Wind-induced effects on Modular Floating Solar units (ERIES-FLOATINGSOLAR)

This project aims to improve the understanding of wind-induced effects acting on floating photovoltaic (FPV) systems. The floating solar units were developed as modular systems by HelioRec. Wind-tunnel experiments were conducted at the Centre Scientifique et Technique du Bâtiment (CSTB) to investigate the aerodynamic loads acting on different FPV configurations.

The experimental campaign includes force-balance measurements on full-scale components, including an isolated floater, a floater equipped with supporting elements, and a complete system integrating the solar panel. In addition, reduced-scale (1:6) models were tested to examine various multi-unit array configurations representative of potential installation layouts. In each reduced-scale configuration, two FPV units were equipped with force balances, while the remaining units served as dummy structures, which purpose was to create the appropriate flow effects.

The resulting dataset characterizes wind–structure interactions for both isolated and clustered FPV systems based on measured aerodynamic forces and moments. For selected configurations, simplified wave-related effects were considered by varying the elevation of the panels relative to the water surface. 

Speciments

1.     Isolated FPV Unit – Full-Scale Measurements

The configuration represents a single, isolated FPV unit used to assess aerodynamic loads under controlled wind-tunnel conditions.

The tested full-scale specimen is a realistic floating photovoltaic (FPV) unit developed by HelioRec. The specimen consists of a floating body with a height of 0.218 m, two front supporting elements (0.384 m) and two rear supporting elements (0.591 m), and a solar panel measuring 2.382 m × 1.134 m, mounted on the supporting structure. The total weight of the specimen is approximately 52 kg.

1.1.     Effect of Wind on the Complete FPV Unit

The experiment investigated the influence of varying wind angles of attack on the aerodynamic loads acting on a complete FPV unit. The specimen was mounted at the center of a turntable and tested at thirteen wind angles: 0°, 15°, 30°, 45°, 60°, 75°, 90°, 105°, 120°, 135°, 150°, 165°, and 180°, for two wind speeds of 15 m/s and 35 m/s.

Additional tests were conducted at a higher wind speed of 55 m/s using six wind angles: 0°, 45°, 90°, 135°, 150°, and 180°.

1.2.     Effect of Wind on the Supporting Structure and Floater (Without Panel)

The experiment investigated the influence of varying wind angles of attack on the aerodynamic loads acting on an isolated floater with supporting elements, excluding the PV panel.

The model was mounted at the center of a turntable and attached to the force balances mounted beneath the model. It was then tested at five wind angles: 0°, 45°, 90°, 135°, and 180°, for a wind speed of 35 m/s. Additional tests were conducted at 55 m/s for wind angles of 0° and 180°.

1.3.     Effect of Wind on the Floater Only

The experiment investigated the influence of varying wind angles of attack on the aerodynamic loads acting on the isolated floater of the FPV unit, without both the panel and its fixtures.

The model was mounted at the center of a turntable and tested at five wind angles: 0°, 45°, 90°, 135°, and 180°, for a wind speed of 35 m/s.

2.     Multi-Unit FPV Array – Reduced-Scale Measurements (1:6)

The tested specimen consists of representative FPV units developed by HelioRec, reproduced at a reduced geometric scale of 1:6. Each unit comprises a floating body, two front and two rear supporting elements, and a solar panel mounted on the supporting structure.

Within the multi-unit configuration, two selected units were instrumented with force balances and positioned near the center of the turntable. These instrumented units remained at fixed locations throughout the measurement campaign and were used to assess aerodynamic loads within different clustered array configurations.

2.1.     Multi-Unit Floating PV Array – 4–3–4–3 Row Configuration

The experiment investigated the influence of varying wind angles of attack on the aerodynamic loads acting on a reduced-scale floating PV array arranged in a four-row configuration (4–3–4–3 units per row).

Two fixed FPV units within the array were instrumented with force balances, enabling simultaneous measurements during each test. By repositioning the non-instrumented (dummy) units, different units within the array were sequentially evaluated.

The tested wind angles were 0°, 45°, 90°, 135°, 180°, 225°, 270° and 315° at a wind speed of 35 m/s. For wind angles of 0° and 180°, this multi-unit configuration was also tested at wind speeds of 15 m/s and 25 m/s.

2.2.     Multi-Unit Floating PV Array – 3–3–3–3 Row Configuration

The experiment investigated the influence of varying wind angles of attack on the aerodynamic loads acting on a reduced-scale floating PV array arranged in a four-row configuration (3–3–3–3 units per row).

The tested wind angles were 0°, 45°, 90°, 135°, 180°, 225°, 270° and 315° at a wind speed of 35 m/s. For wind angles of 0° and 180°, this multi-unit configuration was also tested at wind speeds of 15 m/s and 25 m/s were also considered.

The corner units were equipped with force balances, enabling the measurement of aerodynamic forces and moments within the array configuration.

2.3.     Multi-Unit Floating PV Array – 5–6 Row Configuration

The experiment investigated the influence of varying wind angles of attack on the aerodynamic loads acting on a reduced-scale floating PV array arranged in a two-row configuration (5–6 units per row).

The tested wind angles were 0°, 15°, 45°, 90°, 135°, 180°, 225°, 270°, 315° and 345° at a wind speed of 35 m/s. For wind angles of 0° and 180°, this multi-unit configuration was also tested at wind speeds of 15 m/s and 25 m/s.

The middle and corner units were equipped with force balances, enabling the measurement of aerodynamic forces and moments within the array configuration.

2.4.     Multi-Unit Floating PV Array – 3–3–3 Row Configuration

The experiment investigated the influence of varying wind angles of attack on the aerodynamic loads acting on a reduced-scale floating PV array arranged in a three-row configuration (3–3–3 units per row).

The tested wind angles were 0°, 45°, 90°, 135°, 180°, 225°, 270°, and 345° at a wind speed of 35 m/s. For wind angles of 0° and 180°, this multi-unit configuration was also tested at wind speeds of 15 m/s and 25 m/s.

In this configuration, simplified wave-related effects were simulated by varying the elevation of the middle (second) row relative to the reference level of the additional platform. Three cases were considered: (i) no elevation (reference configuration), (ii) 15 mm elevation, and (iii) 25 mm elevation of the middle row.

The additional wind angle of 345° at 35 m/s was considered only for the reference configuration (no elevation of the middle row) and was applied to the two corner units.

2.5.     Multi-Unit Floating PV Array – 1–1 Row Configuration

The experiment investigated the influence of varying wind angles of attack on the aerodynamic loads acting on a reduced-scale floating PV array arranged in a two-row configuration, with one unit per row.

The tested wind angles were 0°, 45°, 90°, 135°, 180°, 225°, 270°, and 345° at a wind speed of 35 m/s. For wind angles of 0° and 180°, this multi-unit configuration was also tested at wind speeds of 15 m/s and 25 m/s.

In this configuration, simplified wave-related effects were simulated by sequentially varying the elevation of each unit relative to the reference level of the additional platform. Three cases were considered: (i) no elevation (reference configuration), (ii) 15 mm elevation of the unit in the first row, and (iii) 15 mm elevation of the unit in the second row.

An additional wind angle of 190° at 35 m/s was considered only for the configurations in which either the first or the second unit was elevated.

2.6.     Isolated FPV Unit – Reduced-Scale (1:6)

The experiments investigate the influence of varying wind angles of attack on the aerodynamic loads acting on an isolated reduced-scale floating PV unit.

The tested wind angles were 0°, 15°, 30°, 45°, 60°, 75°, 90°, 105°, 120°, 135°, 150°, 165°, 180°, and 195° at a wind speed of 35 m/s. For wind angles of 0° and 180°, the unit was additionally tested for wind speeds of 15 m/s, 25 m/s, and 45 m/s.