Does the lifecycle cost analysis change if I use lead-acid instead of LiFePO4 batteries?

Yes, significantly. Add ₹3,000–₹5,000 per light for 2–3 battery replacements over 10 years with lead-acid. This adds ₹6,000–₹15,000 to the solar 10-year cost, potentially eroding the advantage over grid. LiFePO4 batteries requiring no replacement is one of the key reasons the solar lifecycle cost advantage is real and sustained.

Can I use this analysis to justify the budget for an LED upgrade to my municipal council?

Yes. This framework is exactly what municipal finance committees need. Present the 10-year cost comparison with current electricity bills as the baseline. Xera Tech's project team prepares tailored lifecycle cost reports for municipal presentations - incorporating your municipality's actual electricity rate, current lamp type, and replacement history. Contact connect@xeratech.in.

What discount rate should I use for net present value (NPV) calculation?

For government project evaluation in India: use 10–12% discount rate as per NPC (National Planning Commission) guidelines for social infrastructure projects. For industrial/commercial: use the company's WACC (Weighted Average Cost of Capital), typically 12–18% for Indian manufacturing SMEs. At 12% discount rate, the LED NPV advantage remains strongly positive in all scenarios modelled above.

LED Street Light Lifecycle Cost Analysis - 10-Year Total Cost India

The Four Cost Components

A complete lifecycle cost analysis for street lights includes: (1) Capital cost: product price + installation labour + civil work + infrastructure (cable, transformer for grid; panel, battery for solar). (2) Energy cost: watts × hours/day × 365 days × years × electricity rate. (3) Maintenance cost: lamp replacement cost + labour + access equipment (scissor lift for high poles). (4) Infrastructure cost: ongoing transformer maintenance, cable fault repair, meter charges. Each of these differs dramatically between technology types. Missing any one of them leads to wrong decisions - typically choosing cheaper products that cost more overall.

10-Year Cost Comparison - Grid LED vs HPS Sodium

Per light, 10m pole, 10h/night, 365 days, Maharashtra commercial rate ₹7/unit: HPS 250W sodium: capital ₹8,000 (lamp+fitting+pole+install). Energy: 250W × 10h × 365 × 10 × ₹7 = ₹63,875. Maintenance: 2 lamp replacements (3.5 years × 2) × ₹2,000 = ₹4,000 + 4 access trips × ₹3,000 = ₹12,000 + ₹16,000. Total 10-year: ₹87,875. LED 100W: capital ₹10,000. Energy: 100W × 10h × 365 × 10 × ₹7 = ₹25,550. Maintenance: ₹2,000 (cleaning only, no lamp replacement). Total 10-year: ₹37,550. LED saves ₹50,325 per light over 10 years - a 57% reduction. For a municipality with 10,000 sodium lights: total 10-year saving = ₹50 crore.

10-Year Cost Comparison - Solar vs Grid LED

For a new rural road (no existing grid infrastructure): Solar 40W: capital ₹15,000 (complete installed). Energy: ₹0. Maintenance: ₹5,000 (battery check, cleaning over 10 years). Total 10-year: ₹20,000. Grid LED 40W: capital ₹8,000 (product+pole+install) + ₹6,250 infrastructure share per point (₹2.5 lakh for 40 lights) = ₹14,250 capital. Energy: 40W × 10h × 365 × 10 × ₹7 = ₹10,220. Maintenance: ₹3,000. Total 10-year: ₹27,470. Solar saves ₹7,470 per point over 10 years on a new road. With 40% government subsidy on solar (reducing capital to ₹9,000): solar total = ₹14,000. Saving vs grid: ₹13,470 per point - grid is 96% more expensive.

Sensitivity Analysis - Key Variables

The solar vs grid advantage grows when: electricity rates increase (grid cost rises, solar stays fixed). Power cuts are frequent (grid reliability decreases, solar unaffected). Battery technology is LiFePO4 (no replacement needed in 10 years). Government subsidy is applied (reduces solar capital). The solar vs grid advantage shrinks when: no grid infrastructure cost (existing feeder available). Electricity rates are very low (below ₹4/unit - solar payback extends beyond 10 years without subsidy). Heavy shade reduces solar performance. For the vast majority of Indian rural road lighting scenarios (new roads, unreliable grid, moderate electricity rates): solar lifecycle cost is lower than grid even without subsidy.