How HACE turns waves into electricity
From the physical principle to the sea-deployed module — everything you need to know about the technology.
A piston engine powered by waves
Based on the Multiple Oscillating Water Column (OWC) principle, HACE converts swell into a continuous air flow that drives a turbine generating electricity.
Capture
Swell enters from underneath the module, into open chambers. From just 5 cm of wave height.
Compression
Unidirectional check valves convert the oscillating motion into a continuous air flow in a single direction.
Dry turbine
The air flow drives a turbine above water, protected from saltwater. Maintenance without divers.
Electricity
Electricity is fed into the grid via subsea cable, or used on-site to produce hydrogen.
Why it works — the numbers
9:1 ratio — the key to capacity factor
The turbine is sized for 1 MW while the system can theoretically produce 9 MW. Result: the turbine constantly runs at saturation, regardless of sea conditions. This ratio is what generates a capacity factor of 50 to 90%.
Full swell spectrum
HACE operates across the entire swell spectrum — from 5 cm to over 30 m. Each module is custom-designed for the specific conditions of its site, maximizing energy captured year-round.
Carbon footprint — < 3g CO₂eq/kWh
Over the full life cycle. Comparison: solar ~40g, offshore wind ~11g, nuclear ~6g. HACE achieves this thanks to 95% recyclable steel construction, no concrete, no foundation.
Lifespan > 50 years
Validated through calculations and numerical simulations. No submerged moving parts. Resistant to cyclones, rogue waves and tsunamis. The turbine, the only mechanical part, is accessible above water — components under 25 kg.
Pourquoi les houlomoteurs échouent.
Et pourquoi HACE réussit.
Three fundamental breakthroughs that change the economic equation of wave energy.
The problem
Current wave energy converters adapt poorly to varying swell conditions. Sized for a narrow range, they under-produce in calm seas and shut down in heavy seas. Result: a low capacity factor, and an energy cost that never comes down.
The HACE answer
Each system is custom-designed for its site to maximize capacity factor. This is the key to economic success. The low cost of electricity is the direct consequence of this approach.
The problem
Intermittency is the Achilles' heel of all renewable energies: solar, wind, and current wave energy converters stop or enter protection mode as soon as conditions fall outside their operating range. Every hour of downtime lowers the capacity factor and makes the business model untenable.
The HACE answer
HACE produces in the worst conditions: cyclones, rogue waves, tsunamis. The rougher the sea, the higher the output. The system is unsinkable and designed to last over 50 years.
The problem
The complexity of some wave energy converters prevents mass deployment. They require heavy and costly resources — large-capacity cranes, specialized vessels, custom components.
The HACE answer
HACE can be built in any shipyard, with no heavy equipment. Oscillating water columns in standard steel, industrial mass-production approach. Over 95% recyclable.
Modular architecture — from MW to GW
A single 1 MW rated module. Scalable in line or staggered array up to gigawatt capacity.
2,000 m² capture surface. Less than 5 m above water. Installation with no concrete foundation.
Modules aligned perpendicular to the dominant swell. Ideal for Atlantic coastlines and ports.
Chevron configuration maximizing capture. Dual breakwater effect. Integrated coastal protection.
Three generations — complete results
Ten years of progressive testing, from lake to Atlantic. Each prototype validates an additional milestone.
Prototype 1 — Lake
Validation of the OWC principle in calm water. Confirmation of continuous air flow through unidirectional check valves. First functional demonstrator of the multiple oscillating conversion concept.
Prototype 2 — Open sea
First open-sea trial. Validation of seaworthiness in real swell and of electricity production in marine conditions. Confirmation of structural robustness under variable conditions.
Prototype 3 — Atlantic
1/10th scale module deployed in the Atlantic. Turbine running at full power in calm seas (5 cm visible swell). Resistance validated in heavy seas. 9:1 ratio confirmed in real conditions.
Technical questions
The OWC (Oscillating Water Column) is a semi-submerged chamber open to the sea from below. Swell causes the water inside to rise and fall, compressing and decompressing the air above. Unidirectional check valves convert this alternating motion into a continuous air flow in a single direction, which drives a conventional turbine.
Capacity factor is the ratio between energy actually produced and maximum theoretical energy. HACE achieves 50–90% thanks to the 9:1 ratio: the turbine is sized at 1 MW while the system can theoretically produce 9. The turbine therefore constantly runs at saturation, even in light swell. Offshore wind peaks at 25–35%.
HACE uses flexible moorings (chains or cables) that allow controlled movement with the swell. No concrete foundation, no seabed drilling. The moorings are bio-enhancing — they promote marine colonization without pollution.
Standard steel (available in any shipyard worldwide), 95% recyclable at end of life. Zero concrete. Zero polluting hydraulic fluid. Zero rare earths. The turbine is the only significant mechanical part — accessible above water, components under 25 kg, serviceable by a standard service boat crew.
Via a standard subsea cable. The electricity produced by the turbine is conditioned on board the module (AC/DC converter), then transmitted to the onshore connection point. Production can also directly power an at-sea electrolyzer to produce hydrogen.