First you should choose the type of panel you would like to build.

YES, IT IS POSSIBLE to built it at home.

You can find different types of solar panels, we will mention the two basic and most used:

Photovoltaic solar panels: 

these are generally used to produce electricity and are based on photovoltaic principles, namely the excitation of electrons from a semiconductor surface.

Solar Collectors: 

are used to heat water, (like your uncle´s) using a simpler technology. Where is sought to form a greenhouse effect on a smaller scale that helps keep the water in the home warm.

For a home photovoltaic panel you will need:

-A low power welder  

-36 Solar cells  

-A base of some material that does not transmit electricity. Preferably wood of approximately one square meter 

 -Fuel thermo

-fuse and a blocking diode 

 -Plexiglass the size your solar module is going to have 

 -Painting to protect the wood 

 
Once all the materials to make homemade solar panels are assembled, we proceed as follows:  We paint the wooden base with the paint to cover all sides. This will cause the base to resist the atmospheric conditions to which it will be subjected and may last up to a year in excellent conditions.  Make some marks on each part of the wooden base to know where you are going to place the solar cells. Once this is done, place the cells on both the top and the bottom. That is, 18 on one side and 18 on the other. Then join them together by negative and positive poles. Solar cells usually have wires or tabs to achieve this connection. With the help of the low power welder, we will join the cells together. This must be done with great care because the cells are made of a very weak material and could break. 

 
All this process you will do with the cell looking down. Then, very carefully, we turn the already welded cells and stick them to our base with the help of the thermo-fusible glue and the previously made marks.  To protect the solar module from changes in weather, we protect our base with a Plexiglas or any plastic sheet and screw it over the circuit.  The blocking diode will help the panel not to discharge when there are cloudy days or at night. Finally, we connect the cables to the socket and the panel is ready to be used

I hope I have helped you, don´t burn your house, be careful