Some key facts on solar energy highlight its significant potential in resolving the climate change crisis:
- The Sun has sufficient helium mass to provide the Earth with energy for another five billion years. It emits enough energy to power humankind for an entire year in 1/816,000th of a second!
- The Earth receives only one half of one billionth of the Sun's radiant energy, but in just a few days it gets as much heat and light as could be produced by burning all the oil, coal and wood on the planet.
- Worldwide, some two billion people are still without electricity. For these populations it is more economically viable to install solar panels than to extend established electricity grids.
Harnessing this power can reap significant benefits for businesses, individuals and governments alike. For example, businesses can use solar energy to:
- Reduce the risk of volatile and rising fossil fuel prices, thereby reducing or stabilizing operating costs, particularly as governments move to tax carbon emissions.
- Take advantage of government incentives and rebates which are designed to increase the use of renewable energy sources.
- Reduce the risk and cost of power outages.
- Strengthen relationships with key stakeholders such as customers and the community, by showing concern for climate-related issues.
Find out more about the benefits of solar energy for the global economy, the environment and individuals in our photovoltaics section.
How does sunlight affect life on Earth?
The energy from the Sun is critical to all life on Earth. Evolutionary scientists have shown that the Sun's energy played an essential role in 'spontaneous generation', whereby the very first single-cell amoebae split and developed into more complex lifeforms. Plants require sunlight for the process of photosynthesis or the production of sugars, and a by-product of the photosynthetic process is cellular respiration, which releases the oxygen that we must have to stay alive. All types of animals, including humans, also rely on the Sun's heat to maintain body temperatures and sustain life. Thankfully, the Sun has sufficient helium mass to provide the Earth with energy for another 5 billion years.
How do we get electricity from the sun?
Sunlight is made up of small particles of energy called photons. Photovoltaic (PV) systems use semi-conducting materials such as silicon to absorb some of these photons and transfer them to electrons. This process is known as the photoelectric effect and it is the basic physical process by which PV cells convert sunlight to electricity. Special electrical properties of the Photovoltaic cell provide the voltage needed to drive the current through an external load (such as a light bulb).
ABOUT PHOTOVOLTAICS
What does photovoltaic (PV) mean?
The word 'photovoltaic' essentially means electricity from the energy of sunlight. First used in about 1890, the word has two parts: photo, derived from the Greek 'phos' meaning light, and volt, a unit of measurement named for Alessandro Volta (1745-1827), a pioneer in the study of electricity.
How does PV differ from other solar energy technologies?
There are four main types of solar energy technologies:
Photovoltaic (PV) systems, which convert sunlight directly to electricity by means of PV cells made of semiconductor materials.
Concentrating solar power (CSP) systems, which concentrate the sun's energy using reflective devices such as troughs or mirror panels to produce heat that is then used to generate electricity.
Solar water heating systems, which contain a solar collector that faces the sun and either heats water directly or heats a 'working fluid' that, in turn, is used to heat water.
Transpired solar collectors, or 'solar walls', which use solar energy to preheat ventilation air for a building.
