German turbine manufacturer DIVE Turbinen GmbH & Co. KG and their French partner 2EI Industries have developed the first cooperative hydropower project for Central Asia.

The project “Darkhan” is located in the south of Kazakhstan at the Uzbek border. Two 2.1 MW DIVE-Turbines will generate electricity based on the well-approved DIVE-concept of double regulation by guide vanes and variable runner speed.

Even though the geography of Kazakhstan provides large amounts of fossil resources,  its energy policy is setting its focus on carbon-neutral energy sources. From 2010 on, the strategy is to raise the share of renewables to 50 percent of the total energy production by 2050. Currently most of the energy is produced in the North of the country, whereas energy-demand is higher down South, which is why new power plants are set up  mostly in the South. From all renewable energy sources, hydropower has the largest capacity with 14 percent of the overall energy production capacity, while other renewables have 1 percent. The advantage of hydropower is its long tradition and technological advance which makes it a reliable and highly-efficient source of energy. The Project Darkhan is located in the region Saryagash in Southern Kazakhstan at the river Keles, the landmark of the border to Uzbekistan. Once in operation, it will provide decentralized, CO2-neutral energy supply. Moreover, energy production requires to be connected to the grid-concerning system services, as for example regulation and compensation of over-production. The technology of DIVE-Turbines regulated by inverters provides these services and can be adapted to any local grid requirement, with static and dynamic parameters. Hydropower is also black start capable which is a general requirement for a secure energy supply grid.

History of Project Darkhan
Civil works at hydropower plant Darkhan had started already in 2016, which was before a turbine type had been selected. In 2017 DIVE Turbinen GmbH & Co. KG was con­tracted to deliver two turbines of 2.1 MW each. In these days, there had not been any DIVE-Turbine of this capacity, which meant that the manufacturing facilities for the ­DIVE-Turbine, the generator design and the electronic equipment for DIVE-Turbines had to be upgraded. In very close cooperation be­tween 2EI Industries, responsible for electronic equipment, Oswald Elektromotoren GmbH, manufacturer of the DIVE-Turbines’ generator and DIVE Turbinen GmbH & Co. KG a new generation of DIVE-Turbines had been pushed forward. The challenge was to develop and manufacture a new size of generators for the MW-class, corresponding inverter technology and controls. Moreover, it is a multi-language and multi-culture project with partners from Germany, France and Kazakhstan. In terms of funding, the project is part of the worldwide dena Renewable Energy Solutions Programme coordinated by the Deutsche Energie-Agentur (dena) – the German Energy Agency – and supported by the German Federal Ministry for Economic Affairs and Energy (BMWi) within the German Energy Solutions Initiative.

Turbine Technology
The DIVE-Turbines for Kazakhstan have a runner diameter of 1,800 mm, 6 fixed runner blades and a total weight of more than 23 tons per unit of turbine and generator. The whole electronic equipment except the grid transformer is inside a transport container. The container remains on site and is used as a power house. All the equipment has been installed and pretested in factory. The two DIVE-Turbines were shipped and installed in September 2019, when civil works were still under construction. The power plant was set into operation after the cabling and connecting of the power plant to the public grid.
The DIVE-Turbine is a double regulated turbine with a mechanical adjustment of the guide vanes and speed variable runner. The runner blades are fixed to the runner hub. The generator is located directly on top of the turbine runner and is completely submerged. The submerged system is based on a patented and maintenance-free sealing system. Therefore, the system is flood save. The adaptation of the generated electricity to the grid requirements is done by inverters. Thus, the fixed runner blades and selected materials allow for high loads of sediments and particles, which could be a limiting factor at the given conditions of the rivers in the area of Southern Kazakhstan. Moreover, the inverter technology allows for adaption to static or real-time requirements of the public grid.
The DIVE-Turbine has only one interface with the civil works which is the premanufactured draft tube flange. Thanks to this, the requirements for the tolerances of the local civil works are one magnitude lower than with classical machines, instead of mm or cm the tolerance is about 0.1 m. This attribute meets the local construction work capabilities and simplifies the total project. Moreover, it reduces interface risks significantly.

Project Support
This project is part of the worldwide dena Renewable Energy Solutions Programme coordinated by the Deutsche Energie-Agentur (dena) – the German Energy Agency –and supported by the German Federal Ministry for Economic Affairs and Energy (BMWi) within the German Energy Solutions Initiative.