Solar radiation is the light – also known as electromagnetic radiation – that is emitted by the sun. The enormous amount of energy generated from sunlight makes solar cells a very promising alternative energy source for the future. Solar cells also have the advantage of being a practical energy source considering they do not require transmission because they can be installed in a modular manner at any location where they are needed. Various technologies have been developed in the process of making solar cells to reduce production costs to make them more economical. The aim of this research has been achieved, namely to design an Arduino-based solar tracking system, so that by using a solar tracker solar energy can be absorbed and produced more optimally than without using a solar tracker. This is proven based on the results of the Black box test. As for the results of testing the system in a black box, the result is that solar panels can move to follow the sunlight and produce maximum energy. So that this tool can be applied to all regions and can assist the government in efforts to overcome energy problems, especially optimizing alternative energy.

Most of the water can be found in the sea (salt water) and in the ice caps (at the poles and on the tops of mountains). Apart from that, water can also be found in clouds, rain, rivers, surface fresh water, lakes, water vapor, and sea ice. The water in these objects moves according to a water cycle, namely: through evaporation, rain, and the flow of water over the ground surface (runoff, including springs, rivers, estuaries) towards the sea. Floods are natural disaster events that occur when an excessive flow of water submerges land. Floods can occur within minutes or over a long period of time, and can last days, weeks, or longer. Floods are the most common and widespread of all weather-related natural disasters. The tool can function properly. The height can be set to be displayed with an LED light display. Can be applied to the floodgates to activate the motor driving the floodgates so that the water level through the floodgates can be adjusted in such a way.