Solar energy is a clean and renewable alternative to fossil fuels, and floating solar provides even more benefits to resource intensive industries. With increasing interest in floating solar, also known as floating PV (photovoltaic) or FPV, studies have started emerging where the benefits of installing PV systems on water instead of land are examined.
The future for FPV system looks extremely promising. Floating solar has been around since around 2005, but has up until recently not been profitable, or in many cases even affordable. Between 2009 and 2017, the price per Watt when using solar panels has dropped from $2.60/W to $0.40/W, an almost 85% drop in price. A very strong growth of PV capacity in the multi TW scale is expected till the mid of the 21 st century. However, despite both technologies having shares of the global electricity system for a few decades already, PV and hydropower have only recently started to meet.
The successive union of floats forms a regular grid composing the string configuration of PV panels as depicted in Figure 1b. The union between floats is accomplished by means of a HDPE plate that generates a floating body with partial flexibility that has proven successful hydrodynamic performance in closed and calm water bodies. However, up today, little effort has been made to implement solar floating installations in dams and hydro reservoirs with significant changes in water levels and more demanding mechanical needs due to wind, greater waves and currents (natural or induced to hydropower exploitation).
Attempting to address these facing parameters, ISIFLOATING is a floating solar technology with 10 years’ experience in reservoirs and lakes that aims to further improve the robustness of the floating island with mooring systems specially adapted to the floating solar technology at an affordable costing.
Anchors and mooring chain touchdown points will have direct impact on the habitat on the bed of the water body, that’s one of the reasons the project is focusing on tout lines. Assessments to determine the level of impact will be required. The anchor type and size will be dictated by the characteristics of the water body’s bed. Beds that are overly silty or rocky could cause issues for mooring designs. The depth of some water bodies will prevent bottom anchored moorings from being used and so a shore anchored system will be required if possible. This will have implications on both mooring and cabling costs as well as the sites on the water surface suitable for an array.
Locally generated waves and winds acting on a floating PV array will create forces between the float structures and in the array’s moorings. The design will be required to withstand the largest anticipated load cases and combinations of them with other loading states. On large water bodies, with potentially long fetch lengths, locally generated waves in storms could be significant. Similarly, extreme wind loads from severe storms, hurricanes, typhoons and cyclones will exert large forces on the array structure and will influence a project’s structural and mooring costs. Dynamic loads could be exerted on submerged, floating or overhead cables and need to be carefully considered to ensure that cable tensions do not exceed design conditions, bending and twisting is avoided, and fatigue is minimised.
Objectives of Fresher
Demonstrate an innovative mooring solution in a full-scale floating PV park that is 50% more cost efficient compared to standard solutions making the floating solar parks more sustainable with eased manufacturing and installation, as well as lower the transport and maintenance needs.
Increase TRL levels for the solutions from TRL6 to TRL8 to make the product roll-out for the involved companies feasible.
Increase knowledge on motions and loads on the moorings of a floating solar park, weather impact, maintenance requirements, etc. to enable further improvements of the moorings and anchoring of floating solar parks.
Reduce risks when planning and executing projects due to more certainty on technical challenges and lifetime.
Demonstrate and validate mooring solutions for near-shore and offshore floating PV parks by involving a new industry and its entire value chain in research and innovation process.