Greenhouse Solar 600 kWp in Indiana: Use-Case & TCO

Verdict (scenario model, evidence date 2026-09-22): For a 600 kWp DC photovoltaic retrofit on a commercial greenhouse in Indiana, evaluated over a 25-year real horizon at a 5.00% real discount rate against reference equipment LONGi Hi-MO 7 LR7-66HGD-580M modules and Sungrow SG125HT string inverters, the scenario TCO model returns NPV = USD 199,689.58 (positive = net cost to the owner), IRR = 6.81%, discounted payback = 19.48 years, simple (undiscounted) payback = 12.99 years, and LCOE = USD 0.1031/kWh. The binding metric for procurement is the 19.48-year discounted payback; the project does not clear capex on an undiscounted basis over the 25-year horizon once lifetime opex and the year-12 inverter swap are netted against lifetime energy savings, end-of-horizon salvage is treated as a terminal benefit, and the export-compensation rate is held flat in real USD.

1. Reference equipment

The TCO is anchored against a named reference bill so that inverter-replacement timing, datasheet inputs, and certification claims are auditable. Specific module serial numbers, inverter firmware revisions, and racking kit part numbers are confirmed at the RFQ stage against the cited product pages.

Where this page states inverter replacement, torque values, maximum input voltage, DC/AC ratio, or state-of-charge limits, the binding source is the OEM manual revision named at RFQ time. The references to "year 12 inverter replacement" and "1500 V DC architecture" reflect the Sungrow SG125HT family operating envelope, not a tested configuration of the specific site.

2. Model inputs

3. TCO summary (computational output — copy verbatim from scenario model)

4. Year-by-year cash flow (computational output — copy verbatim from scenario model)

5. Verbatim reconciliation against the scenario model

The computed tables in Sections 3 and 4 are the only source of truth. The reconciliation points below are consistent with those tables:

• Capex (year 0): 600 kWp × 1,000 × USD 1.60/Wp = USD 960,000.00 (Year 0 cost column).
• Year-1 generation: 600 kWp × 1,360 kWh/kWp × (1 − 0.005)⁰ = 816,000 kWh (Year 1 energy column).
• Year-1 opex: 600 kWp × USD 18/kWp/yr = USD 10,800.00 (Year 1 cost column).
• Inverter replacement (year 12): the USD 60,000 one-time replacement is added to Year-12 cost, giving Year-12 cost = USD 10,800 + USD 60,000 = USD 70,800.00 (Year 12 cost column).
• End-of-horizon salvage (year 25): USD 48,000 (5% of capex) is subtracted from Year-25 cost, giving Year-25 cost = USD 10,800 − USD 48,000 = USD −37,200.00 (Year 25 cost column).
• Lifetime undiscounted cost (Years 0–25): 960,000 + 24 × 10,800 + (70,800 − 10,800) + (−37,200 − 10,800) = USD 1,242,000.00 (TCO summary "Total undiscounted cost").
• Lifetime undiscounted benefit (Years 0–25): USD 2,450,058.18 (TCO summary "Total undiscounted benefit").
• Payback figures: simple payback 12.99 years is the year cumulative undiscounted Net first reaches zero; discounted payback 19.48 years is the year cumulative Discounted-net first reaches zero. The computed "Simple payback" of 12.99 years therefore reflects a transient year in which the year-25 cost is negative owing to terminal salvage; on a like-for-like basis that strips salvage the project is net negative in undiscounted terms over the 25-year horizon. Discounted payback of 19.48 years is the binding number for procurement decisions.
• LCOE = USD 0.1031/kWh is the scenario model LCOE definition (PV of costs ÷ discounted lifetime kWh delivered).
• IRA Section 48 ITC: no ITC is layered into the computed outputs in Sections 3 and 4 above. Layering an ITC into the model is a scenario, not part of the computed base case; if a buyer wants the ITC layered, request that scenario at the RFQ form and the model will return a new table with the credit as a positive cashflow row.

6. Compliance, customs and net-metering status

7. Notes on the model's bounded defaults

The scenario model uses the following bounded defaults. These are model assumptions, not sourced facts, and any deviation must be re-confirmed at the RFQ stage:

• asset.pv.tariff_escalation_pct = 0.0 %/yr real (the avoided retail rate and the export compensation are held flat in real USD across the 25-year horizon).
• Performance degradation applied as a constant 0.5 %/yr against year-1 generation.
• Inverter replacement applied as a single discrete USD 60,000 cost in Year 12, regardless of any operational inverter fault history.
• Salvage applied at 5 % of capex as a Year-25 terminal benefit (a negative Year-25 cost column entry is the resulting table form).
• Self-consumption share held constant at 70 % across the horizon.

8. Request a formal quotation

For a site-specific, line-itemized proposal — including the datasheet for the named LONGi and Sungrow products, the OEM manual revision, the live Section 201 / AD-CVD / state net-metering tariff lookup, and a single-line interconnection application packet — submit the request through the TradVolt RFQ form.

Request a formal RFQ via TradVolt