One of the earth's greatest sources of power is the sun. Energy systems that are built to harvest power from this almost bottomless source are therefore very useful today considering the current energy-deficiency. It is in fact possible to enjoy the benefits of solar energy by building your own solar system.
This building project is best carried out when one understands how this energy is harvested and converted into useful form. One can then proceed to collect the necessary tools and equipment and follow a simple set of steps to build the system.
The Concept
Solar energy gets to the earth in form of light and heat. A solar panel system is set up to capture the light energy using a series of photovoltaic cells. Simply put, the conductor that makes up the cell absorbs energy particles (photons) from the sun.
The highly energized photons displace negatively charged particles referred to as electrons from the cell by transferring the energy to them. Because of the nature of the cells, all the electrons only move in one direction and this motion is what produces electricity.
The rest of the system is put in place to ensure that the cells are protected from the elements and to direct these electrons to areas where they are required.
The Basic Requirements
- Plywood or aluminum for the frame backing
- Plexiglass
- Solar cells
- Solder and soldering iron
- UV protective varnish and brush
- Wire – for tabbing and connecting the cells
- Silicone caulk
Solar Panel System Procedure
The first step after collecting all the necessary equipment is to build a frame - the actual panel. This is the structure that will hold the cells and provide protection for them from the elements. It can be a wooden frame made of wood and fitted with a removable cover of plexiglass.
Its shape and size depends on personal preferences and the area on which it is to be placed. Coat its outer sides with UV protective varnish to extend its durability. Make three holes on the bottom side of this panel, two of them to allow for wires to exit and the third one further away to facilitate air movement and prevent moisture accumulation.
It could include a separate substrate onto which the cells will be fixed before being placed into the frame. Such a surface should be light and sufficiently reflective to ensure that it does not absorb rays in the stead of the cells.
The choice of cells made should be guided by the amount of power that one wishes to generate. The most common arrangement utilizes 36 3" by 6” cells of 0.5 Volts each if the purpose is to produce up to 18V of electric energy. The capacity of cells and even their number can of course be altered to accommodate personal requirements.
The most challenging part of the project may be that of building your own photovoltaic cells. Some skip this step and buy factory-produced cells, but one can achieve a greater sense of satisfaction by doing it from scratch. As the most expensive element of the project, one way to cut its cost is by buying damaged solar cells straight from the factory. But ensure that they are not broken too badly to hamper their functioning. Buying brand new cells will however ensure 100% efficiency and is certainly a worthwhile expense.
Arrange them in series, preferably in rows of 4 and columns of 9 cells. They should be tabbed in this series and the tabs then soldered to make strings of cells. This is done while the cells face upside down, so that the complete unit can be turned placed into the frame.
But before this, wires are used to connect the separate strings and finally there are only two wires, a negative and a positive. Glue the complete unit to the frame using silicone caulk by placing reasonably sized lumps strictly in the middle of the cell. The two wires are placed so as to exit at the two bottom holes and from here can be connected to the household's electricity system.
Hold them firmly in place using caulk to prevent them from shifting about and seal the gap that remains around them using caulk as well. Place the plexiglass cover on the frame once the caulk has completely cured and seal off all remaining gaps except for that one breathing space at the base. This will ensure that nothing gains entry into the plate and destroys the components, not even rain water.
The Product
The next step is to test the performance of the system by measuring current and voltage. Attach the negative wire to a multi-meter's negative lead and do the same with the positive. The voltage should be around 18 volts with a current of approximately 3.5 amperes if you used 36 cells of 0.5V each. This translates to a total energy output of 60 watts that is emission-free, does not require maintenance and it does not exhaust any of the earth's natural resources.