Amber Switches are helping the Isle of Eigg, off the west coast of Scotland, to make maximum use of renewable energy.
Its 60kW Sunny Island-inverter-based power system has been providing renewable electricity to Eigg's almost 100 residents and many visitors since 2008.
The wind, solar and hydro generators make sure that at least one renewable source is available to power the island, even when it's calm, or dark, or hasn't rained for a while. Sometimes the island has more renewable power available than can be stored in the system's batteries.
Amber Switches on heaters in the community buildings, and most recently in Eigg's new camping pods, keep the buildings warm when there's plenty of renewable electricity, but don't let the heaters drain the batteries when there isn't.
Because the Amber Switches operate independently by sensing the system frequency, they can be installed all around the island, without needing any communications between them and the main control system.