Accounting for Water-Energy Co-Benefits of Floating Photovoltaics (FPV)

Floating photovoltaic projects, as well as those that span over waterways (i.e. canopy), present potential technological and economic advantages over ground-mounted systems that have fueled rapid global growth in installed capacity in recent years. Aside from expanding generation, FPV present numerous additional benefits (hereafter, co-benefits), such as improved panel efficiency and reduced land usage, others arising from hybrid FPV-hydropower systems (e.g., co-location and co-management), as well as others pertaining to water security, particularly in rural agricultural setting (e.g., reduced evaporation and water temperature from shading, improved water quality). The evidence for this wide range of co-benefits varies widely and measures of positive returns or advantages in FPV alternatives remain under-quantified.

Without reliable assessment and modeling, co-benefits cannot be appropriately considered during project planning. An improved understanding of project co-benefits and impacts on a per-acre basis, relative to alternatives in tradeoff analyses carried out by developers and regulators, may support increasing deployment of FPV and canopy PV projects. For tradeoff analyses carried out by developers and regulators to reach technical potential and account for co-benefits, we identify four priority areas: 1) Develop co-benefit knowledge base, 2) Define regulatory landscape for co-development, 3) Develop co-benefit assessment tools, and 4) Integrate FPV co-benefits in water-energy sector planning. Together, these steps can provide measurable and predictable indicators which can be quantified and localized into "co-benefit per hectare of FPV".