Solar Savings Estimator (Basic Estimate)
Get a simplified estimate of potential savings from home solar panels.
Enter Your Details & Estimates
Understanding Your Solar Savings Estimate
Solar photovoltaic (PV) panels generate electricity from sunlight, potentially reducing your electricity bills and environmental impact. This calculator provides a **highly simplified, basic estimate** of potential annual savings and a simple payback period based on common assumptions.
Disclaimer:** This is NOT a financial forecast. Actual savings depend heavily on many variable factors specific to your home and situation. **Always get detailed quotes and analysis from reputable solar installers.**
How to Use the Calculator
- Current Electricity Use:** Enter your average monthly electricity bill amount and your cost per kWh (kilowatt-hour) from your bill. Select your currency symbol.
- Proposed Solar System:**
- Select a typical **System Size** (in kW - kilowatts peak capacity) or choose "Custom" and enter your own value.
- Adjust the **Sunlight Availability Factor** based on your roof's orientation (North-facing is best in NZ), angle, and potential shading from trees or buildings.
- Estimate your **Self-Consumption Rate** - the percentage of the solar power generated that you expect to use directly in your home as it's produced (typical range 30-60%). Using more yourself saves more, as buying power costs more than selling it.
- Enter the **Export Tariff Rate** your electricity retailer pays you for surplus solar power sent back to the grid (this varies significantly).
- Enter the **Estimated Installed System Cost** (total cost after any potential grants/subsidies).
- Click "Estimate Solar Savings."
Interpreting Your Results
- Est. Annual Consumption:** Rough estimate of your yearly electricity use based on your bill.
- Est. Annual Solar Generation:** Approximate kWh your proposed system might generate per year, based on average NZ sunlight (~1250 kWh/kWp/year used here) and your sunlight factor.
- Savings (Self-Use):** Estimated annual savings from using your own solar power instead of buying from the grid (Value = Self-Consumed kWh * Your Electricity Cost per kWh).
- Revenue (Export):** Estimated annual income from selling surplus solar power back to the grid (Value = Exported kWh * Export Tariff Rate).
- Total Estimated Annual Savings:** The sum of self-use savings and export revenue.
- Estimated Simple Payback Period:** System Cost divided by Total Annual Savings. This is a basic metric and doesn't account for panel degradation, maintenance, inverter replacement, or potential changes in electricity prices/tariffs over time.
Key Factors Affecting Real Savings
- Location & Installation Quality:** Specific sunlight hours, roof angle/direction, shading, and quality of panels/inverter/installation are critical.
- Actual Usage Pattern:** How much electricity you use *during daylight hours* directly impacts your self-consumption rate and savings. Batteries can increase self-consumption but add cost.
- Electricity Retailer Plan:** Your import price per kWh and export buy-back rate significantly affect financial outcomes. Plans change over time.
- System Degradation:** Solar panel output slowly decreases over their lifespan (typically 20-25+ years).
- Maintenance & Future Costs:** Potential costs for cleaning, maintenance, or inverter replacement (often needed after 10-15 years).
- Government Incentives/Policy:** Changes in regulations or tariffs can impact long-term savings.
Next Steps
- Use this estimate as a starting point for discussion only.
- Research current solar technology, costs, and local regulations/incentives (e.g., check EECA GenLess website in NZ).
- Obtain multiple detailed quotes from reputable MCS or SEANZ accredited installers based on an assessment of your specific property.
- Carefully review proposals, including equipment warranties, performance estimates (using specific location data), and payback calculations.
Disclaimer: This calculator provides a highly simplified estimate for informational purposes only and is NOT financial advice. Assumptions used (e.g., average generation rate of ~1250 kWh/kWp/year for NZ, placeholder costs/tariffs) may not reflect your specific situation. Actual financial performance depends on numerous factors not fully captured here. Consult qualified solar installers and financial advisors before making any investment decisions.