Laboratory of the renewable energy sources

Faculty of Electrical Engineering and Information Technologies

Department/Institute: Institute of Power and Applied Electrical Engineering
Contact person: Ing. Marek Pípa, PhD., doc. Mgr. Miroslava Farkas Smitková, PhD.
Contact: +421 2 6029 1783
e-mail: marek.pipa@stuba.sk, miroslava.smitkova@stuba.sk

Description:

Laboratory of the renewable energy sources is orientated to the renewables´ utilization and accumulation. Its equipments are used for research and development projects as well as the education process. Except of laboratory usage for the students of FEI STU, the laboratory is open for primary and secondary schools in the field of excursions or measurements participation.

Main laboratory equipment’s are follows:

Pumping hydro power plant: In the neighbouring of the university is not suitable water stream, where the construction of small hydro power plant could be conducted, thus the technological demonstrator was built on the terraces of the faculty and can be used for accumulation of energy. Power plant uses two cisterns on 2nd and 6th floor of the building with the gradient circa 13 metres and volume of cisterns 20 m³. Water supply to the turbine is controlled by electric servo valve. Turbine spins 24 V truck alternator connected on three-phase transformer 24/400 V. Pumping is assigned to two centrifugal pumps with inputs 1 kW and 2 kW respectively, with separate hydraulic circuit for pumping and drawing – so called four engine configuration.
Fuel cells and electrolysers models: PEM fuel cells and electrolysers for demonstration of the hydrogen production and utilization, hydrogen pumping device, demonstrative car fuelled by hydrogen
Thermo-solar system of hot water preparation: This system consists of a pair of flat hot-water solar collectors, one of which is clear and the other diffusion glazing. The system also includes preparation for the supply from another collector. The system is installed on the 7th floor terrace of the building of our faculty in Mlynská Dolina. The system operates in the DHW cylinder, the circulation being provided by the pump controlled by the automatic switching based on the measured temperatures of the heated water in the tank and the solar fluid in the collectors.
Wind turbines and island solar power plant: Two-blade (200 W currently unused) and three-blade (400 W) generators with horizontal axis is already installed on the premises of the National Center for Research and Application of Renewable Energy Sources. Unit with vertical axis using Savonius design is currently under preparation for installation. Three-blade (400 W) wind generator is combined with photovoltic island powerplant with electro-chemically accumulating system, which illuminates its immediate surroundings. The solar power plant has an installed power of 1.5 kWp of panels and an inverter with a power of 5kVA.
Photovoltaic power plant: Power plant which is situated on the roof, and installed power is 20kWp, is operating to the electrical distribution system.
Experimental biogas power plant: The biogas plant operates in the dry fermentation process. Biomass is transformed into biogas in a pair of fermenters, with the volume 30m3 of each. The station has a gas tank with volume of 28m3. Biogas is produced, stored, pushed, dried, cleaned, measured and then consumed in CGJ or in a burner. Cogeneration unit KATJA 25 CEC: Energy fuel in internal combustion engine is converted to mechanical energy transmitted through a rigid shaft coupling synchronous generators with a rated power of 20 kWe and heat energy tax for the cooling water through a heat exchanger to the water heating system object. This is followed by heating the curd from the combustion engine in the flue gas heat exchanger to the projection system thermal gradient 90/70 ° C. Behind the flue gas heat exchanger follows a pair of silencers of exhaust noise and exhaust fumes are kept to the exterior. Eventual extra heat can be removed to the emergency cooler, which is rated for full output 44 kWt of the unit, so if necessary, CHP unit could serve as an alternative source of energy when power is lost from the network even if they produced heat cannot be rationally utilized.
Thermo solar power plant: consists of concentrator and expansion engine based on Stirling type. The solar concentrator consists of six parabolic mirrors with focal length of 3m. Mirror surface is coated by high reflective special self-adhesive sticker designed for outdoor applications. Each mirror has a reflective area of 1m². The nominal power of concentrated solar radiation in a bundle with a diameter of about 100mm is about 6kWp. Mirrors are fastened to an iron mechanical construction, automatically allowing to the sun in two axes. The concentrator is equipped with two drives for the shooting system of mirrors concentration.

Projects:

Project KEGA 3/7248/09 Integration of the RES laboratory to the education process via internet: development of the educational equipments and devices for the RES laboratory and access to the measurement via internet which were realized for the biogas station
Project of Structural founds of the European Union: National centre for research and application of RES and Finalizing of the National centre for research and application of RES: some of the laboratory´s equipments were bought thanks to the following project.

Publications:

Kubica, J., Pípa, M., Janíček, F.: Laboratórium obnoviteľných zdrojov energie a jeho využitie v pedagogickej a výskumnej praxi. In: EPE2009. Kouty nad Desnou, Czech Republic, 12. ‐ 14.5.2009. ISBN 978‐80‐248‐1947‐1
Pípa, M., Kubica, J.: Výroba bioplynu metódou suchej fermentácie biomasy. In.: 8. Celoštátna konferencia s medzinárodnou účasťou. EEE 2009. Nový Smokovec. 27. ‐ 29.5.2009. ISBN 978‐80‐89402‐08‐3.
Jahnátek, Ľ., Janíček, F., Smitková, M., Kubica, J.: Research Infrastructure For Renewables In Slovakia. In.: 8. C eloštátna konferencia s medzinárodnou účasťou. EEE 2009. Nový Smokovec. 27. ‐ 29. 5. 2009. ISBN 978‐80‐89402‐08‐3.
Kubica, J., Pípa, M., Janíček, F.: Laboratórium OZE na FEI STU v Bratislave. In: EPE 2010. ISBN 978‐80‐214‐4094‐4. CD‐Rom.
Kubica, J., Pípa, M., Janíček, F.: Laboratory for education of renewable energy source on FEI STU in Bratislava. In: International conference Renewable energy sources 2010. ISBN: 978‐80‐89402‐24‐3. CD‐Rom
Kubica, J., Pípa, M., Janíček, F.: Laboratory for education of renewable energy sources on FEI STU in Bratislava. In: International conference Renewable energy sources 2010. ISBN: 978‐80‐89402‐21‐2.
Kment, A., Pípa, M., Janíček F.: BIOGAS STATION OF RENEWABLE ENERGY SOURCES LABORATORY. In: Renewable Energy Sources 2013 : 4th International Scientific Conference OZE 2013. Tatranské Matliare, Slovakia, May 21-23, 2013. ISBN 978-80-89402-64-9.

Photos:

Fig. 1 Pumping power plant