Solar Water Heating System Cost: What to Budget Before Choosing Solar, Heat Pump, Electric or Gas Hot Water

Nov 6, 2024

Solar water heating system cost can vary significantly depending on the system type, roof layout, tank size, booster setup, installation access, plumbing requirements and whether an old system needs to be removed. Solar hot water can be a strong option for some homes, but it is not always the simplest or most cost-effective replacement.

Before choosing solar hot water, it is worth comparing it with heat pump hot water systems, electric hot water systems, gas hot water systems and instant gas hot water systems. The right option depends on your household size, bathrooms, roof conditions, sun exposure, energy source, budget and installation requirements.

Installed Today makes it easy to compare and order hot water systems online, with supply-only ordering available across major Australian metro areas and selected supplied-and-installed options available on eligible products in Brisbane and Gold Coast service areas.

Quick Answer: How Much Does a Solar Water Heating System Cost?

Solar water heating system cost depends on the type of system, storage tank, collectors, booster, roof access and installation complexity. Solar hot water usually costs more upfront than a simple like-for-like electric or gas storage replacement because it can involve roof-mounted collectors, additional pipework, booster connections and more complex installation.

As a general guide:

Solar hot water usually has a higher upfront cost than standard electric or gas storage
Flat-plate solar collectors can be simpler than evacuated tube systems
Evacuated tube systems can be more complex and may cost more
Split solar systems can cost more than roof-mounted close-coupled systems
Electric or gas boosting affects final cost and running cost
Roof access, shading, orientation and structural suitability matter
Old solar collector removal can add cost
Rebates, STCs and incentives can change
Heat pump hot water may be a practical alternative where solar roof conditions are poor

Before ordering any hot water system supply only, confirm product suitability, installation requirements and full site costs with your licensed installer.

What Is a Solar Water Heating System?

A solar water heating system uses roof-mounted collectors to capture heat from the sun and transfer that heat into water stored in a tank. Most solar hot water systems also include a booster so the home still has hot water during cloudy weather, high-demand periods or lower solar gain.

A solar hot water setup may include:

Solar collectors
Hot water storage tank
Electric or gas booster
Circulation pipework
Valves and controls
Roof mounting hardware
Tempering valve
Plumbing connections
Electrical or gas connection where required

Solar hot water is different from rooftop solar PV. Solar PV generates electricity. Solar hot water uses solar heat to heat water directly.

Main Solar Water Heating System Cost Factors

The final cost of a solar water heating system can depend on several site and product factors.

Common cost factors include:

Solar collector type
Tank size
Close-coupled vs split-system design
Electric booster vs gas booster
Roof type
Roof pitch
Roof access
Roof orientation
Shading
Distance between collectors and tank
Whether roof reinforcement is required
Pipework length
Electrical work
Gas work where a gas booster is used
Existing hot water system type
Old solar collector removal
Disposal
Valves and compliance upgrades
Whether rebates or STCs apply
Whether supply-only or supplied-and-installed is available

A product-only price should not be treated as a full installed solar hot water price.

Types of Solar Water Heating Systems

The main solar water heating options include:

Flat-plate collector systems
Evacuated tube collector systems
Close-coupled roof-mounted systems
Split solar hot water systems
Electric-boosted solar hot water
Gas-boosted solar hot water

Each option has different cost, installation and suitability considerations.

Flat-Plate Solar Hot Water Systems

Flat-plate solar collectors are one of the more common solar hot water collector types. They use a flat absorber panel to collect heat from the sun.

Flat-plate systems may suit:

Homes with good sun exposure
Moderate climates
Suitable roof space
Households wanting a more traditional solar hot water setup
Homes where roof-mounted collectors are practical

Cost considerations include:

Collector size
Tank capacity
Roof access
Mounting requirements
Booster type
Pipework route
Installation complexity

Flat-plate collectors may be simpler than some evacuated tube systems, but roof conditions still matter.

Evacuated Tube Solar Hot Water Systems

Evacuated tube solar collectors use rows of glass tubes designed to capture solar heat. They are often compared for performance in cooler or less ideal conditions, depending on the system design.

Evacuated tube systems may suit:

Homes with suitable roof space
Properties where higher collector performance is desired
Some cooler locations
Homes with specialist solar hot water requirements
Households comparing higher-performing solar options

Cost considerations include:

Collector system design
Tube quantity
Roof mounting
Installation complexity
Replacement tube availability
Booster setup
Maintenance requirements

Evacuated tube systems can cost more than simpler solar hot water options, so the performance benefit should be weighed against the upfront cost.

Close-Coupled Solar Hot Water Systems

A close-coupled solar hot water system usually has the tank and collectors mounted together on the roof. This can reduce some pipework complexity but places more weight on the roof.

Close-coupled systems may suit:

Suitable roof structures
Homes with good roof access
Properties with strong solar exposure
Households wanting a roof-mounted solar hot water setup

Cost considerations include:

Roof strength
Roof access
Lifting and mounting requirements
Tank weight
Collector position
Visual impact
Future maintenance access

A roof-mounted tank is not suitable for every home. Roof structure and access should be checked before choosing this type.

Split Solar Hot Water Systems

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

Split systems may suit:

Homes where a roof-mounted tank is not ideal
Properties needing a ground-level tank
Homes with suitable roof collector space
Households wanting easier tank access

Cost considerations include:

Circulation pump
Controller
Longer pipe runs
Roof collector installation
Ground-level tank position
Electrical requirements
Maintenance access

Split solar systems can cost more than simpler setups because there are more components and installation steps.

Electric-Boosted Solar Hot Water

Electric-boosted solar hot water uses an electric element to heat water when solar energy is not enough.

Electric boosting may suit homes that:

Do not have gas
Already use electric hot water
Have suitable electrical supply
Want solar hot water with electric backup
Have roof conditions that support solar collectors

Cost considerations include:

Electrical supply
Booster control setup
Tariff arrangement
Tank size
Solar collector performance
Household hot water demand

Electric boosting can be practical, but it should be compared with electric hot water systems and heat pump hot water systems before making a decision.

Gas-Boosted Solar Hot Water

Gas-boosted solar hot water uses natural gas or LPG as backup heating when solar gain is not enough.

Gas boosting may suit homes that:

Already have natural gas or LPG
Want solar hot water with gas backup
Have suitable gas pipe sizing
Have suitable outdoor installation options
Want to compare gas hot water alternatives

Cost considerations include:

Natural gas vs LPG
Gas pipe sizing
Licensed gas fitting
Booster type
Outdoor installation location
Pipework and valves
Compliance requirements

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

Solar Water Heating System Cost vs Heat Pump Hot Water

A heat pump hot water system is one of the main alternatives to solar hot water. It uses heat from the surrounding air to help heat stored water.

Heat pumps do not need roof-mounted solar collectors, which can make them a practical alternative where roof access, shading or collector placement is difficult.

Option	Upfront Cost Factors	Best Suited To	Key Checks
Solar hot water	Collectors, tank, booster, roof work, pipework	Homes with suitable roof space and sun exposure	Roof orientation, shading, booster, roof access
Heat pump hot water	Tank, compressor, electrical setup, drainage	Homes with suitable outdoor space and airflow	Airflow, condensate drainage, noise, electrical supply
Electric storage	Tank, valves, electrical supply	Simple replacements and homes without gas	Tank size, access, drainage, electrical setup
Gas hot water	Tank or instant gas unit, gas fitting, pipe sizing	Homes with natural gas or LPG	Gas type, gas pipe sizing, water pressure

Heat pump hot water may be worth comparing if the solar hot water cost is high or the roof is not suitable.

Relevant heat pump categories include:

Popular heat pump options to compare include:

Solar Water Heating System Cost vs Electric Storage

Electric hot water systems are usually simpler than solar hot water systems because they do not require roof-mounted collectors.

Electric storage may suit:

Simple like-for-like replacements
Homes without gas
Rental properties
Homes with suitable tank space
Customers wanting a lower-complexity system
Properties where solar roof conditions are poor

Common electric storage categories include:

Popular electric storage systems include:

If your old electric system regularly ran out of hot water, do not automatically replace it with the same size.

Solar Water Heating System Cost vs Gas Hot Water

Gas hot water systems can suit homes already using natural gas or LPG.

Gas hot water options include:

Gas storage hot water
Instant gas hot water
Gas-boosted solar hot water, where suitable

Gas storage may suit homes that want a tank-style system. Instant gas hot water systems may suit homes wanting continuous flow hot water without a large storage tank.

Common gas categories include:

Popular gas hot water options include:

Natural gas and LPG models are different. Always select the correct gas type.

What Can Add to Solar Hot Water Installation Cost?

Solar hot water can involve more site-specific installation work than a standard tank replacement.

Cost add-ons may include:

Difficult roof access
Steep roof pitch
Tile roof work
Roof reinforcement
Crane or lifting requirements
Long pipe runs
Split-system pump and controller setup
Electrical booster work
Gas booster work
Gas pipe upgrades
New valves
Tempering valve upgrades
Pressure limiting valve upgrades
Drainage changes
Old tank removal
Old collector removal
Disposal
Compliance upgrades
Relocation of the system
Non-standard access
Roof plumbing or flashing work

This is why a solar water heating system cost can vary from home to home.

Roof Suitability for Solar Hot Water

Roof conditions are one of the biggest factors in whether solar hot water makes sense.

Before choosing solar hot water, check:

Roof orientation
Roof pitch
Shading from trees or neighbouring buildings
Collector location
Available roof space
Roof age and condition
Roof material
Structural suitability
Access for installation
Access for future maintenance
Distance to the storage tank
Whether the roof can support a close-coupled tank if required

A shaded or unsuitable roof may make a heat pump, electric or gas hot water system more practical.

Solar Hot Water and Booster Costs

Solar hot water systems usually need a booster to provide hot water when solar energy is not enough.

Booster options may include:

Electric booster
Gas booster
In-tank booster
Inline booster
Manual or automatic boosting, depending on system design

Booster setup can affect both upfront and ongoing costs.

Before choosing a booster, confirm:

Energy source
Existing electrical or gas supply
Correct gas type where relevant
Booster location
Control method
Household hot water demand
Installation requirements
Running cost expectations

A solar hot water system without a suitable booster may not meet household demand during poor solar conditions.

Solar Hot Water System Size and Household Demand

The right solar water heating system size depends on the household.

Consider:

Number of people in the home
Number of bathrooms
Shower length
Bath use
Kitchen use
Laundry use
Morning and evening demand
Whether multiple showers run at once
Existing system size
Whether the old system ran out of hot water
Roof collector capacity
Tank size
Booster capacity

Oversizing can increase upfront cost. Undersizing can leave the household short on hot water.

Solar Water Heating System Payback

Solar hot water may reduce the amount of grid electricity or gas used for water heating, but payback depends on the home and usage pattern.

Payback can be affected by:

Upfront system cost
Installation cost
Energy prices
Household hot water use
Solar collector performance
Booster use
Maintenance costs
Rebates or STCs
Roof conditions
How long you stay in the home
Whether another system type would have been cheaper overall

Avoid choosing solar hot water based only on advertised savings. The numbers should make sense for your specific household.

Rebates, STCs and Incentives

Solar hot water, heat pump hot water and some energy-efficient upgrades may be eligible for rebates, STCs or other incentives depending on the product, location, supplier pathway and current program rules.

These incentives can change.

Before relying on any rebate or discount, confirm:

Whether the selected product qualifies
Whether your property qualifies
Whether the old system type matters
Whether supply-only purchases are eligible
Whether an approved supplier or installer is required
Whether pre-approval is needed
Whether the incentive is applied upfront or claimed later
Whether the rebate or STC value is already included in the price

A rebate can improve value, but the system still needs to suit the home.

Maintenance Costs for Solar Water Heating Systems

Solar hot water systems need maintenance like any hot water system. Maintenance requirements vary by model, water quality, roof exposure and installation conditions.

Maintenance may include:

Checking collectors
Checking roof-mounted components
Checking valves
Checking for leaks
Checking the booster
Inspecting pipe insulation
Checking the sacrificial anode where applicable
Checking the pump and controller on split systems
Cleaning collectors where safe and practical
Following manufacturer servicing requirements

Do not climb on the roof or attempt plumbing, gas or electrical repairs yourself.

Maintenance should be factored into the real cost of ownership.

What Is Not Included in Supply-Only Hot Water Pricing?

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
Condensate drainage for heat pumps
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
Solar collector removal
Roof work
Relocation of the system
Rebate administration
Site assessment

Always check the product page and confirm full site requirements with your licensed installer before ordering supply only.

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.

Supply-only may suit you if:

Your installer has confirmed the correct product
The system size suits your household
The energy source has been checked
The correct gas type has been selected where relevant
Electrical requirements have been checked
Water pressure has been reviewed
Roof, access and drainage are suitable
You understand what is not included in the product price

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.

Before choosing a supplied-and-installed option, check exactly what is included and what may be extra.

Brisbane and Gold Coast Considerations

For Brisbane and Gold Coast homes, solar hot water may be worth comparing, but heat pump, electric and gas systems can also be practical depending on the property.

Common local considerations include:

Strong sun exposure on suitable roofs
Shading from trees
Roof orientation
Roof pitch
Tight side access
Replacing older electric storage systems
Comparing heat pump upgrades
Natural gas vs LPG availability
Gas pipe sizing for instant gas
Heat pump airflow and noise placement
Condensate drainage
Old unit removal and disposal
Whether selected products are eligible for supplied-and-installed options

A solar water heating system may look appealing, but the final decision should be based on roof conditions, cost, installation complexity and household demand.

When Solar Hot Water May Be Worth It

Solar hot water may be worth considering where:

The roof has strong sun exposure
Shading is minimal
The home has enough hot water demand
Roof access is suitable
The booster setup is practical
The household plans to stay long term
The installed cost makes sense
Rebates or STCs improve the value
Maintenance access is practical

Solar hot water can be a strong long-term option in the right home.

When Heat Pump Hot Water May Be Better

Heat pump hot water may be better where:

Roof access is difficult
The roof is shaded
The roof structure is unsuitable
You want to avoid roof-mounted collectors
Outdoor ground-level space is available
Airflow is suitable
Condensate drainage is manageable
Electrical supply is suitable
Noise placement is acceptable

A heat pump is not automatically better than solar hot water, but it can be easier to install in many homes.

When Electric or Gas May Be Better

Electric storage may be better where:

You need a simple like-for-like replacement
There is no gas
The budget is limited
Roof conditions are poor
Heat pump location is unsuitable

Gas hot water may be better where:

The home already uses natural gas or LPG
Gas pipe sizing is suitable
Outdoor location is available
Instant gas or gas storage better suits the household
You want a gas-style replacement

The best system depends on site suitability, not just energy type.

Common Mistakes When Comparing Solar Water Heating System Cost

Looking Only at Product Price

Solar hot water cost includes more than the tank and collectors. Installation, roof work, booster setup and old system removal can all affect the final price.

Ignoring Roof Conditions

A shaded, steep or difficult roof can make solar hot water more expensive or less effective.

Forgetting Booster Costs

Solar hot water still needs backup heating during cloudy weather or higher demand.

Assuming Rebates Are Guaranteed

Rebates, STCs and incentives can change and may depend on product, location and installer pathway.

Comparing Solar With Electric Storage Incorrectly

Solar may cost more upfront but may use less grid energy. Electric storage may cost less upfront but could have different running costs.

Ignoring Heat Pump Alternatives

A heat pump may suit homes where roof-mounted solar collectors are not practical.

Forgetting Old Solar Collector Removal

Replacing an old solar hot water system can involve roof collector removal and disposal.

Buying Supply Only Before Installer Confirmation

Supply-only ordering should only happen once your installer confirms the product, site and installation requirements.

Before Ordering Checklist

Before choosing a solar water heating system or alternative hot water system, confirm:

Current system type
Current system size
Whether the old system ran out of hot water
Number of people in the home
Number of bathrooms
Shower habits
Peak hot water demand
Roof orientation
Roof shading
Roof pitch
Roof access
Roof structural suitability
Electric, natural gas or LPG availability
Booster type
Electrical requirements
Gas pipe sizing where relevant
Water pressure
Heat pump airflow and drainage if comparing heat pumps
Outdoor or indoor suitability
Access for delivery and installation
Drainage and overflow requirements
Whether new valves may be needed
Whether old unit removal is included
Whether solar collector removal is needed
Whether disposal is included
Whether rebates or STCs may apply
Whether supply-only affects rebate eligibility
Whether supply-only or supplied-and-installed is the right option
Installer confirmation before buying supply only

Frequently Asked Questions

How much does a solar water heating system cost?

Solar water heating system cost varies depending on the collector type, tank size, booster, roof access, installation complexity, old system removal and whether rebates or STCs apply.

Is solar hot water cheaper than heat pump hot water?

Not always. Solar hot water can cost more upfront because it may involve roof-mounted collectors and more complex installation. Heat pump hot water can be a practical alternative where outdoor space, airflow and drainage suit.

Is solar hot water cheaper than electric hot water?

Solar hot water may reduce grid energy use, but electric storage is often simpler and may cost less upfront. The better option depends on household demand, roof conditions and budget.

What is the cheapest hot water system to install?

A like-for-like replacement is often simpler than changing system type, but the cheapest upfront option is not always the best long-term choice.

Do solar hot water systems need a booster?

Yes, most solar hot water systems need an electric or gas booster for cloudy weather, high-demand use or lower solar gain periods.

Are solar hot water rebates available?

Rebates, STCs and incentives may be available depending on product, location and current program rules. Eligibility can change, so confirm before ordering.

Is solar hot water worth it?

Solar hot water may be worth it where the roof is suitable, the household uses enough hot water and the installed cost makes sense. It should be compared with heat pump, electric and gas options.

Can I install solar hot water myself?

No. Solar hot water systems involve plumbing, roof work, electrical or gas boosting, valves, water pressure and compliance requirements. Use licensed trades where required.

What is better, solar hot water or heat pump?

Solar hot water may suit homes with suitable roof space and sun exposure. Heat pump hot water may suit homes with outdoor space, airflow, drainage and electrical suitability.

Does supply-only hot water pricing include installation?

No. Supply-only generally means the product only unless installation is selected or clearly shown. Installation, valves, electrical work, gas work, pipework, drainage, removal, disposal and compliance upgrades are usually separate.

Final Word

Solar water heating system cost depends on more than the product. Roof access, collector type, tank size, booster setup, pipework, old unit removal, collector removal, valves, rebates and installation complexity can all change the final price.

Solar hot water may suit homes with good roof space and strong sun exposure, but heat pump, electric and gas hot water systems should also be compared. A heat pump may be more practical where the roof is shaded or difficult. Electric storage may suit simple replacements. Gas hot water may suit homes already using natural gas or LPG.

Before ordering supply only through Installed Today, confirm the selected product with your licensed installer. If choosing a supplied-and-installed option in an eligible Brisbane or Gold Coast service area, check exactly what is included before placing the order.

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