Solar Hot Water: Your FAQs Answered

Solar power has been a talking point in Australia for decades. In the mid-2000s it enjoyed massive growth thanks to Government rebates. However, for many of us, there are still lingering questions over how well it works, and how solar hot water systems can benefit us.

Metropolitan Plumbing can answer some of those burning questions which just won’t go away. From the basics of how solar works, to whether you can drink water heated by solar power. If there’s something you need to know, we have the answer.

How Does Solar Hot Water Work?

Firstly, let’s distinguish between two types of solar panels, also known as collectors. They are an evacuated tube or flat plate.

Flat plates (or flat panels) are more common, kind of like a dark blue pane of glass on the roof. Copper pipes directly connected to a roof mounted water tank run through the glass covered panel. The copper is heated by the sun and the absorbed energy is transferred through to a storage tank. When you need hot water, you draw it directly from the tank.

Meanwhile, evacuated tubes are essentially a 2-for-1. There’s an inner and outer glass tube, separated by an insulated vacuum containing a copper pipe for heat transfer. Chemicals help absorb heat, which passes through a manifold and is condensed. The heat absorption process is repeated before the water in the tank is warmed.

Does Solar Power Work On Cloudy Days?

It’s one of the most common questions, and rightly so. What would be the point of a hot water system that doesn’t work on cloudy days or at night?

Of course, a solar hot water system will work best during long summer days with few clouds. There’s more heat energy to absorb. However, they also work well in cold climates because they can better conduct electricity and the heat that is present.

Even on dark winter days, you can expect a solar system to produce about 25 per cent of its regular output. Now, this may not sound like a lot, but often it’s enough to cover all your daily needs. Most solar hot water systems are either gas boosted or electric boosted, too, providing all the energy needed for heating water.

Can We Drink Solar Heated Water?

Regardless if it’s solar hot water, electric or gas, the recommendation is you do not drink hot water from the tap. This is because hot water systems, especially storage tanks, can contain minerals and bacteria from the heating process.

Traces of copper could be found in water if it’s left standing in the pipeline or tank for too long. It’s always good to run your pipes for at least 30 seconds before drinking water from a cold tap. But be sure to not just flush this water away! Use it for watering the garden or dishwashing.

Does Cold Weather Impact Solar Panels?

In the colder parts of Australia which experience frosty winters, can solar power stand tall against the nippy conditions? Yes. Most solar hot water systems include a frost protection valve or anti frost valve. It prevents water from freezing when the temperature drops.

When the temperature falls to 3ºC or lower, the frost protection valve opens. Warm water from the storage tank flows back through the solar panels, limiting the chance for solar collectors to freeze. And once the external temperature picks up to 4ºC – a subtle but important degree change – the valve closes again.

However, even with frost protection it is likely a solar panel will need to have the occasional repair following harsh winters, but it certainly won’t be humbled by the cold. You’ll still have hot water to enjoy!

Is It Worth Getting Solar Hot Water?

Okay, here’s the big answer. Is it worth getting a solar hot water system? In a lot of ways, it does depend on your individual circumstances and there is no one definitive answer.

You may find a gas instantaneous system is best, or even a heat pump. There is a wide range of systems on the market and what works for your neighbour may not be right for you.

But here are the facts.

Typically 25 per cent of electricity bills are spent on water heating each year. If you suddenly swapped to solar power overnight, you’d see anywhere between 50-75 per cent savings on water heating per year, at least when compared to electric storage.

Savings will depend on whether you use electric or gas. Solar is also a long term investment as the upfront costs are higher, so the running costs will lead to an overall average saving, not quite on day 1 or day 100.

It’s not always easy to decide what hot water system is best for you. The experts at Metropolitan Plumbing can help. We’ve been working with all kinds of hot water for over 25 years and can assess your home and your individual needs.

That means we can provide a tailored solution for hot water upgrades or any emergency hot water installation. Just give us a call and our team can help set up a visit from one of our local technicians.