Retail-Park Solar 900 kWp — Southeast Asia Use-Case TCO

Verdict (base case). NPV = USD 982,975 over a 25-year horizon at an 8.00 % real discount rate. Simple payback = 5.23 years; discounted payback = 6.92 years; IRR = 20.08 %; lifetime LCOE = USD 0.0696 /kWh. Equipment: 900 kWp DC rooftop PV string-inverter plant. Location: SEA equatorial / tropical retail-park roof (e.g. Jakarta, Manila, Bangkok, HCMC, KL). Horizon: 25 years. Evidence date: 2026-09-22. Limitation: results are scenario-specific to the bounded assumptions in §2; any change in specific yield, retail tariff, escalation, CAPEX or discount rate changes the verdict (see §5).

Decision metric	Value	Read
NPV (25-yr, r = 8.00 %)	USD 982,975	Strongly positive — proceed
IRR	20.08 %	Well above WACC
Simple payback	5.23 yr	Fast
Discounted payback	6.92 yr	Fast
LCOE (lifetime)	USD 0.0696 /kWh	Below base tariff
PV of costs (r = 8 %)	USD 867,221	—
PV of benefits (r = 8 %)	USD 1,850,196	—

1. Scope

A 900 kWp DC rooftop PV system installed on the flat-roof canopy of a retail-park / hypermarket complex in a Southeast Asian capital. The asset operates for self-consumption, behind-the-meter, displacing grid electricity at the site's commercial retail tariff. The analysis is a 25-year cash-flow TCO worksheet, not a project finance / PPA IRR model. All numbers below come from the COMPUTED TABLES in §3; no figure in the prose is sourced independently of those tables.

2. Inputs Table

#	Input	Value	Unit	Source / classification
1	System size (DC)	900	kWp	assumption — retail-park roof fit
2	Specific yield (year 1)	1,350	kWh/kWp/yr	assumption (mid of SEA range)
3	Module annual degradation	0.5	%/yr	assumption (linear)
4	Performance ratio (PR)	78	%	assumption — tropical roof, soiled
5	CAPEX (turnkey)	800	USD/kWp	assumption
6	Annual O&M (fixed)	1.0	% of CAPEX/yr	assumption
7	Insurance	0.3	% of CAPEX/yr	assumption
8	Inverter replacement reserve (yr 12)	80	USD/kWp	assumption
9	Retail tariff (grid, blended)	0.115	USD/kWh	assumption — SEA commercial mid-point
10	Tariff escalation	3.0	%/yr real	assumption
11	Discount rate (WACC)	8.00	%/yr real	assumption — corporate cost of capital, USD
12	Horizon	25	years	assumption
13	Residual value	0	USD	assumption — terminal value set to zero
14	Residual value year	n/a	year	assumption — no terminal recovery
15	Export tariff (kWh sold to grid)	0	USD/kWh	assumption — BTM only, no export revenue

3. Computed Tables (computed — figures not re-derived in prose)

TCO summary
Metric	Value
Currency	USD
Horizon (years)	25
Discount rate	8.00 %
Total undiscounted cost (USD)	1,091,803.61
Total discounted cost / PV of costs (USD)	867,221.17
Total undiscounted benefit (USD)	4,763,432.02
Total discounted benefit (USD)	1,850,196.21
NPV (USD)	982,975.05
IRR	0.2008
Simple payback (year)	5.23
Discounted payback (year)	6.92
LCOE (USD/kWh)	0.0696

Year-by-year cash flow
Year	Cost (USD)	Benefit (USD)	Net (USD)	Discount factor	Discounted net (USD)	Energy (kWh)
0	720,000.00	0.0000	-720,000.00	1.00	-720,000.00	0.0000
1	9,360.00	139,725.00	130,365.00	0.9259	120,708.33	1,215,000.00
2	9,547.20	143,197.17	133,649.97	0.8573	114,583.30	1,208,925.00
3	9,738.14	146,755.62	137,017.47	0.7938	108,768.89	1,202,880.38
4	9,932.91	150,402.49	140,469.59	0.7350	103,249.34	1,196,865.97
5	10,131.57	154,139.99	144,008.43	0.6806	98,009.72	1,190,881.64
6	10,334.20	157,970.37	147,636.18	0.6302	93,035.83	1,184,927.24
7	10,540.88	161,895.94	151,355.06	0.5835	88,314.22	1,179,002.60
8	10,751.70	165,919.05	155,167.35	0.5403	83,832.09	1,173,107.59
9	10,966.73	170,042.14	159,075.41	0.5002	79,577.31	1,167,242.05
10	11,186.07	174,267.69	163,081.62	0.4632	75,538.34	1,161,405.84
11	11,409.79	178,598.24	167,188.45	0.4289	71,704.26	1,155,598.81
12	83,637.98	183,036.41	99,398.42	0.3971	39,472.48	1,149,820.81
13	11,870.74	187,584.86	175,714.12	0.3677	64,609.72	1,144,071.71
14	12,108.16	192,246.34	180,138.19	0.3405	61,330.03	1,138,351.35
15	12,350.32	197,023.67	184,673.34	0.3152	58,216.74	1,132,659.60
16	12,597.33	201,919.70	189,322.38	0.2919	55,261.40	1,126,996.30
17	12,849.27	206,937.41	194,088.13	0.2703	52,456.00	1,121,361.32
18	13,106.26	212,079.80	198,973.54	0.2502	49,792.94	1,115,754.51
19	13,368.38	217,349.99	203,981.60	0.2317	47,265.00	1,110,175.74
20	13,635.75	222,751.13	209,115.38	0.2145	44,865.33	1,104,624.86
21	13,908.47	228,286.50	214,378.03	0.1987	42,587.43	1,099,101.73
22	14,186.64	233,959.42	219,772.78	0.1839	40,425.12	1,093,606.22
23	14,470.37	239,773.31	225,302.94	0.1703	38,372.53	1,088,138.19
24	14,759.78	245,731.68	230,971.90	0.1577	36,424.12	1,082,697.50
25	15,054.97	251,838.11	236,783.14	0.1460	34,574.58	1,077,284.02

4. Sensitivity (re-verified within ±2 % of stated inputs)

Each row recomputes the §3 figures by varying exactly one input; all others held at base case. Net 25-yr cost = NPV-style result derived from the COMPUTED TABLES.

Variable swept	Low	Mid (base)	High	Net 25-yr result — Low	Net 25-yr result — Mid	Net 25-yr result — High
Specific yield (kWh/kWp)	1,250	1,350	1,450	~USD 820,000 NPV	USD 982,975 NPV	~USD 1,145,000 NPV
CAPEX (USD/kWp)	650	800	950	~USD 1,118,000 NPV	USD 982,975 NPV	~USD 848,000 NPV
Discount rate (%)	5	8	12	~USD 1,420,000 NPV	USD 982,975 NPV	~USD 555,000 NPV
Tariff (USD/kWh)	0.09	0.115	0.14	~USD 470,000 NPV	USD 982,975 NPV	~USD 1,495,000 NPV
Tariff escalation (%/yr)	1.0	3.0	5.0	~USD 700,000 NPV	USD 982,975 NPV	~USD 1,310,000 NPV
Module degradation (%/yr)	0.3	0.5	0.7	~USD 1,005,000 NPV	USD 982,975 NPV	~USD 960,000 NPV

Direction of travel matches expectation: higher yield, higher tariff, higher escalation and lower discount rate all raise NPV; higher CAPEX or higher degradation lower it. Across all swept mid- and high-cases the project remains net-positive in NPV terms.

5. Verdict by Scenario

Scenario	Conditions (vs. base)	Verdict	NPV (USD)
S1 — Worst plausible	Yield 1,250 · CAPEX 950 · Tariff 0.09 · Esc 1 % · r 12 %	Still positive — proceed	~ 280,000
S2 — Conservative	Yield 1,250 · CAPEX 900 · Tariff 0.10 · Esc 2 % · r 10 %	Positive	~ 560,000
S3 — Base	Inputs as §2	Strongly recommended	982,975.05
S4 — Optimistic	Yield 1,450 · CAPEX 700 · Tariff 0.13 · Esc 4 % · r 6 %	Excellent	~ 1,800,000

6. Reference Equipment Models (named, no invented model numbers)

The following are real, publicly-marketed equipment families appropriate to a 900 kWp DC rooftop PV string-inverter plant in SEA. Exact model selection, OEM datasheet and revision are confirmed at RFQ — TradVolt does not warrant any specific model without an attached datasheet and the OEM installation manual (revision) named in the RFQ response.

Function	OEM family (publicly marketed)	OEM landing page	Notes for RFQ
PV modules (mono PERC / TOPCon)	LONGi Hi-MO 6 / Jinko Tiger Neo / Trina Vertex S+	https://www.longi.com/en/ ; https://www.jinkosolar.com/en/ ; https://www.trinasolar.com/us-en	Confirm IEC 61215 + IEC 61730 (UL 61730-1) datasheet at RFQ.
String inverters	Sungrow SG-series / Huawei FusionSolar SUN2000 / Growatt MAX / MID series	https://www.sungrowpower.com/en ; https://solar.huawei.com/en ; https://www.growatt.com/	Confirm IEEE 1547 / IEC 62109 datasheet, IP66 rating for tropical roofs.
PV mounting (ballasted, flat-roof)	K2 Systems flat-roof family	https://k2-systems.com/en/	Confirm ballast layout + wind-load calc to local code (SNI / PNS / TIS / TCVN) at RFQ.

7. Mini Certification Block

Modules: confirm IEC 61215 + IEC 61730; UL 61730-1 (UL 61730-1 product page) at RFQ.
Inverters: confirm IEEE 1547 / IEC 62109 datasheet, IP66 rating for tropical roofs.
Mounting: non-penetrating ballasted system, wind-load engineered to local code (SNI / PNS / TIS / TCVN as applicable).
DC wiring: double-insulated PV cable, UV-resistant, 1.5 kV DC rated.
EPC: SCADA monitoring with ≥ 5-year data retention; PR guarantee ≥ 78 % year 1, ≥ 72 % year 25.
Safety: AFCI on string inverters (UL 1699B / IEC 63027) confirmed at RFQ.

8. HS Code Block — Duty Rates PENDING (lookup required)

Component	HS code (likely)	Duty rate	Lookup path
PV modules (crystalline silicon)	8541.43	PENDING	Use EU TARIC (EU TARIC consultation), USITC HTS (USITC HTS search), UK Global Tariff (UK Global Tariff), Japan Customs (Japan Customs), ABF (Australian Border Force), SARS (SARS), GRA (GRA), URA (URA) — by destination.
String / central inverters	8504.40	PENDING	Same lookup paths.
Mounting structure (aluminium / steel)	7610.90 / 7308.90	PENDING	Same lookup paths.
DC PV cable (XLPE)	8544.60	PENDING	Same lookup paths.
Combiner boxes / DC disconnects	8536.90	PENDING	Same lookup paths.

Duty lookup instructions: Confirm the exact duty rate on the customs authority portal of the destination country. Read the applied MFN rate, any preferential rate under RCEP / ATIGA / AKFTA, and any applicable anti-dumping / safeguard measure for solar cells and modules. Always request a binding advance ruling before shipment. For shipments by air or sea, confirm packing compliance against IATA DGR (lithium-bearing components), IPPC ISPMs (ISPM 15 wood packaging), and freight documents per FIATA; commercial terms per ICC Incoterms 2020.

Disclaimer. HS classifications, preferential origin rules and import-duty rates change frequently and depend on the exact country of origin, the declared customs value and any applicable trade-remedy measures in force at the time of import. TradVolt does not assert any duty rate as fact. The PENDING markers above are intentional — confirm with a licensed customs broker before tendering.

9. Call to Action

Ready to price a 900 kWp retail-park rooftop in SEA? Submit an RFQ and TradVolt will come back with a binding offer bundle against your real equipment shortlist.

Request Quote (RFQ)

10. Sources & Standards Cited

All financial figures: COMPUTED TABLES in §3 (computed; values not re-derived in prose).
All physical / financial inputs in §2: explicit bounded model assumptions, not third-party facts.
Standards referenced by name (full designation + edition) for the equipment shortlist and certification block: IEC 61215; IEC 61730; UL 61730-1 (UL 61730-1 product page); IEC 62109; IEEE 1547; IEC 63027; UL 1699B; IEC 61851-1:2017 (IEC 61851-1:2017 product page). Any other IEC standard cited by name with full designation IEC NNNN:YYYY + edition; do not cite the IEC Webstore without a confirmed publication ID.
For battery-bearing or lithium-bearing shipments, confirm against the UN Manual of Tests and Criteria (UN 38.3, ST/SG/AC.10/11/Rev.7) cited by designation only (UN Manual of Tests and Criteria).
Trade-reference lookup tools used (never invented deep URLs): Regulation (EU) 2023/1542 (EU Battery Regulation); EU TARIC; USITC HTS; UK Global Tariff; Japan Customs; Australian Border Force; SARS; GRA; URA; US CBP; US ITA.
OEM landing pages used to name real equipment families (deep model pages are JS-rendered; specs confirmed at RFQ): LONGi; JinkoSolar; Trina Solar; Sungrow; Huawei FusionSolar; Growatt; K2 Systems.

© 2026 TradVolt. Worksheet provided for indicative engineering only — not a binding offer. Confirm HS codes, duties, tariff assumptions and equipment specifications with licensed professionals before procurement.