There are several methods to generate electricity such as using fossil fuels and nuclear fission. However, burning fossil fuels pollutes the atmosphere and rivers. Besides, they are expensive and limited sources of energy. Similarly, using nuclear fission also harms the environment because it forms dangerous radioactive waste. In contrast, making electricity from sunlight is cleaner and safer.

Sunlight offers many ways to get energy. For instance, a window can allow warm sunlight into your room, or solar water-heating systems can use it to warm water for houses, swimming pools and schools. In addition, sunlight also warms the Earth and causes wind which can be exploited to generate electricity. Lastly, Photovoltaic or TV systems use a type of material that converts sunlight into electricity. PV systems can power air conditions of satellites like the International Space Station. They are also used to run calculators, recharge cell phones, or even power lightweight cars.

 Sunfight creates a large amount of environmentally friendly heat and electricity. Therefore, it can be an alternative source of energy today and in the future.

In paragraph 1, what pollutes the atmosphere and rivers?