Use Solar to Run Your Biggest Energy Costs | GI Energy

Where does your daytime solar actually go?

Solar generation first supplies whatever is operating in the home or business. If a battery is present, surplus generation can then charge it. Once immediate demand has been supplied and the battery is full, the remaining energy is generally exported.

That default flow is not always the most valuable use of the available solar. The alternative is to identify flexible loads that can operate during the day, then configure the system to serve them when sufficient energy is available. The YourHome rooftop solar guide offers further reading on making effective use of solar generation.

Hot water, EV charging and pool equipment are strong candidates because they can represent meaningful loads and often provide some flexibility around operating time. The aim is not simply to switch everything on at once. It is to establish priorities that reflect the household’s needs, equipment and tariff.

How to use solar to run your biggest energy costs intelligently

Electric hot water is often the most straightforward place to begin. Many homes have previously heated water on a controlled-load or off-peak tariff. With solar, that heating cycle can instead be moved towards the middle of the day.

Basic timer versus intelligent control

A 3.6 kW hot-water element is a common example, although some homes may have a 2.4 kW element or another size. With a fixed timer, a 3.6 kW element draws that power from whatever source is available when the timer starts. If solar production is insufficient, some or all of the power may come from the battery or grid.

A smarter arrangement can wait until more than 3.6 kW is being exported and, where relevant, until the battery is full. Heating might begin at 9:30 am on a clear day or closer to midday after an overcast morning. The start time changes, but the objective remains a complete heating cycle.

What if the weather does not cooperate?

Reliable hot water still matters. An intelligent setup can include a fallback point: if the tank has not completed its heating cycle by a specified time, it draws from the available source. That may be solar, the battery or, when necessary, the grid.

A daytime timer can also work well for some households. Its limitation is that it follows the clock rather than actual solar conditions. On a rainy day without a battery, the heating load may therefore come directly from the grid.

How can solar and a battery support EV charging?

An EV is another substantial but potentially flexible household load. The available control depends on how the vehicle is charged. A standard power-point connection provides a lower charging level, with much of the scheduling handled through the vehicle rather than the solar system.

A compatible wall charger can provide more options. When the charger and battery system communicate directly, or when the battery system can control a supported third-party charger, the household can configure charging priorities in an app.

Those priorities might place the vehicle before the battery, charge the battery first, or limit vehicle charging to solar and a chosen time window. A particular tariff may justify drawing as much energy as possible during a nominated period, whether that energy comes from solar or the grid.

For a broader national consumer reference covering EV ownership and charging, see the Australian Government EV information.

Can solar run a pool pump and pool heating?

Pool filtration is commonly scheduled through the pool equipment itself, making it another load that can be moved into daylight hours. Some battery and energy-management systems can also integrate the type of pool heater that resembles an outdoor air-conditioning unit.

The same priority-based thinking applies. A household might choose hot water first, followed by the pool pump or heater once the earlier need has been met. Another household can choose a different order. The useful setting is the one that reflects its actual routine and preferences.

Across hot water, pool equipment and regular EV charging, combined consumption can reach roughly 10 to 15 kWh a day for some households. The result depends on the load, season, location, number of vehicles and charging frequency. That is why small scheduling decisions can accumulate into a meaningful difference over the life of a system, without creating a universal savings promise.

Why system design matters more than individual products

Smart energy use starts with a detailed conversation about the property. The designer needs to understand the major loads, how and when they operate, the household schedule, existing equipment, tariff structure and future plans.

A large battery does not automatically solve every problem. In one household example, a 25 kWh battery had been installed while hot water remained on a controlled load. The battery was filling while 15 to 20 kWh could still be exported, and around 7 to 8 kWh a day could potentially have served hot water. Correcting that arrangement later required another visit.

The example illustrates why commissioning and load integration deserve attention during the original installation. Product quality matters, but so do the electrical configuration, software settings and advice behind the system.

Future changes should also be considered. A household may add an EV, install pool heating or move from gas towards an all-electric home over time. A thoughtfully designed system leaves room to integrate those loads where the equipment permits, rather than forcing the owner to rebuild the energy strategy each time something changes.