The Floating Solar Market

1 BACKGROUND

1.1 Why floating solar?

Floating solar has certain advantages over land-based systems, including improved energy yield thanks to the cooling effects of water and the decreased presence of dust, proximity to demand hotspots, and, in the case of water supply reservoirs, utilisation of existing electricity transmission infrastructure at hydropower sites. Floating solar installations open up new prospects for scaling up solar generating capacity, particularly in countries with high population density and contending uses for the land. The exact magnitude of these upper hands in performance has yet to be corroborated by larger installations over time and across multiple geographies. However, it is expected that they may outweigh any increase in capital cost [1].

The chance of adding floating solar photovoltaic (FPV) capacity to actual large hydropower plants is of particular interest, especially when these sites can be flexibly operated. The extra power capacity can augment the energy yield of such assets and help manage periods of shortfalls in water availability by allowing the hydroelectric facility to operate in “peaking” instead of “baseload” mode. And the paybacks go both ways: hydropower can flatten variable solar output by running in a “load-following” manner. Floating solar may be of particular interest where grids are fragile in terms of stability and robustness, such as in Libya and Sub-Saharan Africa and parts of developing Asia.

Other likely benefits of FPV include:

• Reduction in temperature loss: Evaporative cooling effect from the water (thus lower operating module temperatures) is likely to increase the energy yield of the PV modules, particularly in hot climates. Improvement of above 10% as compared to land-based PV systems had been reported in some early FPV projects;
• No need for major site preparation, such as levelling or the laying of foundations, which must be done for land-based installations;
• Reduced evaporation from water reservoirs, as the solar panels provide shade and diminish the effects of wind;
• Improvements in water quality through decreased algae growth;
• More negligible shading effect on panels by their surroundings;
• Easy deployment in locations with low anchoring and mooring requirements and a high degree of modularity leads to more rapid installation.

1.2 Technology Overview

Aside from the fact that the PV arrays and typically the inverters are positioned on a floating platform, the basic configuration of a floating system is identical to that of a land-based PV system (figure 1). Solar modules generate direct current (DC) electricity collected by combiner boxes and converted to alternating current (AC) by inverters. The inverters can be placed on land—a short distance from the array—for small-scale floating plants near the coast. Otherwise, specially built floats with central and string inverters are commonly employed. Any floating solar installation would be incomplete without the platform, as well as its anchoring and mooring method.

Figure 1. Schematic of a typical large-scale FPV system, showing key components. Source: SERIS and World Bank Group.

1.2.1 Floating Platform

The floating platform and its anchorings are essential parts and enablers of floating solar technology. The floating platform usually consists of a matrix of specially designed HDPE floats connected or floating pontoons with supporting metal frames. Most large-scale FPV plants have pontoon type floats, upon which PV panels are mounted at a fixed tilt angle. Apart from PV panels, other electrical components, such as combiner boxes and string or central inverters, can also be floating on water.

The floating platforms are held in place by the anchoring and mooring system. Depending on the site conditions, the anchoring can be made either to the shore of the water body (bank anchoring) or the water bed (bottom anchoring). The floats and the anchoring designs need to take into account factors such as wind load, float type, water depth, and variations in water level. This often involves careful mechanical design and structural analysis using tools such as Computational Fluid Dynamics (CFD) and Finite Element Methods (FEM). Currently, several companies are supplying specially designed floats for FPV.

1.2.2 Moorings and Anchoring

The mooring system is the component of an FPV power plant that depends most on the nature of the water body where it is installed. It is not just a tying system to the margins, as some more complexity is required due to recorded water depth variations at freshwater ponds and dams. Furthermore, having a tilt angle, the orientation of the system must remain constant, namely true north for installations in the Southern Hemisphere.

In designing both the mooring system and the under-water cable connection to the lake margin, several parameters must be taken into account: the distance of the system from the margin, the steepness of the sides, the reservoir’s maximum bathymetry variation, the morphology of the bed. Moorings are probably the most difficult costs to estimate, as they strongly depend on the design.

1.2.3 Cabling

The entire DC system is equal to that of a ground-mounted PV plant. On the contrary, the AC cable must be water-resistant, which increases sensibly its costs, both because of the costs itself of the under-water cable and for the installation that requires much more time and expensive equipment.

1.2.4 Tracking and Concentration

Other than the standard fixed-tilt floating PV array configuration outlined above, tracking and concentration are also achievable with floating solar. Tracking can be achieved by rotating the entire floating platform to follow the sun from east to west. This type of vertical-axis azimuth tracking is particularly relevant for FPV since it is relatively simpler to move an array on water (with its lower resistance) than on land. In addition, because alignment with the sun’s position does not need to be completely accurate, the disturbances caused by wave movements are of minor impact. Also, other tracking mechanisms, including dual-axis tracking, are possible [2].

Concentration increases the conversion efficiency of solar panels and can be achieved using mirrors or Fresnel lenses. For example, light can be concentrated on a horizontal PV panel using V-shaped mirrors. Concentration in FPV systems pairs naturally with tracking, as indicated by the so-called floating tracking cooling concentrator system. However, these concepts are still at an early stage of development and do not have much commercial relevance yet.

2 MARKET PICTURE

The market for Floating solar is growing exponentially. The installed floating solar capacity has surpassed 1.3 Gigawatt-peak and continues to grow thanks to large installations in Asia, particularly China. Currently, most floating solar deployments are on inland freshwater bodies. This is mainly because there is less challenge from wind, waves and currents for the anchoring and mooring system, and there is less corrosion and degradation stress for floats as well as electrical components.

However, there is a solid interest to install FPV systems offshore (or rather near-shore). The more stringent requirements for floats, anchors, and components imposed by the harsher environment may necessitate a different platform design or the use of other technologies. However, the vast experience of the well-established marine and offshore industries should make it possible to meet the challenges. A few startups are currently exploring offshore floating solutions, but still at a small scale.

The world market for FPV has been surging over the past few years, and the installed capacities of individual projects are increasing year on year. The installed FPV capacity was about 2.6 GW in 2020 from active projects in more than 35 countries [3]; it has doubled since 2018 from 1.1 GW by then and has grown exponentially since 2017. The largest FPV systems in operation are in China, where projects with over 150 megawatt-peak (MWp) have been developed by Sungrow Group and China Three Gorges New Energy Co., Ltd.

Market data suggests that with the installation of a few large FPV systems in the last two years, China has become the FPV market leader with an installed capacity of more than 950 MWp, representing about 73 per cent of the world’s total. The remainder of the installed capacity is mainly spread between Japan (about 16 per cent), the Republic of Korea (about 6 per cent), Taiwan, China (about 2 per cent), the United Kingdom (about 1 per cent), whilst the rest of the world accounts for only 2 per cent. FPV plants totalling more than 180 MWp have been installed in Japan; most of them are below 3 MWp.

Figure 2. Distribution of FPV plants according to their size, as of December 2018. Source: https://openknowledge.worldbank.org/handle/10986/31880

Figure 2 ranks the FPV projects based on their installed capacity. Plants were divided into five categories: (i) smaller than 2 MWp, (ii) between 2 and 3 MWp, (iii) between 3 and 5 MWp, (iv) between 5 and 15 MWp, and (v) larger than 15 MWp. The world’s 13 largest plants (>15 MWp) account for more than 70 per cent of all FPV installed capacity. To date, most of the installations are small systems with capacities below 3 MWp. However, the number of large systems has been increasing significantly since 2017, and this trend is set to continue, with many FPV projects larger than 10 MWp under development.

FPV offers significant advantages in countries where land is scarce or expensive and suitable water bodies are present. Some economies, such as Taiwan and China, provide financial incentives to use water bodies for PV deployment. Several large FPV installations are integrated with hydropower plants. These arrangements increase the overall efficiency of both solar and hydropower production and allow the sharing of existing transmission infrastructure.

3 EARLY PROJECTS AND RESEARCH FINDINGS

3.1 Singapore’s Tengeh Reservoir

Singapore’s floating solar testbed, located at Singapore’s Tengeh Reservoir, comprises ten systems of different floating technologies and system designs, with a total capacity close to 1 MWp (see figure 3). The objectives are to study the economic and technical feasibility and the environmental impacts of deploying large-scale FPV systems on inland water surfaces.

Figure 3. The 1MWp floating solar testbed at Singapore’s Tengeh Reservoir. Source: https://www.euronews.com/green/2021/08/26/singapore-is-turning-to-floating-solar-panels-to-meet-its-green-targets

To study the performance and reliability of the various floating systems, SERIS measures an extensive set of meteorological and electrical parameters, including solar irradiance, air temperature, air humidity, water surface albedo, wind speed and direction, module temperatures, platform motions, DC output on string level and AC energy output per sub-system [4]. This enables in-depth analyses, for instance, to quantify the amount of module temperature reduction, determine the advantages of using bi-facial modules on floating systems, and to assess the increase in energy yield compared to typical PV systems.

Through a comparison of readings of operating conditions from the testbed and a nearby rooftop reference system, it is found that the on-water environment has slightly lower ambient air temperature, higher humidity, and higher wind speed. The comparison clearly shows a dependence on how the PV panels are mounted. Higher values of the heat loss coefficient correspond to better cooling and thus lower module temperatures, leading to better electrical performance. The floating structures in the testbed are roughly categorised into “free-standing” types (with PV panels open to the water surface) and the “pontoon” types differentiated by the extent of water surface coverage beneath the modules (from “small footprint” to “large footprint”). The “insulated” configuration corresponds to a large footprint pontoon structure with modules arranged in a compact, back-to-back east-west facing array.

Under normal operation without major downtimes, the majority of the floating systems reached performance ratio (PR) values of well above 80%, which is not easily achieved in Singapore’s hot climate conditions. This is higher than the average of rooftop PV systems in Singapore. As expected, the system with the highest PR has a free-standing type as a floating structure. Overall, the floating systems clearly benefit from cooler module temperatures.

3.2 China’s New Power Plants

Huainan is a city in the eastern region of China and is known for its past and present coal industry. Lately, this city has drawn the world’s attention by unlocking a new chapter in China’s transition to a low carbon scenario. In 2017, the largest floating solar power plant by that time was inaugurated in the province on a flooded site once used for coal mining [5]. The joint venture belongs to China Energy Conservation and Environmental Protection Group (CECEPe), a state-owned utility conglomerate and a renewable energy project developer. The government has backed this project, which aims to alleviate the damage caused by the overexploitation of coal mines.

The flooded area is 148.4 ha, while the total surface of the floating power plant is 63.6 ha. This 70 MW project was raised by almost 194,700 solar modules and 52,000 afloat elements to keep the islands on water. The power plant is made of 13 floating islands, and the capacity of the largest one is approximately 8.5 MW. The solar arrays are docked to the silty clay soil of the lake bed at depths that reach 14.0 m and less. The floating parts are stabilised using helical anchors to withstand the hydrodynamic impacts of wind and rain and tolerate up to 4 m of water level variations in different seasons.

The capital expenditures of building floating solar power plants are greater than their ground-mounted counterparts. Several factors impact the financial conditions of the FPV projects, going from the characteristics of the soil/bedrock to the location of the water reservoir (logistics) and the type of floats used to bear the PV modules.

Anchoring or securing the floating solar arrays in a way that harmonises the dynamics of the reservoir yet provides long-term reliability takes a substantial part of the costs. For a shallow water body such as the Anhui project in China, the total moorings and anchoring costs were around 10 USD/kW — in Japan, the anchoring price has been substantially higher. The anchors were put from 4 to 15 meters underwater using local manufacturing facilities and labour. The up to date estimate of the floating solar farms’ costs based on the technology used in Anhui ranges from 0.85 to 1.20 USD/Wp. This is based on the assumption that the float parts are manufactured locally, and the logistic impacts for these large plastic parts are reduced to a minimum [6].

3.3 Irrigation Reservoirs in Spain and the U.S.

A full-scale prototype (1:1) of an FPV cover system was built in 2009 over an irrigation water reservoir in Agost, Alicante (figure 4). The implantation area was 350 m2 (around 7% of the whole water surface), conforming to a maximum installed power of 20 kWn. The auspicious results obtained from a correlated pilot plant over two years prompted covering the full of the basin with 1458 PV panels supported on 750 pontoons in 2012, over a 4490 m2 water surface.

The system entails the following key elements [7]:

• Floating platforms (pontoons) maintain the buoyancy and stability of the electricity-generating array. They are manufactured in MDPE by rotational moulding, and each supports two PV panels;
• Supporting structure (metal frames) able to withstand the weight of the solar cells and transmit wind momentum across the pontoons to the anchoring arrangement located above the crest of the embankment;
• Metal chains or cables that constitute the articulated metal couplings between pontoons (tying the floats together, allowing rotations and vertical and horizontal displacements) help the deck fit the reservoir’s concave profile.
• Flexible couplings (MDPE or rubber straps tolerating a stretch up to a fixed length). Hence, the pontoons are able to drift in relation to one another so that the system can readjust to different water levels.
• Ropes (nylon and polyester nautical ropes) are used to lock the external modules of the floating array to the sides of the reservoir.
• A stiff anchoring system (through the passive pressure of the surrounding ground, reinforced concrete piles withstand lateral stresses) fastens the floating cover. It transfers horizontal forces to the sides of the reservoir.

The power plant has a nominal capacity of 300 kWn, giving an annual production of 425,000 kWh/year of renewable energy, which is delivered directly into the network. The water saved thanks to shading the reservoir reaches 5000 m3/year, which means a quarter of the reservoir’s storage capacity. Available data show how the successive cycles of filling and emptying the reservoir, with the consequent inclination of the panels, do not adversely affect the plant’s performance.

Figure 4. Sunset at Agost, Spain. Source: “Error! Hyperlink reference not valid.” by https://www.flickr.com/photos/sergiomas/ is marked with CC BY 2.0.

The work by SPG Solar in 2008 at the Far Niente winery in California, USA, got the most outstanding press attention and is sometimes referred to as the first floating PV project [8]. The winery owner’s purpose for installing the floating PV system on top of their water reservoir was not to take away ground that might be utilised to produce vines, which is a much more valuable resource for their business. The system consisted of modular, crystalline PV panels installed on top of individual pontoons at an ideal tilt angle.

The mounting structure, called ‘Floatovoltaic’ and designed by Thompson Technology Industries, includes walkways between the rows of panels and along the sides to facilitate maintenance and cleaning of the panels. Building the solar arrays on water preserved about 0.6 hectares of valuable Cabernet vineyard acreage from being lost for land-mounted arrays, which would have cost the estate about $150,000 a year in lost earnings. Covering the irrigation pond also resulted in less water loss due to evaporation – and fewer algae growth.

An architect, a structural engineer, a wastewater engineer, and a solar system designer were all part of the design team assembled by the firm. The team considered erecting a massive carport over the irrigation and wastewater recycling pond as a solid foundation for mounting solar panels; designing steel or aluminium trusses to span the 16-foot-deep pond from bank to bank and attach the solar panels to it; or erecting a cable suspension system to support the panels. However, it was evident that more outside help was required. Eight well-known solar energy companies were asked for proposals.

3.4 K-Water

The Korea Water Resources Corporation (한국수자원공사, 韓國水資源公社), or K-water, is the governmental agency for integrated water resource development, providing both public and industrial water in South Korea. K-water mounted a 100 kW floating PV system on the surface of the Hapcheon dam reservoir in October 2011 for grid connection. After successfully deploying the 100 kW system, K-water commissioned a 500 kW FPV array on another nearby location in July 2012. The electricity generated by the two floating systems set up in Hapcheon is generating profits by being sold to the national power grid.

The 100 kW FPV is forming a 33° tilt, and its installed capacity is 99.36 kW, built by 414 240 W modules. The standards for generation performance was the amount read, and the capacity factor was calculated under the following:

The monthly average generation from January 2012 to December 2012 was 10,853 kWh, and the average capacity factor was 14.9%. The maximum monthly generated quantity was 13,792 kWh in October, and the minimum threshold was 8,224 kWh in December. For the capacity factor, the maximum value was 18.7% in October, and the minimum was 11.1% in December.

For a comparative analysis of the generation performance of the Hapcheon FPV power plant, the system was matched with a 1 MW overland PV system installed in Haman-gun, 60 kilometres southeast of Hapcheon, where the solar radiation and temperature are similar. Haman’s 1MW ground-mounted PV system forms a fixed 30° tilt, and its installed capacity is 935.9 MW, composed of 4,000 250 W modules. First of all, for more accurate comparison analysis between the 100 kW floating plant and the 1MW land PV plant, analysts excluded days with blackouts, maintenance, and data error. The examination period consisted of one year, starting from February 2012 to January 2013, while data from 185 days were used for analysis. Hapcheon 100kW and Haman 1MW’s daily generation quantity was 421 kWh/day and 3,486 kWh/day each.

To compare the two power plants with different capacities, the “Daily average generation quantity of Haman 935.9 kW overland PV system when converted into 99.36 kW” was calculated and compared with the “Daily average generation capacity of Hapcheon 99.36 kW floating PV system.”

As a result, the coefficient of utilisation of the 100kW and 1MW were 17.6% and 15.5%, respectively, which means that the Hapcheon 100 kW floating PV system’s value is 13.5% higher than that of the Haman 1 MW system [9].

3.5 Hydrelio

Water solar PV facilities employing anchors were made practical because of advanced design technology. Shell Tail created Hydrelio, a floating module system for water solar photovoltaics (solar power). The Hydrelio system, developed in France, is an innovative water-based solar power-producing system. The basic module consists of two high-density polyethylene floats (HDPE). Solar islands are formed by connecting these floats with a connecting pin system. Solar panels with standard 60 cells can be mounted on the main float, while the second float connects the floats and serves as a footing for maintenance.

The Hydrelio system is a small-scale system that allows solar power generation projects to be implemented without deforestation, soil contamination, or water pollution by employing irrigation ponds, reservoirs, and dams distributed around Japan. Furthermore, because the natural cooling effect for modules and cables is obtained by installing on the water, it is expected to have higher power generation efficiency than the ground installation type, resulting in excellent cost-effectiveness such as shorter construction time with a simple structure.

For the first time in Indonesia, REC demonstrates its FPV installation at a government site in West Java. Through a pilot project at the Electricity & Renewable Energy Museum (Museum Listrik dan Energi Baru – MLEB), Taman Mini Indonesia Indah, REC has teamed with PT Kas Green Energy, a local independent power provider (IPP), to introduce the concept of a floating solar system. REC solar PV panels are readily put on 100% recyclable “Hydrelio” pontoons that are simple to disassemble. They are made of high-density polyethylene (HDPE), which may be securely installed atop drinking water reservoirs and is UV resistant.

4 POTENTIAL CHALLENGES

Many commercial projects, as well as the Singapore testbed, have demonstrated that floating solar is a viable solution. However, best practices are essential to ensure technical quality. In the Singapore testbed, operators also studied the engineering aspects and derived several valuable learnings on floating solar deployment, operation, and maintenance (O&M). Below, we summarise a few issues encountered in the current market.

4.1 Economic and Financial Appraisal

Few countries have provided financial incentives specifically for FPV systems. However, most countries still implementing preferential feed-in tariffs (FiTs) for solar PV also include FPV. This is the case in Japan, Malaysia, and Vietnam.

In a bid to encourage the large-scale implementation of renewable energy technologies, Vietnam’s Ministry of Industry and Trade (MOIT) established a FiT scheme for all on-grid utility-scale solar installations in 2017; it also applies to FPV projects. The scheme was extended for another 12 months in Ninh Thuan province but with a 2 GW capacity ceiling. Before value-added tax, grid-connected power plants are granted a FiT equivalent to $0.0935/kWh. On 29 January 2019, MOIT released a first draft update of the country’s current feed-in tariff structure.

The draft FiTs will vary based on (i) the completion date, (ii) location, and (iii) type of solar projects (i.e., floating, ground-mounted, integrated storage system or rooftop solar). In the latest draft, released on 12 April 2019, the new FiT for floating solar projects will be 8.5% higher than ground-mounted PV but is still subject to potential changes.

In Malaysia, a FiT in force since 2011 has pre-set capacity ceilings for each technology. The so-called “RE quota” administered by the Sustainable Energy Development Authority is set every six months and covers a period of three years. However, there is currently no quota available for FPV projects [10].

Large-scale solar PV (including FPV) projects are implemented via auctions. In Japan, large-scale PV solar systems were eligible for a FiT until 2017, when 2 MWp and above (including FPV) became ineligible. Offtake prices are now determined through a competitive auction system. Some economies have specific FPV support mechanisms. Examples are Taiwan, China; the state of Massachusetts in the United States; and the Republic of Korea.

4.2 Mechanical Wearing

Constant platform movements can cause challenges for mechanical connections and joints. This is especially true for platforms where relative movements between modules are frequent. One example is the breaking of equipotential bonding wires/tapes.

Equipment grounding is vital for the electrical safety of personnel, and equipotential bonding is used to ground modules and frame structures. During the period of operation, the site responsibles can observe several instances of breaking and snapping (figure 5), even for cases where there is sufficient slack. Therefore, it might be necessary to implement improved wire management systems on floating platforms.

Figure 5. Examples of breaking and snapping of equipotential bonding tapes. Source: https://onlinelibrary.wiley.com/doi/10.1002/pip.3039

4.3 Bird Droppings

Although less soiling from dust can be expected, soiling due to bird droppings can sometimes be a severe issue for floating PV systems. It leads to partial shading and a reduction of current. It can even lead to hot spots and accelerate module degradation in extreme cases. Bird droppings were occasionally observed in the Singapore testbed and were mostly washed away by rain.

However, some systems experienced heavier soiling than others, and the accumulation of droppings led to a significant reduction in energy generation. In one episode, the current, and thus PR, dropped by over 10% in the course of around ten days. If not noticed and cleaned in time, the fast accumulation of bird droppings can significantly impact revenue. Therefore, it may be worthwhile to study bird behaviours, install bird deterrent devices, and schedule maintenance accordingly.

4.4 Insulation faults

Due to the high-humidity environment and the proximity to water, the insulation resistance of the system can sometimes drop significantly. This is especially the case if cables or connectors come into contact with water. Low insulation resistance can lead to electrical leakage to the ground, which poses safety hazards to personnel and equipment. Inverters usually check insulation resistance during startup and do not turn on when this value does not meet the minimum requirement.

The floating solar technology is still in its early development and commercialisation phase, and there are several broader challenges to consider in addition to the technical issues aforementioned. In the Singapore testbed, frequent instances of inverters turning on late in the morning are observed for some systems. This leads to a non-negligible loss in energy production. Therefore, suitable cable and connector quality, careful cable management, and proper platform design are crucial to avoid this loss.

5 CONCLUSIONS

There are several proposed benefits of floating solar. Land usage is, if any, reduced in comparison with ground-mounted PV projects. This is important for regions where land resources are scarce, land acquisition costs are high, or land use is for PV installations is in conflict with agricultural and traditional services. Installation and deployment are substantially easier since little civil work is needed to prepare the site. Typical floating platforms in the market are usually modular in nature and easy to assemble.

Solar cells gain productivity thanks to the evaporative cooling effect when placed above water. Some early FPV projects showed efficiency improvement of more than 10% when compared to land-based PV systems. Floating cells are less prone to shading due to more open areas and a flat environment. Also, water bodies tend to be less dusty than other typical locations for PV deployment (e.g. cities, deserts), so less dust soiling effect is expected.

Synergy with existing electrical infrastructure is attainable at many inland freshwater bodies, especially hydropower plant reservoirs with nearby grid connections. When utilising those, the initial CAPEX can be substantially reduced. There is great potential for the combined operation of hydropower stations with FPV as hydro-PV hybrid systems, not only for the diurnal cycle (i.e. generating solar power during the day and hydropower at night). There are often also seasonal complementarities, whereby dry seasons with less water flow correspond to a period of high solar insolation and vice versa. In addition, fast-responding hydro turbines can largely compensate for instantaneous irradiance variability.

Environmental benefits consist of a reduction in algae growth because of a reduced amount of sunlight reaching the water body and water savings resulting from decreasing evaporation loss. Additional benefits may include the potential integration of floating PV with aquaculture and fish farming.

Currently, most floating solar deployments are on inland freshwater bodies. This is mainly because there is less challenge from wind, waves and currents for the anchoring and mooring system, and there is less corrosion and degradation stress for floats as well as electrical components.

We have disclosed a huge market potential: there are 400.000 km2 of artificial reservoirs on the planet. Only covering 10% of those would already unlock a prospect in the Terawatt scale. The future demand for floating solar is expected to be driven by East Asia nations like Indonesia, India, the Republic of Korea, Thailand and Vietnam. Finally, there is excellent potential for installing floating solar panel electricity generating plants to improve the water and energy balances in arid and semi-arid zones with scarce water resources, as in areas near the Spanish eastern Mediterranean coastline.

6 REFERENCES

[1] World Bank Group, ESMAP, and SERIS. (2019). Where sun meets water: floating solar market report. Washington, DC: World Bank

[2] Connor, P. M. (2009). Performance and prospects of a lightweight water-borne PV concentrator, including virtual storage via hydroelectric dams. ISES Solar World Congress. (2009). Renewable Energy Shaping Our Future. South Africa: Johannesburg.

[3] https://www.irena.org/events/2021/May/An-Action-Agenda-for-Deploying-Offshore-Renewables-Worldwide#:~:text=The%20installed%20floating%20solar%20PV,in%20China%20with%20150%20MW.

[4] Liu, H., et al. (2018). Field experience and performance analysis of floating PV technologies in the tropics. Progress in Photovoltaics: Research and Applications, 26(12), 957–967.

[5] https://www.power-technology.com/marketdata/huainan-floating-solar-pv-park-china/

[6] Pouran, H. M. (2018). From collapsed coal mines to floating solar farms, why China’s new power stations matter. Energy Policy, 123, 414-420.

[7] Redón-Santafé, M., Ferrer-Gisbert, P. S., Sánchez-Romero, F. J., Torregrosa Soler, J. B., Ferran Gozalvez, J. J., & Ferrer Gisbert, C. M. (2014). Implementation of a photovoltaic floating cover for irrigation reservoirs. Journal of cleaner production, 66, 568-570.

[8] https://www.sfgate.com/bayarea/article/Winery-goes-solar-with-Floatovoltaics-3282171.php

[9] Choi, Y. K. (2014). A study on power generation analysis of floating PV system considering environmental impact. International journal of software engineering and its applications, 8(1), 75-84.

[10] https://www.seda.gov.my/

BACKGROUND
1.1 Why floating solar?
Floating solar has certain advantages over land-based systems, including improved energy yield thanks to the cooling effects of water and the decreased presence of dust, proximity to demand hotspots, and, in the case of water supply reservoirs, utilisation of existing electricity transmission infrastructure at hydropower sites. Floating solar installations open up new prospects for scaling up solar generating capacity, particularly in countries with high population density and contending uses for the land. The exact magnitude of these upper hands in performance has yet to be corroborated by larger installations over time and across multiple geographies. However, it is expected that they may outweigh any increase in capital cost [1].
The chance of adding floating solar photovoltaic (FPV) capacity to actual large hydropower plants is of particular interest, especially when these sites can be flexibly operated. The extra power capacity can augment the energy yield of such assets and help manage periods of shortfalls in water availability by allowing the hydroelectric facility to operate in “peaking” instead of “baseload” mode. And the paybacks go both ways: hydropower can flatten variable solar output by running in a “load-following” manner. Floating solar may be of particular interest where grids are fragile in terms of stability and robustness, such as in Libya and Sub-Saharan Africa and parts of developing Asia.
Other likely benefits of FPV include:
• Reduction in temperature loss: Evaporative cooling effect from the water (thus lower operating module temperatures) is likely to increase the energy yield of the PV modules, particularly in hot climates. Improvement of above 10% as compared to land-based PV systems had been reported in some early FPV projects;
• No need for major site preparation, such as levelling or the laying of foundations, which must be done for land-based installations;
• Reduced evaporation from water reservoirs, as the solar panels provide shade and diminish the effects of wind;
• Improvements in water quality through decreased algae growth;
• More negligible shading effect on panels by their surroundings;
• Easy deployment in locations with low anchoring and mooring requirements and a high degree of modularity leads to more rapid installation.
1.2 Technology Overview
Aside from the fact that the PV arrays and typically the inverters are positioned on a floating platform, the basic configuration of a floating system is identical to that of a land-based PV system (figure 1). Solar modules generate direct current (DC) electricity collected by combiner boxes and converted to alternating current (AC) by inverters. The inverters can be placed on land—a short distance from the array—for small-scale floating plants near the coast. Otherwise, specially built floats with central and string inverters are commonly employed. Any floating solar installation would be incomplete without the platform, as well as its anchoring and mooring method.