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Solar Hot Water Systems

Rooftop collectors heat your water straight from the sun. It is a proven technology, and in sunny climates it can cut hot water costs by 50 to 90%.

Off hot water costs
50 to 90%
Years of service
15 to 20
Rebates available
$1,000+
Cost on sunny days
$0
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Solar hot water system on a terracotta tile roof: a stainless steel tank mounted above two flat plate collectors
A close-coupled system: the tank sits on the roof above two flat plate collectors.

How solar hot water works

Collectors on the roof capture sunlight and pass the heat to water stored in an insulated tank.

  1. Collect

    Rooftop collectors absorb sunlight and turn it into heat.

  2. Transfer

    The heat moves into the water by direct flow or through a heat exchanger.

  3. Store

    Hot water is stored in an insulated tank, on the roof or at ground level.

  4. Boost

    A gas or electric booster switches on when the sun is not enough.

Solar hot water system types

Choose between flat plate collectors (better value, warm climates) and evacuated tubes (higher efficiency, cooler climates).

Flat plate collector

The traditional design: a dark absorber plate under glass. Simple, durable and cost-effective.

Advantages

  • Lower upfront cost
  • Very durable
  • Easy maintenance
  • Good in warm climates

Watch for

  • Less efficient in cold or cloudy weather
  • Needs more roof area
  • Can overheat in summer
Best for
Warm climates (QLD, NT, northern WA)
Price
$3,000 to $5,000

Evacuated tube collector

Glass tubes with vacuum insulation around the absorber. Holds heat better and performs better in the cold.

Advantages

  • Higher efficiency
  • Works well in cold or cloudy conditions
  • Individual tubes replaceable
  • Needs less roof space

Watch for

  • Higher upfront cost
  • Tubes can break
  • More complex installation
Best for
Cooler climates (VIC, TAS, SA, highlands)
Price
$4,000 to $7,000

Solar hot water vs heat pump

Both are efficient ways to heat water. The better choice depends on your climate, your roof and what you value.
FactorSolar hot waterHeat pump
Upfront cost$3,000 to $7,000$3,500 to $5,500
Running cost$50 to $150 a year$150 to $250 a year
Cloudy daysNeeds boosterFull performance
Roof spaceRequired (north-facing)Not required
MaintenancePeriodic cleaningMinimal
Lifespan15 to 20 years10 to 15 years
Best climateSunny (QLD, WA, NT)All climates

Choose solar hot water if

  • You live in a sunny climate (QLD, NT, WA)
  • You have good north-facing roof space
  • You want the lowest possible running costs
  • You prefer simple, proven technology

Choose a heat pump if

  • You live in a cooler or cloudier climate (VIC, TAS)
  • You have limited or shaded roof space
  • You want steady performance all year
  • You already have solar PV panels
Learn more about heat pumps

Solar hot water brands

Established Australian and international manufacturers of solar hot water systems.

  • Rheem

    Warranty 5 to 10 years

    Flat plate & evacuated tube

  • Solahart

    Warranty 5 to 10 years

    Flat plate & thermosiphon

  • Apricus

    Warranty 10 years

    Evacuated tube specialist

  • Chromagen

    Warranty 5 to 7 years

    Flat plate systems

  • Hills

    Warranty 5 years

    Flat plate & evacuated tube

Solar hot water rebates

Government rebates can take a good part of the upfront cost off a solar hot water system.
  • Federal$600 to $1,200STCs based on system size and location
  • VIC$1,000Solar hot water rebate for eligible homes
  • NSW$600 to $1,200Federal STCs only
  • QLD$600 to $1,200Federal STCs only
  • SA$600 to $1,200Federal STCs only
View all rebates by state

Solar hot water system prices by size

Prices depend on tank size, collector type and how complex the installation is. Here is a guide to typical costs before and after rebates.

  • 180 to 250L

    Best for
    1 to 2 people
    Price installed
    $3,000 to $4,500
    After rebates
    $2,000 to $3,500

  • 300LMost popular

    Best for
    3 to 4 people
    Price installed
    $3,500 to $5,500
    After rebates
    $2,500 to $4,500

  • 325 to 400L

    Best for
    5+ people
    Price installed
    $4,500 to $7,000
    After rebates
    $3,500 to $6,000

Prices are indicative and vary by collector type, brand and installation requirements. Rebate amounts depend on your state and STC zone.

300 litre solar hot water system

The 300L system is the most popular size for Australian families (3 to 4 people). It gives enough hot water for daily showers, laundry and the kitchen while staying cost-effective to install and run.

Installed price
$3,500 to $5,500
STC rebate
$600 to $1,200
Ideal household
3 to 4 people

Solar hot water in South Australia

South Australia's sunny climate suits solar hot water. Adelaide averages 4.7 peak sun hours a day, which keeps the collectors working.

SA solar hot water benefits

  • High sunshine hours, so the collectors perform well
  • Federal STC rebates ($600 to $1,200 depending on the system)
  • SA’s high electricity prices mean faster payback
  • Flat plate collectors work very well in the SA climate

Recommended for SA

Adelaide's warm climate means flat plate collectors are usually the best choice: simpler, more durable and cheaper than evacuated tubes. A 300L flat plate system typically costs $3,000 to $4,500 after rebates.

View SA rebates

Frequently asked questions

How does solar hot water work?
Solar hot water systems use rooftop collectors to absorb sunlight and transfer the heat to water. The heated water is stored in an insulated tank for use through the day. Most systems include a booster (gas or electric) for cloudy days.
What is the difference between flat plate and evacuated tube solar?
Flat plate collectors are simpler, more durable and work well in warm climates. Evacuated tube collectors are more efficient in cooler climates and cloudy conditions because the vacuum insulation reduces heat loss. Tubes are more fragile, but individual tubes can be replaced.
How much does a solar hot water system cost?
Solar hot water systems typically cost $3,000 to $7,000 installed, depending on the system type, tank size and how complex the installation is. After rebates (STCs), you may pay $2,000 to $5,000 out of pocket.
Do solar hot water systems work on cloudy days?
Solar thermal collectors still absorb some heat on cloudy days, but output drops a lot. Most systems include a gas or electric booster that switches on when solar heating is not enough.
What size solar hot water system do I need?
System size depends on household size and hot water use. Typically, 1 to 2 people need 180 to 250L, 3 to 4 people need 250 to 325L, and 5 or more need 325 to 400L. Cooler climates need a larger collector area.
How long do solar hot water systems last?
Quality solar hot water systems last 15 to 20 years. Tanks typically carry 10-year warranties, while collectors can last 20 years or more. Evacuated tubes may need the occasional replacement.

Get a solar hot water quote

Find out if solar hot water suits your home. A licensed local installer looks at your roof, climate and usage, and recommends the system that fits.

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Up to $8,000+ in solar and battery rebates · Federal rebates step down in 80 daysSee how we calculate this