Estimate your solar ROI with realistic assumptions: self-consumption, export credit (net metering vs net billing), panel degradation, and electricity rate growth.
Last Updated: January 2026 | Reviewed by: VerCalc Energy Team
Quick definition (for accuracy)
Solar payback is the time until your cumulative bill savings equals your net solar installation cost. The key driver is not just production — it’s how much solar you use on-site vs export, and how exports are credited.
Disclaimer: All calculators on this website are provided for informational and illustrative purposes only. Calculation results do not constitute legal, tax, or financial advice. Despite careful programming, we assume no liability for the accuracy, completeness, or currency of the results. For matters requiring professional advice, we recommend consulting with an appropriate specialist (tax advisor, lawyer, accountant).
How solar payback really works (the non-marketing version)
Solar payback is not just production. It depends on self-consumption vs exports, export credit policy, electricity price growth, and panel degradation. This calculator is designed to make those assumptions explicit.
1) Self-consumption vs exports (why it matters)
Under net billing (low export credit), the same solar system can have very different payback depending on how much energy you consume while your panels produce (midday).
Batteries and load shifting increase self-consumption — but also add cost. For an advanced battery + TOU analysis, use our Energy Arbitrage Calculator.
2) Degradation and rate growth
Solar production typically declines slowly each year. Meanwhile, retail electricity prices can rise. Payback and long-term ROI depend on the balance of those two trends.
3) Sanity check: are you overbuilding the system?
If your system produces much more than your annual usage and export credits are low, your payback can worsen. In that case, optimizing size or adding flexible loads (EV charging, heat pump water heater) may improve value.
Frequently Asked Questions
Q:Is net metering always better than net billing?
For solar economics, yes — higher export credit generally increases savings. But policies vary by utility and region and can change over time.
Q:Why is my payback different from installer quotes?
Installers may assume optimistic self-consumption, high electricity price growth, and ignore degradation. This calculator makes those variables visible so you can test realistic scenarios.
Q:Does this include maintenance or inverter replacement?
No. This is a simple savings/payback model. For a full TCO model, you’d add maintenance, inverter replacement, and financing costs.