Israel Pioneers Floating Solar Panels on Water Reservoirs: Dual-Use Innovation Cuts Evaporation by 80%

Israel is emerging as a global leader in floating photovoltaic (FPV) technology, deploying solar panels on agricultural and municipal water reservoirs across the country in a dual-use innovation that simultaneously generates clean electricity and dramatically reduces water evaporation — addressing two of the nation's most pressing infrastructure challenges with a single solution. The technology, pioneered by Israeli cleantech firm Ener-T and now being adopted by several other companies, has demonstrated evaporation reduction of up to 80 percent on covered reservoirs while generating electricity that can power local water pumping and treatment operations, creating partially self-sustaining water infrastructure. ## The Evaporation Problem In Israel's hot, arid climate, open water reservoirs lose between 30 and 50 percent of their stored volume to evaporation annually. For a country that has invested billions in desalination to secure its water supply, this evaporative loss represents an enormous waste of both water and the energy used to produce it. The Israel Water Authority estimates that the country's approximately 200 agricultural and municipal reservoirs collectively lose over 100 million cubic meters of water per year to evaporation — enough to supply the annual water needs of a city the size of Beersheba. "Every cubic meter of desalinated water that evaporates from a reservoir represents wasted energy, wasted money, and wasted resources," said a Water Authority engineer. "Floating solar addresses this directly while adding clean energy generation." ## How Floating Solar Works Floating photovoltaic systems consist of solar panels mounted on high-density polyethylene pontoons that are anchored to the reservoir floor or banks. The panels float on the water surface, covering 70–90 percent of the reservoir area while allowing water circulation and fish migration beneath the array. The cooling effect of the water beneath the panels actually improves solar cell efficiency by 5–10 percent compared to ground-mounted installations, as solar panels lose efficiency at high temperatures. This makes Israeli reservoirs particularly well-suited for FPV deployment, combining high solar irradiance with effective passive cooling. Systems typically range from 100 kW for small agricultural reservoirs to 5 MW for large municipal storage facilities. The electricity generated can be used on-site for water pumping and treatment, fed into the local grid, or stored in co-located battery systems for evening use. ## Current Deployments and Expansion Several Israeli water utilities and agricultural cooperatives have already deployed floating solar systems on pilot and commercial scales. The largest installation to date covers a 30-dunam reservoir in the Arava Valley, generating 2.5 MW while reducing evaporation by approximately 75 percent. The Ministry of Energy has identified over 50 reservoirs across the Negev, Arava, and Jordan Valley regions as candidates for FPV deployment within the next three years, with a combined potential capacity of over 200 MW. A dedicated subsidy program, launched in late 2025, provides grants covering up to 30 percent of installation costs for reservoir owners who deploy FPV systems. Mekorot, Israel's national water company, has begun integrating floating solar into its long-term infrastructure planning, with plans to deploy FPV systems on its largest surface reservoirs as part of the company's commitment to reducing the carbon footprint of water delivery. ## Global Implications Israel's experience with floating solar on water reservoirs is attracting significant international attention, particularly from water-stressed countries in the Middle East, North Africa, and South Asia. Delegations from India, Morocco, and the UAE have visited Israeli FPV installations in recent months, and several Israeli companies are now marketing the technology globally. The World Bank estimates that covering just 10 percent of the world's reservoir surface area with floating solar could generate over 400 GW of clean electricity while conserving billions of cubic meters of fresh water annually — a potential that Israeli engineers are helping to unlock through practical, field-tested deployment experience.