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Home-Made Solar Hot Water

In New Zealand we are lucky to have lots of sunshine, and it's actually really easy to build a simple heat collector to harvest this free energy, and make your own solar water...



Why make your own Solar Hot Water?



It seems crazy not to use the free energy from the sun to heat water.

Most people agree with everything said so far, but then start to complain about the cost :(




Well I have a solution :)


Why not make your own Hot Water Panels ??


I have designed a simple and cheap Solar Water Heater, that works very well for 9 months of the year in Christchurch, and only costs NZ $ 65 to make !!

When it's that cheap, if you need more hot water, you simply make more panels :)  




How to make your own Solar Hot Water :

I will try to keep it simple and have taken lots of photo's of how we built the first of my Solar Hot Water Panels... It really is easy, and very cheap !!

It's also a great project to make, and then imagine the satisfaction of free hot water whenever the sun shines!!




This design has evolved, and been optimised to use as many free or 2nd hand resources as possible, please feel free to change anything, or simple copy it as many times as you want.

I don't need to make money from this, I simply want to share this information, and hopefully help others realise how easy it is to have free hot water and reduce your carbon footprint :)

I began with the woodern frame, made from 75mm x 50mm H2 treated timber. 

This was then painted white to reduce the temperature of the wood, this is important as the Tunnel House plastic that forms the front of the panel will perish and tear if exposed to high temperatures.



Here we are sanding the rough sawn timber frame to protect the plastic from any splinters.






The pipes must be pulled TIGHT, on a hot sunny day. This is important because on a hot day the plastic expands, and if not installed tightly, the pipes will sag when in use, and if they touch the Tunnel House plastic, it will degrade because of the heat.





This photo shows the detail of the pipe holder. 

To keep the pipe from touching, and damaging the heat sensitive front plastic, I make a simple pipe holder. This is a piece of 20mm x 50mm wood, with notches cut into the back to hold the pipe away from the front.






Installing the rear insulation into the half finished solar panel. 


The insulation has determined the size of the panels. Here in Christchurch I found cheap 1.1m square 25mm thick polystyrene sheets.

These sheets were used as packing material between layers of car batteries. Ask your local battery importer / retailer to see if they have any :)


Polystyrene is fantastic insulation, light, and easy to use. It's perfect for a home made solar panel. Sadly it's not very eco, but this was a waste product, so I feel ok about using it... please try to find it second hand.



This shows the temperature sensor atached to the pipe at the exit point of the solar panel.

I used black tape to attach the sensor to the pipe, thus the sensor will measure the temperature of the water leaving the solar panel.

The temperature sensor is a 47kΩ Negative Temperature Coefficient resistor. Often known as a NTC thermistor. 

These are simple, robust, very cheap and I have designed a simple temperature circuit that automatically turns on and off a pump to circulate water through the panel when the sun shines.


Total cost of my homemade Hot Water Solar Panel

$20 for 40 metres of black 13mm Polythene farming or garden pipe (must be UV stabilised)

$20 for 7m H2 Treated 50mm x 75mm wood

$10 for "Tunnel House" or "Green House" Clear Plastic (must be UV stabilised)

$5 for 2nd hand Black Plastic sheeting

$5 for Screws

$2 for  2nd hand Polystyrene insulation 

$2 for Staples (to attach the front and rear plastic to solar panel)

Free white paint

Total cost $64

The rest of the stuff was either given to me or found in my workshop :) "The Renewable Energy site for Do-It-Yourselfers" This site is fantastic, a huge resource of solar heating DIY projects

Copyright 1997-2015 by Anthony Field on all images/text/information and graphical materials on this website.