The Top Five Solar Thermal Hot Water Systems that You Can Make at Home

A DiY solar thermal hot water system using a collector plate

A DiY solar thermal hot water system using a collector plate

The Top Five Solar Thermal Hot Water Systems

It is estimated that a typical American family spends at least 30% of their domestic energy consumption on hot water alone. It therefore stands to reason that if this energy can be supplied from a solar water heater, this can amount to huge savings on electricity bills. Even better, it is quite easy to assemble a very effective homemade solar thermal hot water system that performs at the same level as most commercial system.

It may come as a surprise that while solar thermal systems cost more than their cousins the solar PV systems, they are much easier to make at home. In the systems we have featured below you will find at least one you can easily put up even if you have but rudimentary DiY skills.

1. Thermosiphon Thermal Solar Water Heater

A thermosiphon homemade solar thermal systems is one of the most effective solar water heaters for your home. As suggested by the title, the system works by using the siphoning effect of hot water rising up the tubes and being replaced by higher density cooler water in the system. As the video alongside shows, to put up the system you will need some pretty basic items such as plywood, aluminum foil and nails. But the system also requires copper pipes and metal sheets which will cost more. Moreover, you will need to be pretty adept at DiY projects to pull off the project. The system also requires a functional insulated water tank for storage. You do not have to use a new tank though, one salvaged from an ordinary water heater will do the job just fine. Even if you need the right tools and materials to make this system work, when done right, a thermosiphon solar thermal hot water system is one of the most effective ways of supplying your home with adequate hot water.

2. DiY Evacuated Tube Solar Water Heater

This is yet another very technical method of making a homemade solar thermal system. It will give you an evacuated tube type of solar thermal water heater system (there are basically two types of solar water heaters: the evacuated tube variety and those which use a flat plate much like the PV solar panels in appearance). Again here you need to be good enough in DiY projects as some parts of the project will require specialist equipment including an oxy-acetylene welding machine. Again, you will need a number of copper tubes for making the evacuated tube system as well as a certain length of smaller copper tubing. This system may require costlier materials as well as technical expertise than the other systems featured here but it is also by a margin the most efficient in the series.

3. A Simple DiY Solar Water Heater Made from Plastic Bottles

This is by far the most cost effective, simple and yet remarkably one of the most efficient homemade solar hot water systems you are ever likely to come across. The system makes use of ordinary clear plastic (PET) water bottles and other affordable materials chiefly 4 millimeter drip water tubing. You will also need some valves to interconnect the system and that is just about it. The beauty of this system is that it is easily scalable by just adding more water bottles to the system you can heat even more water faster. The system takes advantage of the greenhouse effect and the water circulating in the length of black drip water tubing is heated enough. For the system to be effective though, you will need a small 12 volt DC pump to keep the water flowing. The good thing is that you can use a small solar panel to power the pump, eliminating need for using mains electricity or diesel to power your water heater.

4. DIY Solar Water Heater for Aquaponics

Although designed for use on aquaponics (the practice of agriculture which uses nutrient rich water to grow plants with no need for soil) this is a system that can be used for other applications which require hot water. In real practice, the system may not produce very hot water as the evacuated tube systems covered above but it is adequate enough for average domestic use. However, the system can be made even more effective by daisy-chaining two panels and splitting the water supply so that more water gets heated by each. The video included alongside shows most of the system when it has already been assembled together but as it is a relatively simple project. This should not prove an obstacle to someone with a clue about basic DiY work. As shown in the video above, the system works best on the ground rather than on a rooftop. The wooden rig used to support the system can be fitted with wheels to ensure it is portable.

5. Homemade Absorber Plate Solar Thermal System

This is a solar thermal water heater system which makes use of an absorber plate that is pretty similar in construction and function to the one used for commercial flat plate solar thermal water heaters. Using this video, you will be able to build an effective solar thermal absorber plate that can supply all your domestic hot water needs. The main advantages of this system are its effectiveness as well as durability. The downside is that it requires relatively costly materials and equipment as well as above-average technical knowhow. However, if you can pull off the challenge, there is scarcely a better DiY solar thermal system than this one. This system works best on a rooftop but it is still possible to use a rigging system that works equally well on the ground.


 So,we have shown you five great possibilities for a DiY solar thermal hot water system. We hope that whatever you choose to do, you end up with a great clean hot water system. Let us know which one you tried and how it worked out, or maybe you found another great design you would like to share with everyone.


  • Delores Lyon says:

    Thanks for sharing these different DIY water heater projects for your home. I had no idea that there is a solution that involves plastic bottles and tubing to make an effective solar water heater. If anything, I just need to watch the tutorial just to see how it works exactly. Stuff like this really shows how far people have progressed in terms of solar technology.

    • Jay Ren says:

      That is awesome that solar hot water systems are a thing. Something like this would be great for an off grid home. Maybe I will look more into this and see what it would cost to get my home outfitted with some solar technology.

  • coropool says:

    Interesting designs but…

    Where are the data? no informations about power collected, efficiency of the collector, cost.
    Making a solar collector is not collecting solar energy, most of designs are inefficients (look at solar pool heater with black hose, seems good but measure shows it is not efficient).
    We need to measure and understand, stop spending time at building, publising and sharing ineficient things.

    #3 is inefficient because maker forgot one important thing: we cannot get good efficiency without good water flow. And we can’t get good water flow with low diameter tube. So the heat collected is lost by IR radiation before the water goes out from the tube.

    Also it ‘s really not complicated to measure the power of a solar collector. Simply having a thermometer , a stopwatch and know-how multiplication. Simple calculations here:

  • You should be ashamed of yourselves by running this “story” under the Solar Thermal Magazine banner. You perpetuate myths instead of endorsing your industry. Why is solar thermal down 29% worldwide in the last two years and flat here in the US? You are part of the problem, yet you offer no solutions either than a DIY approach with no discernible facts. Either support the industry your magazine claims to represent, or change its name.

  • William Carr says:

    #2 is not an “Evacuated Tube” system.

    That refers to glass tubing with a partial vacuum inside, and a sealed absorber tube.

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