An introduction to solar hot water systems for the home

Solar panels, while not exactly a common feature on houses, are becoming more and more commonplace. There are two major incentives for using solar power: you can use it to power your home and save on electricity bills; and it's a renewable energy source, which can help the environment. But solar power is not only limited to powering electricity in the home – it can also be used to directly heat your water supply.

Actually, turning solar power into heat is easy.

Although you might be more used to the idea of solar panels transforming solar energy into electricity, it is actually easier to convert solar power into heat. And with Australian's hot summers (that are only getting hotter), it's a great idea to harness this natural resource and save on your hot water bills. After all, most people use hot water every single day – when they take showers, when they wash the dishes, and when doing laundry.

How does a solar hot water system actually work?

At the core of any solar water system is a solar collector. This is essentially a box that contains the water as well as the sun's radiation – the two most fundamental parts of any solar water heating system. Every solar hot water system will have this, and the only distinction that is really made is whether you opt for a passive or an active system.

Passive system. A passive system is more popular because it only relies on the forces of nature to heat the water. The water naturally warms up right there inside the tank, and through the natural force of convection it gets transferred to the pipes of the home.

Active system.  The difference with an active system is that the solar collector doesn't directly heat water, but instead heats a heat transfer solution, such as antifreeze. There is never a risk of the antifreeze mixing with the water because it is located in a separate "closed loop" system to the water. This loop makes a circuit through the solar collector and then transfers the heat via a heat exchanger in another tank.

Are there DIY solar water heater options?

If you are keen on home improvements, you might want to have a go at building your own water collector. After all, in its most basic form, the passive solar heating system is a box, some insulation, glazing, and pipes. You can purchase DIY kits with everything that you need inexpensively from home and garden centres. But it can still definitely be worth parting with some more cash and having a professional install your system. This is because it can be hard for a solar novice to understand where to best position a heater system for maximum exposure to sunlight, and it can also be difficult to know where is the best place to support the weight of giant box filled with water.

The benefits for the environment

The world is heating up, and many people are realising that the only way to kerb the negative effects that climate change is having on the environment (increased risk of drought, increased storm damage, extinction of animal species, and more) is to take personal responsibility for the way their actions impact on the natural world each day. By installing a solar hot water system, you will use a powerful and abundant resource in Australia, the sun, which is far more energy efficient than using electricity to power your hot water. Why is this? Well, although electricity can be generated with green resources such as wind turbines and solar power, the vast majority of electricity is generated by burning natural resources such as coal and oil. These are in limited supply, and burning these fuels is heating up the planet and contributing to climate change. And yes, you could potentially use solar panels to generate the electricity for heating water, but it's more efficient to heat the water directly with a solar hot water system.