Zero your Electricity Bill
How many home solar panels does it take?

roof top home solar panels
  • What is your current electricity consumption?
  • How many solar panels are needed to eliminate your electricity bill in your location?
  • What energy efficiency could be considered before a solar project?
  • How can a building energy consumption and generation be measured in real time?

Suggested Solar Power Home Steps

  1. Examine 1 year of electricity bills and see the total kWh used and yearly cost.
  2. Consider installing a building energy meter. Work out a baseline for energy used per day.Building Energy Measurement
  3. Calculate best suited energy efficiency projects for your situation. Complete projects.Save Energy and Money Checklist
  4. See the new efficient baseline energy used per day.
  5. Run the Solar Panel Power Calculator

Solar Panel Power Calculator

Yearly kWh used kWh
Your local average daily Solar Radiation
World Map Solar Radiation (kWh/m2/day)World Map Solar Radiation small
Yearly electricity cost (optional) currency
Press this button after adjusting values above Electricity Calculator
90% efficiency in the grid inverter or battery charger assumed.
Solar Panel Rating using 1 kW / metre square Standard Test Conditions (STC) at 25 oC assumed.
Amorphous Silicon Solar Panels square metres
or Polycrystalline Silicon Solar Panels square metres
or Mono crystalline Silicon Solar Panels square metres
Total solar panel power target STC watts
Potential 30 year electricity cost savings currency

Solar Panel Sizes

Home solar panels can come in various sizes and power ratings.
See a sample of solar panels below.

Amorphous Silicon
Solar Panels
Polycrystalline Silicon
Solar Panels
Mono crystalline Silicon
Solar Panels
124 watts 190 watts 190 watts
2459 mm long 1571 mm long 1482 mm long
793 mm wide 951 mm wide 992 mm wide
1.95 square metres 1.49 square metres 1.47 square metres

For more solar panel specifications see Solar Panel Calculator

Work out total solar panels area calculator
No. of solar panels
Long mm
Width mm
Solar Panel Area Calculator
square metres

Solar Power System Considerations

Grid connected solar power:

Solar panels + grid inverter + new power meter + installation - government rebates - renewable energy credits


Remote connected solar power:

Solar panels + regulator + batteries + inverter + installation - government rebates - renewable energy credits

Next step to a free energy home

Home Solar Power Alternatives

Community based solar power systems is a group of citizens combining resources for a larger solar system on a community building, school, above a car park etc.
Advantages include:

  • Shared solar installation costs
  • Cost efficiencies with larger scale in terms of shared inverter/s, power meter etc.
  • Improved change of more ideal solar panel aspect and pitch for maximum energy return
  • Project can be independant of you residential location
  • Some savings in cooling costs for the building under the solar panels.