Offshore Wind
Delivered Faster, Cheaper & Greener
The Gravity Tripod™, a unique and globally patented offshore subsea foundation structure designed to reduce the cost of electricity
Financial
The Gravity Tripod™ delivers an 11.7% LCoE
Environmental
The Gravity Tripod™ is available to start reducing the world's carbon emissions today
The Gravity Tripod
“A new asset class in offshore wind”
“Innovative… There are many good aspects of the design that assist in methods of assembly and supply chain options”
The Gravity Tripod
The Gravity Tripod™, globally patented, is an offshore subsea foundation structure designed to deliver up to 11.7% project cost reduction, to reduce project delivery times by up to 1/3 and create almost zero environmental impact.
The Gravity Tripod™ is a component base structure that benefits from the best aspects of other foundation concepts. It is a hydro-dynamic transparent structure which doesn’t require piling, is manufactured from low-cost tubular sections in a rapid assembly process and is installed with minimal seabed intervention.
The Gravity Tripod™ has two distinctive components that act together to ensure the structure has an extremely long design life (up to 100+ years) and is insensitive to turbine loads with a capacity of up to 25MWs. In addition, the structure has a low bearing pressure on the seabed and so is capable of accommodation a huge range of sediment types, with less seabed preparation required than other gravity-based designs.
75
Designed for 20m to 75m water depths
11.7%
11.7% reduction in LCoE
100
Designed to last 100+ years
Key Benefits
11.7% reduction in LCoE
Lower capex & opex, and greatly reduced installation time
Reduced embedded carbon
1,200 tonnes of CO2 saved per structure compared with a Jacket
Noiseless construction
Zero piling creates near noiseless installation
Reduced project construction risk
No requirement for piling
Usable in up to 70m water depth
Scalable to greater depths
Our Partners
Environmental Impact
subsea piling noise has a massive negative impact on marine mammals, fish and invertebrates
“Offshore wind is a huge tool to help the world de-carbonise, however it shouldn’t do further damage to achieve this aim”
Environmental Impact
The Gravity Tripod™ has been designed with minimising environmental impact and generating a biodiversity net gain at its heart. From initial design, materials used, installation, design life and decommissioning the Gravity Tripod™ has the ability to have a net-zero impact.
Prior to installation the Gravity Tripod™ requires no harmful seabed dredging, ensuring no existing habit destruction. The lack of requirement for piling ensures that marine life in all its forms has no negative impact due the tripod installation, mammals and fish are routinely deafened by piling leading to an inability to feed and thrive.
No piling, no dredging, no habitat destruction is reinforced by the use of lower embedded carbon concrete over traditional steel, environmental concrete also fosters marine habitat creation in and around the tripod. With a 100 year design life and a constant re-powering ability, the Gravity Tripod™ greatly increases lifespan and delivers significant environmental gain.
Three key facts to draw out below
Zero Piling
No seabed destruction
Zero Dredging
Existing seabed habitat remains
Reduced embedded carbon
Concrete structure greatly reduced steel usage
Business Case
11.7% LCOE reduction
“The novel substructure is made from concrete and has several advantages over conventional foundations”
Business Case
In 2020 OWLC engaged globally recognised renewable energy consultants BVG Associates to deliver an independent cost analysis of the Gravity Tripod™.
In order to create their report BVG assessed the costs and LCOE for the project using the Gravity Tripod and compared this to a project using a conventional foundation, in both cases it was assumed to be a 504MW farm. The cost and energy elements that were used to estimate the LCOE were development, turbine, foundation, array electrical, installation, transmission, OMS, energy production, construction timing and decommissioning.
The Gravity Tripod key areas of cost advantage were found to be
- Development Cost
- Installation Cost
- 100 Year Design Life
Development cost
The Gravity Tripod shows a significant cost reduction over conventional foundations due to the lack of requirement for environmental, geophysical and geotechnical surveys related to piling as there is none.
Installation cost
The Gravity Tripod™ was found to be 51% cheaper than a jacket substructure and 36% cheaper than a monopile to install – due to its embedded design that allows installation of a complete turbine in one day.
100 year design life
Unlike most substructures that have a 25 year design life, the Gravity Tripod™ has a 100 year design, making re-powering practical and easy to achieve. The Gravity Tripod™ is also designed for turbines up to and beyond 25 MW.
