Lighting control for hybrid work offices

During the COVID-19 pandemic, many people transitioned to remote work and never returned back full-time, leaving office spaces often underutilised. Some companies now mandate dedicated office days, which creates dynamic occupancy. On quieter days, only a fraction of the office is used, leading
to energy wastage from building systems.

While many building systems can adjust based on metrics related to people count such as carbon dioxide levels, the lighting energy consumption remains constant irrespective of the number of people in the space if area sensors are used. Replacing area sensors with sensors in each luminaire can lower
energy consumption in sparsely populated office areas and better respond to the dynamic occupancy resulting from hybrid working arrangements.

This study examined the impact of flexible working on lighting energy usage. It aimed to estimate lighting energy consumption of different hybrid work policies including hybrid, structured hybrid, and in-person. These policies were constructed based on occupancy data from two Finnish offices. The
energy consumption analysis focused on both total and utilisation-based energy consumption of the lighting system. Utilisation-based consumption was included to highlight the impact of efficient space use on relative consumption. Both area and individual lighting controls were evaluated.

The findings showed that controlling luminaires individually saved energy in all scenarios compared to area control. Growing utilisation significantly increased energy consumption in individual control in one Site. However, with group control, the consumption remained stable. The other Site on the other
hand had constant consumption in all scenarios.

While the advantages of granular lighting controls are well-established in the previous literature, flexible work arrangements may present even more compelling reasons to adopt such systems. This study provided more insights into the energy savings of granular controls by introducing utilisation-
based energy consumption metrics for lighting systems.