By Gokin Solar Technical Team | Data year: 2025 | Published: October 2026
Utility-scale solar PV total installed cost (TIC) fell to $667/kW in 2025, down 6% year-on-year, while global weighted-average LCOE held at $44/MWh. For EPCs and developers, cost per MW is a function of DC/AC basis, regional cost structure, module power class, and financing conditions—not a single number to quote.
1. The 2025 Benchmark: $667/kW, With a Wide Dispersion
IRENA's Renewable Power Generation Costs in 2025 reports a global weighted-average TIC of $667/kW for utility-scale solar PV, an 88% reduction since 2010. The global average masks significant dispersion: IRENA reports a wide percentile range around the mean, and project-level TIC depends on land, grid distance, permitting, labour, and financing.
DC vs. AC basis is a procurement discipline, not a footnote. A $/kW figure is meaningless without stating MWdc or MWac. With DC/AC ratios of 1.2:1–1.5:1, comparing a DC-based quote against an AC-based benchmark can distort apparent competitiveness by 20–50%. Require every quote and model to state the basis before supplier comparison.
Project size reduces cost per MW by spreading fixed development costs, but savings are not linear. Land preparation, transmission upgrades, and construction logistics can absorb much of the scale benefit. Cost per MW should be evaluated at site level.
2. What Moves Cost per MW—and Where Gokin Modules Fit
IRENA data for 2025 shows that modules and inverters together account for 25–51% of TIC, averaging 35%; BoS hardware averages 27%, and installation averages 18%. Module power rating affects cost per MW through a less obvious channel: higher-power modules reduce unit count, mounting clamps, connectors, and labour per MW.
At 580 W, a 100 MWdc array needs about 172,414 modules. At 740 W, about 135,135—a 21.6% reduction in module count. At 780 W, about 128,205—a 25.6% reduction. This is a module-count reduction, not a BOS cost reduction; the actual BOS saving depends on the project's mounting, wiring, and labour structure, but the direction is reliably positive as module power increases.
Gokin Solar's utility-scale line enters the cost model here. The GK-2-66HTBD-740M delivers 740 Wat 23.8% efficiency, N-Type TOPCon, bifaciality 80±5%, and a Pmax temperature coefficient of -0.29%/℃. The GK-4-78HTBD-750M delivers 750 W at 23.4% with 156 half-cut cells and a 30-year linear power warranty. The GK-4-78HGBD-780M uses GBC back-contact dual-glass architecture at 760-780 W and 23.7-24.3% efficiency, with bifaciality up to 75%.
On the GK-4-78HGBD's bifaciality: the BC architecture moves all metallisation to the rear, which lifts front-side efficiency by clearing the front surface—but the same rear metal coverage constrains rear-side light capture. The lower bifaciality (up to 75% versus 80±5% for TOPCon) is a design trade-off for higher front-side power density, not a performance shortfall. It is best suited to projects where land or mounting area is the binding constraint, not to high-albedo sites where rear-side gain is the primary value driver.
| Project condition | Suitable Gokin module | Key specs |
| High-irradiance, high-temperature site | GK-2-66HTBD-740M | 740 W / 23.8% / Temp coefficient of Pmax - 0.29%/℃ / bifaciality 80±5% |
| Large-format tracker configuration | GK-4-78HTBD-750M | 750 W / 23.4% / 156 half-cells / 30-year linear warranty/ Temp coefficient of Pmax -0.35%/℃ |
| Land- or area-constrained, maximum power density | GK-4-78HGBD-780M | 760–780 W / 23.7–24.3% / GBC back-contact |
Procurement note: require bidders to state module count per MWdc and the corresponding mounting and connector bill of quantities. This makes the BOS impact of module power class visible and comparable.
3. LCOE and PPA: The Metrics That Drive Investment Decisions
The 2025 data makes one point explicit: TIC fell 6% to $667/kW, but global LCOE remained flat at $44/MWh. Lower equipment costs were offset by higher financing costs and, in some markets, lower capacity factors—global weighted-average capacity factor fell to 16.5% in 2025 from 17.4% in 2024. Capex optimisation alone cannot carry the investment case.
For developers, module selection should be tested in the LCOE model, not only the capex model. A module with higher power and efficiency may carry a small $/Wp premium but reduce BOS cost per MW and improve yield through bifacial gain and temperature performance. **PPA price is the revenue-side counterpart to cost per MW.** A $667/kW project at a 16–17% capacity factor in a $45/MWh PPA market has a different return profile from an identical-cost project in a $65/MWh market. EPCs preparing bids should include a simple LCOE and IRR sensitivity table alongside the cost breakdown.
4. Additional Costs: O&M and Financing
IRENA's 2025 **total O&M benchmark—including insurance and asset management—is approximately $12.2/kW/year at the global weighted-average level**. This is not a single-project reference: the surveyed sample average was $7.54/kW/year, and IRENA's OECD LCOE assumptions use $21.26/kW/year. The spread reflects scope, market, and asset-management intensity.
NREL's modelled O&M range for utility-scale PV spans $0–$40/kWdc/year, with $20/kWdc/year as a commonly cited value for tracking systems in mature markets; this range originates from NREL's 2019 ATB benchmark and should be read as a modelled envelope, not a current-market quotation. A module with a 30-year linear power warranty—such as the GK-2-66HTBD or GK-4-78HTBD—supports a 30-year OPEX assumption rather than the 25-year assumption still common in conservative project finance.
Insurance, taxes, and financing costs are now first-order variables: in higher-rate markets, the cost of capital can add $10–$20/MWh to LCOE.
5. FAQ: Solar Power Plant Cost per MW
Q1: What is the average cost of a 1 MW solar plant in 2025?
A: The 2025 IRENA global weighted-average TIC is $667/kW**, or about **$667,000 for 1 MWdc. Project-level costs vary widely around this mean; site-specific scoping is essential before using the average as a budget.
Q2: What is the difference between MWdc and MWac in cost calculations?
A: MWdc is module capacity at STC; MWac is inverter output. DC/AC ratios typically range from 1.2:1 to 1.5:1. The bases are not interchangeable—comparing /kWdcagainst/kWac can distort apparent competitiveness by 20–50%.
Q3: What percentage of solar plant cost is modules and inverters?
A: IRENA's 2025 data shows modules and inverters together account for 25–51% of TIC, averaging 35%. Higher-efficiency module specifications can push the share toward the upper end. Higher-power modules such as the GK-2-66HTBD-740M reduce module count per MW, which can lower the mounting and labour share.
Q4: How much does utility-scale solar O&M cost per year?
A: IRENA's 2025 **total O&M benchmark is about $12.2/kW/year** (weighted average, including insurance and asset management); the surveyed sample average is $7.54/kW/year, and NREL's modelled range is $0–$40/kWdc/year depending on scope. A 30-year linear power warranty on the GK-2-66HTBD or GK-4-78HTBD supports a 30-year OPEX assumption.
Q5: Which Gokin Solar module is suitable for utility-scale plants?
A: The GK-2-66HTBD-740M (740W, 23.8%, -0.29%/℃, bifaciality 80±5%) suits high-temperature and high-albedo sites. The GK-4-78HTBD-750M (750W, 23.4%) suits large-format tracker configurations. The GK-4-78HGBD-780M (760-780 W, 23.7-24.3%, bifaciality up to 75%) suits land- or area-constrained projects where front-side power density matters more than rear-side gain.
Q6: What LCOE should a utility-scale developer target in 2025-2026?
A: The global weighted-average LCOE is $44/MWh (IRENA 2025). Set the target against your market benchmark, PPA price, financing cost, and capacity factor—not the global average alone.
