My favourite piece of installation from past years’ iLight installation would be (ULTRA) LIGHT NETWORK (featured image) by Felix Raspall, Carlos Bañón, Manuel Garrido and Mohan Elara (Singapore).
This piece of installation made use of geometrical arrangements, incorporating lights within. With more people nearing the installation, it would produce different patterns of light strobes, as well as increased light intensity.
In context to sustainability, this could be used in a way to increase the awareness whereby us as individual could actually do a big part in sustainability. Material usage could also be taken into consideration, whether to make use of environment-friendly materials, or other alternatives.
Image retrieved from: https://www.ura.gov.sg/uol/-/media/User%20Defined/URA%20Online/media-room/2017/pr17-05a.pdf