Is Your Electric Hot Water System Efficient?

With countless choices available on the hot water system market, it’s no surprise some people wonder if their electric water heater is the best choice.

Electric hot water systems are incredibly common; they’re used by about 50% of Australian households. Electric hot water systems are also reasonably priced and can be energy efficient. But that efficiency depends on the type of system and your main energy source.

On face value, electric hot water systems are typically the most expensive type to run. However, it might still be the best hot water choice for your household. The question is: Which is the best hot water system for you?

To help you make the right decision, let’s take a look at the various types of electric hot water systems, their efficiency, and which hot water heater might work best for your home.

Energy Performance Standards for Hot Water Systems

There is no need for water heaters to display an Energy Rating label. However, Minimum Energy Performance Standards (MEPs) apply to electric and gas storage hot water systems and gas continuous flow systems.

MEPs are not yet in place for solar, heat pump or electric continuous flow systems. The energy labels on gas water heaters are not the same as energy ratings on washing machines and dishwashers, as they are run by the industry and not regulated by the government.

An electric hot water system with a storage tank is probably the most common type of water heater used in Australia.

Electric storage hot water systems use an element inside the storage tank to heat the water. Think of it like a giant electric kettle that is constantly switched on. These hot water systems are the most affordable option upfront. They’re also often the easiest to install.

However, if you’re using mains electricity, an electric storage system is not the most energy efficient model to use. The ongoing cost of heating water 24/7 adds up. But if your system is running well, you might have no plans to change it. Electric storage tanks are reliable units which can last for 10 years or longer if well maintained.

Thankfully electric storage hot water systems can be switched to an off-peak tariff to reduce your power costs (only available to dual element 160L to 400L models).

This means water is only heated during the off-peak period when energy prices are lower. Just be careful as some energy providers have very limited off-peak hours.

Unfortunately – or fortunately for the environment – hot water systems that use mains electricity are gradually being phased out by the Federal Government.

The use of fossil fuels and greenhouse gas emissions are being traded for heat pumps and renewable energy. Therefore, it you have to replace an existing electric storage hot water system, chances are you have to consider a new option.

Continuous flow hot water systems are usually powered by gas, but there are electric models available. Also known as instantaneous water heaters, they only power up to heat water when the hot tap is on. There’s no wasted expense.

This method makes continuous flow systems more energy efficient. However, they don’t have the same large output of water flow. So, although they’re perfect for homes with 2-3 hot water outlets, one unit is not enough for a larger home.

Instant flow hot water systems are usually available with a five-year warranty. They also deliver greater longevity than the average storage tank. Versatile installation options also make continuous flow hot water systems ideal for smaller units or apartments.

An electric-boosted solar hot water system is much more efficient than an electric hot water storage system.

However, it’s also the most expensive option. Solar panels have to be installed on your roof and these systems are not cheap to buy, ranging from $4000 to $8000 (not including installation). Your power will still need to be boosted by mains electricity during the colder months when the sun isn’t out as much.

The advantages of installing a solar hot water system are not only the energy efficiency and eco-friendliness, but also lower power bills and you may even receive government rebates.

This kind of system can provide between 50% and 90% of your hot water requirements, making the long-term benefits of an electric-boosted solar hot water system considerable.

Electric heat pump hot water systems are very efficient and use only 30% of the energy of a conventional electric hot water system.

Heat pump hot water heaters use a refrigeration system which extracts heat from the air to heat the water. That’s why an electric heat pump system is best suited to warmer climates, although it still operates efficiently in cooler conditions.

While heat pump hot water heaters are expensive to buy, they are cheaper to run than a standard electric storage hot water system.

There are two main types of heat pump hot water heaters:

• Integrated – in this model the tank and compressor are combined.
• Split – in this type of system the tank and compressor are separate.

These units need good ventilation and are usually installed outside. The compressor can be loud so there are regulations around installation locations, as it cannot be too close to neighbouring windows.

To summarise, your old electric storage hot water system has its advantages and disadvantages, taking into account energy efficiency and power costs.

The pros:

• Reliable systems that last a decade or longer if well maintained.
• Reasonably priced and easy to install.
• Can be installed indoors or outdoors.
• Can be switched to off-peak electricity to reduce power bills (only for dual element tanks, 160L to 400L).
• Easy to maintain.
• Good range of tank sizes (25L to 400L). You’re unlikely to run out, regardless of how much hot water you use.
• Excellent water pressure (delivered at mains pressure).
• Works well in bigger households.

The cons:

• Not as energy efficient as solar power (electric-boosted) or electric heat pump systems.
• Higher running costs than solar power and heat pump systems.
• Uses fossil fuels and emits greenhouse gases.
• Being phased out by the government.

If your electric hot water system is still going strong, keep it well maintained and it will most likely last for a while to come. But knowing what the alternatives in electric hot water systems are, you might choose to upgrade to a more energy efficient, cost-effective model when the time comes for change.

Then there are gas hot water systems to think about. If you’re struggling to make a choice, contact the experts at Mr Emergency for advice.

Please note: This information is provided for advice purposes only. Regulations differ from state to state, so please consult your local authorities or an industry professional before proceeding with any work. See our Terms & Conditions here.