Zero Net Emissions by 2025

Solar hot water

solarhotUsing the sun to heat all, or at least part of your hot water  helps reduce your carbon footprint. A wide variety of solar hot water systems is available.

What is solar hot water?

Solar hot water systems use the sun’s energy to heat water  through solar collectors on the roof. The heated water is stored in an insulated storage tank. A booster heater is included for when there is not enough sun to provide for your hot water needs. Boosters may be run on off-peak electricity, natural or LPG gas, or wood in a heater with a ‘wet-back’.

Why use it?

Using the sun to heat our hot water reduces the amount of fossil fuel you burn. By reducing our fossil fuel use, we reduce our emissions of greenhouse gases and our footprint on the planet.

Greenhouse gas emissions based on 200 litres a day water use for different types of hot water systems in Melbourne

Method of producing hot water compared with tonnes of greenhouse gas produced per year
Totally electric 4.8
Heat pump 2.5
Solar – electric boost 1.9
Two star gas 1.6
Five star gas 1.3
Solar – instantaneous gas boosted 0.6

Source: adapted from the table in Global Warming – Cool It! A Home Guide to Reducing Energy Costs and Greenhouse Gases. Australian Greenhouse Office 2001

Solar hot water:

• will reduce the amount of gas or electricity you use, saving money
• will reduce your greenhouse gas emissions by up to 88%, and
• may qualify you for a government rebate.

Flat plate collector

Flat plate collector

Types of solar collectors

There are two main types of solar collectors:

  • Flat plate collectors: The most common in use in Australia. They consist of a blackened metal absorber plate in a glazed and insulated metal box. Pipes attached to the absorber plate carry the liquid that is heated by the sun.
  • Evacuated glass tube collectors: These are a relatively new design but are becoming more widely used. They consist of two tubes of glass with a vacuum between them. The vacuum acts like a thermos flask, retaining a very high percentage of the thermal energy absorbed from the sun. This results in reduced energy losses and increases the solar savings.

Types of systems

  • Solar collectors on roof, attached to horizontal storage tank – also known as Close-coupled Thermosiphon (mains pressure)
  • Solar collectors on roof, storage tank in roof space – also known as Remote Thermosiphon (low pressure – gravity). The base of the tank must be slightly above the collectors.
  • Solar collectors on roof, storage tank at ground level – also known as Forced Circulation (mains pressure pumped)
  • Solar pre-heaters 
  • Instantaneous gas-boosted system 
  • Heat pump


In certain situations, solar collectors can be connected directly into an existing off-peak electric hot water system. Before you do this, get a thorough, professional evaluation.

jj1For best performance

You can get peak performance from your solar system by obeying simple rules:

  • Install solar panels so that they face true north, or as near as possible.
  • Make sure the solar panels are free from shading by vegetation or surrounding buildings.
  • Position the hot water storage tank as close as possible to where most of the water is going to be used, such as kitchen/bathroom/laundry.
  • Whenever possible do household tasks that require hot water (laundry etc), early in the day so that the water left in the tank can be reheated by the sun.
  • Set the booster thermostat at no more than 60oC, and lower if possible.
  • Use water-efficient appliances.
  • Make sure the system is properly maintained.
  • Make sure that all system design and installation is done by qualified and accredited professionals.

In central Victoria your solar hot water system must have adequate protection against frost. You will need to seek professional advice as to which one of the many types of systems best suits your needs.

green dollarFinancing options

Bendigo Bank offers green loans to help home owners finance the cost of installing a solar hot water system. See Generation Green, or call 1300 366 666.

Some companies offer an innovative financing package with no up-front costs for the supply of solar hot water systems.

Financial assistance

Go to the Clean Energy Regulator website for the latest information.


While we have made every effort to assess the information below, we cannot guarantee its currency. We do not endorse nor will be held responsible for the products or services offered by these companies, nor for any transactions or business contracts entered into with the businesses listed below.

The list is not exhaustive.

Local Contacts

Solar installer Stephen Breheny
Tel: 0415 507 777

The Solar Bloke
Tel: 5475 2062


Department of Environment, Water, Heritage and the Arts

Sustainability Victoria

Alternative Technology Association (ATA)
Tel: (03) 9639 1500

Clean Energy Council
The Clean Energy Council is an amalgamation of the Australian Wind Energy Association (Auswind) and the Australian Business council for Sustainable Energy (BCSE). The Council represents over 400 businesses.
Tel: (03) 9349 3077

Ballarat Renewable Energy and Zero Emissions Inc (BREAZE)
A “sister” organisation to MASG.

Products and Suppliers

Apricus (evacuated tube technology)
Tel: 1300 277 428

Tel: 1800 676 000

Chromagen Solar
Tel: 1300 367 565

Tel: 1300 266 374

Dux Hot Water
Tel: 1300 365 116

EcoSmart Hot Water
Tel: 1300 326 762

Endless Solar
Tel: 1300 889 585

Edwards Solar Hot Water
Tel: 1300 765 277

Tel: 132 552

Rinnai Solar

Tel: 1300 721 984

Wise Living Products
Tel: (02) 6040 6666


(Page updated January 2015)



Our sponsors & supporters