Modular Hydroelectric Generator

grabcad

For my project I built a Modular River Electric Generator that is meant to be used by rural areas of third world countries to cheaply and easily power electrical devices. The lack of electricity in third world countries is a humanitarian crisis, stunting the economy and reducing quality of life. Because of this I created a plane like machine that is placed underwater in a river or stream. One of these devices produces about 30 watts of continuous electricity. Villagers can put as many as they need on the rope to fit their energy needs. The plane is held in place by a rope that goes from one side of river or stream to the other and tied to a tree on each side. On one side there is a battery box that stores energy generated for use later in the day. The device was also designed to transfer energy long distances because most people don’t live right up to the river. The design is injection molded out of ABS so that it could be mass produced at an extremely low cost. Although this prototype was 3D printed because 3D printing is the best way to prototype injection molded parts. The hydroelectric device is meant to operate underwater in order to reduce the chance that a log or boat floating down the river could break the rope. The device also uses an aerodynamic design similar to a plane’s in order to reduce the drag force acting on the rope. It has wings in order to reduce the centrifugal force that could cause it to spin underwater. The hydroelectric plane is kept watertight, using rubber O-rings and washers, to prevent the water from corroding the generator. Using a kaplan turbine, for low pressure high velocity applications such as this, the device converts the linear energy of the river into rotational energy. The rotational energy is then converted into electrical energy using a stepper motor, as an electric alternating current generator. The generator usually outputs around 10 to 20 volts. A bridge rectifier then converts it to directed current(DC), so that it can charge a battery. The current then goes through a variable resistor, due to Ohm’s law the electric current and resistance have a direct relationship. Since the current and the required torque to spin the generator also have a direct relationship, the user can control the amount of rotational resistance of the generator on the off chance it can’t spin freely at the speed of the river. After going through the variable resistor, the current goes through a zener diode to convert the voltages to the charging voltage of the battery. The current then goes through a overcharge protector circuit that keeps the battery from overcharging, The current then reaches the 12 volt lead acid battery, chosen because it is the cheapest battery chemistry by dollars per kilowatt hour. The battery is used to used to store energy during the day to be used at night for lighting houses and charging devices.The battery then discharges to a standard DC to AC car inverter, which has less line loss when transporting long distances. The net result is a device that converts the energy of the river into useful electrical energy. This electricity can then be used to light up homes, medical centers and businesses taking impoverished countries out of the dark.