Solar Energy

Solar energy is the energy that reaches the Earth from the sun's rays. It can be converted into electricity or heat using various technologies. It is among renewable energy sources, meaning the source will not be depleted in the near term.

The most common method used today is photovoltaic cells, which convert sunlight directly into electricity. The second method is solar thermal, in which sunlight heats water or other fluids, and that heat is then used for buildings or industrial facilities. The two methods differ in technology and application.

How Photovoltaic Cells Work

Photovoltaic panels consist of cells made mostly from silicon. When sunlight strikes these cells, it sets electrons in motion, creating an electric current (direct current or DC). An inverter then converts the electricity to alternating current (AC) suitable for household use and the power grid.

Uses and Scale

Systems vary from small installations powering a single home or well to large farms feeding electricity into the grid. In regions with abundant sunlight—including Somalia and East Africa—there is significant potential, especially in areas without grid power. Small systems combining panels and batteries are used there for lighting, mobile charging, and water pumping.

Limitations

Solar energy is variable: there is no generation at night, and output decreases when clouds are present. For this reason, storage (batteries) or alternative sources are necessary. The initial cost of installing systems remains a barrier for many, although panel prices have fallen in recent years. Additionally, panels require cleaning, since dust reduces output.