The science behind generating electricity from hydropower and solar panels is different. Solar power uses the photovoltaic effect, while hydropower uses Faraday's law of electromagnetic induction.
The application of Faraday's law of electromagnetic induction in hydroelectric power generation is that when a conductor moves in a magnetic field, an electric current is generated inside the conductor. When hydropower is generated, the energy conversion form is: gravitational potential energy --> mechanical energy (electromagnetic induction) --> electrical energy. Specific steps are as follows:
1. The water flow falls due to gravity and passes through the turbine blades, causing the turbine to rotate due to force.
2. The rotation of the water turbine drives the generator rotor to rotate. The wires in the generator rotor move in the magnetic field, cutting the magnetic field and generating electromotive force, thereby generating electric current.
Since the gravitational potential energy of water flow is used, the efficiency of hydropower is affected by many factors such as water flow, water level, climate, and geographical conditions. In fact, not only hydropower, but also many forms of power generation, including wind power, fossil fuels, geothermal power, nuclear power, etc., all utilize the law of electromagnetic induction, but the implementation process is different.
Among the many power generation modes, solar power generation is special. It uses the photovoltaic effect of solar cells to generate electricity. When photons (sunlight) strike a solar cell, electrons and holes transition, producing an electric current. In addition, it is worth mentioning that the current of solar cells is direct current. The other power generation modes mentioned above all generate alternating current.
Although the principles of hydropower and solar power utilization are different, in general, hydropower and solar panel power are green energy sources that cause very little pollution to the environment.