The estimations of costs and savings associated with installing solar have been calculated using the following assumptions.

Energy prices
Electricity prices are based on 2022 Australian Energy Market Commission Residential Electricity Price Trends 2021 using 2021/22 market offers for each state. 2022 uniform government tariffs are used for WA and NT electricity pricing.

Energy usage
Electricity usage estimates are based on the Australian Energy Regulator’s 2020 Simple Electricity and Gas Benchmarks. These allow energy customers to compare their usage with similar households in their area. WA and NT customers are not included in the National Energy Market, so we estimated by using equivalent climate zones in Qld and SA.

Electricity price inflation
Because solar systems have a payback time that can exceed 5 years, and solar-plus-battery systems can exceed a 10-year payback period, our calculations allow for a 3% annual increase in grid electricity prices.

Solar feed-in tariffs Solar feed-in tariffs have tended to decrease over time. Our calculations take this into account when predicting long-term savings.

Solar installation costs
We have used SolarQuotes’ Solar Price Index to estimate solar system installation costs in each state. Customers who find a solar installer through SolarQuotes can report the price they paid when they install a solar system. This data forms the basis of the Solar Price Index.

Home solar batteries
We have estimated the purchase cost of battery storage at $1200 per KwH of capacity. Some battery systems cost less and some cost more than this. If you add battery storage, we show combined savings and payback time for both. Most savings will come from solar panels: batteries currently have payback times that are longer than their warranty period (typically 10 years).