Upgrade old outdated technology and install renewable options for hot water and electricity as your existing systems wear out.
Home Battery with Solar Electricity
By installing a home battery clean rooftop solar electricity is used during the day, and excess power then stored for later use at night. Moreover, home batteries help stabilise the grid, and promote the transition away from coal and gas generators sooner, while keeping a lid on your energy costs.
Home batteries help establish distributed electricity generation - they store solar electricity coming into the grid during the day and then pass it back out to the grid at peak demand times in the evening.
Moreover individuals with more electricity than they can use, can sell the electricity back to the grid at a higher price than you generated it for. A feed-in tariff (FIT) is the means of payment from the retailer to the customer.
In 2022, FITs are offered at variable rates, typically between 10-30 cents kWh at peak times; whereas during the day, when there is greater solar electricity in the grid, the FIT is around 4-10 cents kWh. FITs enable a possible payback time on a home battery of potentially 10 years. That time varies depending on your retailer, PV system, grid-tied battery and smart controls.
Customers who cannot install rooftop solar can still install a home battery to buy cheaper power during the day when renewable energy is 25-50% of the electricity mix, to then sell it during the peak demand times at a higher tariff, when there isn’t as much renewable energy in the mix. The financial benefit will vary dependent on using a retailer who trades on the live wholesale market.
Heat Pump Hot Water System
Heat pumps are not new technology.
Every refrigerator has a heat pump to move the heat from the fridge and freezer compartment to the outside air. Every Reverse cycle air conditioner (RC/AC) uses a heat pump to move heat from outside, to inside your home on heating cycle and from the inside to the outside of your home on cooling cycle.
A heat-pump is generally the most efficient and cheapest method of heating water. They work by absorbing heat from the ambient air to ‘pump’ it into the water tank. A heat pump uses the ‘refrigeration cycle’ to transfer the heat. To drive the heat pump, electricity is used. For every 1 unit of electricity used, around 4 units of ‘free’ heat are drawn from the air making them extremely efficient.
When used in combination with solar electricity, an electric hot water system can act as a renewable energy storage system. If the heat pump is programmed to run during the day, when solar energy is abundant, and especially from a rooftop solar system, this generally creates the cleanest and cheapest hot water available.
Rooftop Solar hot water vs Heat Pump hot water Systems?
A rooftop solar hot water system is the most expensive kind of hot water system to install, yet when operating, they are almost as low-cost to run as a heat pump. Heat pump hot water systems are among the more expensive types to purchase, but in general, the savings will recover the purchase price within about three to eight years.
Overall a heat pump is considered a better choice as it can extract renewable heat energy at any time including during the night and when its raining or cloudy. It also means you can free up your roof space for a larger solar electric (PV) system.
Did you Know?
In 2022 the NSW electricity grid's average renewable energy share is between 25-50% during the middle four hours of the day. But overnight the renewable energy portion drops to as low as 2-10% (June 2021). Renewable electricity during the day has rapidly risen because wind farms and solar panels produce the cheapest electricity. Overnight electricity is currently in 2022 mainly coal-fired power.
An electric hot water system that has a tank can be used as a renewable energy storage system.
By setting the timer on the heat pump (of a conventional electric HWS) to operate during the day, when there is a greater renewable energy in the electricity grid, it will majorly use renewable electricity.
Off-peak electricity is a relic of centralised coal fired power generators - is it time to disconnect it?
Off-peak power remains a source of high emissions electricity. It was designed to soak up the night-time power generation, as coal fired generators could not be easily ‘turned down’
However, an electrician, or HWS plumber-installer, can install a timer and contactor in your switchboard to enable disconnection from Off-peak power overnight. The cost of doing this will be around $500 (in 2022). A heat pump, or an electric element HWS, are cheaper to operate on home solar than Off peak electricity.