Guide

Solar Payback Estimate Guide

Estimate solar payback and long-horizon savings with incentive, rate growth, and maintenance assumptions.

Quick answer: Solar payback depends on net installed cost, offset production, local tariff rules, and how long you stay.

How to use this guide

  1. Enter system cost and incentive percentage.
  2. Input annual kWh offset and current electric rate assumptions.
  3. Review payback and horizon savings with conservative maintenance assumptions.

Common mistakes

  • Production and export-credit policies vary by utility and regulation.
  • Ignoring degradation and maintenance can overstate long-term savings.
  • Assuming constant occupancy horizon can misalign investment timing.

FAQs

Does this include battery economics?
No. Battery dispatch and time-of-use arbitrage need separate modeling.
Are incentives guaranteed?
Incentive availability and rules can change; verify current local and federal program details.
Should I model utility rate increases?
Yes. Long-horizon savings are sensitive to future utility price assumptions.