Solar water heaters are a very effective method of using natural energy to save you money on your energy bills. There are hundreds of designs available to fit any budget. You can search online and find many solar water heaters for sale in a variety of sizes and price ranges, some of which are more effective than others. However, if you are a true do it yourself person, you can easily build a solar water heater yourself and save some money in the process.

How Solar Water Heaters Work

Solar water heaters function by absorbing the sun’s rays and transferring them to a water tank, thus heating the water in the tank. While this may sound simple, these systems are a little more complicated than simply placing a tank of water in the sun and waiting for it to warm up. 

Solar water heaters usually consist of a storage tank, which is normally painted black to absorb the most possible energy from the sun. This water is then transferred into the house, and often into a normal hot water heater. The water is essentially pre-heated which means that the conventional hot water heater has to do much less work.

Click on the image to the right to see the full-scale diagram.

Consider Your Location Before Your Build a Solar Water Heater

The first thing you should think about before building a solar water heater is the location. The storage/heating tank must be placed in a location where it will receive maximum sunlight. The longer your tank is exposed to the sun, the more hot water your system will produce, so it’s essential to place the tank is the best possible location. Therefore, you should choose the location, and then build and install your water heater in that location.

The Solar Water Batch Heater

The most basic type of solar water heater is the batch heater. This is actually a very primitive system of water heating which has been used by mankind for centuries. Batch heaters are basically based on a system that keeps water in a black storage tank and waits for the sun’s rays to heat the water. This system can be quite effective in all climates, provided the water is drained from the system during periods of cold weather.

Of course these systems are most effective in warmer climates, but they can still be used during the warm months in colder climates as well, thus still reducing CO2 emissions. The batch system consists of a tank or drum painted black, an input hose for cold water, and an output hose where the heated water exits the system. The beauty of the batch system is in its simplicity, as it can be built and installed quickly and cheaply. While not the ideal choice for heating water for an entire home, the batch system is at least a good start for those who wish to build a solar water heating system for their home and family.

Step by Step Instructions for Building a Solar Water Batch Heater

Building a solar batch heater is incredibly simple and only requires a 55 gallon drum, flat black spray paint, two garden hoses, one hose shut-off valve and two male-female garden hoses. Although you may also want to build a mounting bracket to keep the drum at an angle so it will work better. This can be done by simply bolting two by sixes together to create a brace for holding the drum at a 45 degree angle.

Step 1: First, you’ll need to thoroughly wash out the inside of your drum to ensure your water won’t be contaminated. You should never use a drum that held any toxic substances, as it may not be possible to completely remove all traces.

Step 2: After you’ve cleaned your drum, you’ll need to paint the entire tank with black spray paint or any other flat black paint. This will ensure that your drum soaks up the sun’s heat.

Step 3: You’ll now want to drill two holes in the top of the drum for each of your hose connections. One hose should extend almost to the bottom of the drum, while the other should only stick a few inches into the drum. The hose which extends to the bottom will be your cold water input, while the other hose will be where your hot water comes out. 

Since heat rises, the hot water will be on the top of the tank, so you’ll want your output hose to be as close to the top as possible. You should attach the shut off valve to the hot water output hose, so you can turn the flow of hot water on and off. Make sure you seal around the holes in the lid with a non-toxic sealant such as silicon.

Step 4: Now you should angle your drum at around 45 degrees and fill it up using the cold water input. The sun will then heat your water, and after a period of time, you can turn on the hot water valve and you should be able to draw hot water out of the tank. 

Things to Consider Before You Build a Solar Water Heater

• Perform a solar site survey
• Examine your local regulations
• DIY vs. Purchase and Self-Installation
• Cost Effectiveness
• Choosing the appropriate size for your solar water heating system

If you’ve been considering installing or building a solar water heater on your property, one of the very first things you need to take into consideration is the amount of sunlight on your property. For a solar water heater - or any other solar product, for that matter - to function correctly, the most important factor is sunlight.

Solar water heaters use a storage tank to heat the water with the sun’s rays, and if the tank does not receive the proper amount of sunlight, then the whole system will not function at its maximum potential. Therefore, it is necessary to measure the amount of sunlight in the area where you wish to install your solar water heater. This can be done by simply using a sunlight calculator, which you can find at most gardening stores. The device will measure the amount of sunlight in a particular area for 12 hours, and any area that reads “full sunlight” should be a suitable place for your storage tank.

The size of your water heater will also help to determine the amount of sun you need for your system to work correctly, although it is always best to err on the side of caution and to install your solar water heating system wherever it receives the most sunlight.

Examine your local regulations

While this should be a given for any DIY project, it is necessary to consult your local city or country regulations to ensure that you are not in violation of any of them before starting to construct your solar water heater. In some places, there are strict codes for any type of new building, as well as plumbing codes that may cover your heating unit. If you are in doubt, it’s best to call your local building inspector’s office to see what the particular regulations in your area are.

DIY vs. Purchase and Self-Installation

For those of you determined to build a solar water heater completely from scratch, there are hundreds of plans available online to suit almost any need. However, the first question to ask before building your own solar water heater is how effective the final product will be, compared to the relatively cheap solar water heating systems that can be purchased on the market today.

Many people love the idea of being completely energy independent and running their homes using eco-friendly products that they built themselves. The only problem is that many people do not have the tools or knowledge required to build a long-lasting and effective product. 

If you feel that you have what it takes, then by all means give it a go, but just be sure to measure the time you put into it and how effective the end result will finally be.

Choosing the appropriate size for your solar water heating system

Another important item to consider before you start construction is the size of your solar storage tank. You don’t want to build too small of a system for your needs, although if you are stuck with a limited space, do what you can as it will still save you money and help to reduce your environmental footprint at the same time.