Best Solar Hot Water Systems in Australia 2023: What to Compare Before Choosing

Solar hot water can be a smart option for Australian homes with suitable roof space, strong sun exposure and the right household usage pattern. But the “best” solar hot water system is not the same for every home.

A roof-mounted solar hot water system may suit one property, while a split solar system or heat pump hot water system may be a better fit for another. The right choice depends on roof orientation, roof pitch, shading, roof structure, tank size, booster type, household demand, installation access, maintenance access and available incentives at the time of purchase.

Installed Today helps customers compare hot water options online, including hot water systems, heat pump hot water systems, electric hot water systems and gas hot water systems. Supply-only ordering is available across major Australian metro areas, with selected supplied-and-installed options available on eligible products in Brisbane and Gold Coast service areas where shown.

Quick Answer

The best solar hot water system in Australia in 2023 depends on your roof, climate, household size and backup heating requirements.

A solar hot water system may suit homes with:

• Good north-facing or high-sun roof space

• Minimal shading from trees, buildings or roof features

• Suitable roof structure for collectors or a roof-mounted tank

• Enough hot water demand to justify the system

• A suitable electric or gas booster

• Safe access for installation and future maintenance

• Eligibility for current STCs, rebates or incentives where available

A heat pump hot water system may be a practical alternative where solar panels are difficult because of roof shading, roof structure, limited roof space or access issues.

What Is a Solar Hot Water System?

A solar hot water system uses solar collectors to capture heat from the sun and transfer that heat into water stored in a tank.

Most solar hot water systems include:

• Solar collectors

• A storage tank

• A circulation method

• Electric or gas boosting

• Valves and pipework

• Controls or sensors on some systems

Solar hot water is different from solar PV. Solar PV panels generate electricity, while solar hot water collectors are designed specifically to heat water.

Solar hot water can reduce reliance on electricity or gas, but performance depends heavily on the property. Roof direction, roof pitch, shading, weather, tank size and booster use all affect results.

Main Types of Solar Hot Water Systems

Roof-Mounted Solar Hot Water Systems

A roof-mounted solar hot water system usually has both the tank and collectors installed on the roof. These are often called thermosiphon systems because they use natural circulation as hot water rises.

Roof-mounted systems can be simple and efficient in the right location, but they are heavier because the tank sits on the roof.

They may suit homes with:

• Strong roof structure

• Good sun exposure

• Suitable roof pitch

• Minimal shading

• Safe installation access

• Enough roof space for the tank and collectors

They may not suit homes where the roof is shaded, fragile, difficult to access or not suitable for the extra weight.

Split Solar Hot Water Systems

A split solar hot water system has collectors on the roof and a storage tank installed at ground level. A pump circulates water or heat transfer fluid between the collectors and tank.

Split systems can reduce roof weight because only the collectors are on the roof. They can also keep the tank easier to access for servicing.

They may suit homes with:

• Suitable collector roof space

• Limited roof load capacity

• Ground-level space for the tank

• Practical pipe runs between roof and tank

• Easy access for servicing

• A suitable booster location

Split systems can involve more components than roof-mounted systems, so installation quality and maintenance access matter.

Heat Pump Hot Water Systems as a Solar Alternative

A heat pump hot water system is not a solar hot water system, because it does not use roof-mounted solar collectors. Instead, it uses electricity to move heat from the surrounding air into water stored in a tank.

However, heat pumps are often compared with solar hot water because they can be an efficient electric hot water option and may pair well with solar PV where timer operation and household usage suit.

A heat pump hot water system may be worth considering where:

• The roof is shaded

• Roof access is difficult

• Roof structure is not suitable for solar collectors

• The home already has solar PV

• Outdoor tank space is available

• Clear airflow is available

• Condensate drainage can be managed

• Noise placement is suitable

Heat pumps are not automatically the best choice for every home. Outdoor location, airflow, drainage, tank size, electrical suitability and noise placement all need to be checked.

Customers comparing sizes can browse medium heat pump hot water systems from 200L to 280L or large heat pump hot water systems over 280L.

Solar Hot Water vs Heat Pump Hot Water

Solar hot water and heat pump hot water can both be efficient options, but they suit different homes.

Solar Hot Water May Suit:

• Homes with excellent roof sun exposure

• Properties with minimal shading

• Homes with suitable roof structure

• Households with consistent daily hot water use

• Customers who want a solar thermal system

• Properties where roof access and maintenance access are practical

Heat Pump Hot Water May Suit:

• Homes with shaded or difficult roofs

• Homes with solar PV already installed

• Properties with outdoor tank space

• Customers wanting an efficient electric replacement

• Homes without natural gas or LPG

• Brisbane and Gold Coast homes with suitable outdoor airflow and drainage

For many homes, heat pump hot water systems can be a practical alternative to traditional solar hot water where the roof is not ideal.

Solar Hot Water vs Electric Hot Water

A standard electric hot water system is often simpler and cheaper upfront than solar hot water, but it may use more electricity depending on tariff, usage and setup.

Electric storage may suit homes that want a straightforward like-for-like replacement and do not have gas. Common replacement sizes include 250L electric hot water systems, 315L electric hot water systems and 400L electric hot water systems.

Solar hot water may suit homes with suitable roof conditions and higher long-term efficiency goals, but the installation is more complex and roof suitability matters.

Do not automatically replace an old electric system with the same size if the old unit regularly ran out of hot water. Household demand should be checked first.

Solar Hot Water vs Gas Hot Water

Gas hot water systems can be a practical option where natural gas or LPG is already available. Gas systems include gas storage and instant gas hot water.

Instant gas hot water systems heat water on demand and do not store hot water in a tank. They can suit homes with limited space and suitable gas supply.

Solar hot water may reduce reliance on gas or electricity, but it needs suitable roof conditions and a booster for cloudy weather or high-demand periods.

Natural gas and LPG are not interchangeable. Gas work must be completed by a licensed gas fitter.

What Size Solar Hot Water System Do You Need?

Solar hot water sizing depends on household demand and available solar gain.

Key factors include:

• Number of people in the home

• Number of bathrooms

• Shower length and frequency

• Bath use

• Kitchen and laundry use

• Whether hot water is used at the same time

• Tank size

• Collector size

• Booster type

• Roof orientation and shading

• Local climate

• Whether the old system ran out of hot water

A system that is too small may rely heavily on boosting. A system that is too large may cost more upfront than necessary. Sizing should be confirmed by a suitable hot water professional before ordering.

Roof Factors That Matter

Solar hot water is heavily affected by roof conditions. Before choosing a system, check:

• Roof orientation

• Roof pitch

• Shading from trees or neighbouring buildings

• Roof age and condition

• Roof structure

• Roof material

• Collector layout

• Tank weight if roof-mounted

• Wind exposure

• Access for installation

• Access for future servicing

A shaded roof or difficult roof layout can reduce performance and increase installation complexity. In these cases, a heat pump may be a more practical alternative.

Booster Options: Electric or Gas

Most solar hot water systems need a booster to maintain hot water supply when solar input is low.

Common booster options include:

• Electric boosting

• Gas boosting

Electric boosting may suit homes without gas or homes with suitable electrical supply. Gas boosting may suit homes with an existing natural gas or LPG connection.

The booster should match the household’s usage pattern and installation requirements. Electrical work must be completed by a licensed electrician where required, and gas work must be completed by a licensed gas fitter.

Are Solar Hot Water Rebates Available?

Solar hot water systems and heat pump hot water systems may be eligible for STCs, rebates or incentives depending on the product, installation location, program rules and current eligibility requirements.

Rebates, STCs and incentives can change. Do not choose a hot water system based only on a possible rebate. Always confirm current eligibility before relying on any discount, certificate or incentive.

The right system should suit the home first. Roof conditions, tank size, booster type, access, energy source and household demand matter more than rebate potential alone.

Common Solar Hot Water Mistakes

Choosing Solar Without Checking Roof Shading

Even a good system can underperform if collectors are shaded for too much of the day.

Ignoring Roof Structure

Roof-mounted tanks are heavy. The roof structure must be suitable before choosing this type of system.

Assuming Solar Means No Booster

Solar hot water systems usually need electric or gas boosting for cloudy weather, winter periods or high-demand use.

Choosing the Wrong Tank Size

A tank that is too small may run out of hot water. A tank that is too large may add unnecessary cost.

Forgetting Maintenance Access

Solar collectors, valves, pipework and tanks need access for inspection and maintenance.

Relying Only on Rebates

Rebates and STCs can change. Suitability should come before incentives.

Not Comparing Heat Pump Alternatives

Where the roof is shaded, complex or unsuitable, a heat pump can sometimes be the more practical efficient hot water option.

Brisbane and Gold Coast Considerations

Brisbane and Gold Coast homes can be suitable for solar hot water because of strong sun exposure, but property conditions still matter.

Homes with north-facing roof space, minimal shading and good installation access may be better suited to solar collectors. Homes with shaded roofs, narrow access, complex roof lines or limited roof strength may be better suited to a heat pump hot water system or another replacement option.

Coastal properties may also need careful product placement and maintenance planning due to exposure. Always confirm suitability before ordering.

Selected supplied-and-installed options are available on eligible Installed Today products in Brisbane and Gold Coast service areas where shown. Availability depends on the product, address and installation requirements.

Supply-Only vs Supplied-and-Installed

Installed Today offers supply-only ordering across major Australian metro areas. This can suit customers who already have a licensed installer organised and want to order the product online.

Selected supplied-and-installed options are available on eligible products in Brisbane and Gold Coast service areas. Availability depends on the product, address and installation requirements.

For supply-only products, the listed product price generally covers the product only.

It does not usually include:

• Installation labour

• Plumbing alterations

• Electrical work

• Gas work

• New valves

• Pipework changes

• Gas pipe upgrades

• Drainage changes

• Tempering valve upgrades

• Pressure limiting valve upgrades

• Expansion control valves

• Old unit removal

• Disposal

• Compliance upgrades

• Concrete bases or slab work

• Flue kits unless listed

• Temperature controllers unless listed

• Relocation of the system

• Rebate administration

• Site assessment

For solar hot water specifically, confirm roof suitability, collector placement, booster type, tank location and installation requirements with a qualified installer before ordering.

Before Ordering Checklist

Before choosing a solar hot water system, check:

• Is the roof orientation suitable?

• Is the roof pitch suitable?

• Is there shading from trees, buildings or roof features?

• Is the roof structure suitable for collectors or a tank?

• Is there safe roof access?

• Is future maintenance access practical?

• What tank size does the household need?

• Is an electric or gas booster required?

• Is the electrical supply suitable?

• Is natural gas or LPG available if gas boosting is needed?

• Is there enough ground space for a split system tank?

• Would a heat pump be more practical than roof collectors?

• Are STCs, rebates or incentives currently available?

• Is the product supply-only or supplied-and-installed?

• Has a licensed installer confirmed suitability?

Frequently Asked Questions

What is the best solar hot water system in Australia in 2023?

The best solar hot water system depends on the home. Roof-mounted systems may suit strong roofs with good sun exposure. Split systems may suit homes where the tank is better kept at ground level. Heat pumps may suit homes where the roof is shaded, difficult or unsuitable for solar collectors.

Is solar hot water worth it?

Solar hot water can be worth considering where the home has suitable roof space, minimal shading, good installation access and consistent hot water demand. It may not be the best option where the roof is heavily shaded, access is difficult or the installation cost is too high.

Is a heat pump the same as solar hot water?

No. A heat pump does not use roof-mounted solar collectors. It uses electricity to move heat from the air into a storage tank. However, heat pumps are often compared with solar hot water because they can be an efficient hot water option and may pair with solar PV where the setup suits.

Do solar hot water systems need a booster?

Yes, most solar hot water systems use an electric or gas booster to maintain hot water during cloudy weather, winter periods or high hot water demand.

What roof direction is best for solar hot water?

A high-sun roof position is generally preferred, with minimal shading throughout the day. The best orientation and layout should be checked by an installer because roof pitch, local conditions and system type all matter.

Can I install solar hot water myself?

No. Solar hot water installation involves plumbing and may involve electrical or gas work. Licensed trades should complete the work where required.

Are rebates available for solar hot water?

STCs, rebates or incentives may be available depending on the product, location and current program rules. These can change, so eligibility should be confirmed before purchase.

Is solar hot water better than heat pump hot water?

Not always. Solar hot water can suit homes with excellent roof conditions. Heat pumps can be better where roof space is shaded, limited or difficult. The better option depends on the property and household usage.

Final Word

The best solar hot water system in Australia in 2023 is the one that suits your roof, household demand, booster setup and installation requirements.

Solar hot water can be a strong option where the home has excellent roof exposure and practical installation access. A split solar system may suit homes where the tank is better positioned at ground level. A heat pump may be a better alternative where roof shading, roof weight, access or complexity makes solar collectors less practical.

Before ordering, compare your energy source, roof conditions, tank size, booster requirements and long-term maintenance access. For supply-only orders, confirm suitability with a licensed installer first.

Customers comparing hot water options can browse hot water systems, heat pump hot water systems, electric hot water systems and gas hot water systems online with Installed Today.