisations to address a fundamental area.  One that could help garner real cost saving benefits and help reduce Co₂ emissions.

Whatever the driver for particular lighting considerations:  public safety, building occupant comfort or business security – all objectives should be underpinned by an overall energy management strategy.  Such a strategy should include and utilise the advantages of lighting control technology to deliver access to appropriate lighting for any given situation – but do it in the most energy efficient manner possible.  By adopting such an approach, a path to both short-term and ongoing cost savings is entirely feasible.  Indeed, organisations across the UK are already reaping the rewards of implementing lighting control requirements and by using lighting control system measures are seeing a proven return on investment – without compromising on comfort, safety or security.

When it comes to lighting in a commercial or public building, the typical advice from energy specialists to conserve power is to reduce the strength of the lamps being used.  In other words, reduce the lamp load from 55 watts to 32 watts which will provide the same luminescence and rendition but through a lower wattage power level.   If applied to all the lamps in a building, a collective energy reduction will occur and subsequent business revenue savings achieved.

However, taking strategic energy management thinking further and embracing the operational benefits of lighting control system technology could deliver so much more.

At a fundamental level, those in charge of a building should ask themselves if they are making the most to harvest and control access to what is a ‘free’ commodity – natural daylight.  Every time a light is turned on in a building it generates a cost.  By applying a level of automated lighting control technology to the fabric of a building,  and adopting an intelligence-led approach, users can really begin to maximise use of both natural light (no cost) and artificial light (business cost), so that an optimum lighting platform is achieved.

Making a building think for itself in conjunction with its natural environment is the key objective.  The current digital world provides the means to achieve accurate lighting control.  Digital Addressable Lighting Interface (DALI) is the most flexible way of controlling lighting running gear to deliver the precise amount of light constantly to keep occupants and guests of a building safe and in comfort at all times through the day.  But it isn’t just these factors that are affected.  There are also bottom line benefits.

It is generally accepted that in a typical building the total level of electrical energy consumed and which can be attributed to lighting is around 28%.  For a typical annual energy bill of £1 million, lighting therefore accounts for some £280,000.  But real inroads can be made into such a substantial business cost.  Installing a digital ballast control gear system - such as Siemens’ GAMMA that complies with the KNX ‘open’ control system for building controls - will, for example, only illuminate areas when occupied.  Intelligent building management systems enable less focus on a single issue and more focus on the total picture by getting ‘islands of intelligence’ communicating and working in unison with each other.  As a result of such holistic controls, estimated energy reductions of 44% can be achieved.  In money terms, this equates to a £120,000 saving in the energy bill, based on an annual £1 million electrical energy spend each year.   With capital payback period on such a system amounting to approximately two years – it is clear that investment in such systems will generate both short-term and long-term cost benefit.

As well as the cost saving, comfort and security issues that are addressed through a strategic approach to lighting control we can also accrue other spin-off benefits.  A system such as the Siemens’ GAMMA –KNK can contribute towards an overall ‘Excellence’ rating for BREEAM regulations that promote environmentally aware construction.

Such Government-backed requirements for more energy efficient buildings demand that from a building control perspective, integrated systems must be able to detect and communicate status with others.  This is a pre-requisite for the Excellence standard.   Such a status is achieved by control devices talking to relevant control devices within in a single communications platform. This means the GAMMA system senses event or demand changes in parts of the building where energy reduction is required and ‘talks’ to the building management system to help achieve this.

A prime example could be a conference room where the lighting is switched on when a person enters the room, and if the room is pre-booked the heating is turned on to the desired level.  After the event, and with the room now empty, the room’s presence detection controls signal ‘absence’ and then automatically turns off the lights and lowers the heating to a pre-set point. Controlling the space where the initial design sets out to use energy when and where demanded significantly reduces the carbon footprint of the building.

For public and open spaces the same strategic approach to lighting control is applicable.  For the operators of a busy airport public car park, controls to dim lights in accordance with natural surrounding lighting conditions delivers immediate cost savings.  In addition, flexible illumination can support security-related capability and reliability by enhancing, if required, artificial lighting in designated areas so that the work of CCTV cameras can be supported.  Likewise, dark areas or obscure areas of car parks can be lit intelligently and appropriately from a timing standpoint to reassure public users – without excessive energy waste and resulting costs.

Shopping malls where ‘presence detectors’ linked to a lighting control system can help ramp lighting up or down depending on appropriate need; façade lighting linked to time clocks that adjust illumination (and energy use) according to pre-set timings, or fire and emergency exits illuminated directly as a result of incidents to support safety procedures are key examples where taking control of lighting needs through the use of technology can support safety and security factors.  At the same time such examples ensure that electrical energy consumption is undertaken in the most effective manner possible.

Businesses or public organisations should be examining ways of managing energy use more strategically.  The daily requirements for lighting can play a central role in any such thinking.   By using ‘open based’ lighting control systems, either large-scale multi-point applications or low level presence detection devices can form an integral part of any energy management focus.   Lighting control systems can help fulfil all or any one of user and occupant security, safety or comfort objectives for building or public space operators, and, importantly, help to do so in the most energy efficient manner possible.

It really is a win-win situation.