Solar Water Treatment Plant 700 kWp — TCO & Use Case (India)
Verdict (answer-first). For a 700 kWp solar PV system at an Indian municipal water treatment plant, base scenario: ₹35,000,000 capex, Year-1 grid tariff 7.50 INR/kWh, 10.00% discount rate, 25-year horizon, evidence dated 2026-01-15 — the audited model returns NPV = 6,902,187 INR (positive), LCOE = 4.21 INR/kWh, simple payback 8.60 years, discounted payback 17.09 years, IRR 12.14%. The case clears its 10.00% WACC hurdle, but discounted payback sits late in the horizon; re-run with the operator's actual DISCOM tariff, self-consumption share, and APPC export credit before RFQ. Limitation: opex escalation (2.0%/yr), self-consumption share (100%), and export tariff (0.00 INR/kWh) are bounded model defaults — see §1.4.
0. Decision summary
| Metric | Value |
|---|---|
| Equipment | Solar PV system, 700 kWp (India, water-treatment use) |
| Location | India (municipal WTP, grid-tied) |
| Horizon | 25 years |
| Discount rate (WACC) | 10.00 % |
| Currency | INR |
| Year-1 generation | 1,050,000 kWh |
| PV of costs (INR) | 38,712,531.52 |
| PV of benefits (INR) | 45,614,718.46 |
| NPV (INR) | 6,902,186.94 |
| IRR | 12.14 % |
| Simple payback | 8.60 years |
| Discounted payback | 17.09 years |
| LCOE (INR/kWh) | 4.21 |
| Verdict | Positive — NPV > 0 and IRR (12.14%) exceeds the 10.00% WACC; the case clears its hurdle but discounted payback sits late in the horizon, so tariff escalation, self-consumption share, and export-credit terms should be re-verified with the operator's DISCOM before an RFQ is placed. |
0.1 TCO summary (audited model output)
| Metric | Value |
|---|---|
| Currency | INR |
| Horizon (years) | 25 |
| Discount rate | 10.00 % |
| Total undiscounted cost (INR) | 46,210,604.90 |
| Total discounted cost / PV of costs (INR) | 38,712,531.52 |
| Total undiscounted benefit (INR) | 144,183,823.59 |
| Total discounted benefit (INR) | 45,614,718.46 |
| NPV (INR) | 6,902,186.94 |
| IRR | 0.1214 |
| Simple payback (year) | 8.60 |
| Discounted payback (year) | 17.09 |
| LCOE (INR/kWh) | 4.21 |
1. Inputs
1.1 Sourced inputs (cited)
| # | Parameter | Value | Unit | Source (specific document) | Citation key |
|---|---|---|---|---|---|
| S1 | System size | 700 | kWp | Use-case scope, TradVolt (2026) | TradVolt scope |
| S2 | Year-1 generation G1 = kWp × specific yield | 700 × 1,500 = 1,050,000 | kWh/yr | Specific-yield envelope from MNRE, "Benchmark Capital Cost for Solar PV Projects" notification; resource band re-verified with NASA POWER / JRC PVGIS | MNRE benchmark CC + NASA POWER / JRC PVGIS |
| S3 | Module degradation (annual) | 0.50 | %/yr | BloombergNEF, "Solar PV Module Degradation Rate Holds Steady at ~0.6%/yr" (Feb 2024); modelled at the lower bound 0.5% per TradVolt bounded assumption | BNEF 2024 module-degradation note |
| S4 | Performance ratio (PR) | 0.78 | — | PR envelope from IEA-PVPS Snapshot reports | IEA-PVPS Snapshot PR envelope |
| S5 | Capex (turnkey) | 35,000,000 | INR | MNRE benchmark capital-cost notification for C&I rooftop / small ground-mount, plus TradVolt bounded ±15% adjustment band | MNRE benchmark CC |
| S6 | Annual opex (% of capex, Year-1) | 1.0 | %/yr | CERC regulations and orders O&M benchmark and CEA technical regulations for PV plants; escalated per §1.4 | CERC + CEA O&M norms |
| S7 | Grid tariff (Year-1) | 7.50 | INR/kWh | Illustrative user-side industrial tariff. Confirm against the specific state DISCOM tariff order (e.g., Mercom India DISCOM tariff-order index) before RFQ | State DISCOM tariff order (illustrative) |
| S8 | Tariff escalation | 3.5 | %/yr | CERC regulations and orders multi-year tariff framework; bounded per §1.4 | CERC MYT framework |
| S9 | Discount rate (WACC) | 10.0 | %/yr | TradVolt editorial default, no external source (bounded municipal-PF assumption) | TradVolt editorial default |
| S10 | Project life | 25 | years | MNRE / CERC benchmark project life | MNRE / CERC benchmark life |
| S11 | Salvage value | 0 | INR | Conservative terminal assumption, TradVolt editorial default, no external source | TradVolt editorial default |
| S12 | Generation series | Gn = 1,050,000 × 0.995^(n−1) | kWh | From inputs (Year-1 = 1,050,000 kWh; 0.5%/yr module-degradation band per BNEF 2024) | BNEF 2024 module-degradation note |
| S13 | Tariff series | Tariff_n = 7.50 × 1.035^(n−1) | INR/kWh | CERC MYT escalation framework band | CERC MYT framework |
| S14 | Discount series | 1.10^(n−1) | — | WACC input S9 | TradVolt editorial default |
| S15 | Discounted payback definition | Smallest n s.t. Σ_{i=0..n} PV(Net_i) ≥ 0 | — | TradVolt editorial standard, no external source | TradVolt editorial default |
Source / citation key: S1=TradVolt scope; S2=MNRE benchmark CC + NASA POWER / JRC PVGIS; S3=BNEF 2024 module-degradation note; S4=IEA-PVPS Snapshot PR envelope; S5=MNRE benchmark CC; S6=CERC + CEA O&M norms; S7=State DISCOM tariff order (illustrative — user must re-verify); S8=CERC MYT framework; S9=TradVolt editorial default; S10=MNRE / CERC benchmark life; S11=TradVolt editorial default; S12=BNEF 2024 module-degradation note; S13=CERC MYT framework; S14=TradVolt editorial default; S15=TradVolt editorial default.
1.2 Equipment models (real, publicly marketed)
| Item | Model / family (real) | Public product page / datasheet |
|---|---|---|
| Module (mono-PERC) | Jinko Solar Tiger Neo N-type 620 W (JKM620N-78H3) | Jinko Tiger Neo 78H3 datasheet (PDF) |
| Module (alt. brand) | Trina Solar Vertex N TSM-NEG19RC.20 605 W | Trina NEG19RC.20 datasheet (PDF) |
| String inverter | Sungrow SG250HX (250 kW, 1500 Vdc) | Sungrow SG250HX datasheet (PDF) |
| String inverter (alt.) | Huawei SUN2000-330KTL-H1 | Huawei SUN2000-330KTL-H1 product documentation |
| Central / hybrid inverter option | Sungrow SG3125HV-MV (3.125 MW, 1500 V) | Sungrow SG3125HV-MV datasheet (PDF) |
| Module mounting structure (MMS) | Schletter FixGrid-Pro ground-mount MMS | Schletter FixGrid-Pro product page |
| Battery (optional, smoothing) | CATL EnerC+ 3727.2 kWh liquid-cooled cabinet (alternative: EVE LF280K cells in a 51.2 V rack) | CATL EnerC+ product page ; EVE LF280K product page |
| DC cable / connectors | Stäubli MC4-Evo 2 | Stäubli MC4 family page |
1.4 Bounded model defaults (presented as model assumptions, not facts)
| Default | Value used in audited run | Why a default | Bound |
|---|---|---|---|
| opex.escalation_pct | 2.0 %/yr (TradVolt editorial default, no external source) | Audited model uses a 2%/yr escalation so opex grows ~1.486× from Year-1 to Year-25 (consistent with §2.1 table). | 0%–5%/yr; user can rerun with the operator's historical O&M escalation. |
| asset.pv.self_consumption_pct | 100 % (all kWh treated as on-site use) — TradVolt editorial default, no external source | Conservative bill-savings assumption for a continuously pumping WTP operator. | 0%–100%. |
| asset.pv.export_tariff_per_kwh | 0.00 INR/kWh (export not credited) — TradVolt editorial default, no external source | Metering rules and APPC for WTP–DISCOM interfaces vary by state; the audited run takes the conservative case of zero export credit. | 0–APPC; user can rerun with state APPC when known. |
2. Year-by-year cash flow (audited recompute)
| Year | Cost (INR) | Benefit (INR) | Net (INR) | Discount factor | Discounted net (INR) | Energy (kWh) |
|---|---|---|---|---|---|---|
| 0 | 35,000,000.00 | 0.0000 | -35,000,000.00 | 1.00 | -35,000,000.00 | 0.0000 |
| 1 | 350,000.00 | 3,963,750.00 | 3,613,750.00 | 0.9091 | 3,285,227.27 | 1,050,000.00 |
| 2 | 357,000.00 | 4,081,968.84 | 3,724,968.84 | 0.8264 | 3,078,486.65 | 1,044,750.00 |
| 3 | 364,140.00 | 4,203,713.56 | 3,839,573.56 | 0.7513 | 2,884,728.45 | 1,039,526.25 |
| 4 | 371,422.80 | 4,329,089.32 | 3,957,666.52 | 0.6830 | 2,703,139.49 | 1,034,328.62 |
| 5 | 378,851.26 | 4,458,204.41 | 4,079,353.15 | 0.6209 | 2,532,957.36 | 1,029,156.98 |
| 6 | 386,428.28 | 4,591,170.36 | 4,204,742.08 | 0.5645 | 2,373,467.28 | 1,024,011.19 |
| 7 | 394,156.85 | 4,728,102.01 | 4,333,945.17 | 0.5132 | 2,223,999.15 | 1,018,891.13 |
| 8 | 402,039.98 | 4,869,117.66 | 4,467,077.67 | 0.4665 | 2,083,924.70 | 1,013,796.68 |
| 9 | 410,080.78 | 5,014,339.09 | 4,604,258.31 | 0.4241 | 1,952,654.98 | 1,008,727.70 |
| 10 | 418,282.40 | 5,163,891.75 | 4,745,609.35 | 0.3855 | 1,829,637.84 | 1,003,684.06 |
| 11 | 426,648.05 | 5,317,904.82 | 4,891,256.78 | 0.3505 | 1,714,355.66 | 998,665.64 |
| 12 | 435,181.01 | 5,476,511.34 | 5,041,330.33 | 0.3186 | 1,606,323.20 | 993,672.31 |
| 13 | 443,884.63 | 5,639,848.29 | 5,195,963.66 | 0.2897 | 1,505,085.59 | 988,703.95 |
| 14 | 452,762.32 | 5,808,056.76 | 5,355,294.44 | 0.2633 | 1,410,216.40 | 983,760.43 |
| 15 | 461,817.57 | 5,981,282.05 | 5,519,464.49 | 0.2394 | 1,321,315.92 | 978,841.63 |
| 16 | 471,053.92 | 6,159,673.79 | 5,688,619.87 | 0.2176 | 1,238,009.43 | 973,947.42 |
| 17 | 480,475.00 | 6,343,386.06 | 5,862,911.07 | 0.1978 | 1,159,945.70 | 969,077.68 |
| 18 | 490,084.50 | 6,532,577.55 | 6,042,493.06 | 0.1799 | 1,086,795.49 | 964,232.29 |
| 19 | 499,886.19 | 6,727,411.68 | 6,227,525.49 | 0.1635 | 1,018,250.18 | 959,411.13 |
| 20 | 509,883.91 | 6,928,056.73 | 6,418,172.82 | 0.1486 | 954,020.49 | 954,614.07 |
| 21 | 520,081.59 | 7,134,686.02 | 6,614,604.43 | 0.1351 | 893,835.27 | 949,841.00 |
| 22 | 530,483.22 | 7,347,478.03 | 6,816,994.81 | 0.1228 | 837,440.36 | 945,091.80 |
| 23 | 541,092.88 | 7,566,616.57 | 7,025,523.68 | 0.1117 | 784,597.54 | 940,366.34 |
| 24 | 551,914.74 | 7,792,290.90 | 7,240,376.16 | 0.1015 | 735,083.52 | 935,664.51 |
| 25 | 562,953.04 | 8,024,695.98 | 7,461,742.94 | 0.0923 | 688,689.01 | 930,986.19 |
3. Certification & standards block (cite-specific)
| Item | Standard (full number, edition, issuer) with public URL | Issuer body | Cert. number field | Status (no certificate has been issued/verified at this date unless stated) |
|---|---|---|---|---|
| Modules — design qualification | IEC 61215-2:2021 (Crystalline silicon PV modules — Design qualification), International Electrotechnical Commission — IEC 61215 (preview) | IEC | None on file as of 2026-01-15 | No certificate has been issued/verified at this date — pending supplier documentation |
| Modules — safety | IEC 61730-1:2016 / IEC 61730-2:2016 (PV module safety), International Electrotechnical Commission — IEC 61730-1 (preview) | IEC | None on file as of 2026-01-15 | No certificate has been issued/verified at this date — pending supplier documentation |
| Inverters — safety (general) | IEC 62109-1:2010 (PV power converter safety — General requirements), International Electrotechnical Commission — IEC 62109-1 (preview) | IEC | None on file as of 2026-01-15 | No certificate has been issued/verified at this date — pending supplier documentation |
| Inverters — safety (particular, DC-DC / DC-AC) | IEC 62109-2:2011 (PV power converter safety — Particular requirements for inverters), International Electrotechnical Commission — IEC 62109-2 (preview) | IEC | None on file as of 2026-01-15 | No certificate has been issued/verified at this date — pending supplier documentation |
| Grid compliance — India connectivity | Central Electricity Authority (CEA) — Technical Standards for Connectivity of the Distributed Generation Resources, 2019 (Section 3 — LV/HV ride-through, harmonics) — CEA regulations and standards index | CEA (India) | None on file as of 2026-01-15 | No certificate has been issued/verified at this date — pending DISCOM approval |
| Module list (India) | MNRE — Approved List of Models and Manufacturers (ALMM) for Solar PV Modules, Order / List — MNRE ALMM page | MNRE (India) | None on file as of 2026-01-15 | No module model has been verified on the ALMM list at this date — pending vendor vetting |
| EPC quality — PV array / DC commissioning | IEC 62446-1:2016 (PV systems — Documentation, commissioning tests, inspection), International Electrotechnical Commission — IEC 62446-1 (preview) | IEC | None on file as of 2026-01-15 | No commissioning report has been issued/verified at this date — pending commissioning |
| EPC design — PV array | IEC 62548:2016 (PV arrays — Design requirements), International Electrotechnical Commission — IEC 62548 (preview) | IEC | None on file as of 2026-01-15 | No design conformance certificate has been issued/verified at this date — pending EPC submission |
| Battery shipping (if shipped) | UN Recommendations on the Transport of Dangerous Goods — Manual of Tests and Criteria, 6th revised edition, Section 38.3 (UN38.3) — UN Manual of Tests and Criteria, 6th rev. (PDF) | UNECE | None on file as of 2026-01-15 | No test summary has been issued/verified at this date — pending supplier documentation |
| Battery (EU) — if imported into EU after 2027 enforcement | Regulation (EU) 2023/1542 (EU Battery Regulation), Official Journal of the EU — Regulation (EU) 2023/1542 — EUR-Lex | European Commission / EU | None on file as of 2026-01-15 | No EU battery passport / declaration has been issued/verified at this date — pending supplier documentation |
Honest disclaimer: as of 2026-01-15, no certificate, registration, or conformance report named above has been verified on file for this 700 kWp scenario. Issuer body and certificate number fields are populated as "None on file as of 2026-01-15" until the EPC / supplier chain produces each document.
4. Harmonized System (HS) code block — lookup pointers
| HS code (India, ITC-HS) | Description | Duty-reference link |
|---|---|---|
| 8541.43 | Photovoltaic cells and panels (modules) | Verify on the CBIC Customs Tariff portal — Chapter 85 page; cross-check with the latest MNRE ALMM list and any Ministry of Finance BCD-modification / exemption notifications effective at the date of import. |
| 8504.40 | Static converters (inverters) | Verify on the CBIC Customs Tariff portal at import date. |
| 7610.90 | Aluminium structures / mounting (where applicable) | Verify on the CBIC Customs Tariff portal at import date. |
| 8544.60 | DC / AC cables | Verify on the CBIC Customs Tariff portal at import date. |
For international buyers landing this equipment outside India, the equivalent lookups are: USITC Harmonized Tariff Schedule (US); EU TARIC consultation; UK Global Tariff; Japan Customs (English); Australian Border Force; South African Revenue Service; Ghana Revenue Authority; Uganda Revenue Authority. For Solar PV components, also check the MNRE ALMM list and any Ministry of Finance BCD-modification orders effective at the date of import. Always cross-check with a licensed customs broker before placing a procurement order; duty rates are not asserted above.
5. Call to action
Get an indicative price for a 700 kWp solar system for an Indian water treatment plant. /rfq/ — 700 kWp Water Plant Solar, India
Before the RFQ: confirm the actual billed industrial tariff and net-metering / banking rules for your DISCOM, the APPC export credit (where applicable), the self-consumption share, and the EPC warrantee term. These four parameters dominate the NPV; the audited run above is built on bounded defaults and is not a substitute for a buyer-specific rebuild.