What is a brief definition of solar energy?

Solar energy is the light and heat radiated from the Sun. Solar technologies capture and distribute sunlight that reaches the earth, which can be converted into other forms of energy, such as heat (thermal) and electricity.

Solar Thermal Heat

Energy absorbed from the Sun produces Solar Thermal Heat, which is frequently used for heating water and heating spaces for homes and buildings. Solar space heating systems can be classified as passive or active. Passive space heating occurs without use of mechanical equipment, when air is circulated past a heated surface(s) and less dense warm air rises while denser cold air moves downward. A car that gets hot on a sunny day is an example of passive solar thermal heat. Active heating systems require a collector to absorb and collect solar radiation. Fans or pumps then circulate the heated air or heat absorbing fluid. Active systems often include some form of energy storage system.

Solar Powered Electricity

Solar energy can be converted into electricity in two ways:

1. Directly, through Photovoltaic (PV devices) or “solar cells”, which change sunlight into electricity. Photovoltaic cells (or panels) are made of two layers of silicon containing special chemicals. Sunlight is used to charge electrons in the silicon layers. The energized electrons move through the cell and flow into a wire, creating an electric current. PV systems are often used in remote locations that are not connected to the electric grid.
2. Indirectly through Solar Power Plants that generate electricity when the heat from solar thermal collectors is used to heat a fluid, which in turn produces steam to drive a small turbine generating electricity.

References:

DOE: Energy Information Administration (EIA): Energy Kid’s Page: http://www.eia.doe.gov/kids/energyfacts/sources/renewable/solar.html

EnergyKids: EnergyAustralia: Renewable Energy: Sun webpage: http://www.energykids.energyaustralia.com.au/renewable_energy/sun [n.d.]

Research by Diane Meade