Industrialized Gravity Anchors for Floating Photovoltaics

Floating solar photovoltaics is poised for rapid growth in the United States and globally because it offers new cost-competitive solar deployment options and unique advantages, including avoiding land-use conflicts, higher panel efficiency due to evaporative cooling, and improved water quality and conservation. However, modest cost reductions are still required for floating solar to compete with ground-mounted utility-scale solar. Much of the floating solar cost premium (17–20% higher levelized cost of energy than ground-mounted utility-scale solar) arises from mooring and anchoring. Lower-cost floating solar anchors will reduce the cost of deployments, benefiting electricity ratepayers and accelerating floating solar deployment. Shore-mounted piles are presently the lowest-cost floating solar anchoring solution for reservoirs, but work only in smaller bodies of water, are not scalable to offshore installations, and obstruct the shoreline and water surface with their horizontal mooring lines. Floating solar plants must use gravity anchors wherever (1) the soil is too soft or hard, (2) penetration of the reservoir is forbidden due to soil contamination or impermeable liners, or (3) water depth exceeds 5 meters. The project will develop an innovative, industrialized, low-cost gravity (deadweight) anchor for floating solar, manufactured using 3D concrete printing. The anchor reduces balance-of-system costs, reduces carbon dioxide emissions from anchor manufacture and transport and will boost floating solar deployment in the United States. These high-performance floating solar gravity anchors comprise a 3D-printed shell that is parametrically designed to maximize site-specific performance and minimize material use. After installation, the shell is then filled with low-cost ballast such as gravel or crushed rock. Phase I Project Scope. This Phase I SBIR/STTR project will advance the 3D concrete printed floating solar anchor technology from technology readiness level 3 (characteristic proof of concept) to technology readiness level 4 (component validation in a laboratory environment). Phase I includes techno-economic analysis, geotechnical and structural analyses of full-scale anchors, fabrication of anchor prototypes, and planning of Phase II. Deliverables include anchor designs for various soil types and load cases, refined designs that minimize material usage, refined techno-economic models for anchor production and cost impact, and a full-scale prototype anchor ready for testing and installation in a commercial floating solar array in Phase II. Commercial Applications and Other Benefits. These material-sparing anchors reduce CO2 emissions from concrete by 65% and cost 42% less installed than bulky, block-shaped gravity anchors. These low-cost, low-carbon gravity anchors for floating solar will significantly lower floating solar costs reducing electricity costs for ratepayers and accelerating deployment. A large United States and global market is about to open for floating solar gravity anchors. Recent analyses have predicted rapid floating solar growth with a global compound annual growth rate of 25% over 2022–2030, and a 2030 market valuation of $4.25 billion. There are almost 24,000 United States reservoirs suitable for floating solar. Using only 27% of water area, these bodies have a technical potential equal to 10% of United States electricity demand.