Solar vs Grid vs Generator Cost Calculator
How It Works
This solar vs grid vs generator cost calculator uses established formulas to provide accurate results.
The basic rule:
- Grid 20-Year Cost = Sum of annual electricity costs with 3% annual rate increase
- Solar 20-Year Cost = (System Cost x (1 - Tax Credit)) + maintenance + inverter replacement
- Solar Payback = Net System Cost / First Year Grid Savings
- Generator 20-Year Cost = Purchase + fuel (4% annual increase) + maintenance + replacements every 7 years
Results are estimates. Consult a professional for critical decisions.
Frequently Asked Questions
What solar tax credit is available?
The federal Investment Tax Credit (ITC) currently offers 30% off solar installation costs through 2032, stepping down to 26% in 2033 and 22% in 2034. Some states offer additional incentives. The calculator lets you adjust the credit percentage to match current programs.
How is the generator cost calculated?
Generator costs include the initial purchase, fuel consumption (based on ~8 kWh per gallon for a typical standby generator), annual maintenance ($800/year), and replacement units every 7 years at 70% of original cost. Fuel costs increase at 4% annually.
Does the solar calculation include battery storage?
The base calculation assumes a grid-tied solar system without battery storage. Battery systems add $10,000-$15,000 to the upfront cost. If you need off-grid capability, increase the Solar System Cost to include battery costs.
How long do solar panels last?
Modern solar panels are warranted for 25 years and often produce power for 30+ years with gradual efficiency loss (~0.5% per year). The calculator uses a 20-year comparison period. Inverters typically need replacement around year 12, which is included in the solar cost.