A gardening club in a high school in Southern Germany wanted to install a new automatic irrigation system for their school garden. Initially, they only had a very laborious and time-consuming irrigation system with a 30-meter hose coming from the biology labs.
There were two possible options: either to pump the water from a nearby stream, or to use the rain water from a bee hotel inside the school garden. Knowing that they had a 12-volt solar panel already installed in their garden (on top of the bee hotel!) the team initially thought that they might be able to use the electricity it generated to pump the water up from the stream. However, they soon realised that the 12 volts supplied by the solar panel wasn’t strong enough to pump the water all the way up the hill from the stream. Instead, they decided to install a system which would allow them to collect water from the bee hotel in a water butt. They then used the electricity from the solar panel to run a pump that distributes the water from the water butt around the garden.
What a great way to keep their garden truly sustainable and tackle Sustainable Development Goal 7 (affordable and clean energy) at the same time!