Energy Pros & Cons

Solar Power

Solar power is often used to power calculators and other electronic accessories. Solar panels – made up of photovoltaic cells – are also sometimes used on roofs to provide electricity to households

	Solar energy is free and renewable, generates no emissions and is silent
	The cost of photovoltaic cells has dropped significantly in the past few years and is predicted to fall further as mass production increases
	Photovoltaics are one of the few renewable technologies that can be integrated into the urban landscape
	They are useful in remote areas far from a source of conventional electricity
	Unused electricity can be fed back into a country’s national grid

	Solar energy is of limited use in cloudy places and also in some cities where roof space is tight
	PV cells are not very efficient, absorbing only about 15% of the sunlight’s energy
	There are extra costs, such as systems to store the energy for when the sun is not shining
	Some of the huge batteries used contain heavy metals, so pose an environmental risk if not properly disposed of
	Toxic chemicals are also used in the production of semiconductors

1 Some electrons move from one semiconductor layer to another 2 This electron migration creates an electrical field at the junction 3 Light shines on the whole cell, knocking electrons free 4 Electrical field causes free elections to build up in one layer 5 Built-up electrons flow through a circuit to the other layer 6 Anti-reflecting coating helps cell absorb maximum sunlight