Smart home automation for energy savings
You don't need a smart home to save on energy — most of the gains come from the manual changes described in earlier pages. But automation helps you maintain good habits without the daily effort.
Do you need smart home tech?
Let’s be upfront: smart home technology is not necessary for significant energy savings. Shifting your pool pump with a $20 mechanical timer, running your dishwasher at lunchtime instead of after dinner, and switching to a time-of-use tariff are all free or near-free changes that deliver most of the benefit.
Smart home tech adds value when you want to:
- Automate load shifting so you don’t have to think about it day after day
- React to real-time conditions (solar production, grid prices, weather) that a static timer can’t
- Coordinate multiple devices — solar, battery, EV, hot water, AC — as a system rather than individually
- Monitor your energy production and consumption with detailed data
Smart plugs and switches
The simplest entry point into smart energy management. A smart plug sits between an appliance and the power point, giving you app control, scheduling, and energy monitoring.
What they do
- Turn appliances on/off from your phone or on a schedule
- Monitor real-time power consumption of individual appliances
- Set rules: “turn on pool pump when solar export exceeds 2 kW”
- Track historical energy use to identify waste
Popular Australian options
- TP-Link Tapo — Cheap, reliable, good app ($15–$25)
- Shelly — Local control, no cloud needed ($25–$50)
- Arlec Grid Connect — Available at Bunnings ($15–$30)
- Eve Energy — Apple HomeKit/Thread ($60–$80)
Check the power rating
Smart thermostats
Heating and cooling is a major electricity consumer, especially in southern states. A smart thermostat learns your patterns and optimises when and how hard your system runs:
- Pre-cooling with solar — On a hot day, the thermostat runs the AC during the afternoon while your panels are producing, so the house is cool by the time the evening peak hits. You ride through peak hours on stored coolness rather than running the AC at 45c/kWh.
- Occupancy sensing — No point heating or cooling an empty house. Smart thermostats detect when no one is home and reduce output, then ramp up before you return.
- Zone control — Only heat or cool the rooms people are actually using. Many ducted systems can close zones, and a smart thermostat can automate this based on sensors or schedules.
- Weather anticipation — Some systems check the weather forecast and pre-heat or pre-cool ahead of extreme temperatures, using cheaper energy before the demand spike.
Home Energy Management Systems (HEMS)
A HEMS is the most advanced option: a centralised controller that coordinates your solar, battery, EV charger, hot water, and other loads as a single integrated system. It makes decisions in real time based on:
- Current solar production and forecast for the rest of the day
- Battery state of charge
- Your tariff structure (peak, off-peak, shoulder rates)
- Weather forecast (cloud cover, temperature)
- Your historical usage patterns
- Grid export limits and feed-in tariff rates
For example, a HEMS might decide: “Solar production is strong but clouds are forecast for 2pm. Prioritise charging the battery now, delay the pool pump until the battery is full, and pre-heat water while there’s still excess solar.”
Some battery systems (like Tesla Powerwall and Enphase) include basic HEMS functionality in their software. Dedicated HEMS products include Reposit, Evergen, and SwitchDin, as well as open-source options like Home Assistant with energy integrations.
Solar diverters
A solar diverter monitors your solar export in real time and redirects surplus electricity to your hot water element (or another resistive load) instead of sending it to the grid. It’s a simple, targeted form of automation.
How it works: the diverter sits at your switchboard and continuously measures how much solar electricity is being exported. When there’s a surplus, it diverts exactly that amount to the hot water element, varying the power smoothly to match the available excess. When a cloud passes and production drops, it instantly reduces the diversion.
Popular brands in Australia include Catch Power, myenergi Eddi, and Solar Analytics with hot water control. Expect to pay $800–$1,500 installed.
Practical automation examples
Here are some real-world automations that solar households use to save money:
Pre-cool during solar
Set AC to turn on at 1pm and cool the house to 22 degrees using solar electricity. At 4pm, raise the setpoint to 25 degrees. The house coasts through the expensive evening peak.
Solar-aware pool pump
A smart relay turns on the pool pump when solar export exceeds 1.5 kW, and turns it off when clouds reduce production. The pump runs only on free electricity.
Smart EV charging
The EV charger adjusts its charging speed based on available solar surplus. When production is high, it charges at 7 kW. When clouds pass, it slows to 1.4 kW. When solar drops below household demand, it pauses.
Overnight battery + off-peak
If tomorrow’s weather forecast is cloudy, the HEMS charges the battery from the grid overnight at off-peak rates, so you’re covered for the next day’s peak without relying on solar.
The bottom line
Smart home energy technology is a force multiplier, not a prerequisite. The biggest savings come from the fundamentals covered in the earlier pages of this section:
- Maximise self-consumption of your solar
- Shift flexible loads to cheap times
- Get on the right tariff structure for your usage patterns
Smart automation then helps you maintain those habits effortlessly and squeeze out additional savings by reacting to conditions a human wouldn’t track minute by minute. Start simple, automate what annoys you, and add complexity only when it earns its cost.
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