Which renewable energy source is harnessed using solar panels?

Solar energy is the correct answer because it is directly harnessed using solar panels, which are specifically designed to capture sunlight and convert it into electricity. Solar panels work through photovoltaic cells that absorb sunlight, causing the electrons in the cells to move and generate an electric current. This process is fundamental to how solar energy systems operate.

The other options represent different types of renewable energy that rely on their respective natural resources. Wind energy is generated by harnessing the kinetic energy from wind using turbines, while water energy typically refers to hydropower, which generates electricity from flowing or falling water. Geothermal energy taps into heat from the Earth's interior, utilizing steam or hot water from geothermal reservoirs. These energy sources do not involve solar panels, which is what distinguishes solar energy as the focus of this question.