Solar energy technology work by converting sunlight into electricity. Sunlight is needed to excite electrons in a photovoltaic(PV) material, also called a solar cell. Solar cells or photovoltaic (PV) cells work using the photoelectric effect principle where electrons in a semiconductor material are excited giving rise to free electrons that move in one direction through a PN junction. Semiconductor materials are used in solar cells because they exhibit the characteristics of producing free electrons that flow in one direction in a PN junction. A semiconductor material can be defined as a material that has an electrical conductivity value below that of a conductor (such as copper or aluminum) and an insulator such as glass.
How does the solar energy work?
To understand how the solar energy work, it is good to capture the requirements of a solar energy system as shown in the diagram above.
- First, solar cells or solar photovoltaic material is needed to capture sunlight and convert it into useful solar energy through the photoelectric effect as mentioned above.
- In most cases, if you are connected to the grid, your solar energy system will be connected to an inverter and a bi-directional meter (as shown above). The meter moves forward or backward depending on the electricity demand needed in your household or business. During the day because your solar energy system is generating solar power, your bi-directional meter will tend to move backward and thus helping to lower your utility bill. As such, it will move backward because your electricity demand is low when your lights are off, or you probably at work if you are not working from home, etc.
- On the other hand, there is sunlight during the day, and in most cases depending on what time of the day, your solar energy system is producing excess solar power that will move your power meter in the opposite direction, and as a result, any excess solar power will be fed to the grid. At night, since there is no sunlight to generate solar energy, the meter will move forward because your electricity demand is high
- Solar houses or businesses connected to the grid use net-metering to provide for this type of arrangement where you get credit for solar power produced and fed to the grid through your solar energy system. For households or businesses not connected to the grid, excess solar energy can be stored in batteries to be later used when is needed, perhaps at night. A net-metering system allows for excess solar energy to feed into the grid by use of a bi-directional meter provided through a power utility.
- The inverter as shown in the picture is connected to your solar energy system to convert the direct current (DC) produced by the moving electrons into alternating current (AC) which can be used in your household or business.
In addition, the solar energy technology is being applied in very many other applications not just in powering homes and businesses, but also in off-grid solar applications such as RVs, cabins, boats, etc. Also, people that are hiking, camping, walking around, etc can use the free energy of the sun, for instance, a solar phone charger uses the same technology as regular solar panels but on a much smaller scale.
The sun hits a small solar panel which in turn either charges a battery bank or the solar electricity produced is directly used into your cellphone. Although, since the power produced for cellphones is very small compared to what a household uses, it is measured in Amp-hours instead of kilowatt-hours. Amp-hour is the consumption of the amount of current in a single hour. For instance, solar phone batteries use amp-hour units to describe the amount of solar energy that a battery can store. For instance, the battery of a typical smartphone has a capacity of 3 Amp-hours or 3,000 milli-Amp-hours. 1 Ampere is equal to 1000 milliamperes.
A lot of solar-powered battery chargers can be tremendously useful even when they are small. Solar panels that are only capable of producing as little as 4 watts of power are still valuable. They can charge batteries with no load, including smartphone and cell phone batteries. Learn more about other solar applications or how does the solar energy work by visiting this blog.