Offshore Wind Cost Calculator
Offshore wind is the most capital-intensive form of wind generation, but it also taps a far stronger, more consistent wind resource than onshore sites. This calculator takes your project capacity, installed cost per kW, annual O&M cost per kW, capacity factor, and project lifetime, then reports the total installed capital cost, annual O&M cost, annual energy production, and a simplified levelized cost of energy (LCOE). Start with the capacity factor from our Wind Farm Capacity Factor Calculator to reflect offshore conditions, and convert that production into total energy delivered with our Annual Energy Production Calculator.
The total nameplate capacity of the offshore wind project. Modern fixed-bottom projects commonly range from a few hundred MW to over 1 GW.
Fixed-bottom offshore wind installed costs typically run $3,500-6,500/kW, with Europe's mature sites at the lower end and recent U.S. projects at the higher end amid inflation and supply-chain constraints.
Offshore O&M typically runs $60-90/kW/year, substantially higher than onshore wind due to the logistics of at-sea access and maintenance.
Offshore wind typically achieves 40-45%+ capacity factor thanks to stronger, more consistent ocean winds, compared to roughly 33-36% for the onshore U.S. fleet average.
The assumed operating life of the project, used to total O&M costs and lifetime energy production. Offshore wind projects are typically financed over 20-30 year horizons.
project capacity (MW) × 1,000 × installed cost per kW ($/kW)
project capacity (MW) × 1,000 × annual O&M cost per kW ($/kW/year)
project capacity (MW) × 8,760 × (capacity factor (%) ÷ 100)
(total installed capital cost + annual O&M cost × project lifetime) ÷ (annual energy production × project lifetime)
This is a simplified, undiscounted LCOE calculation (total lifetime cost divided by total lifetime energy), useful for quick comparisons. A full financial LCOE model would discount future costs and revenues to present value, account for financing structure and cost of capital, and include additional factors like decommissioning -- all of which can meaningfully shift the result.
Results update live as you type. For planning and field-check estimates — always verify against applicable standards and equipment ratings.
How we calculate this →Offshore wind's brutal capital intensity is real: a 500 MW project at a representative $5,000/kW installed cost requires $2.5 billion in upfront capital alone, before a single turbine spins. But offshore's much stronger, more consistent wind resource -- driving capacity factors of 40-45%+ versus roughly 35% onshore -- helps offset that cost disadvantage. This example's simplified levelized cost lands around $70/MWh, within today's real-world $47-95/MWh range for new offshore projects, and falling as turbines scale toward 15-18 MW and construction experience matures.
How offshore wind cost is calculated
This calculator estimates the capital cost, operating cost, energy production, and simplified levelized cost of energy (LCOE) for an offshore wind project, tying five inputs together: the project capacity, the installed cost per kW, the annual O&M cost per kW, the capacity factor, and the project lifetime. Four quantities tie the calculation together.
Total Installed Capital Cost ($) = Project Capacity (MW) × 1,000 × Installed Cost per kW ($/kW). Converting megawatts to kilowatts and multiplying by the per-kW installed cost gives the total upfront capital required to build the project. At the defaults (500 MW, $5,000/kW), that is 500 × 1,000 × 5,000 = $2,500,000,000.
Annual O&M Cost ($/year) = Project Capacity (MW) × 1,000 × Annual O&M Cost per kW ($/kW/year). The per-kW annual operations and maintenance cost, scaled to the project size, gives the recurring yearly cost of running the wind farm. At the defaults (500 MW, $75/kW/year), that is 500 × 1,000 × 75 = $37,500,000/year.
Annual Energy Production (MWh/year) = Project Capacity (MW) × 8,760 × (Capacity Factor (%) ÷ 100). Multiplying the nameplate capacity by the 8,760 hours in a year gives the theoretical maximum energy if the project ran at full output continuously; the capacity factor converts that into real annual production. At the defaults (500 MW, 45% capacity factor), that is 500 × 8,760 × 0.45 = 1,971,000 MWh/year.
Simplified LCOE ($/MWh) = (Total Installed Capital Cost ($) + (Annual O&M Cost ($/year) × Project Lifetime (years))) ÷ (Annual Energy Production (MWh/year) × Project Lifetime (years)). The numerator totals every dollar spent over the project life -- the upfront capital plus the lifetime O&M -- and the denominator totals every megawatt-hour produced over that same life. Dividing the two gives a levelized cost per megawatt-hour. At the defaults (25-year lifetime), the numerator is $2,500,000,000 + ($37,500,000 × 25) = $2,500,000,000 + $937,500,000 = $3,437,500,000, the denominator is 1,971,000 × 25 = 49,275,000 MWh, and the LCOE is $3,437,500,000 ÷ 49,275,000 = $69.8/MWh.
Two notes on the model. First, this is a simplified, undiscounted LCOE -- it divides total lifetime cost by total lifetime energy without discounting future cash flows to present value, so it is useful for quick comparisons but not a substitute for a full financial model. A real LCOE model discounts future costs and energy production to present value and incorporates specific financing structure, cost of capital, tax treatment, and decommissioning costs, all of which can meaningfully change the result. Second, the installed cost and O&M cost inputs are the dominant drivers of the result, and both vary widely by region, water depth, foundation type (fixed-bottom vs. floating), and supply-chain conditions -- recent U.S. projects have come in at the higher end of the cost range amid inflation and supply-chain constraints, while Europe's more mature market sits at the lower end. Data sources: offshore wind installed cost data from NREL cost and performance analysis, IEA offshore wind cost reports, and recent U.S. and European offshore wind project case studies; offshore O&M cost estimates from industry reports and operational wind farm data; offshore capacity factor data from European offshore wind projects and emerging U.S. offshore wind resource assessments; LCOE methodology from NREL levelized cost of energy analysis; turbine scaling trends and cost projections from manufacturer roadmaps and industry forecasts; decommissioning and financial modeling considerations from offshore wind project finance literature. Verification: with defaults (500 MW, $5,000/kW, $75/kW/year, 45% CF, 25 years), Total Installed Capital Cost = $2,500,000,000, Annual O&M Cost = $37,500,000, Annual Energy Production = 1,971,000 MWh/year, Simplified LCOE = $69.8/MWh.