In short: Floating solar (FPV) plants sit on high-density polyethylene (HDPE) floats in a humid, moving environment. The World Bank / SERIS handbook says cable routing is more critical than on land, that cables should stay above the water unless they are submarine grade, and that walkways make maintenance cheaper and safer than working from boats. FRP fits FPV in three places: cable trays and supports that keep cables out of the water, walkway decks and grating that do not rust, and fixed access structures on shore such as jetties and inverter platforms. Float-mounted FRP walkways and tray assemblies are custom / available on request and are designed with the float supplier.
How this guide fits with our others
This guide covers solar plants on water. For ground-mounted plants in hot or salty climates, read solar farm cable tray in desert and coastal sites. Other sectors are on our industries page and emerging industries page.
What makes floating solar different
The World Bank and SERIS handbook Where Sun Meets Water: Floating Solar Handbook for Practitioners compares FPV with land-based PV. For floating plants it lists:
- A floating platform with an anchoring and mooring system, which feels wind, snow, waves and currents.
- A need to provide maintenance walkways.
- Cables mainly routed on floats, with many platform designs needing equipotential bonding wires.
- A high-humidity environment that lowers insulation resistance and raises the risk of electrical leakage.
- Cable management that must cope with constant movement, which could otherwise lead to cable damage and fire risk.
DNV's recommended practice DNV-RP-0584 (current edition 2026-09) covers FPV on sheltered inland water and near-shore sites with significant wave heights up to 2–3 m, in fresh, brackish or salt water. Offshore sites are outside its scope. If your client cites it, tell us which clauses apply to the parts we supply.
Walkways: why they pay for themselves
The handbook notes that many floating plants built to date have maintenance walkways. Without them, trained staff need boats and special equipment to reach the panels, which adds time and cost to routine work. It recommends a cost-benefit analysis of the extra floats for walkways during design, and notes that some designs have no permanent walkways but allow temporary bridges or planks.
Most FPV walkways today are part of the HDPE float system itself: secondary floats laid between module rows. The handbook says floats are generally HDPE with UV additives. Where a project needs more, FRP can add:
- Walkway decks on floats or frames. Grating or plate panels fixed to float rails, giving a flat, slip-resistant surface wider than a float.
- Main access spines. Wider routes for carrying spare modules, inverters or tools, where loads are higher than on a float path.
- Bridges between islands and to the shore, which must allow for movement and water-level change.
- Fixed structures on shore: jetties, landing stages, inverter and transformer platforms on piles, with molded grating, stair treads and handrail.
Float-mounted decks, spines and bridges are custom / available on request. They are designed together with the float supplier, because the float sets the buoyancy, fixing points and allowed loads. Fixed shore structures use our standard grating and handrail ranges.
What to specify for walkway grating
- Load. Foot traffic only, or carts and spare modules? Give a uniform load and a point load. Our span and load tables show how loads relate to span.
- Surface. Grit or concave top for wet surfaces; see slip resistance testing for FRP grating.
- UV. Panels lie in full sun on reflective water. Ask for UV-inhibited resin; see our UV degradation guide.
- Fixings. Clip and bolt material to suit the water; agree the stainless grade with your corrosion engineer for brackish or salt water.
- Water quality. On drinking water reservoirs, the handbook asks for float materials to be checked for contaminants. Tell us if the site is a potable reservoir so we can discuss resin and documents.
Cable management on water
What the handbook asks for
The handbook's cable section says slack must allow for island movement and changes in water level, or cables will snap. Cables need to be tied with UV-resistant cable ties or stainless steel clamps, routed and protected so excess slack keeps them from touching water. In its operations chapter it states that all DC and AC cables and connectors should be secured above the water surface, unless they are submarine grade. It warns that submerged connectors and cables cause leakage, low insulation resistance, corrosion of cables and loss of power, and that submerged cables can suffer biofouling. It also notes that cables rubbing on moving parts chafe.
On procurement, the handbook says the specification should include cable trays, cable conduits and cable clip holders so cables are managed above water, and that the floating structure should have a 25-year design life. Its inspection plan includes a quarterly check of the "mechanical and watertight integrity of cable conduits and/or cable trays".
Where FRP fits
- Cable trays on floats and walkways. FRP cable trays with covers carry string and collection cables above the water line. FRP does not rust in the humid air the handbook describes.
- Cable supports and brackets. FRP cable supports and pultruded profiles lift trays and conduits above float level.
- Shore landing. Cable routes from the islands to the shore need tray, supports and covers on the bank and on the jetty.
- Inverter and transformer platforms. Tray, grating and handrail on floating or piled platforms.
Check every point where cables leave a tray or cross an edge, because island movement turns small contact points into chafe points. Our installation guide explains how to seal cut edges. Tray-on-float mounting kits are custom / available on request, matched to the float type.
Bonding and grounding
FRP is non-conductive, so the tray itself is not a path for fault current. Whether metal fittings on it need bonding is for your electrical engineer to decide. The handbook notes that many floating platform designs need equipotential bonding wires and that FPV grounding can take different forms from land plants. Your electrical engineer sets that design; we supply tray and supports to suit the route of bonding conductors.
| FPV area | FRP items | Status |
|---|---|---|
| Fixed shore jetty, stairs | Molded grating, stair treads, handrail | Standard range |
| Inverter or transformer platform | Grating, handrail, cable tray | Standard range, cut to fit |
| Cable route to shore | Cable tray, supports, covers | Standard range |
| Cable tray on floats | Tray with float-mounting kit | Custom / available on request |
| Walkway decks and spines on floats | Grating or plate decks | Custom / available on request |
| Bridges between islands | Pultruded frame and deck | Custom / available on request |
Loads and movement
A floating island is never still. The handbook says the floating platform feels wind, snow, waves and water currents, and that the maximum size of an island depends on how well the floats can withstand those stresses, typically checked with finite element analysis (FEA) and computational fluid dynamics (CFD). It adds that coastal and offshore sites bring larger waves and more platform movement.
For FRP parts on floats, this means:
- Flexible joints. Long rigid tray or walkway runs must not bridge across float joints that flex. Splices or gaps at agreed points let the island move.
- Fixing loads. Fixings into floats must carry wind uplift on covers and decks as well as dead weight. The float supplier gives the allowed load per fixing point.
- Fatigue. Repeated small movements load bolts and clips over the 25-year design life. Tell us the expected movement so we can detail the joints.
- Light weight. FRP adds little dead load, which matters when every kilogram uses buoyancy.
Give us the island layout and the float supplier's movement and load data, and we will propose splice and fixing positions for the tray and deck runs.
Construction and maintenance
The handbook's operations chapter sets out inspection plans. For cables it lists monthly checks that cables and connectors are still above water, quarterly checks of tray and conduit integrity and of slack, and yearly thermal inspection and insulation resistance testing. It also notes that one worker over two days can generally check the floating structures of a 1 MWp plant.
FRP parts suit this routine. They do not need repainting, and inspection is visual: look for loose covers, cracked fixings, chafe marks and UV wear on sun-facing surfaces. Walkway decks give inspectors a stable surface to work from, which is the point the handbook makes about walkways in the first place. Plan spare tray covers and clips into the O&M stock, because these are the parts most often lost in storms.
The handbook notes that FPV islands can be assembled on the bank and launched from a ramp or temporary structure. Light FRP tray and deck sections can be fitted before launch, which reduces work on the water.
Salt, brackish and fresh water
The handbook says mounting structures of aluminum or stainless steel are sometimes used with the pontoons, usually galvanized for corrosion resistance, and that anti-corrosion tests matter most when the water analysis shows high salinity. It lists early signs of rust on frames, fasteners and cable clips as an inspection item. FRP walkway and tray parts remove one group of metal parts from that list. Fasteners still need a grade that suits the water.
What to send us
- Site: water type (fresh, brackish, salt), potable or not, wave height and water-level range.
- Float system: supplier, float type and drawings of fixing points.
- Walkway layout with widths and loads.
- Cable schedule and routes on the islands and to shore.
- Shore structures: jetty, stairs and platform drawings.
- Standards and documents your client names, such as DNV-RP-0584 clauses.
How FIBROVX builds for floating solar
We make grating, handrail, cable trays, supports and pultruded profiles to your drawings. Mesh size, thickness, resin, UV protection, grit and color are set per project. Float-mounted walkways, tray kits and bridges are custom / available on request and are developed with your float supplier's data. See custom FRP manufacturing for how a custom order runs. We do not claim DNV or any other certification for these parts. Tell us your client's requirements and we will state which tests and records we can supply for that order.
Need a quote or a drawing check?
FIBROVX manufactures FRP products in our own factory in China and builds every item to order: sizes, resin system, color, molds and OEM branding. Send your application, dimensions or drawing, quantity and destination port.
Request a QuoteWatch: FRP on Floating Solar in 27 Seconds
FAQ
Do floating solar plants need walkways?
Not always, but the World Bank / SERIS handbook says plants without walkways need boats and special equipment for maintenance, which adds time and cost.
Can cables lie on the floats or in the water?
The handbook says DC and AC cables and connectors should be secured above the water unless they are submarine grade.
Do you sell complete floating walkways?
We supply FRP decks, trays and supports. Float-mounted assemblies are custom / available on request and designed with the float supplier.
What does DNV-RP-0584 cover?
Floating solar on sheltered inland water and near-shore sites with significant wave heights up to 2–3 m. Offshore sites are out of scope.
How often should cable trays on a floating plant be checked?
The handbook's inspection plan lists a quarterly check of the mechanical and watertight integrity of cable trays and conduits, with monthly checks that cables stay above water.
Is FRP suitable for salt water FPV sites?
FRP does not rust. Choose a resin and fastener grade for the water, and check the float supplier's limits.
Sources
- World Bank Group, ESMAP and SERIS, Where Sun Meets Water: Floating Solar Handbook for Practitioners (2019): https://documents1.worldbank.org/curated/en/418961572293438109/pdf/Where-Sun-Meets-Water-Floating-Solar-Handbook-for-Practitioners.pdf
- DNV, DNV-RP-0584 Design, development and operation of floating solar photovoltaic systems (edition 2026-09): https://www.dnv.com/energy/standards-guidelines/dnv-rp-0584-design-development-and-operation-of-floating-solar-photovoltaic-systems/
- SERIS copy of the Where Sun Meets Water handbook: https://www.seris.nus.edu.sg/wp-content/uploads/2023/09/ESMAP_FloatingSolar_Gde_A4-WEBL-REV2.pdf