When water is supplied to the tank, the water flows into a region, the region is blocked by an arc as in your conventional dam, the pressure of the water will increase, the arc opens and the pressure reduces. According to Bernoulli principle, the lower the pressure increases the speed of the fluid(water) and higher the pressure, the speed (velocity) reduces. The water speed is maintained by Pascal principle, which states the fluid at a point or region is evenly distributed . The flow to a region of empty space , gravity and magnetic field of the magnet pull it towards the turbine as in the mountain fall. As the water turns the turbine , Faraday law of magnetic field will occur. a small electric current will be supplied to the coil and the rotor which strengthens the electricity and supplies it to the battery, and your home. The water will flow back to the tank passing through the non-return valve to continue the thermodynamic flow equation. This process conserves energy and requires minimum electricity to operate and also it is efficient. The body of the RET system is made of an insulator to prevent escape of electricity.