In Bouddi, water heating is one of the biggest users of household energy – and therefore one of the highest costs (this doesn’t include cars). It accounts for almost 30% of our household greenhouse gas emissions – much more than our heating and cooling combined! (see the graph).
By using a hot water tank, we’re building up an energy store for when we need to use it – just like a battery.
Ideally we heat our tank during the day using cheap and available solar energy, either from our own rooftop solar panels or from the electricity grid.
All of us can make improvements – by planning to change equipment when the time is right or simply by reducing our use.
On this page you can find helpful information on:
The general principle is that we should all try to heat water during the day, as efficiently as possible, using cheap and plentiful electricity generated from renewable energy sources. We can do this by:
If you wait until your current water heater fails, you are likely to have fewer choices and end up with the same as you had before!
You should start to think about a replacement once your current system is 8-10 years old.
We’ve put together a list of installers that can help you select a system that works for you. Each have agreed to the Electrify Bouddi Hot Water Installers Code of Conduct.
Our installers have years of experience and know the brands that perform best. Most can also access grants available in NSW for switching to heat pumps.
If you are not sure you can afford to upgrade your hot water system, or make your home more energy efficient, read our guide to finance for solar and energy.
The systems featured below are the most common types used in the Bouddi area.
Electric storage
The simplest and most common system comprises a large tank, usually outdoors, heated by an electric immersion heater and often powered by off-peak electricity.
Electric heat pump
A heat pump is like an air conditioner unit in reverse, heating the water in a conventional storage tank directly.
Solar thermal
Uses the sun to heat water through rooftop flatplate or evaculated tubes. Requires ‘top-up’ usually by electric immersion heater.
Gas instantaneous
Delivers unlimited hot water when required. Small in size and can be wall mounted. Flow of hot water may be less than that of other systems.
The cost information in this figure is based on delivery of 125 L of hot water per day over a 13 year lifetime. Capital costs includes supply and installation in NSW less available government rebates. Electricity cost of $0.27/kWh and gas cost $0.0325/MJ.
The different types of water heaters cost varying amounts to buy and operate.
In selecting the right water heater for your household, it is important to consider the total cost you will pay for the system, i.e. both the supply and installation costs, and the fuel costs.
As shown in the graph, electric heat pumps have a higher initial cost, but are by far the most efficient, so that they work out the cheapest in the long run.
Tackling how we produce and use hot water is vital if we are to cut greenhouse gas emissions in Bouddi.
While using bottled gas is not currently the worst option, there is very little potential for any improvement and it is getting more expensive.
On the other hand, heating water using electricity offers the chance to reduce emissions and costs, by taking advantage of grid electricity during the daytime. During the daytime, emissions from grid electricity are low and falling as more renewables are added to the system.
Heating water is during the day is also a great way to get the most value out of your own rooftop solar panels.
Heat pumps are by far the most efficient water heaters available, typically using up to 65-75% less energy compared to normal electric heaters.
As shown above, they have a higher upfront cost, however, this is partially offset with current government rebates. Since they use so much less energy that other types, they are usually the cheapest in the long run.
Heat pumps have been used extensively overseas for many years, and are now gaining popularity in Australia. There are many happy customers in Bouddi!
The wide range of products available offer different price points and features. See here for a comparison of individual models.
Our installers have plenty of experience with many of these models and can help you to find the one suitable for you.
Many households use off-peak electricity to heat their water during the evenings and at nighttime. However, at night most of the electricity is generated by fossil fuels and causes the most greenhouse gas emissions. Historically, the cost of off-peak electricity is lower than at other times, but this doesn’t reflect the supplier costs and is likely to increase. Also some retailers have reduced their daytime rates.
This is why we encourage local households to take the simple step of switching away from off-peak water heating. It makes even more sense if you have a rooftop solar system.
This section explains what is involved in making this switch.
Off-peak water heating automatically uses electricity during the night to heat hot water. It requires its own meter in your meter box, which is usually separate from your general use electricity meter.
Sometimes, off-peak is also called a ‘controlled load’ tariff on your bill.
Off-peak is timed to use energy when most of the electricity supplying the grid is generated by fossil fuels. As a result, it causes a large quantity of greenhouse gas emissions.
When we are trying to reduce our reliance on fossil fuels, it doesn’t make sense to be using electricity at night if we can avoid it.
This is especially true, when we have an alternative source in solar energy, which is cheaper and readily available.
If you currently have off-peak water heating, it is relatively easy and inexpensive to switch.
You will need an electrician to switch the cables feeding your hot water tank from your off-peak meter to your general meter.
You will also need the electrician to install either a timeswitch or smart switch at the same time to ensure that you are only heating water when you want to!
Most electricians can do this work for you. The parts and labour for this work should cost in the region of $350-$500 in total.
After this change you will still have the same quantity of hot water available for when you need it. Typically, a tank will stay hot for 2-3 days, depending on how you use it, so you should have plenty throughout the day.
If you have very high demand for hot water at special times, e.g. lots of visitors, you can always extend the heating times to give you an extra boost.
Once the water in an electric storage water tank reaches a safe temperature, a thermostat stops further heating until the water temperature drops appreciably.
Therefore, when you switch to the general supply meter, you will need to install additional controls to prevent your water heater continually heating every time you use hot water.
The most common type of control is a timeclock which sits within your meter box to switch on water heating for a set number of hours per day. For those with solar power, they typically set the timer to come on for a few hours each day (e.g. between 10am-3pm).
Alternatively, you can use a smart switch controlled by an app on your phone, which can be programmed to divert any excess solar generated electricity to your water heater.
Both of these alternatives work well, and cost the about same, so the choice is largely about which you are most comfortable with.
This will depend on your circumstances, and what electricity retailer you are with, however if you have access to solar rooftop electricity you will save money!
The off-peak tariffs are generally around 15-25cents per kWh, but the solar power tariff is generally only 5-7cents/kWh. So if you use excess solar power you will be cutting your hot water bills by 50-80%.
If you do not have solar power, you can still cut emissions by scheduling your water heating to coincide with the most solar power in grid, which is also the lowest cost daytime electricity from your supplier. Overall, this may result in a small increase in your bill, but you will be using electricity that is largely supplied by solar.
Alternatively, you can also explore powersharing with others in the community that have excess solar power to sell to you at a price that will be similar to the off-peak rate.
Once you are sure that your heating times are set to provide sufficient hot water, there is no need to adjust anything further.
This local household has changed from off-peak to heating their water during the middle of the day, when most solar power is being generated. Take a look at the video to see how they did it.
Install a low-flow shower head
Most hot water is used in the shower. Low-flow shower heads use less water than a standard shower head while still providing strong water pressure. When buying a low-flow shower head look for the water rating and flow rate. The higher the water rating and the lower the flow rate, the less energy and water you will use.
Take shorter showers
The shorter the shower, the less hot water you will use. Use a shower timer to motivate you to take showers that are 4-minutes or less.
Wash your clothes in cold water
Delicate and everyday items don’t need to be washed in warm water. Hot water can damage certain fabrics and fade colours. Unless something is really dirty or needs to be sanitised, cold water will do the job.
Spare the hot tap
Try to avoid using hot water when cold water will do the job! If you have a mixer tap, leave it on cold it so that the next user doesn’t automatically draw off hot water.
Fix dripping hot water taps
A dripping tap can use a surprising amount of water, draining your hot water tank and leaving you less hot water for the things that matter.
