Waterise put its modules under the ocean, making use of water pressure to save energy. By 2030, there could be a 40% global shortfall in freshwater. One way to meet water demand is desalination, removing salt from seawater. But the usual method, reverse osmosis, requires a lot of energy to push water through fine membranes at high pressure. However, Waterise locates its plant 400 metres below the surface. The hydrostatic pressure of the ocean at that depth reduces the energy required by up to 40%. This cuts CO2 emissions while causing minimal impact on marine life.