Australian solar hot water installations top one million mark

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More than one million solar hot water systems have been installed in Australia, adding to the more than 1.5 million rooftop PV systems.

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The number of solar hot water systems installed in Australia has topped the one million mark, according to the Clean Energy Regulator, but the rate of installation is at its lowest in a decade.

The CER said in a statement on Friday that the one-millionth system was installed in Weston, New South Wales and demonstrates the “continuing strong interest from households to participate in the small-scale renewable energy scheme and enjoy the financial and environmental benefits that come along with that.”\


But the data also shows that the rate of installations has slowed rapidly. So far in 2016, some 33,000 systems have been installed, suggesting that the country is heading for its lowest total since 2006, when nearly 36,000 were installed.

The peak years, as this table below shows, were in 2009, with nearly 200,000 installations, and 2010 and 2011, with more than 100,000.

More than 258 000 solar hot water systems have been installed in New South Wales, making it the state with the largest uptake in the country, but closely followed by Queensland and Victoria.


solar water

“An average household can use around 25 per cent of its total energy on heating water and so solar water heaters are an excellent way to reduce energy bills,” said Mark Williamson, executive general manager at the Clean Energy Regulator.

More than 2.5 million small-scale systems have been installed across Australia since the scheme began in 2001. In total, these installations now have the capacity to generate or displace approximately 9.5 million megawatt hours of electricity each year, enough to power more than 1.4 million average Australian homes.

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  1. John Saint-Smith 3 years ago

    If all these hot water units were still connected to the grid on night rates, where excess ‘spin’ energy is generated by base load coal fired power stations which cannot switch off and must maintain a steady 3000rpm, they would be consuming 4 million kwh per night, or 1.5 Twh of fossil generated grid electricity per year. Since they’re no longer connected, I assume that most of that power would be wasted – or sold even more cheaply for some industrial process.

    Why not re-direct that ‘unavoidable’ fossil fuelled power to battery or pumped hydro storage, thereby reducing the ‘ramping problem’ faced by a proposed 50% renewable/coal fired grid mix like Queensland or Victoria?. Since it could be delivered as needed and therefore sold at ‘peak’ prices, it would also be worth $100s millions more!

    As more and more bulk electricity storage is installed, night-rate electricity would become more costly, encouraging more consumers to switch to solar, a win-win-win for the operator, consumer and the environment.

  2. john 3 years ago

    I put a solar hot water system on my roof from an Australian maker in 1995, with no subsidy, when i purchased the residence my results most years only in the middle of winter, if it rains for 3 days i have to augment the output with power from fortunately the solar PV system, so yes putting solar especially now as you pay a lot less than i did makes sense.

    • solarguy 3 years ago

      John,you would only hope PV would boost on rainy days, but it won’t as PV output on rainy days can be between 5-25% of normal output. So no it isn’t happening.

      • john 3 years ago

        I am very aware of that.
        My worst days production was 3 KWr of power.
        However over the last 20 years using solar hot water system which boils most days before 10 am is that on average it needs help for about 3 days a year.
        Some times the PV array has enough output to help but in the middle of winter with 3 days of constant rain and cloud cover obviously not.
        So i am realistic about the situation.

    • Rod 3 years ago

      We were given three used Solar hot water collectors around the same time and hooked them up to a locally (SA) made gravity feed tank. Worked flawlessly for 15 odd years until the collectors finally corroded.
      Replaced them with Rinnai (I think) for an overpriced $700 each.
      This set up should last 20 years at least due to the non pressurised system. No pumps to run either. Some people don’t like gravity feed though.
      Like you, I only boost during Winter as needed. Given the wet/cold Winter we have just had the $70 cost to heat our water is tolerable.
      I’m on a higher FiT so boost comes from the grid for now.

      • john 3 years ago

        Considering it is a 1500 watt heater and only runs for say 3 hours for a few days a year the total cost would be $5.00 a year

        • Rod 3 years ago

          I wish mine was $5.00 per year!
          I’m in Adelaide and only have flat panel collectors which aren’t as efficient in cloudy conditions as the evacuated tube type.
          Also a 420 ltr tank (I think) which is too big for our needs in Winter but handy for storing more heat when the sun does shine.
          I boost every 2nd or 3rd day during June and August but just about every day in July.

          • john 3 years ago

            Yes i do understand your situation unfortunately you get rain in winter whereas i get it in summer so your situation is not the best, however even so the yearly outcome is cost beneficial for you.
            Today there has been overcast conditions and light rain my solar output is terrible however the solar hot water will be hot just as well it has a temperature control valve on it to reduce it to a safe temperature.
            A lot of early systems did not have a regulator valve and were basically dangerous as the water could be approaching 100 C extremely dangerous.

  3. wmh 3 years ago

    The 25% figure only considers domestic hot water heating.
    In SA, hot water heating is 23% and home heating is 40% and in NSW the total is 59% (Ausgrid data) so it would make sense to heat the house as well with solar hot water.
    Hot water can store 52
    kWh per 1000 litres (45 C to 90 C operating range) and such storage is a lot cheaper than batteries.
    These days the economic way to collect solar energy is PV panels not solar thermal collectors: cheap panel price, no expensive plumbing and much reduced need to climb on the roof to do maintenance. This is why solar thermal is dying off.

    • solarguy 3 years ago

      To heat 1000 litres of water to 60c would require in excess of 57kwh. That would need a 15kw PV array, cost circa $21,000. Then extra expenditure for the plumbing to get it to each room and then the heat exchangers.
      Are you thinking?

      • wmh 3 years ago

        Solarguy, this is a storage system.
        Lets work it out: 57kWh every day over winter (say 90 days) at my average Time of Use cost ($0.291/kWh) is $1522 per annum which is a return on $21,000 of 7.25%.
        Summer time use – day time air conditioner, pool pump or charging a few kWh of batteries for the fridge (3kWh/day) and led lighting (5W/light) – would improve the return even further.
        Yes, one would have to put in a tank, radiators, a small pump (a heat exchanger is not necessary) but I am assuming that one would be wanting a silent, draft free central heating system anyway.

        • Ian 3 years ago

          WHM I thought I would check your calls so I lifted this calculation from :

          Water is heated to 90oC. The surrounding temperature (where the energy can be transferred to) is 20oC.

          The energy stored in the water tank can be calculated as

          E = (4.2 kJ/kgoC) ((90 oC) – (20 oC)) (1000 liter) (1 kg/liter)

          = 294000 kJ

          = (294000 kWs) (1/3600 h/s)

          = 81.7 kWh

          • wmh 3 years ago

            I used a minimum temperature of 45 C in my calculation of 52 kWh/m^3. This higher temperature provides a 25 C temperature differential so that reasonably sized radiators can be used. It also provides a minimum water temperature for showers.

            Price is crucial of course. Reverse cycle air conditioning has no storage which may be OK in summer when you need less cooling at night and can rely on some house thermal mass but in the depths of winter you are using grid sourced electricity at whatever the price is. In the long term, aircon units may have to be replaced every ten years but at longer intervals if they are not used for winter heating. The hot water heating system uses a small pump which runs continuously in winter presumably needing new bearings and seals after a while.

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