Many factors have influenced that between renewable (ecological as well), and conventional (non-renewable and non-ecological) energy sources, the first choice is always conventional energy source with profit as the only important criterion. For example, high profit is obtained by monopoly on strategic crude-oil reserves. Keep on reading to see how a small man can make a difference by building diy solar panels.
Ingenious solar system solution shown on the cansolair website served as inspiration to build “home-made” efficient diy solar panels. Basically, it is incredibly simple and cheap solar panel for supplemental home heating, which heats the air directly. The most interesting is the fact that solar collector is almost entirely home built and constructed out of empty aluminum cans!
Housing for diy solar panels is made of wood (plywood 15mm), while its front is 3 mm (0.12 inches) Plexiglas/polycarbonate (you can use tempered glass as well). The back of the case set is made of 20mm rock wool (or styrodur) as insulation. Solar absorber is made out of beer and soda cans, painted in matte-black paint, resistant to high temperature. The upper part (cover) of cans is specifically designed to provide greater efficiency in heat exchange between the cans and the passing air.
When it is sunny, regardless of outside temperature, cans and inside air heat up very quickly. The fan drives heated air back into the room. If you wan to achieve full off grid autonomy, it is possible to buy small PV solar panels and wire them to supply electricity for the fan.
I have to mention that, before going solar, it would be advisable to perform a thorough self-assessment of your home heat / energy efficiency and to cut all possible losses first. It is really important to perform this because after minimizing heat loss in your home, you can actually install smaller solar system and get the same result as with twice bigger heating system. Some great articles on energy efficiency topics can be found on how to go solar website.
POP-CAN DIY SOLAR PANELS – HEATER BUILDING MANUAL
To begin with, we have collected empty cans from which we will assemble diy solar panels. It is necessary to wash the cans immediately, because they very quickly begin to spread odors. Attention! Cans are generally made of aluminum, but there are some iron specimens. You can test cans easily with magnet.
Please pay attention and try to cut and form a small fin at the top of the can as precisely as you can. Their task is to encourage turbulent flow of air within each solar tube of our diy solar panels so that air passing through the pipe can collect more heat from the heated wall of cans. Carefully cut the top of the cans in the form of star, and then distort free parts using pliers (Picture 1). All this is necessary to do before gluing the cans. We have marked three holes on each can with nail, then drilled the bottom using the tools shown in Picture 2 and 3.
Picture 1 Picture 2 Picture 3
WARNING! This procedure is extremely dangerous because the can walls are very thin. Sharp parts may cause hand injury.
When the drilling is completed, small parts of the metal could remain in the can. Use pliers to remove these parts.
Do not remove pieces of sheet metal and debris with bare hands!
Remove grease and dirt from the surface of cans. Any synthetic degrease agent will serve quite well for this purpose. Do this outdoors or in well-ventilated room.
WARNING! This procedure is flammable and a potential risk of explosion! It is dangerous to do this near open flame or cigarette!!!
Glue all cans using any adhesive silicone resistant to high temperatures, at least up to 200 ° C. There are products for bonding that can withstand up to 280 ° C or 300 ° C. Top and the bottom of cans are compatible and fit perfectly to each other. Put glue/silicone on the edge of can and press other can on it. In this way the glue/silicone will not run away from the edge. Detail of the soldering tin, you can see in Picture 4, and series of taped and finished cans are shown in Picture 5.
Prepare a template for stacking cans – shown in Figure 6. You can use the two most ordinary flat boards and connect them with nails. Template will provide support during the drying cans to get a straight pipe – solar tunnel. In addition, attach the cans for a template using the jar rubber.
Pictures 7, 8 and 9 show the process of gluing. A series of glued cans form a solar tube. Picture 10 shows the pipe that must be fixed and motionless until the glue is completely dry.
Boxes of intake and exhaust parts for our diy solar panels are made of wood or aluminum, 1 mm (Figures 11 and 12), gaps around the edges are filled with adhesive tape or heat-resistant silicone. The box are drilled, cut-outs are 55mm in diameter. Drilled parts can be seen in Figures 12 and 13 The first row of cans is glued to the cover of the suction boxes, see how it looks when all parts are assembled and prepared for painting (Figure 13).
The adhesive dries very slowly. It is necessary to leave it to dry for at least 24 hours.
Solar absorber fits in the casing made of wood (Fig. 14). Back side of the diy solar panels box is made of the plywood. In order to further consolidate the structure, you can make the inner wall of the strip. Isolation between partitions set – rock wool or styrodur insulation. Cover all this with a thin plywood panel. Installed insulation can be seen in Figure 15. Pay special attention to the insulation around the opening for the exit and entrance of air in the solar collector.
Preparation, protection and paint of timber from which the box is assembled is finished. Hooks are attached to all four corners of the solar collector, so it can be mounted on the wall (Fig. 16) using 10 mm screws (Fig. 17). An empty box is placed on the wall in order to precisely determine the place and mark the spot of drilling the inlet/exhaust.
At the end, the solar absorber is painted black and placed in the diy solar panels casing. The casing is covered with plexiglass that we attach to the frame and thoroughly corked with silicone. Polycarbonate / plexiglass is slightly convex in order to gain greater strength. You can see installed solar absorber without plexiglass in picture 18. Complete solar collector is shown on Picture 19, and finally, installed solar system can be seen in Picture 20. The following page shows complete specification of parts and material needed for building diy solar panels. If you want to learn more about solar heating, check out how do pop can solar panels work.
On YouTube you can see how our diy pop-can solar panels work. Video shows how solar panel operates on a bright day. After first 20 minutes, panel heated up the air inside living room at 50 °C.
Important note: Our solar system is not able to accumulate thermal energy after producing it. When it’s sunny, the solar collector produces heat, but it is necessary to use it immediately for heating the air inside the house. If the sun does not shine, it is necessary to interrupt the supply of air in the solar collector, because otherwise the room will begin to cool off. This can be solved in a simple way – by installing the valve, which will reduce the heat loss to a minimum.
Differential thermostat (snap disc) controls the fan. This thermostat can be bought in better-equipped electronic component stores. The unit has two sensors. One placed inside the top opening for warm air, the other inside the lower opening for the supply of cold air in the solar collector.
If on/off temperatures are set carefully, diy solar panels are able to produce an average 2 kW of energy for home heating. This generally depends on how much sun do we have during the day.
Dress rehearsal of solar collectors carried out in the backyard before installing the system on the house. It was a sunny winter day, no clouds. As a fan is used a small cooler extracted from a faulty power supply of PC. After 10 minutes in the sun from the solar collector is out hot air temperatures of 70 ° C! The test results have encouraged us to install solar heater on the house as soon as possible.
After completing installation of collector, the outside temperature was -3 ° C, and from the solar collector is coming out 3 m3/min (3 cubic meters per minute) of heated air. In the home version we used more powerful fan than for the test. Heated air temperature went up to +72 ° C. Temperature was measured by digital thermometer. To calculate the heating power of the collector, we took the air flow, and average air temperature exiting from the device. Calculated power that the solar panel produced, was approximately 1950 W (watts) which is almost 3 HP (3 horsepower)!!!
CONCLUSION: Considering that the results are quite satisfactory, we can conclude that DIY solar panels are definitely worth making. The collector, at the very least, can be used for additional heating of our home, and it is up to you to calculate and figure out how much savings you can achieve.