Free Home Solar Water Heater with PET Bottles

In this article I will teach you how to make a Free Home Solar Water Heater with PET Bottles in a simple and very cheap way.

Home Solar Water Heater

Today we are going to see three different ways to create a home solar water heater, both the version of 100% recycled materials, to supply our home with hot water, and two others based on materials that we must buy (if we do not have them at home. ).

Free Home Solar Water Heater with PET Bottles

Let’s look at this example first. A couple of decades ago, José Alano, a retired Brazilian mechanic, was inspired to collect used plastic (PET) bottles and milk cartons to develop a simple solar-powered water heating system, an inexpensive home solar heater that anyone could build.
The Ecologist  dedicates a  great article to him telling his story :

… Seeing that in their small town of Tubarão there was no infrastructure to recycle the containers and feeling unable to throw all those containers in the trash, Alano and his wife soon found a room full of empty milk bottles and cartons. […]

Using his ingenuity and experience with solar collectors, he and his wife built an alternative version using 100 used PET bottles and 100 cartons of milk. The prototype worked flawlessly, while they responsibly breathed new life into all that waste .

Since the invention of this solar heater back in 2002, Alano has not stopped spreading this idea in Brazil through conferences and workshops in neighboring communities and schools. Local entities, the media and even electricity companies have collaborated in the dissemination of this magnificent practice. The exact figures are not known, although Alano mentions a few:

More than 7,000 people are already benefiting from these self-built collectors (DIY) in the state of Santa Catarina alone. There are already two cooperatives, one in Tubarão and the other in Florianópolis, the last of which has produced 437 collectors that will be installed in municipalities. In the state of Paraná, the number of collectors installed in 2008 was 6,000, thanks to workshops and brochures distributed to the population .

What is most impressive is hearing how Alano describes himself:

I do not consider myself an inventor, but a simple citizen trying to find solutions to problems.

How to make a solar water heater with bottles

Let’s see what are the basic materials needed:

• 2L plastic bottles (60)
• cardboard boxes (50)
• 100mm (70cm) PVC pipe
• 20mm (11.7m) PVC pipe
• PVC elbows 90 degrees and 20 mm (4)
• 20mm PVC T-connectors (20)
• 20mm PVC plugs (2)
• glue for PVC
• matte black paint
• 1 roller
• sandpaper
• self-melting tape
• rubber hammer
• saw
• a wood or other material for the support

The 100mm PVC tube is used as a mold and the bottom of the bottles is cut. The 20 mm PVC pipe is cut into 10 x 20 x 1m and 8.5 cm pieces and assembled with the T connectors. The cartons are cut and painted in a matte black tone, as well as the one meter long pipes . And they are assembled.

The panels of the home solar heater must be placed at least 30 cm below the tank and be located to the south, in the northern hemisphere, and to the north in the southern hemisphere, on a wall or roof.

To optimize heat absorption, the panels should be mounted at the angle of their latitude, plus 10 °. This varies depending on the geographic area where it is installed.

The PET bottles are replaced every 5 years or when they have been bleached due to being outdoors and the cardboard is only repainted, with all this described, we only need to give us a weekend to assemble it and have an alley of these characteristics so peculiar.