Master plan and teamwork: success factors for the E-175 EP5 market launch

The installation of a wind turbine prototype always puts a certain level of pressure on the teams involved. All eyes are on the site where the new wind turbine type will be installed – after months of development and preparation, the new product is finally becoming a reality. This is exactly how the ENERCON team at the Borchen-Etteln wind farm is feeling, where the first E-175 EP5 is currently under construction.  ‘Of course we are aware of the excitement and the many eyes that are watching our construction site’, says ENERCON project manager Vahdettin Congar. ‘But we are thoroughly prepared. We have experience with prototype installation, and we proceed carefully to ensure that the first E-175 EP5 will be up and running as planned. So we are pretty good at handling the pressure.’

ENERCON CTO Jörg Scholle is equally untroubled: ‘No doubt, the E-175 EP5 is the ENERCON wind turbine with the largest rotor to date. It is our new top model, taking us to the next performance level. But on the other hand, wind turbines with large rotors haven’t suddenly appeared out of nowhere. Our team has been planning this market launch well in advance in painstaking detail. The E-175 EP5 is the result of our technology and product roadmap. This machine combines a number of features we’ve introduced gradually in other system types. This means that this new wind turbine type relies on existing technologies that we have already been using in the field. This mitigates risks, simplifies the market launch and helps us ensure the tried-and-trusted ENERCON standards for product and process quality.’

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Field-tested technology components

One example is the E-nacelle, says the ENERCON CTO. The new box-shaped machine house with built-in power components was introduced with the E-160 EP5 and E-138 EP3 model series, and more than 400 units have been built. The E-175 EP5 contains the latest evolutionary stage with a monocoque design, which is by now a standard feature of the E-160 EP5 series and which will also be used for E-138 EP3 wind turbines in the future. This means that all three new ENERCON system types will use the same machine house, manufactured in series at ENERCON’s Mechatronic centre of excellence in Aurich on a mixed-model assembly line  

Likewise, the E-175 EP5 power components follow the tried-and-tested ENERCON standard. The power boost converters – developed in-house at ENERCON based on decades of expertise in converter development and manufacture – are also installed in the current E-160 EP5 model. The WEC control system is borrowed from the EP3 platform: the new generation of pitch system and yaw system as well as the new PI-CS controller for flexible wind turbine operating modes were introduced in the series for the first time with the E-138 EP3 model.

The E-175 EP5 rotor blade has also been developed in-house, building on decades of experience in rotor blade development and production at ENERCON. The generator used at market launch is based on the E5 platform PM generator, with its power bumped up to 6.0 MW for the E-175 EP5. It will be replaced at a later point in time in the E2 with a newly developed divided PM generator with 7.0 MW, which is currently at the prototype stage. The tower technology for the E-175 EP5 is also based on tried-and-tested components of ENERCON’s EP5 platform. The tower portfolio includes a variety of hybrid towers and steel towers with hub heights up to 175 metres.

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Numerous test runs for preparation

‘What is also crucial for the smooth launch of a new product is excellent preparation’, adds Jörg Scholle. ‘In the E-175 EP5 prototype programme, the entire ENERCON team worked closely together. They coordinated all necessary steps systematically along the entire process chain and conducted extensive field tests before starting the installation of the wind energy converter in Borchen-Etteln.’ The testing included both mandatory test campaigns required for certification and internal test runs whose goal was to put equipment and processes to the test and to familiarise the logistics and installation teams with the new features.

For example, while test components of the new E-175 EP5 rotor blade were undergoing rigorous testing at ENERCON’s own rotor blade test station and in test facilities operated by independent inspection bodies, the ENERCON logistics team conducted its own field tests with a pre-series component. These comprehensive tests covered the transport and handling of the rotor blade using the equipment intended for road transport and installation work at the construction site. The Portuguese rotor blade factory provided a pre-series rotor blade for this purpose, which was shipped to Cuxhaven together with a consignment of rotor blades destined for Germany.

In cooperation with experts from project management and ENERCON R&D, the construction site delivery and installation processes were first simulated in Cuxhaven using the designated handling and installation equipment. This included picking up the rotor blade using the blade installation lifting device and imitating the installation on a wind turbine. In addition, the test blade was mounted on the so-called ‘blade lifter’, a multi-axle remote-controlled transport vehicle with a movable transport frame that allows raising the rotor blade until it is nearly vertical in order to clear narrow sections on the transport route. This technology is used for long rotor blades and difficult-to-reach installation sites.

The vehicle is able to change the tilt and rotational angle of the rotor blade in order to manoeuvre through narrow sections of the road. Because the pitch angle is crucial for the bending behaviour of the blade during transport, the relevant elastic curves were recorded via a 3D scan. These data will be used as input for route inspections and road usability assessments when planning customer projects with E-175 EP5 machines.

The goal of these test runs on the road was to expose the rotor blade to various driving manoeuvres during road transport using a trailing dolly. For the purpose of the analysis, the rotor blade was fitted with measuring instruments. The first tests were performed on the harbour premises; next, the rotor blade went on a round trip to Leipzig and back using public roads.

‘This has allowed us to gain valuable insights for the practical application, and we were able to fine-tune our approach’, says Hendrik Peterburs, Vice President of Global Logistics. ‘The purpose of these tests is to become familiar with this new 86-metre rotor blade, which is significantly longer than the longest components we’ve transported so far. For the E-175 EP5 as for all our products, our goal is to ensure our high standards of quality – ENERCON Quality.’

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New production processes

The ramp-up of the E-175 EP5 series production is also the dominant subject at ENERCON’s production organisation. While blade manufacturing has already begun at the factory in Viana do Castelo in Portugal, the modifications required for the manufacturing of nacelles and hubs are in full swing at the Mechatronic centre of excellence in Aurich. ‘We are getting ready to build E-nacelles and hubs for the E-175 EP5, E-160 EP5 and E-138 EP3 models. Our new assembly line design will allow us to achieve faster throughput times as well as higher output numbers’, says Matthias Drong, Managing Director at Mechatronic. ‘For the final stage of expansion, we are aiming to output a total of up to 1000 components per year for these three system types.’

The new set-up includes a division of the production lines into main lines and pre-assembly lines. The pre-assembly lines will produce separate component modules and feed them into the main lines. This makes it possible to untangle the complexities of the production lines and ensure precise and efficient timing in production. For example, the transfer of the components within the production lines is accomplished via an automated conveyor for the hub, and self-driving transport vehicles for the E-nacelle. This provides a significant gain in terms of safety, and it reduces the non-productive time caused by crane-based transfer. Intralogistics processes present another significant challenge. At the final stage of development, the goal is for one finished component to come off the production line every 3.75 hours. This will require the precisely timed supply of materials to each production cell.

Another building block of the new concept is currently being put into operation in the hub manufacturing bay. ‘Here, we use automation to reduce throughput times even further’, explains Matthias Drong. The 381 bolts of the blade flange bearings are now tightened by an industrial robot: fully automated and with consistent quality. ‘All of these measures create the right conditions for increasing our output to reach the projected targets’, says Matthias Drong.

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ENERCON CCO satisfied with market launch

The master plan devised well in advance as well as the smoothly coordinated teamwork are proving to be the crucial success factors for the progress of the E-175 EP5 ramp-up. ‘We are very happy with how the market launch of our new system type is coming along’, says ENERCON CCO Uli Schulze Südhoff at this halfway point. And the customers’ reaction to ENERCON’s new top model also makes him very happy: ‘We’ve already sold our volume for 2025. And for the 24 months after that, we are in concrete negotiations with customers for numerous projects – and on top of that, we’ve received more enquiries, including from an increasing number of international customers. We listen to our customers. Our mission is to provide a competitive product in ENERCON Quality that is the ideal match for the requirements in many international onshore wind markets. This type of product, accompanied by outstanding service, an equal partnership philosophy and comprehensive customer solutions from planning to project financing – this is what makes the difference!’