Innovative floating bifacial photovoltaic solutions for inland water areas

Abstract

Photovoltaic (PV) technology has the potential to be integrated on many surfaces in various environments, even on water. Modeling, design, and realization of a floating PV system have more challenges than conventional rooftop or freestanding PV system. In this work, we introduce two innovative concepts for floating bifacial PV systems, describing their modeling, design, and performance monitoring. The developed concepts are retractable and enable maximum energy production through tracking the Sun. Various floating PV systems (monofacial, bifacial with and without reflectors) with different tilts and tracking capabilities are installed on a Dutch pond and are being monitored. Results of the thermal study showed that partially soaking the frame of PV modules into water does not bring a considerable additional yield (+0.17%) and revealed that floating PV modules experience higher temperature special variance compared with land-based systems.Observations showed that the birds' presence has a severe effect on floating PV performance in the short term. Electrical yield investigation concluded that due to low albedo of inland water areas (6.5%), bifacial PV systems must have reflectors. One-year monitoring showed that a bifacial PV system with reflector and horizontal tracking delivers 17.3% more specific yield (up to 29% in a clear-sky month) compared with a monofacial PV system installed on land. Ecological monitoring showed no discernable impacts on the water quality in weekly samplings but did show significant impacts on the aquatic plant biomass and periods of low oxygen concentrations.

In-Situ Water Quality Observations under a Large-Scale Floating Solar Farm Using Sensors and Underwater Drones

“…A few studies have addressed the potential impacts of floating solar panels [28,29] and other types of structures, but often rely on models without validation with in situ data. A recent monitoring campaign in the Netherlands [15] did not detect significant changes in water quality parameters, such as total nitrogen, water temperature, total phosphorus, Chlorophyll-a or cyanobacteria concentrations, but does report changes in plant biomass and an increase in the frequency of hypoxia conditions (concentrations of dissolved oxygen lower than 6 mg/L). Water managers need a deep understanding of the effects to prevent water quality problems that may lead to, for example, algae blooms, loss of aquatic life, or unfavorable oxygen balances.…”

“…It was noticeable that the part of the solar park located closer to open water (west part) was covered by droppings of birds (Figure 12a), while the remaining part of the solar panels was less affected. The coverage of the panels with bird droppings may reduce the efficiency of the solar panels [15]. It can also have a deteriorating influence on the water quality as it may lead to higher nutrient levels in the area, due to flushing after rainfall events.…”

“…Higher efficiency of PV systems than land-based solutions, due to water cooling and reflecting light from water surface [14], although conflicting information can be found in the literature [15]. • Reduces evaporation in lakes, which could have a positive impact in locations prone to drought or water shortages [16].…”

Impacts of floating urbanization on water quality and aquatic ecosystems: a study based on in situ data and observations

“…Additionally, as floating structures often include terraces/docks above the water, they also often attract birds or insects (Ziar et al 2020) and provide space for nests/shelter, which could enrich local ecosystems. Floating projects offer the opportunity to incorporate eco-friendly measures to stimulate biodiversity and provide habitat/food for fish and birds (Continued.…”

“…The rapid implementation of novel large-scale floating solar parks worldwide generated a need for updating and adjusting legal policies and guidelines, and therefore several studies have been conducted recently that address potential impacts of floating solar panels (Armstrong et al 2020;Haas et al 2020;Ziar et al 2020). Some of the studies report findings based on in situ measurements (Costa 2017;Pimentel Da Silva & Branco 2018;Ziar et al 2020), but often rely on models without validation with in situ data.…”