The workshop was conceived to bring increasing attention to the importance of energy sustainability in Hawaii’s water sector, which has the highest electricity costs in the USA (typically 300–400% more than the mainland). In general, the drinking water sector uses energy to pump groundwater, to treat water, and to convey water. The wastewater sector uses even more energy to pump and treat the wastewater, and often to distribute the recycled water. Together, the water sector currently uses approximately 4.5% of the electricity generated on Oahu (>95% of which is allocated for wastewater). This usage equates to a cost in excess of $80 million for electricity produced from imported oil. There is currently a revolution of sorts in the wastewater industry to evolve from primarily treating and disposing of water, to recovering valuable resources such as recycled water, nutrients, and renewable energy. Current innovations include converting the wastewater treatment plants with massive electricity demands that flare off methane containing biogas into net positive energy production plants.