Report

Teaser, summary, work performed and final results

Periodic Reporting for period 2 - Liftra Crane (Liftra Self-Hoisting Crane (LSHC) - a disruptive crane solution for cost effective exchange and service of major wind turbine components)

Teaser

Modern wind turbines (WTs) are designed to work for 120 000 hours throughout their estimated life-span of 20 years. However, throughout its lifetime, several of its components will have to be replaced due to damage caused by operational wear and tear. In particular, failure in...

Summary

Modern wind turbines (WTs) are designed to work for 120 000 hours throughout their estimated life-span of 20 years. However, throughout its lifetime, several of its components will have to be replaced due to damage caused by operational wear and tear. In particular, failure in critical major components of the WT such as the gearboxes and generators, can cause long downtimes and costly reparations. The economic burden on the wind farm owners stems not only from the parts’ to be replaced and from the energy production halt, but it is also strongly associated with the required setup to enable the components exchange itself. Indeed, the large cranes required to hoist the components to the WTs nacelle are a critical element, since their availability is often reduced on a short notice and their mobilization/setup costs are very high, causing a significant overhead for maintenance operations in wind farms.

Liftra (www.liftra.com) is a leading provider of lifting and transport technology for the wind turbine industry. Liftra has developed and patented a special crane technology Liftra Self Hoisting Crane (hereafter LSHC or Liftra crane), that can be used to exchange major components of a wind turbine - like gearbox or generator. The technology takes advantage of the existing wind turbine structure to avoid the need for assembling a large conventional mobile crane.

The Liftra crane is built into the format of a standard 40-foot container and can be easily mobilised to a wind turbine site, even in the most difficult locations, and operate without extensive and costly site preparation. In comparison, a conventional mobile crane comes on multiple trucks (up to 20 truckloads) and has a very high mobilisation cost.

The crane consists of a universal crane system that is combined with a simple set of adaptor components that are specific to a wind turbine model. The technology makes it possible to change major components on wind turbines, such as gearboxes and generators, on turbines up to 150 m hub height and weight of components of up to 24 tons, with significant cost savings.

By reducing the cost associated with regular maintenance operations of wind turbines, and thereby overall costs of energy throughout the entire lifecycle of wind turbines, Liftra’s technology will significantly contribute to a sustainable energy system and the supply of low-carbon electricity based on economically competitive wind power.


The goals for the project are:
- Adapt and ensure compliance of the technology with the standards, regulations and local practice in major markets
- Develop interface adaptors for additional wind turbine models to support a broad market uptake
- Demonstrate the technology in key markets
- Develop operator training that utilises virtual technologies to minimise the need for access to a full scale crane
- Elaborate viable business models and plans for the LSHC technology

Work performed

Through the first 28 months of the project, the project has followed the planned activities regarding:
- Market intelligence and business plans for the US, EU, CA, MX, CN and IN markets. Plans have been documented and will form the basis for continued work in these markets. Plans will naturally continue to be adapted to developments seen in these markets.
- Mapping and study of standards and regulations relevant to comply with market requirements in US, EU, CA, MX, IN and CN is completed. 3rd party verification will follow.
- Development of additional 5 adapters for different wind turbine platforms has been completed. Besides the functional engineering, this includes also the implementation of the identified compliance requirements. 3rd party design verifications are pending.
- Updating crane design in response to both test and demonstration feedback as well as identified compliance requirements.
- Prototypes of adapters for Suzlon S88 and Mitsubishi 1000a turbines have been manufactured and tested.
- The LSHC technology has been demonstrated to customers and other stakeholders (including the Danish Minister of Energy, Utilities and Climate), in EU, US, MX, CA, IN and CN, and groups of technicians from these areas have been trained in the use of the technology.
- A virtual training environment has been developed and is now in production.

Final results

All components of the Liftra crane have been developed 100% through Liftra’s own R&D efforts. At project start, Liftra had invested more than 50,000 engineering hours in the development of the LSHC technology and auxiliaries, corresponding to a private investment of over €2 million in the development of the LSHC technology. The LSHC technology is still the only real multi-brand technology to address major components exchanges on wind turbines, without use of conventional cranes. The project contributes to widening the applicability of the technology, reinforces market understanding and compliance, and thereby consolidates its position to achieve an accelerated market uptake.

Standing on the shoulders of the project, Liftra has now also
- prototyped a solution for exchange of blades and blade bearing - again without use of conventional cranes.
- completed development of an even larger LSHC type that will be able to handle major components up to 75ton and increase the capability of the technology to also exchange blades and full rotors.

Website & more info

More info: http://www.liftra.com.