A twelve-month Innovate UK Energy Catalyst study completed in September 2017 confirms the practicality of the innovative SENSE turbine installation and maintenance system. The SENSE installation process has been modelled using data typical of a standard construction vessel when operating in various sea states.
- SENSE equipment is modular and designed to mount on a standard construction vessel.
- a simple mechanical interface allows SENSE to be used with any turbine design.
- automated lifting controls means no human interaction during heavy load transfer operations.
- SENSE allows rapid turbine installation and major maintenance on tall onshore towers and deep-water offshore sites, including floating foundation technology.
- SENSE equipment is cheap enough to be retained by a project for use throughout the operational life.
LIMITATIONS OF CURRENT INSTALLATION METHODS
The jack up approach has a limited water depth capability and current deep water sites – e.g. Hywind Scotland (100m depth) – are beyond any jack up technology.
Special vessels will always be expensive and in limited supply.
What size do you make the ‘special vessel’? After you have invested, will it keep up with the rapid growth in turbine size?
Complicated piece by piece installation takes a long time and is vulnerable to changes in weather conditions.
More operations = higher risk of accidents.
Onshore turbines are getting taller – already over 160m for a production turbine.
SENSE CHANGES EVERYTHING
- eliminate the need for expensive purpose-built vessels or cranes
- exploit narrow weather windows and install multiple units in parallel
- the water depth at the project site is irrelevant – works equally well with fixed or floating foundations
- scalable without limit – will keep up with the rapid development of larger turbines.
- reduce exposure to technology risk – turbines with limited track record can be considered because serial faults (if they occur) can be repaired faster and with less downtime.
A NEW SYSTEM FOR INSTALLING WIND TURBINES & REDUCING THE COST OF WIND ENERGY
For offshore turbines the rotor nacelle assembly, fitted with a special carriage, is transported to site using a standard construction vessel. When close to the tower, the rotor nacelle assembly is transferred to the base of the tower in one rapid operation where the special carriage attaches to the tower under automatic control, allowing the transport vessel to quickly move away.
For on-shore turbines the nacelle, hub and blades are transported to site as normal. A standard (far smaller) crane assembles the special carriage, the nacelle and the rotor to the base of the tower using a standard (far smaller) crane.
For both on and off-shore turbines, once the rotor nacelle assembly is attached on the tower the special carriage, equipped with power supply and automatic controls, lifts it to the top of the tower and rotates it into position and hold it until bolted down quickly and safely. Once installed, the special carriage is retrieved and can be used for the next turbine.
How are the towers installed?
For an onshore turbine there are many self-erecting tower systems in the market.
For offshore, towers will be installed at the same time and with the same equipment as the fixed foundation structure or become part of the floating foundation.
RESULTS FROM THE INNOVATE UK STUDY
The North Sea Giant is a typical construction vessel which could be used to deploy SENSE
Modelling response, showing that SENSE can transfer a 700 t Rotor Nacelle Assembly from the vessel to the tower base in sea states typical of the North Sea
Turbine installation using conventional methods for a 1200 MW North Sea project
Turbine installation for the same 1200MW north sea project under identical weather conditions using SENSE