How Do You Know a Floating Solar System Can Survive Waves? Inside HelioRec's Full-Scale Wave Tank Testing
- HelioRec Company
- Jun 30
- 5 min read
Introduction
Floating solar is rapidly becoming one of the fastest-growing renewable energy technologies. While thousands of floating solar power plants already operate successfully on reservoirs and lakes, expanding into ports and coastal waters introduces a completely new engineering challenge: waves.
Unlike land-based solar farms, floating solar platforms are constantly moving. Every wave creates forces that travel through the floating structure, the connectors, and the mooring system. Over a project lifetime of 25 years, millions of wave cycles can affect the performance and durability of the installation.
So how can engineers be sure that a floating solar system is ready for the real world?
The answer is simple: test it.
From Computer Models to Real Waves
Computer simulations are essential when developing modern engineering systems. However, every numerical model must first be validated using experimental data.
To better understand how an articulated floating solar array behaves under wave loading, HelioRec partnered with Centrale Nantes, one of Europe's leading ocean engineering research centres. The project was supported by the Marine Energy Alliance (MEA) programme, and the results were published in the peer-reviewed journal Energies in the paper "Experimental Modelling of a Floating Solar Power Plant Array under Wave Forcing."
This work provided one of the first full-scale experimental studies of an articulated floating photovoltaic (FPV) array exposed to waves.
Building a Full-Scale Floating Solar Array
Instead of testing a small laboratory model, HelioRec built a 1:1 scale prototype consisting of:
16 floating solar modules
12 floating maintenance walkways
articulated mechanical connectors
realistic structural weight and geometry
The complete floating array measured approximately 8.2 × 7.3 metres, allowing engineers to observe the behaviour of a realistic floating solar system under controlled wave conditions.
Simulating the Ocean in a Laboratory
Inside the ocean engineering wave basin, engineers generated dozens of sea conditions, including:
regular waves,
irregular sea states,
waves arriving from different directions,
multiple wave heights and wave periods.
Every floating module was tracked using a high-precision optical motion capture system while additional sensors measured wave elevation and structural behaviour throughout the experiments.
The Most Interesting Discovery: Every Floating Structure Has a Natural Rhythm
One of the most valuable findings was the discovery of a pitch resonance.
When the wavelength became approximately twice the length of a single floater, the entire articulated floating structure started moving in a highly organised pattern.
Imagine pushing a child on a swing.
If you push at exactly the right moment, the swing moves higher and higher.
Floating solar systems behave in a similar way. Under a specific wave length, neighbouring rows of floating modules pitched in opposite directions, creating the highest structural loads on the connectors between them.
Identifying this critical operating condition allows engineers to optimise future designs and improve long-term durability.
Waves Become Weaker as They Move Through the Solar Farm
Another fascinating observation was the wave shadowing effect.
The first rows of floating modules absorbed part of the incoming wave energy.
As a result:
front modules experienced the largest motions,
middle rows moved less,
rear rows moved even less for shorter waves.
This means that a floating solar farm does not behave as a collection of independent floaters. Instead, the entire structure works together, with each module influencing the behaviour of its neighbours.
Why Experimental Testing Matters
Wave tank testing is much more than an academic exercise.
It helps engineers:
identify critical design conditions,
improve structural components,
validate numerical simulation models,
optimise future floating solar systems,
reduce technical risks before commercial deployment.
For investors, customers and certification bodies, independently validated experimental results provide confidence that the technology has been developed using sound engineering principles rather than assumptions.
Building on This Research
The system tested in this publication represented an early generation of HelioRec's technology.
Since then, the company has significantly advanced its engineering through:
improved structural design,
advanced OrcaFlex hydrodynamic simulations,
structural optimisation,
Bureau Veritas Approval in Principle (AiP),
independent technology due diligence by ERM.
Today's W300A floating solar technology builds directly upon the lessons learned during this experimental campaign, combining scientific validation with several years of additional engineering development.
Innovation Begins with Evidence
Floating solar is opening new opportunities for renewable energy in ports, industrial basins, reservoirs, and coastal infrastructure.
As projects become larger and move into more challenging environments, experimental validation becomes increasingly important.
At HelioRec, we believe that the best engineering decisions are based on evidence. Every experiment improves our understanding of floating solar technology and helps us build safer, more reliable, and more bankable floating solar power plants.
FAQs
Why should a floating solar technology be tested in a wave tank? - Wave tank testing allows engineers to validate the structural behaviour of a floating solar system under controlled conditions before deploying it in the field. It helps identify critical loads, optimise the design, and reduce technical risks.
At what stage of development should testing be performed? - Wave tank testing is typically most valuable between TRL 4 and TRL 7, when a technology has progressed beyond laboratory concepts but still requires engineering validation before commercial deployment.
Should I test a scale model or a full-scale prototype? - Both approaches have advantages.
Scale models are less expensive and allow testing of larger arrays under a wider range of sea states. Full-scale prototypes eliminate scaling effects and provide the highest confidence in the structural performance of the actual product.
The best choice depends on your objectives, budget, and technology maturity.
What wave conditions should be included in a test campaign? - A comprehensive programme should include:
Regular waves
Irregular sea states
Different wave heights
Various wave periods
Waves approaching from multiple directions
Extreme design conditions representative of the future installation site
What should be measured during testing? - A typical wave tank campaign records:
Heave, surge and sway motions
Pitch, roll and yaw rotations
Mooring loads
Connector loads
Wave elevation
Relative motion between floating modules
These measurements provide the data needed to validate numerical models and improve the design.
Can wave tank testing replace numerical simulations? - No.
Experimental testing and numerical simulations complement each other. Laboratory results validate numerical models such as OrcaFlex, CFD or SPH simulations, which can then be used to analyse much larger floating solar farms and long-term operating conditions.
What is the most common mistake during wave testing? - Many developers simply try to prove that their platform floats.
A successful test campaign should answer engineering questions, such as:
Which wave conditions create the highest structural loads?
Where are the weakest components?
How can the design be improved?
Are the numerical models accurate?
The objective is to generate engineering knowledge—not just demonstrate buoyancy.
How large should the tested array be? - Testing a single floater is useful for understanding hydrodynamic behaviour, but testing multiple interconnected modules provides much more valuable information about structural interactions, connector performance, and wave propagation through the array.
How long does a typical wave tank campaign take? - The experimental testing usually lasts two to five days, but preparation often requires several months to design the prototype, define the test programme, install instrumentation, calibrate equipment, and analyse the results.
Is wave tank testing worth the investment? - Absolutely.
The cost of experimental validation is often much lower than the cost of redesigning a commercial product after unexpected problems appear during field deployment. Testing reduces technical uncertainty and increases confidence among investors, customers, and certification bodies.
How does wave tank testing support certification and fundraising? - ndependent experimental validation demonstrates that a technology has been assessed using recognised engineering methods. This technical evidence strengthens discussions with certification bodies, insurers, investors, grant agencies, and commercial customers by reducing perceived technical risk.
HelioRec designs, manufactures, and deploys floating solar systems for both inland and marine nearshore environments. To discuss whether floating solar is suited to your site, *contact us
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