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Congratulations on the installation of your new solar hot water system. Your new system is better for the environment as it uses the sun’s energy during the day to heat your water.

Your solar hot water system is likely to use electricity to heat water, especially on cloudy days and during the winter months. In winter, the days are shorter and there is less sunlight available to heat your water so you may notice higher electricity bills during this time.

Using solar hot water efficiently

Hot water is the largest user of electricity in most households. Using your solar hot water system efficiently will save you money on your electricity bill. The most savings can be made when you:

  • use hot water in the morning
  • use less hot water.

Running out of hot water

If you’re frequently running out of hot water, you may need to connect to a different electricity tariff to suit your household needs.

Your electricity tariff is the price you are charged for electricity. Because you pay your own electricity bill, it’s your responsibility to check that you are on the most suitable electricity tariff for your household. Check your bill to find out which tariff you are on or contact your electricity supplier for information about tariffs.

It’s important to note that electricity customers can choose which tariff they are on. If it has changed, or you are not sure which one is best for you, contact your electricity supplier to discuss your options. There are 4 types of electricity tariffs for hot water systems:

  • Off Peak 1: Electricity will only be used to heat your water between 10pm and 7am. This is the cheapest rate and is most suitable for small households of 1 or 2 people. You may run out of hot water on cloudy days or if you use more hot water in the afternoons and evenings.
  • Off Peak 2: Electricity can be used to heat water for up to 16 hours a day. This rate is cheaper than the continuous tariff but more expensive than Off Peak 1. It is more convenient for larger families who are likely to use hot water in the afternoon and evenings, and is handy for cloudy days and during winter months.
  • Continuous or day rate: Electricity can be used to heat your water at any time of the day so you will not run out of hot water. This rate is more expensive and you may not save as much money with a solar hot water system on this rate.
  • Time of use: This tariff only applies to homes where a new digital or smart meter has been installed. Time of use tariffs are broken into peak, off peak and shoulder time periods. All electricity use is charged at different rates depending on the time you use the electricity. Households on this tariff should minimise the use of electrical appliances and hot water between 2pm and 8pm on weekdays due to higher peak tariff rates.

Use hot water in the morning

Your solar hot water system is the most efficient between 10am and 3pm on sunny days when the sun is keeping your water hot. You will save the most money if you use hot water in the mornings between 7am and midday when the sun can heat water in the tank during the day

If you use most of your hot water in the afternoons or evenings there may not be enough sun to heat the water. You may even run out of hot water and not see any savings in your next electricity bill.

Use less hot water

Hot water is used mainly for showers, baths, washing hands, dishwashing, and washing clothes. Using less will save electricity, water and money.

You can save on the hot water you use at home by:

  • taking shorter showers
  • taking short showers instead of baths
  • rinsing vegetables in cold water instead of warm water
  • using cold water for washing clothes
  • if purchasing a new washing machine buying an energy and water efficient one
  • reporting leaking taps to the Housing Contact Centre
  • ensuring DCJ Housing water saving shower heads are not removed.

Important solar hot water information

  • Do not turn the solar hot water system off at the power point – a small amount of power is needed to monitor and control the temperature of the solar panels so they do not get too hot or too cold.
  • If the solar hot water system has not been used for two weeks or more - it is recommended by the manufacturer to turn on a sink, basin or bath tap for a couple of minutes to allow any hydrogen gas that may have built up in the water heater to escape safely via the tap.
  • Do not personally inspect or service the solar hot water system.
  • New hot water systems are required by law to be set at 50°C, so your water may not feel as hot as your previous hot water system. This is to reduce the risk of scald injury, something particularly important for children and elderly people.

If you have problems with your solar hot water system, call us to arrange maintenance. If you live in community housing, you’ll need to contact your housing provider directly for any maintenance issues.

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Last updated: 16 Aug 2023