Overhead water tanks are placed on the terrace of the house and filled from the underground sump or borewell using an electric pump for domestic use. Water has high kinetic energy when it flows from a high to low level. Electricity can be generated using this kinetic energy with the help of a suitable microturbine. Based on the amount of water flow in the pipe, the power generated using the turbine can be varied.
Circuit and working
The circuit diagram for hydropower generation from a water pipe is shown in Fig. 1. It is built around six rectifier diodes 1N4007 (D1 through D6), DC-to-DC regulator LM2596 (IC1), Schottky diode 1N5822 (D7), inductor (L1), micro hydro-turbine (MHT) and a few other components.
The circuit is built around DC-to-DC step-down switching regulator IC LM2596. The three-phase outputs (RYB) of MHT are connected to CON1. The image of MHT used in this project is shown in Fig. 2.
Bridge rectifiers (comprising diodes D1 through D6) convert AC output from MHT to DC voltage. IC1, L1 and D7 perform the step-down operation that converts high voltage to 5V DC. Capacitor C1 smoothens the rectified DC voltage, and C2 acts as a buffer for the output. 5V DC available at connector CON2 can be used to charge the single 18650 lithium-ion cells using the TP4056 module shown in Fig. 3. An emergency light or some other gadgets can be powered by a single lithium-ion cell.
LM2596 series of regulators are monolithic ICs that provide all active functions for a step-down (buck) switching regulator, which is capable of driving a 3A load with excellent line and load regulation. These devices are available in fixed output voltages of 3.3V, 5V, 12V and an adjustable output version. For example, LM2596-5.0 gives 5V fixed output.
LM2596 series offers a high-efficiency replacement for the popular three-terminal linear regulators. It substantially reduces the size of the heat-sink, and in some cases, no heat-sink is required.
Requiring a minimum number of external components, this regulator is simple to use and includes fault protection and a fixed-frequency oscillator. LM2596 is the upgraded version of IC LM2576, which has 52kHz switching frequency. LM2596 has a 150kHz switching frequency that offers usage of low-value capacitors and filters.
A generic MHT generator is used in this project. It has a maximum output voltage of about 20V, three-phase AC, maximum output current of about 150mA with a flow rate of about 2.5 to 25 litres per minute.
Construction and testing
A PCB layout for hydropower generation from a water pipe is shown in Fig. 4 and its components layout in Fig. 5. Assemble the circuit on the designed PCB. Connect MHT RYB outputs across CON1 using external wires. The power supply for the circuit is provided by MHT.
Download PCB and Component Layout PFDs: click here
After assembling the circuit on the PCB, fix MHT with a suitably sized water pipe—size of the water pipe depends on the coupling heads of MHT. When water starts flowing through the pipe continuously, you should be able to get 5V DC across CON2.
A. Samiuddhin is B.Tech in electrical and electronics engineering. His interests include LED lighting, power electronics, microcontrollers and Arduino programming