DIY Solar Water Heater

Building a DIY solar water heater is a great way of providing your home with a free and abundant source of hot water and by building it yourself you can save up to $2000 off the cost of a standard solar water heating system.

Below: A shop bought, evacuated tube, active solar power water heater.

solar power water heater, evacuated tube

Depending on the type of solar water heating system you decide to build, you could potentially supply yourself with between 50% and 100% of your home's hot water needs, drastically reducing your carbon footprint and saving a fortune off your power bills at the same time.

On this page I hope to go through the several different types of home DIY solar water heaters to help you decide which one is right for you.

You can also find links to other resources including ebooks, guides, DIY solar water heater plans and case studies etc.

Right: Flat plate, active DIY solar water heater.

Solar hot water types

There are two main different types of solar hot water heaters: active and passive.

Active solar hot water heaters

If you live in a cold climate where the temperature drops below freezing for long periods of time then you need to build yourself a n active solar water heater. In active systems, water is actually in motion inside the system which means that they can't freeze.

Right: Active solar water heaters require electricity to power pumps.

active solar heater water system, diagram

Active solar water heaters are far more difficult to build yourself as they require some plumbing skills.

In this active category there are two different types of water heaters. The first is the flat plate solar water heater.

Active flat plater solar water heater

A flat plate system, as the name suggests, is a big flat plate that stands alone or sits on your roof. It is connected to your water tank which detects when the water is hot enough in which case it switches on a pump which drains the hot water and refills the flat plate with cooler water ready to be heated again.

Evacuated Tube collector

The other type, known as an evacuated tube collector is perhaps one of the most efficient types DIY solar water heater. It consists of, as you can see in the picture, several upright tubes. A special liquid in the tubes heats up. This hot liquid rises to the top of the pipe and heats water at the top. This system is the most expensive and difficult to build but is the best for colder climates. Liquid drains out of the system when the water heater is not in use to stop the water from freezing.

Below: A homemade evacuated tube solar water heater which has been built as a freestanding unit.

diy solar water heater, active

Passive solar water heater system

A passive DIY solar hot water heater is the best for those people who live in a warmer climate. They use no moving parts and are the simplest and cheapest to build at home. If you live in a region where it freezes then this system is not suitable for you as it will be easily damaged.

Right: Passive solar water heaters are self contained units and have no moving parts

It is essentially a big sort of (specially designed) water tank which sits on your roof. It heats up water and stores it until it is needed. It is then either drawn into a conventional water system where it is heated even more or it goes directly to the tap.

You can buy a complete passive solar water heating system for just over $2000 or you could easily build one for yourself in a weekend for about $300 - $600.

Advantages of solar over conventional water heaters

The advantages that come with building your own DIY solar water heater are massive and can range from saving the planet, saving you money and even adding value to your property.

DIY solar heating system plans

With the marvelous invention of the internet you now have a massive range of plans and information relating to DIY solar hot water systems so you will never feel alone while creating your system.

One of the best guides that I have come across for building your own system is actually the same one with which I used to build my own DIY solar water heater. It claims a fully functional system can be built for less than $90 but in reality it is a bit more than this. If I remember well I spent about $200 on my system. Despite this, the guide is completely accurate with clear directions, videos and information. Follow this link to get the instructions for this passive solar water heater.

If you think that your location and situation is more suited to an active heating system then follow this link for DIY plans for an active solar water system.

Below: Example of a DIY solar water heater plan for a single passive integral tank system.

How much can I save

Depending on where you live and how much ho water you use you could save about a third off you power bill and between 50% and 100% off your hot water bill. Use the link to the DIY solar hot water heater savings calculator below to find to work out exactly how much money and carbon you could save.

Solar water heater calculator

If you want to know how much money you could save by using the sun to heat your water then have a look at this solar hot water calculator. By taking some basic information about your current water consumption, bills and current heating method, you can more or less calculate exactly how much money you can save with a solar water heater.

How much CO2 can I save

The average family of 4 uses just over 6000KWH a year for just heating water. This releases about 8 tons of CO2. If your water heater runs on gas you will release about 2 tons of CO2.

But I'm no DIY expert

To build a passive DIY solar water heater you do not need much DIY experience, but you do need to know how to use a screw driver and a pair of pliars. The plans which are linked to above for an active power system are a bit more complicated so if you're not a confident DIYer then it is probably best to invest in a 'plug and play' solar electric hot water system. They cost between $1500 and $3000 meaning that they will pay for themselves in about 4 to 6 years.

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