Renewable power sources

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Wind turbine development

The producer of electric motors, Konesko, began developing wind turbines which needed control systems.

We developed the azimuth turbine control to take into account wind direction, grid inverter, turbine load control, and dump load systems for three turbine models of 5kW, 10kW, and 20kW. The control system had a graphical user interface, with control and monitoring being handled via an Ethernet. We have implemented the first technical documentation requirements and assisted in turbine testing and certification of the grid inverter system.

Development and production were later transferred to a separate, daughter company. Wind turbine development has been supported by Estonian Enterprise.

Erecting the first wind turbine

A smart grid for the Estonian University of Life Sciences

Study and research in the field of renewable energy sources, energy storage systems, and the control mechanisms required real-world study objects within the proximity of the Estonian University of Life Sciences. (EMU)

ET-EX Machina won the public tender to design and install the smart grid system for the EMU. The PV solar panels can be manually realigned. The wind turbine has a horizontal axle. Energy storage is carried out by means of electrochemical batteries and ultra capacitors.

 

Wind turbine installation on the roof of the EMU

Smart grid solar PV modules on the roof of the EMU

The control centre for the smart grid

A web page for the Smart grid system at the EMU (http://energia.emu.ee/?q=wholeSystem)

The local grid is of the AC voltage type, with a synthetic generator to the simulate renewable energy production during any weather condition in any place on Earth based on wind and solar power being measured there. The main complexity point for the project has related to wind turbine safety on the roof of a public university building. The control system for the smart grid has a PLC, a touch screen module, a server, an external hard disk, a router, a teacher’s PC, and a big screen TV to show the actual power values. The system’s website shows the same values, but in addition permits access to energy production statistics. The project has been supported by Estonian Enterprise and EU funds.

A smart grid for Tallinn University of Technology

Study and research in the field of renewable energy sources, energy storage systems, and the necessary control systems required real-world objects within the proximity of Tallinn TU.

ET-EX Machina won the public tender to design and install the smart grid system for Tallinn TU.

The 5kW vertical axle wind turbine, a Tuge V, is placed behind the power engineering building. The Savonius rotor is seen as necessary to start up the turbine at low wind speeds. The main problems encountered in the realisation of the project have been connected to the installation process and safety standards in a public area, but also to wind turbulence thanks to surrounding buildings and trees.

The set of solar PV panels with our original tracker which had been designed for use in the Nordic countries was installed on the roof of the power engineering building. The azimuth angle can be changed by 270 degrees by the help of a motor and specially reinforced worm gears. The tilt angle can be changed anywhere within a window of zero to ninety degrees by the help of a linear actuator. Tracking is controlled by a microcontroller, based on information of apparent solar movement in the given location, and on the date and time. When the weather is cloudy the tracker turns the panels to the horizontal position to be able to collect the maximum solar output. The panels are automatically turned to the horizontal also in strong winds which could endanger the PV panels or the tracker framework.

The electrolyser produces hydrogen, which is stored in the tanks outside the building. The stored hydrogen can be converted back into electricity and water by the help of a fuel cell. Hydrogen storage is mainly foreseen for the storage of excess energy that may be produced by the solar panels and wind turbine. The main issue has been in achieving proper levels of safety for a public building.

The smart grid has additional energy storage facilities with electrochemical batteries and an ultra capacitor bank. The local energy island has a 365V DC bus, which connects together all of the converters in the system.

The control system for the smart grid has a PLC, a touch screen module, server, external hard disk, router, a teacher’s PC, and a big screen TV to show the actual power values. The system’s web page shows the same values, but also permits access to energy production statistics. The project has been supported by Estonian Enterprise and EU funds.

Vertical axle wind turbine

Solar PV modules on the roof with original tracker for Nordic countries

Fuel cell and electrolyser set