DIY Solar Panels: The Ultimate Guide (Update 2018)
Today you’re going to learn if DIY solar is for you and how to build diy solar panels that are much cooler than Tesla’s solar roof.
Note: This post was first published in 2013. I recently gave it a much needed update and added a lot of great tips and enhancement that I recently learned. Enjoy!
The concept of building a solar panel system by yourself is not new – some homeowners choose diy to save a few bucks, others do it for fun or simply because they want to build something useful and learn something new.
In fact, going solar has 4 major benefit for homeowners:
- Solar increases the value of your home;
- Decreases environment pollution by lowering the carbon footprint;
- Solar brings considerable savings by lowering electricity expenses;
- It makes you feel good (because you did something right!).
Because of high price tags on commercial systems, solar can be a big investment. To save money, many homeowners are turning to DIY or buying solar kits.
To help you make a decision to DIY (or not to DIY) a solar system, I have compiled a list of 4 basic solar project steps that you need to evaluate and figure out if this is something you can do or not.
4 Step Process to DIY Solar Panels
These are the exact steps that I will be explaining in depth with this solar guide:
- Determine energy consumption and optimal energy needs for your home;
- Choose size and design of your system: photovoltaic solar PV system or solar thermal;
- Acquire solar system components (solar cells, racking, solar inverter);
- Build and install solar panels, connect them to your home.
Back in in 2009 when I first started researching this topic, I reached out to several residential solar companies and professional solar panel system installers for advice.
What they told me is that installing solar is complicated, and that I would have to pass a special training in order to install and build solar energy systems myself.
And guess what? They were all wrong!
Thanks to Gary Reysa and Mother Earth News, I have stumbled across cansolair solar furnace on the web. It took me exactly 0.5 seconds to realize how awesome this project is and I instantly decided to build similar do-it-yourself solar panel.
By studying their commercial version of solar system I have learned that even simple solar construction can produce around 2 KiloWatts of power. That makes such solar panel perfect for supplemental home heating.
Want to know the best part?
My first DIY solar collector was almost entirely built with empty soda cans!
How DIY Solar Panels Work?
Let`s take a look at how DIY solar thermal system actually works. When it is sunny, regardless of outdoor temperature, black solar cells heat up very quickly. The fan drives cold air from the inside of the home, through heated solar cells and then back into the room.
Moving air acts as a medium for collecting solar power from each cell and then brings the heat back into the room. The room, solar panel, air inlet and air outlet form a closed loop air circulation system.
The air can not escape outside of the solar cell walls (tube out of pop cans) which helps to avoid fogging and deposition of dust on the inner side of Plexiglas. The following image shows a simplified sketch of all solar power system elements for air heating.
Ok, let`s summarize how this thing works:
Fan draws cold air from the room, into the solar panel. The air goes through the filter and passes a one-way-pass-valve. For the purpose of distributing the air through the solar system, there are separate air-directing compartments made of aluminum sheet 1 mm (0.04 inches).
These boxes are strategically placed on the lower and upper part of the solar system. The bottom of the collector’s box has a purpose to channel the air into the solar cells – tunnels constructed using pop cans. As the air heats coming into contact with solar cell wall, raises and goes toward the output which is located in the upper corner of the room which we are heating.
Although DIY solar panels are sun powered, electricity is stil needed to supply the fan for driving airflow. For those living in remote places, or those who want to achieve full off-grid autonomy, simply hook up small PV solar panels or wind generator to power the air blower.
If you manage to build a fully autonomous diy solar panel aided with wind generator – you’ll be a master of sustainable living.
But before you do, make sure to read the next technique on my list…
First Step – Cut Your Home`s Heat Loss
Before going solar, it is advisable to perform thorough assessment of your home insulation in order to improve heating efficiency and minimize all possible losses.
Why is this step so important?
Because after reducing heat losses in your home, you can actually install smaller solar panels and get the same result as with the twice bigger solar system.
If you want to achieve this with only one simple (and dirt cheap) hack, then check out my post on how to improve thermal efficiency of your home using bubble wrap insulation on windows.
Do-It-Yourself Solar Panel Construction
Housing for diy solar panels is made using plywood (15mm/0.6in thick), while its front is polycarbonate sheet, 3mm/0.12in thick. Tempered glass can be used as well but it will make your solar panels much heavier. The back side of the solar collector is insulated with 20mm/0.8in rock-wool or styrodur.
Solar collector is made with aluminum beer and soda cans, painted matte-black (paint resistant to high temperature). The top of each can is cut and bent in a way to ensure efficient heat exchange between the pop cans and the flowing air.
Step by Step Guide: Building DIY Solar Panels
I have to warn you – solar installation is not very easy for the complete and total beginner. But do not get discouraged – that is basically why I have created this do-it-yourself solar guide. I’ll walk you through the exact procedure and steps that I used, step-by-step.
Let’s dive right in.
First, let’s collect empty pop cans for solar panel assembly. Wash them thoroughly to prevent strange odors from showing up during the first run of solar collector. Cans are generally produced out of aluminum, but there are some made of iron. For this solar project we need aluminum cans. You can test them easily with magnet.
Try to cut and form small fins at the top of each can as precisely as you can. Idea is to encourage turbulent airflow inside pop cans so that air passing through the tube can collect more heat from the warm wall of pop cans.
Carefully cut the top of the can in the form of a star, and then distort free parts using pliers (Image no. 1). It is important to do this before gluing the cans together. We have marked three holes on each can with a nail, then drilled the bottom using tools shown on images 2 and 3. More details can be found on diy solar panels video tutorial page.
Image 1 Image 2 Image 3
BE CAREFUL! This procedure is extremely dangerous because pop can walls are very thin. Sharp parts may cause hand injury.
After 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 your bare hands!
Remove grease and dirt from the surface of cans. Any synthetic de-grease agent will do the job. Do this outdoors or in a well-ventilated room.
BE CAREFUL! This procedure is flammable! It is dangerous to do this near open flame or cigarette!!!
Glue all cans together using adhesive silicone resistant to high temperatures, at least up to 200°C/400°F. There are glues and silicons on the market that can easily withstand temperatures up to 300°C/570°F. Top and bottom of all pop cans are compatible and fit perfectly one onto another.
Put some glue or silicone on the edge of one can and press it against the other. In this way the glue/silicone will not run away from the edge. Image 4 shows inside view of two pop cans glued together, while series of stacked and finished cans is shown on img 5.
Picture 4 Picture 5 Picture 6
Image 7 Image 8 Image 9
Prepare a template for stacking cans – “L” profile shown on image 6. You can use two ordinary flat wooden planks and nail them together. Wooden template will provide necessary support for solar pipe during the drying process. In addition, secure the cans onto a template using jar rubbers.
Images 7, 8 and 9 show the gluing process. Series of glued cans form a solar pipe. Image 10 shows the pipe fixed in motionless position until the glue gets completely dry.
Image 11 Image 12 Image 13
Air intake and exhaust junction box for diy solar panels is made using wood or aluminum, 1mm/0.04in thick (Images 11 and 12). Gaps around the edges are filled with adhesive tape or heat-resistant silicone. 55mm/2.16in diameter cut-outs are drilled on one side of intake/exhaust box.
Drilled parts can be seen on images 12 and 13. This is where the first row of cans will be glued to the air intake/exhaust boxes. Check out how it looks when all parts are assembled and prepared for painting (img. 13).
Let the adhesive dry for at least 24 hours.
Solar cell perfectly fits into wooden casing (img. 14). Back side of solar panel box is made out of plywood. Rock wool or styrodur is used as insulation – image 15. Special attention is needed for insulating openings around solar collector air intake/outlet.
How to Install Solar Panels Yourself Step by Step
Next step is preparation, protection and painting of a wooden box (solar panel housing). Special hooks have to be attached to all four corners of the solar collector, so that it can be easily mounted on the wall (img. 16) using 10mm/0.4in screws (img. 17). Empty box is placed on the wall in order to precisely mark the spot for drilling the air inlet/exhaust.
Picture 14 Picture 15 Picture 16 Picture 17
Picture 18 Picture 19 Picture 20
Finally, we have painted our diy solar panel (black matte) and placed it inside the wooden case. The case is covered with poly-carbonate sheet, and thoroughly corked with silicone. To prevent bending when the unit is extremely heated during the summer, we have bent the poly-carbonate / plexiglass and made is slightly curved (convex).
Installed solar cells without plexiglass are shown on picture 18. Complete solar collector is shown on image 19, and finally, installed solar power system can be seen in image 20. You have probably noticed that we have decided not to use the ground mount.
Ideally, solar panels should be installed south-facing, but if that is not possible then the south-east or south-west side is acceptable as well. When determining the angle for solar collector mounting position, consider the angle of the sun’s rays in the winter season.
Instead of a roof or ground mounting with 60° angle, we have installed our solar panels on the wall, in a vertical position (90° angle) which is not the perfect angle but is the most practical and also prevents overheating during the summer.
Check out DIY solar panels on YouTube. Video shows how solar panel operates on a clear sunny day. After only 20 minutes, temperature of air entering our solar powered home rose to 50°C/122°F.
Differential thermostat (snap disc) controls the fan. You can get it from almost any electronic component store. Thermostat has two sensors – one inside the top opening (hot air), second inside the bottom opening where cold air is supplied to the solar collector.
If on/off temperature values are set correctly, diy solar panels are able to produce an average 2 kWatt of free energy for home heating. Solar power output generally depends on how much sun do we have during the day.
Homemade Solar Panel Test Drive
First dress rehearsal of solar collector was carried out in the backyard, on a sunny winter day without any clouds. After only 10 minutes in the sun, solar furnace started to blow very hot air (70°C/158°F)! For air blower fan we have used big cooler extracted from a faulty PC power supply.
Test results and solar panel efficiency encouraged us to have the panels installed on the house as soon as possible.
With our solar panels installed, the outside temperature fell below -3°C/26°F, and surprisingly solar collector was already supplying the room with 3 m3/min (3 cubic meters per minute) of warm air. At the same time we have switched to more powerful fan. Hot air temperature went up to +72°C/162°F (measured with digital thermometer).
To calculate total energy production of solar furnace, we have entered the air flow and average air temperature output into formula. Calculated solar power output from DIY solar panels was approximately 1950 W (watts) which is almost 3 HP (3 horsepower)!!!
Pros and Cons of DIY Solar
CONS: This solar thermal system does not have battery bank and is not able to accumulate thermal energy after producing it. When it’s sunny, solar collector produces heat, but it is necessary to use it instantly for space heating. If the sun does not shine, it is necessary to block the solar collector air supply, otherwise the room will begin to slowly cool off. This can be solved by installing shut-off valve, which reduces unnecessary heat loss.
PROS: Solar kits are easier to install comparing to DIY solar install, but given the cost effectiveness and satisfactory results, conclusion is that DIY solar panels are definitely worth making. Solar collector, at the very least, can be used for additional heating of your home, and it is up to you to calculate and figure out how much money you can save with renewable energy.
By building cheap DIY solar panels, you can achieve significant savings during the heating season. Depending on construction and material quality, one square meter of solar heating system can supply soler energy for cca 10 – 15 m² of your living space. In other words, 2x1m solar panels (2 square meters covered with pop cans) can heat up to 30m² (square meters) of your home.
The bottom line?
DIY Solar panels can be quite efficient and quite cheap at the same time. In New York City latitude, the sun delivers up to 1000 Watts per m². PhotoVoltaic panels can capture around 200 W / m² out of those 1000 Watts, while DIY solar thermal system can capture 500 – 800W / m², which is up to four times more!
On top of everything I have saved almost $1K on my electric bill last year thanks to this solar furnace.
But wait, there’s more…
…Subscribe to FreeOnPlate.com notifications and you’ll also learn how I lowered the cost of solar including the payback period, without rebate, solar tax credit or solar financing.
What do you think, to DIY or not to DIY? Let me know in the comments section.