How to build a passive Homemade Solar Water Heater for about $100. Step by Step Directions !!

A solar water heater is a great project to work on if you want to reduce your water bills. Simply by harnessing the power of the sun, you will be able to heat your water for free, just by cutting down on your energy bills.

This is an easy project that anyone can do.No pumps or controls, completely passive.We start with the glass from old sliding glass doors and use a water heater as storage tank.Have hot water even if the power is out and save $30 a month on power bill.

The materials needed for this build are Old Water Tank – This will be used to store your water as it is heated up.
Black Paint – Primer and heat resistant black paint will be used on the tank and interior,Tempered Glass – The larger the better. An old sliding glass door would be perfect for this,2-3 2×4’s And Plywood- This will be used to construct the frame that contains the tank,Miter Saw – Use this to cut the 2×4’s and plywood for the frame.
Nail Gun – To put the frame together.

The steps mentioned in the video :

The first part of this project is to find the materials. Start with an old water tank. It does not have to be in the best shape since you are going to paint it later. As long as it is solid, it will work for this project. If it has any holes or attachments that you do not need, make sure you plug them up. Remove the casing and scrape away the foam. We want to be left with a tank that is a thin layer of metal so that the sun can heat up the water inside of it.

Once the tank is prepared, use a coat of primer on it and paint it with black heat resistant paint. This will absorb more of the sunlight, heating up the water even further. While you allow it to dry, move on to building the frame of the tank.


Before you begin constructing the frame, find out what angle the sunlight hits you. In order to maximize the heat that our water heater collects, we want to make sure the angle of the glass face matches the angle of the sun so it receives as much direct sunlight as possible. This will vary depending on your location. If you live in the US, you will want to mount it at roughly 30°.

Once you have the correct angle figured out, begin constructing your frame with the 2×4’s. Encase the frame with plywood and mount the tempered glass on the front of the frame. Once the plywood is secured, paint the entire frame black. This, again, will absorb more of the sunlight, making your water that much hotter.

Once all the paint has dried, place your tank inside of it. Cut out holes in the back side of the plywood to allow for the water pipes to flow in and out of it. Place the frame and tank in an area that will receive direct sunlight throughout the day and you can enjoy your solar powered hot water heater.

A solar water heater like this will save you roughly $30 per month. It should raise the temperature of the water from a normal 70°, all the way up to 140° on your standard sunny day. It’s an easy project that will save you hundreds of dollars, in the long run, thanks to the free solar power that you are harnessing to eat your water.

Watch this Step by step Solar Water Heater DIY Video