Go Big, Save Bigger – Discover the Power of a 20kW Solar System

A 20 kW solar system is ideal for small to medium businesses, farms, schools, and large homes with high daytime energy consumption. It suits properties where electricity bills are consistently in the range of $1,000–$1,500 per month and where power is used mostly during daylight hours.

On average, a 20 kW system in Australia generates between 70–85 kWh per day, depending on location, panel orientation, and weather conditions. In sunnier states like Queensland and Western Australia, production is usually on the higher end, while in southern regions like Victoria or Tasmania, the output may be slightly lower.

A 20 kW system typically requires around 100–120 square metres of roof space, depending on the efficiency and size of the panels used. A clear, unshaded roof facing north is ideal, but east- or west-facing installations can also work effectively with only minor production losses.

In 2025, a quality 20 kW solar system in Australia generally costs between $18,000 and $25,000 after government rebates (STCs). The final price depends on the choice of panels, inverter brand, installation complexity, and whether additional electrical upgrades are required.

The number of panels depends on the wattage of the panels selected. For example:

1. With 500W panels → around 40 panels
2. With 400W panels → around 50 panels

Installers usually recommend higher-wattage panels to save space and reduce overall system size.

For most Australian businesses and households with high electricity usage, the payback period is typically 3 to 5 years. Properties with high daytime power demand, such as workshops, offices, and farms, tend to recover costs faster because they use most of the solar power directly instead of exporting it.

Yes, a 20 kW solar system can be paired with a battery storage solution. Adding batteries helps you store excess solar power for use at night or during peak tariff times. This can be especially helpful for businesses that run after hours or for households wanting to rely less on the grid. Even though solar batteries add to the upfront cost, they give you more energy independence and help guard against rising electricity prices.