The Water-Energy Nexus Competition
Water Businesses that Save Energy
Hydrovolts makes portable floating turbines that make renewable energy and clean water from an untapped global resource of hydrokinetic energy in water canals.
BlackGold Biofuels recovers energy from wastewater streams, creating lucrative renewable energy assets from pollution liabilities.
FogBusters treats petroleum, biofuel and food processing wastewater “better, faster, cheaper, cleaner and greener” while capturing the FOG (fat, oil and grease) to make into biodiesel.
Agua Via develops a 1-atomic layer thick nanotech membrane that enables desalination at a 66% energy reduction and 50% cost reduction, providing energy efficient purification and wastewater remediation.
NLine Energy Inc. converts wasted energy found in water transmission and distribution systems into renewable energy.
Pilus Energy harnesses genetically enhanced bacteria in scalable electrogenic bioreactor and harvests the electricity and biogases from their metabolism of organics like those found in wastewater.
Solar Machines' non-PV based technology directly and efficiently converts solar energy into mechanical work for water pumping applications.
Water Resources Management Corp helps water utilities realize the full benefits of their investments in advanced meter reading, system control and asset management.
Context: Why the Water-Energy Nexus Matters
Delivery and production of clean water currently come at sizable energy costs. The more than 60,000 water systems and 15,000 wastewater systems through the country are huge energy consumers, using 3% of annual electricity consumption in the United States (3).
The EPA estimates that retrofitting one out of every 100 homes with water-efficient technologies could save 100 million kilowatt-hours of electricity per year and avoid adding 80,000 tons of greenhouse gas to the atmosphere (6). In some parts of the country, you can save more energy by turning off the tap than by turning off the lights.
Provision of water cannot rely on cheap, abundant energy supplies forever. Tomorrow's water supply system is an energy-efficient one, and Imagine H2O's prize competition will highlight the ideas that will get us there.
The Water-Energy Nexus Defined:
The Water-Energy Nexus competition will identify promising start-ups that save energy in moving, treating and using water and wastewater.
Criteria for a water-energy nexus start-up (see upcoming prize rules and eligibility requirements for more details):
Below you’ll find areas within the water system that are prime for improvement in energy efficiency. These areas are meant to frame the relevance of this prize competition and are not exhaustive of eligible applications.
To provide for growing demand, accessing water supplies is of utmost importance, and this first step of acquiring fresh water is very energy intensive. Throughout the world, we mainly acquire fresh water by diverting surface waters (lakes and rivers) or pumping from groundwater aquifers. Another source of our freshwater is in desalinating saltwater or recycling wastewater, both of which have high – and often prohibitive – energy costs.
Water must often travel over significant distances and elevations to get where it is ultimately treated and used. For example, in California, delivering water from the San Francisco Bay Delta to Southern California consumes 2-3% of all electricity used in the state (5). The State Water Project, which is responsible for this conveyance, is the single largest electricity user in the state. In distribution systems, there are multiple opportunities for energy savings, including pump efficiencies, leak detection, pressure management, and automation (1).
Treatment for urban water use has significant energy demands. Further, as source water quality worsens and quality standards tighten, more advanced treatment (such as ozonation and ultraviolet radiation) will require even more energy (2).
Collecting and treating wastewater for proper disposal or reuse calls for a great deal of energy. In fact, almost 30% of a wastewater treatment plant’s operation and maintenance costs go toward energy provisions (4). There are many opportunities for innovation in pumping, aeration, and solids handling to save energy the wastewater treatment process.
(1) Barry, J. “WATERGY: Energy and Water Efficiency in Municipal Water Supply and Wastewater Treatment: Cost-Effective Savings of Water and Energy.” The Alliance to Save Energy. February 2007.
(2) Burton, F. “Water and Wastewater Industries: Characteristics and Energy Management Opportunities.” Electric Power Research Institute, 1996.
(3) EPRI. Quality Energy Efficiency Retrofits for Wastewater Systems. December, 1998.
(4) Jones, T. Consortium for Energy Efficiency. Municipal Water and Wastewater Presentation, January 2007. Available here.
(5) National Resources Defense Council and the Pacific Institute. “Energy Down the Drain: The Hidden Costs of California’s Water Supply.” Available here.
(6) U.S. Environmental Projection Agency. “Sustainable Infrastructure for Water and Wastewater”. Available here.