HOT WATER - the biggest energy offender
You may be surprised to know that heating water accounts for the largest percentage of energy use in Hunter homes. Water heating is responsible for around 25-40% of the energy used in an average home, and therefore is responsible for approximately 28% of the home's total greenhouse gas emissions*. Switching from an electric hot water system to gas, solar or heat pump can reduce green house gas emissions by up to 75%, which is equivalent to leaving a small car at home for almost a year! It can also save up to $700 a year on your household energy bills. That's a significant saving.
The phasing out of electric hot water systems
Due to the fact that they are intense consumers of energy, electric hot water systems are being phased out by the Federal Government in most States and Territories, including NSW. The BASIX* system currently does not allow people to install an electric hot water system in any new building or renovation, but the phase out will mean that from 2010 no electric hot water systems will be able to be installed in any existing detached, terraced or town house which has access to piped gas.
By 2012 Hunter households will no longer be able to install an electric hot water system in any existing detached, terraced or town house. This also applies to any new flats and apartments which have access to piped gas (except where an exemption applies).
If you're thinking about installing a new hot water system have a quick look at the information below. We've tried to simplify the mass of information in the market to help you decide which system best suits your needs. And if you've already decided upon the system you want, but are interested in details of government rebates and the savings you can make, just click here.
What hot water system is right for me?
There are so many different types of hot water systems on the market, choosing a system can be overwhelming. The right system for your home will depend on a number of factors. So consider the following:
The number of people living in your home and your current water consumption patterns (i.e. do you run the dishwasher, washing machine and showers at the same time) will help determine what type of system and energy source for your needs
The purchase cost and operating costs of your new hot water system needs to fit with your budget as the energy used by your system will impact your bills for the life of the system. However, you can save thousands of dollars on your energy bills over the lifetime of the system. A solar water heater costs around $1500* more than a conventional system, but will pay for itself with the savings made in 5 - 10 years, and should last much longer.
(*This estimate is based on a standard solar hot water system suitable for most average size families and homes)
Some systems may not be suitable due to the design and layout of your home. There may be additional installation costs.
Existing water heater
Some existing hot water systems can be easily converted to more sustainable types. However, you may not be eligible for a Government rebate.
Available energy sources
Some energy sources are not available everywhere in Australia. For example, natural gas is not available in some areas and solar energy may not be ideal in cooler climates or shaded areas.
Sunny locations and where solar collectors can face north allow solar hot water systems to operate most effectively. Whilst a north aspect is ideal it is not always possible. Do note that solar collectors can be placed on the roof facing the east or west. In this situation their efficiency will only be reduced by 2%-6% if the collectors are placed 90 off North. And consider placing an additional panel which can make up for lost efficiency. This is important for some households where the visual appearance of the home and placement of panels is a consideration.
What Climate-friendly hot water systems are available for the rebates?
There are currently rebates for the replacement of electric hot water systems with:
- solar hot water systems
- gas hot water systems with a 5 star or higher energy rating
- heat pump hot water systems (these systems do require the use of electricity to operate)
These systems are either based on storage or instantaneous flow (or continuous flow)
- Storage water heaters allow heated water to be stored in an insulated tank ready for use when required.
- Instantaneous water heaters only heat the water when required and do not use a storage tank. They can operate on natural gas, LPG or electricity. Because instantaneous systems heat the water as it is used, they cannot run out of hot water.
Consider solar energy
Solar hot water systems, also known as electric boosted solar hot water systems, are storage systems which use the sun's energy to heat water. Using solar energy to heat water produces no harmful greenhouse gas emissions*. Solar systems can provide between 50% and 90% of your hot water requirements if used to their full potential and can require minimum electricity for boosting the supply.
A solar hot water system uses solar collectors or panels to absorb energy from the sun. The water passes through the collectors which trap and use heat from the sun to raise the temperature of the water, it then flows into an insulated storage tank for later use.
There are two main types of solar collectors: flat-plate and evacuated tube collectors. This can be quite complicated and confusing. So we recommend if you're considering solar energy to refer to our useful links and Eco Directory to get the opinion of highly experienced professionals who can assess your individual household needs
What type of solar system do I choose?
Solar systems can be open or closed circuit. Put simply, an open circuit system works by allowing water to flow directly through the solar collectors into the storage tank and then through your household water pipes.
Closed circuit systems contain glycol (antifreeze fluid)which flows through the system to avoid ice formation in the collectors. Closed Circuit systems are designed to offer the best frost protection for heavy frost areas. An alternative is the open circuit streamline system (this is a split system with tanks on the ground and panels on the roof) which has a sensor on the panels which indicates when the water is below 3. This activates a pump which circulates warm water from the tank through the panels to help aid against frost damage.
Where do you locate the solar system?
There are two ways of setting up your solar hot water system, passive system or an active system. The best set up for your solar system will depend on your roof structure, roof orientation and budget.
Talk to the experts about what's best for your home. Please refer to the Together Today Eco Directory(click here for the Eco Directory) to find a professional who can give you the right advice.
What is a Booster Switch and do I need one?
The storage tank is usually fitted with a back-up booster switch. This is either electric, gas (storage gas or instantaneous) or solid fuel booster. This switch can be turned on, or can cut in, to heat the water when sunlight is insufficient (e.g. cloudy days and night time). Boosters are an important component of the system but they must be managed appropriately to ensure your system is working efficiently. Therefore override switches and timers can give you management of when the booster is turned on and off. For example, if you do not require hot water in the morning than there is no need for the booster to be on heating water during the night. Please Note: To be able to use your booster switch properly, It is important to know what type of tariff your hot water system is connected to, Off Peak 1, Off Peak 2, Direct or Smart Metering – this is usually stated on your energy bill or by contacting your energy provider. For more information on tariffs and how they can affect your boosting, your solar hot water system supplier can offer more education.
Do I need frost protection?
Frost can damage your solar hot water system due to water freezing in the collectors. If you live in a climate area prone to frosts then you should invest in frost protection. The most common types of frost protection include:
- Mechanical drain down values (Knock Valves) – can be problematic as they can jam open and drain the tank, or fail to operate, causing severe damage.
- Electric heating elements – are vulnerable in the event of power failure
- Closed circuit systems which keep the heating fluid running through the collectors as it has a lower freezing point than water2. These are usually the best option in frost prone areas as they ensure that water does not flow through the solar collectors and therefore cannot freeze in the collectors.
What's the cost of a solar system?
The cost of a solar hot water system will vary depending on your climate, the type of system you install and if you need to reinforce your roof.
Generally the upfront cost of a solar hot water system (including installation) is generally higher than electric or gas hot water systems. However, the extra upfront cost will be recovered over the life of the system through reduced energy bills. The payback period is typically 5 to 10 years and remember solar hot water systems last longer than conventional hot water systems.
What are heat pumps?
A heat pump is a different way to use renewable energy to heat water without using solar panels. A heat pump draws the heat from the air to heat your hot water. They only use about a quarter to a third of the electricity of a standard electric storage system, therefore reducing greenhouse gas emissions.
A heat pump works like a refrigerator but in reverse. It draws heat from the air to heat a refrigerant, which is converted into a gas. The gas is then compressed which generates heat to heat your water. The refrigerant then expands back to a gas and the cycle repeats itself, creating a constant supply of hot water.
There have been reports that some heat pumps can be noisy, so consider where you will be locating your system.
- Most heat pumps can only draw the ambient temperature air. So when temperatures fall below 5°-7° they cannot draw in ambient air without a back up element, run by electricity, as an additional source to heat the water
- Heat pumps need electricity to move the refrigerant around the system, not to heat the water directly. Therefore they are more energy efficient than an electric hot water system.
- Like solar water heaters, heat pumps cost more to install and can pay back the extra initial investment over time through reduced energy bills.
- Heat pumps are ideal for homes that have steep pitched roofs and heavy shading.
Gas Hot water Systems
Natural gas water heaters generate far fewer (about one third) greenhouse gas emission*s than electric hot water systems. This is because natural gas burns cleaner than the coal that is burnt to generate most electricity in mainland Australia.
There are two types of gas hot water heaters: storage systems and instantaneous systems.
Storage systems are similar to an electric hot water system but they have a gas burner which heats the water. The heated water is stored in a tank and then reheated by the gas burner when the temperature falls below a certain level. The gas burner is ignited by a pilot light. A gas storage system can provide full pressure to all taps in the house and rapid reheat. They have quicker heat recovery times and generally use a smaller tank than a comparable electric storage system. Systems can be installed inside the house, but will need to have a flue that leads outside to vent the exhaust gas.
Also known as continuous flow hot water systems offer an efficient alternative to traditional gas and electric storage units. As their name suggests, they heat water on demand as required by the user, so you will never run out of hot water. A hot water circulator is a unit installed with an instantaneous gas hot water system which is more efficient than the regular instantaneous system. A circulator system recirculates the cold water sitting in the hot water pipe back to the water heating system for re-use. As no storage tank is required for an instantaneous system they are more compact than traditional hot water systems and can easily be mounted on an outside wall.
The newest technology available for instantaneous hot water systems are highly efficient with electronic ignition, solar compatible, full flame protection, and user adjustable temperature electronic control pads with a wide range of capacities. There are products available with energy efficiency ratings in excess of five stars, which only use purchased energy when it is required to heat water.
The cost of a gas hot water system will vary depending on if it is storage or an instantaneous system and the brand. Generally they are cheaper than solar hot water systems. The latest instantaneous systems only heat water when a tap is turned on; and when the tap is closed the system turns off. This saves energy and contributes to considerable savings on your household bills.
For more information and details of professionals who can assist you with advice on the supply and installation of climate friendly hot water systems, click here to go to the Together Today Eco Directory
How to Keep Saving
The Federal and State Governments are offering rebates for the installation of climate friendly hot water systems For details of this rebate simply click here.
To help Australian families with the cost of installing water saving and energy efficient products the Commonwealth Government is offering interest free Green Loans of up to $10,000. A Green Loan does not affect or make you ineligible for any available Government Rebates. To find out more about Green Loans click here.
* Please refer to the Together Today Glossary for more details
- DECCW (2009) NSW Climate Change Fund: Hot Water System Rebate Application Form
- Riedy, C (2008) Commonwealth Government Your Home Technical Manual –Hot Water Service, pp.197-204, 4th edition
- Australian Government (2009) Nation Building Economic Stimulus Plan - Energy Efficient Homes Package: Solar Hot Water Rebate Guidelines and Application Form
- Australian Government 2009) Energy Efficient Homes Package: fact sheet for householders From 1 July 2009
- DEWHA (2009) Phase out of Greenhouse Intensive Hot Water Systems
- Australian Government Office of the Renewable Energy Regulator (2009) SWH Owners Guide
- DEWHA (2009) Green Loans: what could you be saving? Fact sheet
- DEWHA (2009) Living Greener: Heatpump Hot Water
- EnergyMatters (2009) Heatpumps