Solar Hot Water Systems Explained

A Complete Guide for Adelaide Homes

Solar hot water systems are one of the most energy-efficient and environmentally friendly ways to heat water for your home.

With Adelaide’s long sunny days and over 2,500 hours of sunshine each year, solar hot water can supply the majority of your household’s hot water using free energy from the sun – helping reduce energy bills and lower your carbon footprint at the same time.

At SA Hot Water Adelaide, we’ve worked with solar hot water systems for over 40 years. This guide explains how they work, the different system types available, typical costs, and how to decide if solar is right for your home.

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Why Consider Solar Hot Water?

Water heating accounts for around 25% of the average Australian home’s energy use. Switching to solar can significantly reduce that cost.

Many Adelaide households see:

✔ Lower electricity or gas bills
✔ 60–90% of hot water heated by the sun
✔ Reduced environmental impact
✔ Long system lifespan
✔ Less reliance on rising energy prices

When installed correctly, solar hot water can be one of the most cost-effective long-term solutions available.

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How Solar Hot Water Systems Work

A solar hot water system uses roof-mounted collectors to absorb heat from the sun and transfer it into your home’s water supply.

Most systems include:

Solar collectors

Panels or tubes that capture sunlight and convert it into heat.

Storage tank

Stores heated water for household use.

Booster (gas or electric)

Automatically heats water when solar gain is low (cloudy days or high demand).

During sunny periods, the sun does most of the work. The booster only runs when needed, keeping running costs low while ensuring reliable hot water all year.

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Types of Solar Hot Water Systems

There are two main system designs used in Adelaide homes.

Thermosiphon (Close-Coupled) Systems

The tank and collectors are mounted together on the roof.

Best for:

• Simpler installations

• Lower upfront cost

• Strong natural water circulation

• Fewer moving parts

Considerations:

• Heavier roof load

• Tank visible from the ground

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Split Systems

Collectors are mounted on the roof while the storage tank sits on the ground.

Best for:

• Cleaner roof appearance

• Easier maintenance access

• Heavy tanks off the roof

• Flexible placement

• Adelaide climate

Considerations:

• Slightly higher installation cost

• Requires a small circulation pump

Both systems work well – the right choice depends on your roof structure, space and preferences.

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Collector Types: Flat Plate vs Evacuated Tube

Flat Plate Collectors

Traditional panel design that performs well in sunny climates.

✔ Reliable
✔ Affordable
✔ Proven technology

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Evacuated Tube Collectors

More advanced tubes that capture and retain heat more efficiently.

✔ Higher efficiency
✔ Better performance in cold or cloudy weather
✔ Frost resistant
✔ Easy tube replacement if damaged

Many Adelaide homes choose evacuated tubes for improved year-round performance.

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Choosing the Right Size System

Sizing your system correctly ensures consistent performance and lower running costs.

As a general guide:

Actual requirements vary depending on usage habits and peak demand times.

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Running Costs & Savings

Although solar systems typically cost more upfront than electric or gas systems, they are much cheaper to run.

Because most heating is powered by the sun:

• Daily energy use is lower

• Boosters run less often

• Bills decrease over time

Many households recover installation costs through energy savings within several years.

Long-term, solar hot water often has the lowest operating cost of any hot water system.

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Solar Hot Water Boosters Explained

Even in Adelaide’s sunny climate, backup heating is important.

Boosters ensure you always have hot water by activating automatically when needed.

Gas Boosters

✔ Fast heating
✔ Lower running cost
✔ Popular in homes with mains gas

Electric Boosters

✔ Simple and reliable
✔ Easy installation

Both options provide seamless, year-round hot water regardless of weather.

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Solar Hot Water Rebates & Incentives

Solar systems may be eligible for government incentives or Small-scale Technology Certificates (STCs), which can help reduce upfront costs.

Available rebates change over time, so it’s worth checking current programs before installing.

(For detailed rebate information, visit our dedicated rebates page or speak with a licensed installer.)

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Is Solar Hot Water Right for Your Home?

Solar can be a great option if:

✔ Your roof receives good sunlight
✔ You want lower long-term running costs
✔ You plan to stay in your home long term
✔ You want a more sustainable solution

It may be less suitable if:

• Roof space is limited

• Heavy shading

• Short-term property ownership

An onsite assessment helps determine the best solution.

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Trusted Solar Hot Water Brands

At SA Hot Water Adelaide, we work with proven brands designed for Australian conditions, including:

• Rheem

• Apricus

• Rinnai

• Dux

• Aquamax

Choosing a reputable brand ensures better performance, warranty support and parts availability.

Solar vs Gas vs Electric vs Heat Pump – Which Hot Water System Is Best?

Choosing the right hot water system depends on your budget, home setup, and long-term running costs. Each type has different installation costs, efficiency levels and ongoing expenses.

Here’s a simple comparison to help Adelaide homeowners understand the differences:

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Solar Hot Water

Uses free energy from the sun to heat most of your water, with a gas or electric booster for cloudy days.
✔ Lowest long-term running costs
✔ Excellent for Adelaide’s sunny climate
✔ Higher upfront cost but biggest savings over time

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Gas Continuous Flow

Heats water instantly only when needed.
✔ Reliable and fast
✔ No storage tank required
✔ Good option if your home already has natural gas
✖ Still relies on gas daily

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Heat Pump Systems

Extract heat from the surrounding air to warm your water.
✔ Very energy efficient
✔ Lower running costs than standard electric
✔ Works well in most Adelaide conditions
✖ Slightly higher upfront cost than electric

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Electric Storage

Traditional tank system using electricity.
✔ Cheapest to install
✔ Simple setup
✖ Highest running costs long term
✖ Less energy efficient

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So, Which Is Best for Adelaide Homes?

• Best long-term savings: Solar

• Best balance of cost & performance: Heat Pump

• Best if you already have gas: Gas Continuous Flow

• Lowest upfront cost: Electric Storage

The right choice depends on your roof space, budget, energy usage and how long you plan to stay in your home.

If you’re unsure, getting professional advice can help you compare options and choose the most cost-effective system for your situation.

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Frequently Asked Questions

How much can I save with solar hot water?

Many homes reduce water heating costs by 60-90%, depending on usage and system size.

Will I still have hot water on cloudy days?

Yes. Your booster automatically heats water when solar energy isn’t sufficient.

How long do solar hot water systems last?

Most systems last 10–20+ years with proper maintenance.

Are solar systems expensive to maintain?

Maintenance is generally minimal, with occasional servicing recommended.

Can I replace my existing gas or electric system with solar?

Yes. Most homes can upgrade to solar with the correct setup.

Need Advice About Solar Hot Water?

If you’re researching solar hot water systems and want clear, professional advice, our Adelaide team is happy to help you understand your options and choose the right solution for your home.

📞 Call (08) 8444 7320 to speak with a local hot water specialist