Solar energy can be direct or indirect, or active or passive. How does solar energy work" is a question of which the answers can be classified also by focus type.
First, there are two approaches towards solar energy conversion into energy we may use, both involving the use of a solar panel. Let’s start with those shall we? These are
* Solar thermal and
* Photovoltaic
Solar thermal
The solar thermal method uses energy from the sun directly to generate heat. Solar panels can be used to collect heat from the sun to capture its heat and transfer it for water and space heating in buildings. Commonly such panels are positioned to maximise absorption of heat from the sun throughout the day and contain tubing through which water circulates. This tubing is known as solar thermal collectors There is also an indirect method where not water but a non-toxic anti-freeze liquid is used. The sun warms this liquid which in turn transfers this heat to water held in a tank. Passive thermal building design is as simple as designing to maximise the sun’s use.
Photovoltaic
This method converts the sun’s power into electricity. This is the photovoltaic process.
* Solar cells, or photovoltaic cells are often silicon-based pieces of material that absorb the sun’s light. Not warmth, as in the thermal application
* Many of these solar cells are often combined in solar panels
* Numbers of solar panels can be combined and interlinked for greater power
* Solar energy excites the electrons in the solar cell and electricity is produced
* This electricity is in the form of direct current or DC
* DC however is not useable for most common purposes
* So, next DC power is transformed through an inverter to alternating current, or AC at 120 Volt, a common-use voltage
* A small amount of solar energy is lost in this DC to AC conversion but is now ready for distribution to household appliances night time use and reduced sunlight
* You may be connected to the regular power grid. It may be possible to feed any excess energy that your batteries cannot hold, back to the grid. In this way you may become a green contributor to a public utility.
A further classification that I need to cover in answering your question How does solar energy work? is this one.
Direct and indirect solar energy
Direct solar energy
Using direct solar power involves only one step in transforming it to useable energy, its electromagnetic radiation. Some examples of direct solar energy include
* Sunlight striking a solar cell by which electricity is immediately generated
* Sunlight that is absorbed by the dark surface warms water in solar thermal collectors
* Sunlight absorbed by a fibre optic cable that is fixed on the exterior of a building and lights the inside
* Amazingly a solar sail on a spacecraft can move it through the direct force of sunlight. How does solar energy work? Mysteriously it seems sometimes.
Indirect solar energy
You probably guessed it! This process involves more than one step from sunlight to useable energy. Here are some examples
* I mentioned photosynthesis already. Plants convert sunlight into chemical energy, including carbon. Biofuel can be made from them as well as methane gas and hydrogen without waiting billions of years for them to turn into fossil fuels, a very indirect method indeed!
* Hydroelectric dams and wind turbines derive energy from solar-caused wind, rain and other climatic interactions
* Ocean thermal energy is indirect too through its solar-caused differences in temperatures at various depths and wave movement by the wind
After all this, I still have not answered your question: "What is solar energy?" as fully as I might. So, keep moving along with me please…
Active and passive solar energy systems
Passive
A passive system only requires direct sunlight without the aid of any other energy. Sunlight warming an area through a window for example is used in housing and hothouses. Passive solar water heaters for instance use no pump to circulate its water.
Active
And yes, active systems do use the aid of energy besides that of the sun to make them work. Active systems may have electronic tracking devices to maximise sunlight absorption. They may use electric pumps, air blowers, shutters and so on. They can be computer-controlled.
Another way of answering "How does solar energy work?" is by focus type of the solar collector.
Focus types
When very high temperatures are required from solar radiation, its normally diffuse, non-concentrated, light is not enough. Solar energy applications can therefore also be classified as
* Point focus
* Line focus
* Non-focus
Point focus
A saucer-shaped, or parabolic, dish is used to focus diffuse sunlight into a concentrated point of solar radiation. At this point a cluster of solar cells, or a thermal energy receiver convert t