The Power Of The Sun

We consume energy in dozens of forms. Yet virtually all of the energy we use originates in the power of the atom. Nuclear fusion reactions energize stars, including the Sun, and the resulting sunlight has profound effects on our planet.

Sunlight contains a surprisingly large amount of energy. On average, even after passing through hundreds of kilometers of air on a clear day, solar radiation reaches Earth with enough energy in a single square meter to run a mid-size desktop computer—if all the sunlight could be captured and converted to electricity. Photovoltaic and solar thermal technologies harvest some of that energy now and will grow in both usage and efficiency in the future.

What is Solar Energy?

Solar energy is, simply, energy provided by the sun. This energy is in the form of solar radiation, which makes the production of solar electricity possible.

Electricity can be produced directly from photovoltaic, PV, cells. (Photovoltaic literally means “light” and “electric.”) These cells are made from materials which exhibit the “photovoltaic effect” i.e. when sunshine hits the PV cell, the photons of light excite the electrons in the cell and cause them to flow, generating electricity.

Solar energy produces electricity when it is in demand – during the day particularly hot days when air-conditioners drive up electricity demand.

In use, solar energy produces no emissions. One megawatt hour of solar electricity offsets about 0.75 to 1 tonne of CO2.

PV panels are being used increasingly, both in the city and in remote locations, to produce electricity for households, schools, and communities, and to supply power for equipment such as telecommunication and water pumps.

How Do Solar Panels Work?

When photons hit a solar cell, they knock electrons lose from their atoms. If conductors are attached to the positive and negative sides of a cell, it forms an electrical circuit. When electrons flow through such a circuit, they generate electricity. Multiple cells make up a solar panel, and multiple panels (modules) can be wired together to form a solar array. The more panels you can deploy, the more energy you can expect to generate.