The Reservoir Opportunity: How a Water Utility Used Bespoke Research and Strategy Advisory to Build the Business Case for Floating Solar Across Its Reservoir Portfolio

Floating solar — photovoltaic arrays deployed on the surface of reservoirs, lakes, and other water bodies — offers a distinctive value proposition that combines two infrastructure needs: it generates renewable electricity without competing for the land that solar developers and farmers both want, and it measurably reduces evaporation losses from the water bodies it covers, an increasingly material consideration for utilities managing water security in regions experiencing more frequent drought conditions.

The client recognised this dual value proposition in principle and had internal champions advocating for a floating solar programme across its reservoir portfolio, but lacked the reservoir-by-reservoir assessment needed to convert enthusiasm into an investable proposal.

Without this assessment, the floating solar proposal remained a general aspiration competing against other capital programmes with more rigorously quantified business cases — and aspirations rarely win capital allocation battles against rigour, regardless of how compelling the underlying logic appears.

Key Challenges

• No reservoir-by-reservoir technical assessment identifying which sites combined sufficient surface area, water depth, and bed stability for deployment
• No quantification of the evaporation reduction value specific to each reservoir’s surface area, regional climate conditions, and existing water security planning relevance
• No grid connection feasibility assessment determining which reservoirs offered cost-effective interconnection versus those requiring substantial new transmission infrastructure investment
• No environmental and permitting complexity screening distinguishing straightforward regulatory pathways from ecological sensitivities or recreational use conflicts
• A capital proposal process in which other infrastructure programmes with rigorously quantified business cases consistently outcompeted the floating solar proposal for available investment
• Board expectation that any capital commitment to a new infrastructure category be supported by portfolio-wide, site-specific analysis rather than a general directional case

Floating solar’s distinctive value proposition — generating renewable energy while reducing evaporation losses — is precisely the kind of dual-benefit infrastructure case that boards find compelling in principle and difficult to approve in practice without granular, site-specific evidence demonstrating where the theoretical benefit becomes a viable, fundable project.