1Solar Solution Cost
USD
Panels + battery + pole + installation (CNY 180,000 ÷ 7.2)
USD/year
years
Lithium 5–8 years, lead-acid 2–3 years
USD/replacement
2Diesel Solution Cost
USD
Generator + fuel tank + pole (CNY 50,000 ÷ 7.2)
kWh/year
= number of luminaires × power per luminaire × operating hours per night × 365 (shown: 20 × 0.1 kW × 11 h × 365)
gal/kWh
Typical 0.066–0.092 gal/kWh
USD/gal
US EIA average Aug 2026
USD/year
Oil, maintenance, manual refueling (CNY 8,000 ÷ 7.2)
3Economic Parameters
%
years
4Comparison Results
Empirical Findings
| Scenario | Conclusion |
|---|---|
| Off-grid for 10+ years | Solar TCO is usually lower than diesel (saves about 30%–50%) |
| Regions with expensive diesel | Payback can be as short as 2–3 years |
| Extreme cold / frequent cloudy-rainy weather | Larger battery needed; advantage slightly reduced |