Tips for making a solar thermal panel yourself in self-construction
Keywords: energy, solar, thermal, heating, self-construction, homemade, DIY, Do-It-Yourself, construction, tips, tricks, ideas, help ...
With a minimum of tools and materials it is possible to build an efficient and durable solar thermal panel yourself. A solar water-water system will heat your domestic hot water (DHW): sink, washbasins, bath, showers, swimming pool, spa ... According to the means you put into it you can claim a large share of energy autonomy during the beautiful days!
Making your own thermal solar panels is good, but for an even greener house, and without having to invest, you can also think about taking a green electricity supplier.
Indeed, signing a green electricity contract guarantees you a supply of electricity from renewable or carbon-free sources, without having to invest the least euro! The prices may be slightly higher but it remains very reasonable when you know the climatic damage to come! Switching to green electricity means investing in future generations, something that unfortunately many parents seem to ignore!
This file presents 5 technical methods to make a homemade solar thermal panel according to the material you have.
General principle of self-construction of solar panels
A solar water heater is less complicated than you might think. Here is the principle of operation of solar panels as they are sold and installed by professionals.
If you have a pool and a small room you can improvise at a very low cost a solar water heater:
- Place a good length of PER or garden hoses directly on a roof or on a support made for the occasion.
The roof and the pipe should preferably be dark in color. The optimal tilt of a solar panel depends on your latitude and the date
- In France, the optimal solar inclination varies in an amplitude of 40 °. That's a lot, so you have to know if you want to use it in summer (swimming pool for example) or in winter (heating solar heated floors for example). A simple solution giving an “average” result all year round is to take the latitude of the place as the slope.
- To have a measurable result on a swimming pool, the surface must be at least the equivalent of 2 m² depending on the size, shape and capacity of your pool.
- The inlet and return pipes of the sensor must be diametrically or diagonally opposite in the pool.
The inlet pipe to the sensor must be placed at the bottom of the pool (or it is the coldest).
- A large capacity aquarium pump or a small pump could serve as water circulation.
- Adjust the flow rate of the pump, if possible, to obtain the desired temperature at the sensor outlet.
- A valve and a strainer can be installed on the suction side to avoid de-priming the pump at each stop. It is easier to prime the pump. This should be installed closer to the water level.
Such a system, despite its extreme simplicity, can heat your swimming pool water in a few days, but you can also do a similar test with a simple basin or children's pool.
Solar panel with plates
Get a corrugated iron panel. Make a simple structure as suggested. Position your panel facing the sun.
Solar panel with an old water radiator
A fairly economical solution and very quick to achieve is to use simple hydraulic radiators (water) painted black.
A current new radiator generally consists of 2 parts containing water and fins. Just remove the fins and “open” this heater as shown in the image below to get a very economical solar panel.
An aluminum radiator with an "open" area of between 2 and 3 m2 can be found new between 150 and 200 € in any DIY store.
The heating power given corresponds roughly to the 1,5 times the maximum solar power that can give your panel. An 2000 W radiator will give about 1300 W of solar power.
Take care of the electrolytic copper-aluminum pair: you must electrically isolate the 2 metals if you use them on the same network (plastic ring or end of hose).
Solar panel in EPDM flexible panel
Sold in the swimming pool departments at an unbeatable price per m² (from 150 to 250 € for 6 to 7 m²) these panels can very well constitute a permanent back-up panel for the summer. In winter, in case of frost, they must absolutely be drained but EPDM alone is resistant to frost on the other hand. Here is an example of a 7 m2 solar panel sold in France at the beginning of summer 2007 for 189 €.
The system can be used as it is, but a sight under glass could only improve performance!
On the right, an example of EPDM solar panels integrated into a roof in a Mediterranean region.
"Classic" copper solar panel with glazing: the basics of construction
A solar panel is not complex, and we can obtain very honorable performance with
basic materials. In addition, self-construction generally allows better integration of the panels
So you can build your solar panel simply, with readily available materials. The costs are usually quite low.
Your tools will be reduced, jigsaw, handsaw, hammer, etc.
a) The case: will be made of plywood from 10 to 15 mm, exterior quality if possible. Reinforcements, simple squares of wood. The absorber panel ideally copper first choice but expensive. Then galvanized sheet or aluminum sheet. The collector pipes will be 12 plumbing copper tubes at 20 mm in diameter.
Glass wool or rock wool insulation (the best: a natural insulator, see natural insulating folder).
b) Glass surfaces: Quality glass by checking that this glass has little or no iron. This is easily controlled by checking the edge of the glass.
If you see a lot of green color on the edge, do not use this glass and ask for a glass with less iron.
The use of plexiglass is possible, you will opt for plexiglass at least 4mm thick. Otherwise you can use semi-opaque panels (preferably dark color).