ENERCON has a degree of vertical integration unparalleled in the wind energy industry. All main components of ENERCON wind energy converters - such as annular generators, inverters, rotor blades, cast components, towers and machine houses - are produced at ENERCON’s own factories. With this high level of in-house production ENERCON ensures optimum quality control, stays independent of suppliers and in addition reduces the risk of know-how losses. What is also important is the feedback of experiences from manufacture to product development.more
In consideration with this entrepreneurial decision, ENERCON has systematically consolidated and extended its own production section at home and abroad since the early 1990s. ENERCON introduced automated processes and the line production principle based on the model of the automotive and supplier industry at an early stage. Industrialisation of manufacture is part of ENERCON’s production policy. This is a fact that finds expression, among other things, in top modern and efficient production facilities and in the use of industrial robots. The high quality and labour safety standards that are partially clearly stricter than the Health & Safety inspectorate’s and liability insurance associations’ requirements are also outstanding.
The annular generator is a key component of ENERCON’s gearless wind energy converter design. The ENERCON annular generator is a multi-polar synchronous generator that is manufactured by the generator plants that produce exclusively for ENERCON at the German production sites Aurich and Magdeburg and in Viana do Castelo/Portugal.
The copper winding in the stator - the stationary part of the annular generator - consists of individual, enamelled round wires gathered together in bundles. The copper winding is exclusively done manually. In spite of increasing automation in other manufacturing areas, manual labour has proven successful in this area. It ensures that all materials are fully inspected. Furthermore, a special work process allows continuous windings to be produced. Each individual wire strand is continuous from start to end.
Since ENERCON annular generators have been designed for particularly high stress and a long service life, they are impregnated with resin and powder-coated in subsequent manufacturing steps to protect them against corrosion. Completion of the annular generators for delivery is made at the final assembly factories that work exclusively for ENERCON.
The machine and plant manufacturing companies that work exclusively for ENERCON are in charge of the final assembly of annular generators, rotor hubs and machine houses. Besides the German sites Aurich and Magdeburg, ENERCON has another final assembly line in Viana do Castelo/Portugal that works mainly for export.
In the final assembly the large components are completed in efficient line production, they are subjected to a functional test and finally made ready for shipment. The individual work steps are performed at several stations in the assembly line.
ENERCON is the only wind energy converter manufacturer in the world to operate its own foundry. Gusszentrum Ostfriesland GmbH (GZO) at Georgsheil (Lower Saxony) produces mainly rotor hubs, main carriers, axle pins and stator shields for the megawatt-class ENERCON WECs. ENERCON only accepts highest quality standards for these load-carrying spheroidal graphite cast components. A pioneering quality assurance system in which all production steps are monitored and documented is the quality guarantee at GZO.
GZO is one of the most modern foundries in Europe. The production is performed according to the series and line production principle. Mould making, casting and subsequent cast processing are located in separate areas. Labour safety and environment protection measures are also groundbreaking and clearly above the standard in the branch. Efficient filter plants clean the waste air, self-propelled transporters move the moulds in the danger areas. The cast blanks are subsequently taken to further processing to Aurich and Magdeburg by ENERCON’s own rail company e.g.o.o. mbH.
Stanztechnologie Aurich GmbH (STA) is a supplier that works exclusively for ENERCON for the ENERCON generator production. The segment and pole sheets needed for the production of ENERCON’s annular generators are punched out of special electric strips.
Besides the highly automated production processes, the recycling concept at STA is exemplary for ENERCON’s demands for a modern production: Chads are collected automatically in containers and transported to the foundry GZO. The chads are recycled there in the casting of WEC components
ENERCON’s rotor blade concept sets new standards with regard to yield, noise emission and stress minimisation. The same applies to the production of these main components that has been carried out by factories producing exclusively for ENERCON since the 1990s.
Most of ENERCON rotor blades are manufactured using a vacuum infusion system with the so-called sandwich technique. Glass fibre mats placed in the mould are vacuum-impregnated with resin by means of a pump and hose system. In order to efficiently protect the rotor blade surface against weather elements such as wind and water, UV radiation, as well as erosion and bending loads, the rotor blades’ protective finish is composed of gel coat, filler, edge protection and top coat.
For the first time, ENERCON implemented an optimised line production in rotor blade manufacture in connection with production logistics with improved efficiency at the new main rotor blade factory Kunststofftechnologie Aurich GmbH (KTA). Following the model of automotive industry, the moulds are moved from one work station to the next at KTA. Exactly defined work steps are carried out at every work station. The production of small parts has been relocated to the upper floor of the factory from where they are directly lowered into the moulds in the blade manufacturing process. Laying of glass matting during the production of the spar booms and gluing of the half shells proceeds automatically.
After the blade blank has been removed from the mould, it is traversed to another hall part where the mechanical treatment of the blade surface and of the blade connection takes place. Industrial robots are mainly used for this hard work. After the so-called finish where the rotor blades are given their protective coating and where they are subsequently balanced, also by robots, they are delivered to the installation site or to the export port in Emden.
ENERCON WECs are available with steel tube tower or precast concrete tower depending on site and hub height. Both tower types are manufactured at factories that work exclusively for ENERCON. ENERCON steel tube towers are manufactured in several tower sections that are connected with stress-reducing L-flanges. The production facilities for these components are located in Magdeburg and Malmö/Sweden.
The precast concrete tower that is mainly used today is a hybrid tower consisting of prefabricated concrete segments (for the ca. two lower thirds of the tower) and steel sections (for the top third). The prefabricated concrete elements have diameters to 14.5 m. Segments with large diameters are produced in two or three half shells so that they can also be transported to locations otherwise difficult to manoeuvre. After installation at the construction site, the full circle segments are tensioned with prestressing strands that run along the tower wall.
The precast segments are manufactured and quality-controlled at the precasting plant. In addition to the German concrete tower factories in Emden and Magdeburg, ENERCON has seven more factories around the globe. Specially constructed steel moulds assure manufacturing precision for each individual concrete segment. To guarantee optimum quality, the properties of the high-strength concrete are tested by specialised material testing authorities. The concrete tower factories also produce according to the line production principle: In the reinforcement area the steel frames of the segments are manufactured that are subsequently cast in special concrete at the concrete pouring station. At the finish station the segments are given their coating with the typical green shading colour of ENERCON at the lowest segments.
The inverter system of the ENERCON WECs defines the essential performance characteristics for feeding into the power grid and ensures that the power output corresponds to grid specifications. Here voltage, frequency and power are converted accordingly.
The inverters are ENERCON core technology that is contained in all ENERCON wind energy converters. To date, ENERCON has manufactured about 142,000 of these 300 kW power cabinets. The production is carried out at Elektric Schaltanlagenfertigung GmbH in Aurich in series and line production. After a thorough function test, the standard components are installed in different configurations in the so-called e-modules of the respective WEC series. The pre-assembled e-modules are transported by truck to the installation site where they are installed in the two bottom tower segments during the tower construction phase.