Solar-Powered Atmospheric Water Generation Hydropanels

Solution Overview

The San Francisco Public Utilities Commission completed a 2-year pilot project in May 2023 that tested atmospheric water generation technology to extract water from the air using solar power at two locations in the city.[1] This approach has the potential to produce water that meets drinking water standards, though current applications focus on irrigation purposes.[5] The technology addresses water supply vulnerabilities created by climate change and more frequent droughts.[2]

Technical Components

The hydropanel technology deploys solar photovoltaic power to trap and condense water vapor from the air as it passes through a series of fans and water-absorbing materials.[4] The water is then stored in a reservoir beneath the panel.[4] The panels function independently of the grid, operating as standalone units.[4] The SFPUC collected both water quality and water quantity data from the two AWG hydropanels installed at the San Francisco Botanical Garden and Hummingbird Farm.[1] Testing evaluated whether the water produced meets drinking water safety standards for possible future applications.[4] The manufacturer's hydropanels are constructed to create four to five litres of drink per panel per day, though AI and machine learning algorithms can increase production to seven, eight, or nine litres.[6] The technology can create water in environments with sub-5% relative humidity, such as Scottsdale, Arizona in summer.[6]

Implementation Details

The SFPUC installed two hydropanels at Hummingbird Farm and the SF Botanical Garden to test the atmospheric water generation technology.[2][3] Averaged across the 2-year pilot, each hydropanel produced approximately 11-12 gallons of water per month, which was used for irrigation of the surrounding landscapes at both locations.[1] The hydropanels at Hummingbird Farm produce about a gallon of water each per day.[4] A hydropanel costs approximately $2,000 and lasts at least 15 years.[6] Paula Kehoe, director of water resources at SFPUC, stated the pilot program aimed to understand how much water is produced and how easy it is to use the water that's produced.[4] Following the pilot, the SFPUC is exploring new opportunities to continue learning about the scalability of AWG and the value for San Francisco's future water supply.[1] The agency plans to explore opportunities for other pilot atmospheric water generation projects.[5]

Benefits and Impacts

The hydropanel at Hummingbird Farm is helping to irrigate organic produce grown in one of the oldest and most culturally diverse areas in San Francisco.[4] The AWG hydropanels served as helpful teaching tools and promoted active engagement with school groups and community members from the neighborhood.[1] The SFPUC will continue to implement the pilot atmospheric water generation project to test the viability of the technology to produce water for irrigation in a community garden setting.[5] Internationally, the manufacturer has implemented hydropanels in 45 countries over the company's five-year history.[7] In Bahia Hondita, Colombia, the company installed 156 hydropanels to bring renewable water to more than 300 residents of the Wayuu Tribe, eliminating the six-mile daily journey to haul clean water.[7]

Climate Adaptation Relevance

Climate change and the more frequent droughts it brings have made San Francisco's water supply more vulnerable, prompting the SFPUC to research and find new water supply sources.[2] The atmospheric water generation technology provides an alternative water source that operates independently of traditional water infrastructure and can function during drought conditions.[3][4]