17 Nov 2022
Today, the IEA 4E Solid State Lighting Annex is publishing a major report on Smart Lighting. This report focuses on the smart lighting features that impact energy consumption, and provides a comprehensive overview on various features, based on real-life test data. It offers advice to policy makers, specifiers and manufacturers on important issues to consider in order to maximise the savings potential of smart lighting products.
* * * Click here to download the new report * * *
Smart lamps and luminaires are common in today’s lighting market. Smart lighting provides an opportunity for the consumer to benefit from wireless control of lighting products, e.g. by dimming, colour tuning and scheduling. These functions can provide energy saving but they also require energy consumption to supply standby power and gateways.
In 2016, the first SSL Annex status report found a large variation in the standby power consumption from 0.15 to 2.70 Watts with an average of 0.50 W. These findings were based on indicative measurements from laboratories in Australia, Europe and the USA. It was clear that design improvements in terms of reduced standby power were possible for many of these products. For a typical 11 W lamp with a 0.50 W standby power that is turned ON for one hour per day, the standby energy consumption accounted for 51% of the total energy consumption. For the same lamp turned ON for two hours per day, the standby consumption accounted for 35% of the total energy consumption.
Based on these test results, the SSL Annex updated its recommended quality and performance requirements in 2016 with maximum standby power limits of 0.5 W for Tier 1, 0.3 W for Tier 2 and 0.2 W for Tier 3. In the years that followed, a maximum standby power consumption of 0.5 W was implemented in the US ENERGY STAR programme, the EU Ecodesign regulation, and regional and national standards in several African countries. Furthermore, this maximum standby power consumption has also been proposed for an Australia/New Zealand lighting regulation (taking effect from 2024).
This second SSL Annex Smart Lighting report includes:
- Guidance on how to test the smart lighting products, providing an update of the test procedure included in the first status report;
- Standby power analysis based on measurements performed in the period 2015-2020 including 236 smart lamps/luminaires coming from 67 different manufacturers;
- An analysis on how dimming and colour tuning influences efficacy and luminous flux;
- Impact on standby power consumption when the product becomes more complex by addition of new features; and
- An assessment of smart lighting market barriers including user-friendliness, interoperability, consistency, open systems, standards, and connection/co-operation with existing wired control systems.
This updated report describes how industry is working to simplify the products/systems, e.g. by control via smart buttons, voice and/or home automation, more user-friendly interfaces, plug and play and interoperability with wired lighting control systems. New test data published in the report shows that standby power varied between 0.08 W and 3.5 W with an average (mean) of 0.51 W and a median of 0.39 W. 72% of the products had standby power ≤ 0.5 W with an average 0.33 W. Only 6% of the products had standby power ≤ 0.2 W with an average 0.16 W.
The smart lamps/luminaires with standby power greater than 1 W were either products sold in Asian countries with no standby power regulation, or they were products that incorporated non-lighting related features such as cameras, WiFi boosters and/or speakers. These features are typically always ON without the possibility for switching them OFF. It is recommended that manufacturers: (1) make it possible to switch these non-lighting features ON and OFF, and (2) consider using the wake-up standby concept for these features.
In 2019, California implemented a maximum standby power limit of 0.2 W. By July 2022, the California database of compliant products contained 558 certified smart lighting products with standby power of ≤ 0.2 W, including lighting products from all the major manufacturers. This policy measure in California seems to have also impacted the rest of North America, as 81% (504 products) of smart lighting products listed in the US ENERGY STAR database have standby power ≤ 0.2 W.
Many smart lighting products include a dimming function, and for many products the efficacy decreases with increased dimming. To determine energy savings through dimming, manufacturers would have to declare the efficacy at multiple pre-defined dimming levels.
Many products also include a colour-tuning function, where the correlated colour temperature (CCT) can be adjusted. In most cases the declared luminous flux is at a CCT of 4000 K while the luminous flux may be much lower at a warm colour temperature around 2700 K. Variations in luminous efficacy have also been measured with colour temperature changes. For CCT-adjustable smart lighting products, it is recommended that manufacturers declare the luminous flux, power consumption and luminous efficacy at both a warm colour (2700 K) and a cool colour (4000 or 5000 K) to cover the different CCT preferences around the world.