Solar Hot Water

Solar Hot Water Heater Top Three List

There are so many solar hot water systems available it can become a nightmare choosing between all the possibilities.

And what's worse, a wrong choice can be costly because there is a marked efficiency difference between them, they are not all created equal.

So to make things easier I've compared thousands of solar water heating systems based on their performance, to find the best three in each specific country and tank size.

If you're thinking of installing one at your home then this top three list below could provide useful information for you.

Contents of the List

  • The brand names of the three best solar hot water systems in each of the following countries: South Africa, India, Australia, USA.
  • The opportunity to request a quote so that you can find out what each system costs directly from the manufacturer/installer.
  • The list is categorized by water tank size and divided into two sections where applicable namely indirect and direct systems...

      If you live in area where water freezing temperatures occur then you should only look at the indirect section because if you install a direct system the water in the collector could freeze and rupture the pipes.

      Don't experience water freezing temperatures where you stay? Then you can consider installing a direct or indirect unit so look at both sections.

    How To Get the List

    The solar hot water top three ranking list is available free of charge.

    You will need to choose below according to the water tank size that is relevant to you and your family. Use the following formula to roughly work out what your household's ideal solar water heater tank size is...

    Multiply the number of people in your household by 50 litres (15 gal.), and then add 50 litres (15 gal.) to that amount to get the final total of estimated hot water consumption per day in your particular situation.

    This list is for domestic solar geysers from 150L to 499L. If you're looking for commercial large scale solar water heating then these 500L to 2000L solar tanks might provide a solution for you.

    Choose your country below and click on the tank size that comes closest to your estimated consumption. Then complete the form on the page that follows and I will e-mail that top three list to you right away...

    How The Top Three Ranking List is Compiled

    India / South Africa / Australia / United States


    The Ministry of New and Renewable Energy is responsible for maintaining the standards of solar water heating in India and they provide approval for a number of efficiency test centres around the country such as the School Of Energy Studies , University of Pune.

    These efficiency centres conduct solar water heater tests at regular intervals that conform to the specifications set by the Bureau of Indian Standards (BIS). Only companies that have a current BIS licence from an approved MNRE test centre are included on the top three list.

    South Africa

    Eskom launched a rebate program for solar geysers in 2008. To qualify for a rebate, all systems need to undergo testing carried out by the South African Bureau of Standards (SABS).

    Each one tested by the SABS receives a rating (Q-factor), which indicates the kilowatt-hours (kWh) of electricity it's expected to save on a typical day and the units ability to produce hot water.

    The Eskom solar hot water rebate amount is calculated based on these test results and I've used them to compare 449 different solar geyser systems to find the final top three.


    Rebate amounts reflect performance in Australia so the systems with the highest rebates are the ones that should perform the best.

    The Office of the Renewable Energy Regulator (ORER) maintains a register where they award small-scale technology certificates (STCs) to each solar hot water system based on performance measured by them so that an appropriate rebate can be calculated.

    I've compared the 6394 different models on that register to find the best of the best in each category.

    United States

    The body responsible for rating solar water heaters in the USA is the Solar Rating and Certification Corporation and they make use of the Solar Energy Factor (SEF) as the performance parameter for each system.

    I've compared the 1580 different systems rated by them and found the top three in each tank size category with the highest SEF numbers as these should be the best performers.

    And then to confirm their efficiency I've also indicated which of these systems has managed to achieved Energy Star status.