Not so clever when they are off: standby power use in smart lamps

Panel: 7. Appliances, product policy and the ICT supply chain

This is a peer-reviewed paper.

Authors:
Erik Page, Erik Page & Associates, Inc., USA
Steven Beletich, Beletich Associates, Australia
Stuart Jeffcott, Jeffcott Associates
Eamon Kummert, USA

Abstract

Smart lamps, or wirelessly controllable lamps, represent one of the fastest growing residential lighting market segments, as well as one of the first products in the category of the Internet of Things. The rapid growth of smart lamps can be traced to the convergence of two market developments: (1) the emergence of LED lighting, which can readily offer dimming as well as enhanced control features such as colour tunability and (2) the ubiquity of wireless networks and smart phones, which allow consumers to easily send control signals to the lamps. Today, dozens of manufacturers have smart lamps on the market.

During normal operation (or active mode), smart lamps can be expected to be efficient devices. The lamps rely on LEDs, which continue to post impressive improvements in efficacy, and add features, such as dimming and scheduling, that could decrease energy use even further. However, smart lamps risk compromising much of the energy they save because of their standby losses. Unlike traditional lamps that use no power when turned off, smart lamps use power for their communication systems when they are off (or in “network standby” mode). Initial measurements indicate that energy use of smart lamps in standby mode varies from less than 0.25W to over 2.5W per lamp.

In this study, we present the results of laboratory research looking at active mode and standby mode energy use of 11 commercially available smart lamp models. Active mode testing includes measurements of lamp efficacy at full output as well as documenting how efficacy changes as the lamp is dimmed. Standby mode testing includes documenting the power consumption of smart lamps (and any associated control gear, such as wireless bridges) when the lamps are turned off. We explore how the design parameters of the smart lamps (e.g., Bluetooth vs. Wi-Fi, etc.) may impact standby energy use. We also discuss how much energy smart lamps can be expected to consume while in active mode and in standby mode, given typical residential usage patterns.