Wireless meets lighting control
How can you bring the benefits of sophisticated lighting to existing lighting installations and provide a simple approach to controlling new installations. Dr Andy Davies of Harvard Engineering puts forward a solution.
Igniting the spark that will take indoor lighting controls mainstream has been uphill work, even though lighting is a clear target for energy savings. Lighting is typically is the single highest contributory factor on a building’s electricity bill, representing 40% of the total. Lighting controls, used with LEDs, can deliver electricity savings of up to 50%. The case for installation should be watertight — both financially and environmentally.
So why is it that of all the controllable indoor lighting sold in Europe today, only 30% of it is linked to any kind of controls other than the on/off switch? In comparison, the market for outdoor lighting controls has taken off, with authorities around the world rolling out systems in response to government carbon-emissions targets.
We believe that the reasons are 2-fold.
The first is that installing existing lighting control technology can be a messy and disruptive process which involves rewiring and offers no flexibility for altered patterns of use.
The second is expense. The current generation of lighting controls is complicated, and a specialist engineer is required both for installation and for commissioning.
These problems could be addressed by lighting controls that can be wirelessly added to existing lighting installation.
Exactly that can be achieved by our EyeNut system. It draws on elements of our control and monitoring system for street lights, LeafNut, which controls lamps over the internet using GPS and radio-frequency identification (RFID). It also provides a 2-way flow of information, sending data on energy spend and faults to the user.
Just like LeafNut, EyeNut is wire free and can be simply applied to existing lighting fittings, identifying devices via either discovery or radio frequency. It is operated over the Internet. Up to 500 light points can be managed from a single gateway via a robust and secure ZigBee wireless mesh network. This compares favourably with the offer of 64 points using DALI controls.
There is no limit to the number of gateways, so it is possible to operate lights for several buildings or multiple sites from one single computer hub. This means that the facilities manager of a large supermarket could, for example, choose to control lighting for all its stores from one centre to achieve maximum energy and maintenance savings.
EyeNut is completely customisable, allowing the user to fully and precisely control individual lights or groups of lights at the press of a button on a computer, laptop or tablet. Assigned schedules can be simple or sophisticated with variations possible every 15 minutes, every day of the a year. Installation doesn’t require the services of a specialist engineer and devices are simply commissioned using an RFID scanner.
The concept also has built in emergency integration. Users can set up automatic scheduling of tests via the calendar feature in the user interface. The test can run automatically when a building is empty or be distributed throughout the building to minimise interruption to business operations. Once tests are complete, results automatically appear in the EyeNut interface and can be exported to external systems for audit tracking.
Users can manage and customise their lighting scheme using an intuitive user-friendly dashboard or graphical user interface. Accessed over the Internet, the dashboard shows all light points, their status and energy spend over an imported image of the building layout. Energy ‘heat spots’ and specific energy consumption can clearly be seen and easily altered to meet energy targets. The reporting system is an essential tool for organisations that have to comply with new mandatory energy audits.
The system can implement a wide range of energy-saving strategies, working in parallel with photocell sensors to augment levels of natural daylight and connecting with passive infrared (PIR) detectors to switch lights on and off or dim them, depending on occupancy. It can also integrate with existing building-management systems to collect occupancy data.
One of the first users of this technology was a 4500 m2 department store which required a lighting control solution to accompany an LED retrofit. It has reported a reduction of electricity usage from 1500 kWh a day to 330 kWh a day for the LED lighting and the control system. The control system itself added a further 40% to the energy savings achieved by switching to LED, representing a 2- year payback on the client’s investment.
Dr Andy Davies is business-development manager for indoor controls at Harvard Engineering.