Green energy production has become more and more important in the last decade, thus many innovative devices have been developed to produce energy from renewable sources. Most of them are based on solar wind and water energy. In the past, centralization of energy production represented the preferred way to produce energy, but today, especially in the western countries, the construction of new large hydroelectric plants is considered no more sustainable due to several reasons, such as the scarcity of new sites and the big environmental impact of the structures. The distributed generation is playing an increasingly important role in the sustainable energy production.
Regarding energy from water, the research group of professor Malavasi is involved in several projects that are described below.
At the end of 2012, professor Stefano Malavasi patented the GreenValve, a control valve able to recover the energy dissipated in flow rate control process. Then, a prototype of the device was created to be tested in Fantoli laboratory of the Politecnico di Milano. Meanwhile CFD analysis have been made to extend experimental results both to optimize GreenValve components and study its functioning under a wide range of boundary conditions. Some media about the project can be found Here. In 2017 has been succesfully partecipated a call for tenders published by regione Lombardia. The project nemed SmartWater is in collaboration with some small and medium-sized businesses located in the territory of regione Lombardia.
- Giacomo Ferrarese, Stefano Malavasi, (2016). Contribution to "Energy Harvesting: Technology, Methods and Applications", Nova Science Publishers.
- Malavasi, S., Ferrarese, G., & Rossi, M. M. A. (2014). Experimental and Numerical Characterization of a New Control Valve. In Water Ideas. Bologna, Italy.
- Malavasi, S., Ferrarese, G., & Rossi, M. M. A. (2016). A Control Valve for Energy Harvesting and Stand Alone Applications. In XXXV Convegno di Idraulica e Costruzioni Idrauliche. Bologna.
Renee, W. (2015). Energy Harvesting: Technology, Methods and Applications. New York, USA: Nova Science Publisher.
- Malavasi, S., Rossi, M. M. A., & Ferrarese, G. (2016). GreenValve: Hydrodynamics and Applications of the Control Valve for Energy Harvesting. Urban Water Journal.
- Malavasi, S., Ferrarese, G., & Rossi, M. M. A. (2014). A Control Valve for Energy Harvesting. Procedia Engineering, 89, 588–594.
- Italian Patent n° IT1410406 - 9/9/2014;
- American Patent n° US2015/0041002 - il 21/03/2017;
- Chinese Patent n°CN104145148B - 18/05/2016;
- European Patent n° EP13713985.3 - 24/12/2014 n°EP2815159;
- Canadian Patent n° CA2,864,054 - 13/12/2016.
- Paris, C. (2013). Analisi teorica e sperimentale di una valvola di regolazione per il recupero di energia. Politecnico di Milano.
- Baccino, O. (2015). One Way Fluid Structure Interaction for GreenValve's Rotors Analysis. Politecnico di Milano.
- Sacchi, M. (2017). Numerical Analysis of the Globe GreenValve. Politecnico di Milano.
- Castellini, L. (2017). Energy Recovery from Water Distribution Systems. Politecnico di Milano.
- Parodi, M. (2017). Recupero di Energia da una Rete di Distribuzione. Politecnico di Milano.
- Morelli, A. (2018). Caratterizzazione Sperimentale della GreenValve: Coefficeinte di Flusso e Indice di Cavitazione. Politecnico di Milano.
- Monza, F., & Speranza, C. (2017). Ottimizzazione Energetica di Reti in Pressione e Caratterizzazione Sperimentale di un Dispositivo per il Recupero di Energia. Politecnico di Milano.
Waves are a promising resource of renewable energy. The wave energy converters (WEC) are distinguished into three main categories: oscillating bodies, oscillating water columns, overtopping devices. The oscillating bodies are floats or other bodies which are moved by waves. The oscillating water columns exploit pressure generated by water surface oscillation for moving air through a turbine. Overtopping devices take advantage of the raise of water level caused by waves for storing the water in a reservoir and then exploiting the hydraulic head by an hydraulic turbine.
Here at Politecnico we are studying a particular wave energy converter composed by two oscillating bodies, the EDS (Energy Double System). It consists of a float and a paddle mounted on the same arm, and it is designed for working in the nearshore region, close to the breaker zone.
The float exploits the heave wave force, while the paddle exploits the surge wave force, which can be very high in shallow waters. The advantages of having two different bodies is the versatility of the system to wave characteristics. EDS can be attached to existinD:\Dottorato\Fluids Labs\Sito internetg structures, like piers and docks.
We are testing a scale model of EDS in the wave flume of the Hydraulics laboratory. The model is equipped with two hydraulic PTO (power take off) for measuring the mechanical power absorbed by EDS. Several tests of the EDS model are being performed, in various configurations and with different waves.
A numerical model of EDS, based on CFD simulation, has been developed and verified on the laboratory data. It is now used to predict the system behavior in many possible configurations.
- Negri M., Malavasi S., 2018, Wave energy harnessing in shallow water through oscillating bodies, Energies, 11 (10), 2730;
- Marchesi E., Negri M., Malavasi S. CFD modeling of a two-oscillating-body wave energy converter in shallow water. XXXVI Convegno Nazionale di Idraulica e Costruzioni Idrauliche. Ancona, 12-14 September 2018;
- Malavasi S., Negri M., 2015. Double system wave energy converter for the breaker zone. Special Issue Ocean energy: Ongoing research in Italy. Rivista EAI, ENEA. DOI: 10.12910/EAI2015-047;
- M. Negri. S. Malavasi , 2014. “Analisi sperimentale di un WEC per la zona dei frangenti”. Poster. XXXIV Convegno di Idraulica e Costruzioni Idrauliche IDRA14. Bari, Italy (In Italian);
- M. Negri, F. Clerici, S. Malavasi , 2013. “A breaker-zone wave energy converter”. International Conference on Renewable Energies and Power Quality ICREPQ’ 13. Bilbao, Spain;
- M. Negri, S. Malavasi, 2013. “Harvesting breaking wave energy”. Poster. Young Coastal and Scientists European Conference YCSEC 2013. Aberdeen, Scotland.
- Negri M., 2016. Modeling of a two-oscillating-body wave energy converter for shallow water. PhD Thesis in Environmental and Infrastructure Engineering. Politecnico di Milano, Milano, Italy.
- Marchesi E., 2018. Modellazione numerica del wave energy converter EDS. MS Thesis in mechanical Engineering, Politecnico di Milano, Milano, Italy (in Italian);
- Incampo N., 2015. Analisi numerico-sperimentale del wave energy converter EDS. MS Thesis in mechanical Engineering, Politecnico di Milano, Milano, Italy (in Italian);
- Clerici F, 2012. Verifica sperimentale ed ottimizzazione di un sistema di generazione di energia dal moto ondoso sotto costa. MS Thesis in Civil Engineering, Politecnico di Milano, Milano, Italy (in Italian);
- Cometti S, Fioletti S, 2011. Wave energy converter “EDS”: progettazione e messa in opera del modello fisico. MS Thesis in Civil Engineering, Politecnico di Milano, Milano, Italy (in Italian).
- 2014 "Rendimento teorico di sistemi WEC (wave energy converter)".
- 2010/12 “High Efficient System for the Wave Energy Production” REGIONE LOMBARDIA, Call 2009 Energy Efficiency.
Vortex-induced vibrations (VIV) have recently being studied under the point of view of the energy harnessing: the movement of a body induced by vortex shedding can be exploited to generate clean electricity. In this perspective, VIV should be enhanced rather than suppressed (VIV are normally very dangerous for structures). We are experimentally testing an elastically mounted sphere undergoing VIV in a water flow, with a particular kind of power take-off inside it, which produces electric energy.
- 2005/07 “Flow induced vibration on flexible structures” - PRIN2005 project.