How Does Solar Power Work?

A solar panel is made of many photovoltaic cells, typically silicon-based. Each cell has two layers: an n-type (electron-rich) layer and a p-type (electron-poor) layer. When photons from sunlight hit the cell, they knock electrons free from silicon atoms. The electric field at the p-n junction pushes these free electrons in one direction, creating a flow of direct current (DC) electricity. An inverter then converts DC to alternating current (AC) for use in homes and the grid. Modern commercial panels convert about 20-25% of incoming sunlight into electricity, with laboratory cells achieving over 47% efficiency using multi-junction designs.