enter annual PV generation、storage sizing and local peak-valley / feed-in tariff，estimate peak-valley arbitrage and PV self-consumption revenue、static payback years。for C&I solar+storage and home storage economics。
formula：annual arbitrage energy = capacity × efficiency × daily cycles × days；arbitrage revenue = arbitrage energy ×(peak−valley)；
PV revenue = generation×self-consumption ratio×(peak−grid export) + generation×(1−self-consumption ratio)×grid export。
payback = total investment ÷ annual net revenue（not discounted、battery degradation and tariff changes，results are on the optimistic side）。