Solar and Battery Savings Calculator

Estimate how much solar and battery storage could reduce your electricity costs. This tool uses simple average production assumptions and your own energy usage inputs to provide a guide only.

📍 Closest capital city

Determines estimated solar production using average peak sun hours for your region.

⚡ Your current electricity usage

kWh per day

$ per kWh

$ per day

$ per kWh

Energy used during solar production hours 50%
10%90%

Estimated percentage of daily electricity use occurring during daylight hours while solar is producing.

☀️ Proposed solar and battery system size

The solar size below represents new solar being added. Treat this as total solar if you have no existing system.

Proposed new solar size 10 kW
3 kW40 kW
Battery size 15 kWh
5 kWh100 kWh

🏠 Existing solar

💳 Finance option

Estimated annual savings
$0
Based on your inputs and average solar production
Simple payback
Daily solar generation
Solar used directly
Battery energy used later
Solar exported to grid
Grid energy still needed
This estimate is based on your inputs and average production assumptions. A final result depends on roof layout, shading, tariffs, export limits, battery settings and final system design.

📊 Savings breakdown

Solar used directly
Battery energy used later
Solar exported to grid

📈 Projected savings over time

Annual savings

Assumes 5% annual electricity price increase. Feed-in tariff held constant.

Cumulative savings over 10 years

Total estimated savings

Want a more accurate assessment?

This calculator is a useful guide, but a proper solar and battery recommendation should consider your roof, usage profile, tariff, backup needs, export limits and long-term energy goals.

Request a tailored savings assessment
Built by GI Energy
Premium solar and battery design since 2011
NETCC Approved Seller
Residential and commercial solar and battery systems across Queensland, New South Wales and Victoria
Long-term energy partner, not just a discount installer
  • This calculator uses a simplified daily energy balance model.
  • Solar production is estimated using average peak sun hours for the selected capital city.
  • The daytime usage percentage estimates how much of your electricity use occurs while solar is being produced.
  • Battery storage is assumed to charge from excess solar and discharge later to offset grid imports.
  • Battery round trip efficiency is assumed to be 90%.
  • Battery stored solar is valued using the difference between your usage rate and feed-in tariff.
  • Feed-in tariffs are not assumed to increase over time.
  • Electricity usage rates are assumed to increase by 5% per year in the projection graph.
  • Estimated system cost is calculated using $650 per kW of solar and $800 per kWh of battery storage.
  • The calculator does not account for shading, roof orientation, panel orientation, inverter clipping, seasonal variation, export limits, demand tariffs, controlled loads, backup reserve settings, blackout backup design, rebates, final product selection or site-specific installation requirements.
Disclaimer: This calculator provides general estimates only and should not be relied on as a guaranteed financial outcome, quote, engineering assessment or final system recommendation. Results are based on the information entered, simplified modelling and average solar production assumptions.

Actual results can vary depending on roof orientation, shading, weather, seasonal variation, system design, inverter selection, battery settings, usable battery capacity, export limits, DNSP requirements, tariff structure, controlled load tariffs, demand tariffs, metering configuration, installation requirements, rebates, finance terms and changes to electricity prices or feed-in tariffs.

GI Energy accepts no liability for decisions made based on this estimate. A final recommendation should be based on a proper assessment of your property, electricity usage, tariff, goals and site conditions.