Project Nexus involves installation of solar panel canopies over various sections of Turlock Irrigation District’s 250 miles of open irrigation canals. Project Nexus will serve as a Proof of Concept to pilot and further study solar over canal design, deployment, and co-benefits on behalf of the State of California using TID infrastructure and electrical grid access. The Project is underway and expected to be completed in 2025.

The pilot project is called Project Nexus as a nod to the water-energy nexus paradigm gaining attention among public utilities. Utilities are increasingly recognizing the interrelationship between water management and energy management and are finding ways to design infrastructure and actions that benefit the management of both resources beyond what has been done historically.

Project Nexus goes beyond recognizing the linkage that water is used for energy production and energy is used for water treatment and conveyance. With Project Nexus, existing water conveyance infrastructure will serve as the foundation for solar canopies to produce renewable energy. The water in the conveyance infrastructure has the potential to cool the solar panels, increasing their efficiency. The solar panels provide shade and wind protection over the water, reducing evaporation and also inhibiting aquatic weed growth and improving water quality.

Project Nexus has the potential to define a new model for irrigation districts and public utilities that can be replicated elsewhere in the state and nation to increase efficiencies in managing limited natural resources.

The primary goals of Project Nexus include:

• Demonstrating proof of concept of narrow and wide-span canal coverage with solar panel canopies

• Increasing renewable power generation

• Reducing water evaporation

• Reducing vegetative growth in the canals

• Studying overall water quality improvements

• Advancing integration of renewable power generation and energy storage

The first test deployment of solar panels over open canals in the nation is being developed as a public-private-academic collaboration, including:

• Turlock Irrigation District – The first irrigation district in California, TID is uniquely suited to pilot this project as both an irrigation district with 250 miles of canals and a retail electricity provider to homes, businesses, and farms in California’s Central Valley.

• CA Department of Water Resources – DWR is committed to exploring all efforts meant to advance integration of renewable energy to provide clean energy to California. The Department is providing funding support from the state general fund and technical assistance to TID.

• Solar AquaGrid – Bay Area development firm Solar AquaGrid serves as project developer and program manager for Project Nexus. Solar AquaGrid originated the pilot project after first commissioning the UC Merced Study in 2015 and is facilitating collaboration among TID and the various parties to bring Project Nexus to fruition.

• University of California Merced – Located just miles from TID, UC Merced researchers have been contracted to provide ongoing support, research and analysis of the project for the state and public.

• Additionally, the Project has the support of several other state agencies, such as the CA Environmental Protection Agency and the CA Natural Resources Agency.

It is expected that the solar shading over canals will provide various co-benefits, including reduced water evaporation resulting from mid-day shade and wind, water quality improvements through reduced vegetative growth, reduced canal maintenance through reduced vegetative growth, renewable electricity generation, and air quality improvements, among others. Working with the research team at UC Merced, Project partners anticipate adding energy storage capabilities that can support the local electric grid when solar generation is suboptimal.

In addition to advancing both renewable energy and water conservation locally, solar shaded canals offer much promise statewide; covering all of the approximately 4,000 miles of public water delivery canals has benefits related to efficiency, cost, air-quality, land savings, and ecology. Because solar cells become less efficient as they heat up, the water’s cooling effect can increase their conversion ability. Locating solar panels over water rather than land can help cool solar panels, making them more efficient. Shading exposed waterways can not only reduce evaporation loss, it can curtail the growth of aquatic weeds, reducing canal maintenance costs. In addition, building solar canopies over canals rather than on land can save money and permitting time, and give already disturbed land a dual use instead of building on otherwise productive, undisturbed land.

To put Project Nexus in context: California has the largest water conveyance system in the world – 4,000 miles of open canals. Seventy-five percent of the state’s water emanates from Northern California, yet 80% of its water is used in Southern California. Consequently, more electricity is used for moving and treating water in California than for anything else. Electricity generation represents the second largest use of California's water after agriculture. Project Nexus and solar canal projects like it offer the possibility of increasing the amount of renewable energy while saving water and avoiding the use of undisturbed land, all to help California meet its climate goals.

The study showed that:

● Covering all 4,000 miles of California’s canals with solar panels would save more than 63 billion gallons of water annually by reducing evaporation. That's enough to irrigate 50,000 acres of farmland or meet the residential water needs of more than 2 million people.

● Cooling produced by the panels' proximity to water boosted their electricity production by up to 3% and the shade they generated mitigates aquatic weed maintenance.

● Shade from panels also mitigates aquatic weed maintenance. We estimate that shading 100-foot-wide canals in California with solar panels would save about $40,000 per mile. Statewide, that savings could reach $69 million per year.

Solar panels are expected to be built over both wide-span and narrow-span sections of TID canals in Stanislaus County. The sections range from 20 to 110 feet wide. Project completion is expected in 2025, along with the release of initial published results.

The Project Nexus budget is $20 million, and is funded by the state of California’s Department of Water Resources through the state's general fund. Partners determined the overall cost by putting science and evidence first and factoring in all the accompanying advantages – economic, environmental, and social – of an integrated system, including energy storage. Solar AquaGrid is developing additional sources of public-private support to enable additional projects and stimulate long-term market and investment opportunities to sustain this critical drought-related work, which will be key to a resilient California and nation.