Control lighting digitally DALI-2 saves energy and reduces installation costs

Related Vendors

FAULHABER Drive Systems

Wuxi InfiMotion Technology Co., Ltd.

Open standards in the lighting industry help to save energy and to expand plants without problems in the future. Certified components are also available on the market for a longer time.

Paul Drosihn is the General Manager at the DALI Alliance.

Climate change and rising costs are forcing companies to become more sustainable. This also includes reducing energy consumption and the CO₂ footprint. With a share of about 15 percent of worldwide electricity consumption and five percent of worldwide greenhouse gas emissions, the lighting industry has a great chance to contribute to global sustainability goals and to satisfy customers. This is stated in the Global Lighting Report 2022, published by Lighting Global, an initiative of the World Bank. The report provides an overview of the global lighting market and analyzes the trends in the industry.

In addition, the trend towards a more circular economy requires products that can be easily reused, overhauled, upgraded, and recycled, offering the potential for lower energy consumption, less waste, and financial savings. Established global standards such as the DALI-2 certification program, developed and maintained by the DALI (Digital Addressable Lighting Interface) Alliance, play a crucial role in meeting all aspects of sustainability.

Gallery

How to reduce energy consumption in lighting

Despite the use of efficient lighting fixtures, lighting efficiency in most commercially used buildings is poor, as the lights are still on even when the illuminated rooms are not being used. Depending on the type of building, the proportion of lighting in the total energy costs is often between 20 and 30 percent, so the potential for savings could be substantial. Even simple time switches are better than relying on the occupants to turn off the lights.

However, a much more efficient approach is the introduction of automatic light controls with presence, motion, and daylight sensors. Through standardization, it is possible to combine multiple sensors from various manufacturers in a single light control system. PIR sensors (Passive Infrared Sensors) can detect the occupancy of various parts of the building and the system can switch the lighting on and off accordingly.

Control artificial lighting with sensors

Brightness sensors also contribute to energy savings. Since the sensor data tells the system how much natural light is present at a certain location, the artificial lighting can be controlled accordingly. The so-called Daylight Harvesting takes into account factors such as the time of day, the position of the sun, and even the season, thereby minimizing energy consumption. The more sophisticated, feature-rich, and smart a light management system is, the higher the possible energy savings.

Of course, this requires suitable software that is intuitive and user-friendly, as well as simple controls and user interfaces that can be understood and operated by the building users. This also includes the standardization of the functionality of input devices such as switches, sliders and buttons.

Standardization helps the lighting industry

In an ideal scenario, planners and installers should be able to choose the most sustainable lighting solution regardless of the manufacturer. In reality, an optimal and sustainable lighting system may be complicated by the fact that the best products for the particular application simply aren't compatible with each other. A short-term solution could be to source everything from a single supplier, which, however, could impact future system expansions and updates. Outdated products or the inability to obtain spare parts could result in the entire system having to be replaced prematurely, which is anything but environmentally friendly.

A standardization where multiple manufacturers use the same open protocol reduces this risk. Thus, the DALI-2 certification has created an ecosystem of interoperable products from various manufacturers, ensuring the long-term availability of compatible components for improved sustainability (Image 1). Due to their longevity, DALI-2 certification offers both forward and backward compatibility and is supported by all major players in the lighting industry. This ensures long-term availability of compatible components and avoids issues related to tying to a specific manufacturer and dependency on proprietary solutions that may not be supported in the future.

Standardized systems are flexible and support future-proof designs that extend the life of a lighting control system and make it more sustainable. For example, changes to the design and operation of a DALI system can often be made by programming the software, not by rewiring or replacing luminaires and other devices.

Feedback and data exchange through digital two-way communication

To quantify the savings achieved through the efficient use of a lighting control system, effective monitoring of energy consumption is required - the savings must be measured and not estimated. It is not only necessary to measure the total energy consumption, but also to get more detailed information about what is actually happening in specific areas of a building or even with individual luminaires. Such data can be crucial when applying for energy rebates.

Standardization allows for data-rich networks where feedback and data exchange are possible through digital two-way communication. In this way, components can report their performance levels, information about lamp failures, emergency test data, and other information to application controls. Energy consumption and diagnostic data, as well as luminaire information, are stored and reported in a standardized format. The data analysis can then predict when individual components or luminaires should be replaced, instead of applying a comprehensive replacement plan based on a fixed period. This supports a data-driven predictive maintenance strategy, leading to significant cost savings and contributing to the overall sustainability of the lighting control system.

Examples of standardization in practice

The new Grafton Way Building of the University College London Hospital demonstrates what can be achieved with a standardized lighting control system. The eleven-story building, with five floors underground, was equipped with a DALI lighting system that contributes to minimizing energy consumption, improving sustainability, and optimizing operational efficiency.

Precise dimming and scene settings, depending on daylight and occupancy, allow for flexible lighting schemes in different areas of the hospital and enhance the comfort and wellbeing of patients and staff. The lighting system contributed to the building receiving the BREEAM 'Highly Commended' certification – a challenge for a heavily frequented health building with energy-intensive medical devices.

A second example comes from Spain, where the city of Algeciras has replaced its old street lighting with a DALI-based LED lighting system. The town hall achieved a total energy saving of more than 50 percent compared to the previous lighting system.

Another current application is the Elizabeth Line, the new 118 km long high-speed railway network for London and the southeast of England. This is the largest infrastructure project in Europe, where more than 35,000 DALI devices, including lights, sensors, switches, and controls, are used to optimize efficiency, safety, and aesthetics. It is one of the first projects of this magnitude where sustainability was considered from the start.

Conclusion: How standardization helps in lighting

Sustainable principles such as waste prevention, improved energy efficiency and the identification of cost-saving potential make economic sense. Standardization can meet all aspects of sustainability. An advanced lighting control system, based on a global standard like DALI, reduces energy consumption, improves the CO₂ balance, and lowers the total operating costs. As a global industry organization focused on standardization and market acceptance, the DALI Alliance will continue to promote the broad adoption, scope, and technology leadership that the industry needs to offer more sustainable and energy-efficient lighting solutions.