Micro-hydro-power Station for the Conversion of Flowing Water Kinetic Energy into Mechanical or Electrical Energy 

Micro hydropower stations are utilized to satisfy the energy needs of decentralized consumers without building dams. The proposed micro hydropower station operates on the basis of the principle of flowing water kinetic energy conversion into mechanical or electrical energy. On the basis of the carried out theoretical research and undertaken computer simulations the conceptual diagram of micro-hydro-power stations with pintle and blades fixed on vertical axles has been elaborated. The conceptual diagram of the micro hydropower station is based on the conversion efficiency increase (Betz coefficient) by utilizing the hydrodynamic effect of the blades and by orientating the blades towards the water stream in optimum positions from the point of view energy conversion. On the basis of this conceptual diagram the pilot-station of the bi-functional micro hydropower station(fig.1) has been elaborated. Blades positioning mechanism will provide for their optimal position dependent on the water streams in any phase of rotor rotation. The rotor with hydro-dynamic profile blades, precessional multiplier, impeller pump and electrical generator are fixed on the housing made from a metal framing. The framing, in its turn, is mounted on four landing pontoons.  The communicating bridge and the mode of fixing to the bank by cables allow the pilot –station to float depending on the changing level of flowing water. The pilot-station will serve as site for experimental research on more technical solutions and working elements in natural conditions, but, in particular, for research on efficient blades with hydro-dynamic profile. The pilot-station will be anchored to the bank with adjustable cables on its length via a communicating bridge. The scheme of industrial prototype is proposed in fig. 2. It has a very simple construction and is destined to produce 3-10kW/h. The vertical rotor has 3 or 5 blades with hydrodynamic profile, positioned under an entering angle a which is variable concerning the water stream speed.

Innovative Aspect and Main Advantages:
The efficiency of the micro hydropower plant depends completely on the efficiency of the multi-blade vertical axis rotor. The proposed multi-blade rotor with pintle allows the increase of conversion efficiency (Betz coefficient) up to 0.45 (the maximum theoretical value is  0.59), but the known technical solutions reach the value of approx. 0.3. The proposed diagram of the micro hydropower station axle ensures the following basic advantages: utilization of hydrodynamic profiles oriented to an entering angle which is variable concerning the flowing water speed; inefficient zones from the point of view of energy conversion are excluded by repositioning of blades which cross these zones; and the civil engineering expenses are minimum.  All blades participate actively in flowing water kinetic energy conversion whatever the rotor angular position.

Areas of Application:
The designed micro hydropower stations aim at the satisfaction of energy needs (for example, electrical or mechanical energy utilization for water pumping for irrigation purposes) of decentralized consumers, especially in rural districts, without building dams or lakes for water accumulation. It can be used separately or in a system integrated into other renewable energy conversion systems.

Pilot-station of the bi-functional micro-hydro-power plant
Fig.1 Pilot-station of the bi-functional micro-hydro-power plant
Industrial prototype of the micro-hydro-power plant
Fig. 2 Industrial prototype of the micro-hydro-power plant

Stage of Development:
The designed micro hydropower station is protected by the following patents: nr. 2981MD; 2991MD; 2992MD; 2993MD; 3104MD. Actually the pilot station of the micro hydropower station is in the final fabrication stage and will be mounted on the Prut River in Stoienesti village. The industrial prototype is in the designing stage. Mechanical enterprises INCOMAŞ, Hidrotehnica and Topaz, which have hold of fabrication technologies for components, will produce low cost micro hydropower stations at the demand of the decentralized consumers.

Contact Details:
Technical University of Moldova
Contact persons:
Ion Bostan, Valeriu Dulgheru
Republic of Moldova, Chisinau, 168, Stefan cel Mare Ave., Centre for the Elaboration of Renewable Energy Conversion Systems (CERECS)
+ (373 22) 23 78 61,
+ (373 22) 44 50 88