How Solar Power Works

There's more than one answer to the question "how does solar power work?"

Wonder How Solar Power Works? All the basics about how solar energy works to accomplish different tasks from heating a room to making ice cubes.

Here's how passive, thermal and pv solar power works to power households day and night.

How does solar energy work? It depends entirely on what you wish to accomplish.

The methods used to regulate household temperature differ from the way solar is used to heat water and making electricity is by far the most complex way in which solar energy can be used.

Below are explanations and information about passive, thermal and photovoltaic techniques for collecting solar power.

• Passive solar energy is the simplest and least expensive method of using the sun for energy. Basically it's about controlling the temperature of a home by directing the sun to enter spaces during cool seasons and keeping it from entering during hot seasons. more passive solar power
• Thermal solar collectors amplify the heat of the sun and transfer it to water, air or a solution.
• Photovoltaic panels convert light from the sun into electricity. Most people asking the question "how does solar power work?" are referring to photovoltaic energy.

How Solar Power Works - Thermal Collectors

The simplest form of solar energy collection is the Thermal Collector a long flat rectangle that is mounted in a sunny area to heat water or air.

In the photo to the right is a glazed thermal collector - meaning that the panel is covered with a sheet of glass (glazing). Dark metal plates within the collector absorb and hold the heat. Coils of tubing are looped throughout the collector next to the metal plates with air, water or an anitfreeze solution circulating within them.

The heat is transferred into the coils and thus the fluid/air as it circulates through the tubing.The air or fluid is either used immediately (as hot water or to heat a room, swimming pool, etc.) or it is transferred to a well insulated holding tank for later use.

Solar hot water heaters are capable of reaching temperatures of 82 degrees celsius (180F) - ideal for heating water or a space. Concentrators, reflectors or mirrors can boost these temperatures to well above the boiling point.

Check out this video demonstrating a bare bones project for an unglazed solar water heater.

How Solar Power Works - Photovoltaic Panels

A photovoltaic (photo = light, voltaic = electricity) panel is formed by sandwiching thin layers of positive and negative silicon beneath a layer of non-reflective glass. Silicon is a semi conductive substance that is able to alter the sun's energy into electricity.

It's relatively easy to see how solar power works to heat water or air but... how does solar energy work when what you want is ice cubes?

That's where photovoltaic technology makes an entrance. Photovoltaic panels actually turn the sun's light rays into electricity. Once the solar rays have been converted into electricity it can be used the same as any electricity. Direct it to a freezer and tada... ice cubes. It's a little more complicated than that.

It begins with 2 sheets of silicon which, although they are an important building block, have limited semi conductor abilities on their own. Adding impurities to the silicon greatly enhances it's semi conductor properties. This procedure is called "doping". Doping the silicon makes it much easier for the electrons to become mobile.

One sheet is treated with phosphorus. The second sheet is treated with boron. One sheet now has a positive charge and the other has a negative charge.

When the 2 sheets are sandwiched together there exists an energy field between them. When sunlight strikes the silicon sandwich this energy field becomes a hotbed of electrical activity.

Photons from the sunlight collide with the atoms contained in the layers, freeing charged electrons and bumping them into the energy field. Like a waterfall, the electrons are able to move in only one direction causing a buildup on one side of the energy field. To give those crowded electrons somewhere to go, an external circuit (wire leading out of the over full side and around to the other) is created and directs the charged electrons out of the panel and back in to the other side. Before the electrons are directed to the opposite side they are used to power household electronics.

The resulting electricity can be used in its natural form (DC or 12 volt) if you have appliances that use 12 volt energy. Alternatively the energy can be directed through an inverter which will alter the energy to the more prevalent AC (alternating current) or 110 V.

Here's a video showing an animation of how solar power works.

Silicon is a shiny substance and has a tendency to reflect the sunlight. A non reflective sheet (usually glass) covering the panels helps the silicon to absorb the sunlight.

The dynamics of how solar power works are undergoing some changes and refinements. Thin film technology explores some different methods of producing solar power.

Want more? Here is an in depth, technical description of how solar power works.

Here's a great video that demonstrates how solar power works on a small scale.

How does solar power work at night?

Home Solar Power Systems require electricity 24 hours a day. In order for a solar energy system to provide all day and night power the panels must be tied to a utility grid or a battery bank.

• A utility grid provides power to your home during night hours and cloudy days when your panels don't keep up with demand. Also, when your system is humming along making more power than your household needs the extra energy is sent to the grid rather than your home and the power company buys the energy from you and sells it to your neighbors.
  More about grid tied systems



• A battery bank stores excess energy for powering your household at night and on cloudy days or weeks. The addition of batteries is what makes a solar power system completely independent. The system is now capable of making energy and storing it for use later so that power is available to the home at night and on cloudy days.
  
  That's how solar power works in your home when the sun isn't shining.
  More about Independent systems.

If you want the technical answer to the question "how does solar power work" here's a website that provides a good in-depth description.
How Does Solar Energy Work .

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