How Much Do Hydroelectric Power Plants Cost Per KWH?

Updated on July 18, 2026 | Written by Alec Pow
This article was researched using 7 sources. See our methodology and corrections policy.

New utility-scale hydroelectric projects cost approximately $0.03 to $0.15+ per kilowatt-hour, with the global weighted-average cost of newly commissioned hydropower reaching about $0.062 per kWh in 2025. Favorable large projects can fall near $0.03 to $0.07 per kWh, while difficult sites, small hydro, and micro-hydro systems may cost $0.15 to $0.60+ per kWh.

Existing large hydropower plants can have operating and maintenance expenses near $0.01 to $0.02 per kWh, but that figure does not include the original dam, powerhouse, transmission, financing, environmental mitigation, or major rehabilitation costs. It should not be compared directly with the full levelized cost of a new plant.

The final cost depends on dam and civil works, installed capacity, annual water flow, capacity factor, financing rate, construction duration, environmental requirements, transmission access, project lifespan, and whether the development uses an existing dam or requires an entirely new reservoir.

Article Highlights

Jump to sections

• New hydropower averaged approximately $0.062 per kWh globally in 2025.
• Favorable large projects may generate electricity for $0.03 to $0.07 per kWh.
• Difficult utility-scale projects may cost $0.07 to $0.15+ per kWh.
• Small hydro can cost $0.08 to $0.25+ per kWh.
• Micro-hydro can exceed $0.15 to $0.60 per kWh.
• Existing large plants may have O&M expenses near $0.01 per kWh.
• Recent new U.S. hydropower projects have reported capital costs near $5,000 to $10,000 (at $30 per hour, earning that amount would take about 4.2 to 8.3 full-time workweeks, before taxes) per kW.

How Much Does Hydroelectric Power Cost per kWh?

The International Renewable Energy Agency reports that the global weighted-average levelized cost of electricity for newly commissioned hydropower rose to approximately $62 (about 2.1 hours of work at $30 per hour) per megawatt-hour in 2025. That equals $0.062 per kilowatt-hour.

The current benchmark appears in IRENA’s Renewable Power Generation Costs in 2025. It represents an international average across projects completed during the year, not a guaranteed price for every dam or the retail rate paid by electricity customers.

Hydropower category	Planning cost per kWh	What the figure represents
Existing large plant O&M	$0.01 to $0.02	Routine operation and maintenance, excluding original construction
New global hydropower average	About $0.062	2025 weighted-average LCOE for newly commissioned projects
Favorable large project	$0.03 to $0.07	Strong water resource, high output, and manageable civil works
Difficult utility project	$0.07 to $0.15+	Expensive geology, transmission, mitigation, or financing
Small hydropower	$0.08 to $0.25+	Limited economies of scale and site-specific development
Micro-hydro	$0.15 to $0.60+	Small output spread across permitting, equipment, and civil costs

These are generation-cost planning ranges. They do not include retail utility distribution charges, customer service, taxes, transmission tariffs, or profit margins that may appear on an electricity bill.

Operating Cost vs Levelized Cost

Hydropower costs are commonly reported using several measurements that answer different questions.

Operating and maintenance cost measures expenses incurred after the plant exists. These can include employees, routine repairs, inspections, insurance, materials, vegetation control, license administration, and other recurring work.

Levelized cost of electricity, or LCOE, spreads the plant’s lifetime costs across its expected electricity generation. It may include:

• Development and engineering
• Dam, tunnel, canal, and powerhouse construction
• Turbines and generators
• Transmission connection
• Financing and required investment return
• Operations and maintenance
• Major equipment replacement
• Environmental mitigation
• Decommissioning or residual value assumptions

The U.S. Department of Energy found strong economies of scale in hydropower O&M. Its 2023 U.S. Hydropower Market Report showed average costs of roughly 1 cent per kWh for large and very large nonfederal plants, approximately 1.5 cents for medium plants, and about 5.4 cents for small plants over the examined period.

Those figures describe an established fleet. They do not mean a developer can build a new hydropower facility and sell power profitably for one cent per kWh.

Cost by Project Type

The type of hydropower development can matter as much as its generating capacity.

New reservoir project: A new dam and reservoir can require property acquisition, relocation, river diversion, access roads, tunnels, spillways, foundations, transmission, and extensive environmental review. This is generally the most capital-intensive conventional form.

Run-of-river project: A run-of-river facility uses river flow with limited storage. It may avoid a massive reservoir but can still require an intake, penstock, powerhouse, fish passage, roads, and interconnection. Seasonal output can increase the cost per generated kWh.

Non-powered dam retrofit: A developer adds turbines and electrical equipment to an existing dam built for navigation, water supply, flood control, or another purpose. Reusing civil infrastructure can reduce construction cost, although the site may still need substantial modification.

Existing plant upgrade: Replacing runners, generators, controls, transformers, or other equipment can increase output without constructing a new dam. Upgrades are often among the least expensive opportunities per added kilowatt.

Canal or conduit project: Small turbines can be placed in existing irrigation canals, municipal water systems, or industrial conduits. The available head and flow may be modest, but major river works can sometimes be avoided.

What New Hydropower Costs per kW

Hydropower capital cost is often expressed in dollars per kilowatt of installed capacity. Older industry ranges of $1,500 to $5,500 (about 1.3 to 4.6 full-time workweeks at $30 per hour) per kW no longer describe every new project adequately.

DOE reported that five new U.S. conventional hydropower projects entering service since 2020 had disclosed capital costs of approximately $5,000 to $10,000 per kW. The projects were small and site-specific, but they demonstrate how expensive current greenfield and retrofit construction can become.

Illustrative capital ranges include:

• Existing-unit modernization: $1,000 to $4,000 per added kW
• Favorable existing-dam retrofit: $3,000 to $7,000 per kW
• New small or run-of-river project: $4,000 to $10,000+ per kW
• Complex new dam or underground project: $7,000 to $15,000+ per kW

The cost per kW does not show how much electricity the facility will produce. A $5,000-per-kW plant with steady water flow can generate cheaper electricity than a $4,000-per-kW plant that runs at a low capacity factor.

How LCOE Is Calculated

A simplified hydropower cost calculation divides annualized lifetime costs by annual electricity production:

Annual capital recovery + annual O&M + other annual costs ÷ annual kWh generated

Suppose a 10 MW plant costs $60 million to develop. Its annual capital recovery is estimated at $4.8 million, and annual O&M is $900,000.

If it operates at a 50% capacity factor, annual production is:

10 MW × 8,760 hours × 50% = 43,800 MWh

That equals 43.8 million kWh. Dividing annual costs of $5.7 million by 43.8 million kWh produces a simplified cost of approximately $0.13 per kWh.

If the same facility achieves a 70% capacity factor, output rises to 61.32 million kWh and the simplified cost falls to approximately $0.093 per kWh.

This is why water availability and annual generation are central to hydropower economics.

The Role of Capacity Factor

Capacity factor compares actual electricity production with the output the plant would generate if it operated at full nameplate capacity every hour of the year.

The formula is:

Annual generation ÷ maximum theoretical annual generation

U.S. hydroelectric capacity factors have commonly averaged around 30% to 40%, although individual plants can be far above or below that range. EIA explains that available water, reservoir obligations, irrigation, municipal supply, fish protection, and other operating limits affect output in its hydropower capacity-factor analysis.

A 500 MW plant operating at a 50% capacity factor produces:

• 6,000 MWh per day
• 6 million kWh per day
• 2.19 billion kWh per year

The earlier article incorrectly stated that this plant would generate 2.2 million kWh per day. The 2.19 billion figure applies to annual production.

Large Hydro vs Small and Micro-Hydro

Large facilities can spread engineering, licensing, staffing, and maintenance costs across billions of kilowatt-hours. Small projects pay many of the same categories of cost while producing much less electricity.

A micro-hydro installation may require:

• Hydrology and site surveys
• Water-right and environmental review
• Intake and screening equipment
• Penstock
• Turbine and generator
• Power electronics and controls
• Building or weather enclosure
• Grid connection or battery equipment
• Access and construction work

Consider a 25 kW project costing $250,000. At a 45% capacity factor, it generates approximately 98,550 kWh per year.

If simplified annual capital recovery is $10,000 and annual O&M is $5,000, the cost is:

$15,000 ÷ 98,550 kWh = $0.152 per kWh

If weak water flow reduces the capacity factor to 20%, annual production falls to 43,800 kWh. The same annual cost becomes approximately $0.342 per kWh.

Financing, major repairs, insurance, and environmental requirements could push the full levelized cost higher.

Existing Dam Upgrades

Much of the practical U.S. hydropower opportunity involves modernizing existing plants or adding generation to dams that do not currently produce electricity.

DOE’s hydropower market reporting program notes that non-powered dam development represents most proposed conventional hydropower capacity in the U.S. pipeline.

Reusing an existing site may avoid some costs for:

• Dam construction
• Reservoir creation
• Road access
• Land acquisition
• River impoundment
• Existing transmission corridors

It does not eliminate all development expense. The dam may require structural reinforcement, new water passages, environmental mitigation, transmission upgrades, and extensive licensing work.

Modern turbine runners, digital controls, generator rewinds, and improved water passage can raise output at an existing plant. The economic value depends on the additional annual generation, not simply the nameplate capacity added.

Pumped Storage Is Different

Pumped-storage hydropower is primarily an energy-storage technology rather than a source of net electricity from natural water flow.

During periods of lower electricity prices, pumps move water to an upper reservoir. When demand and prices rise, the water passes through turbines to generate electricity. Because of pumping and conversion losses, the plant returns less electricity than it consumed.

Its value comes from:

• Long-duration energy storage
• Peak capacity
• Grid balancing
• Frequency regulation
• Operating reserves
• Black-start capability
• Integration of wind and solar

The Department of Energy treats pumped storage separately in its Pumped Storage Hydropower Technology Strategy Assessment.

A pumped-storage project should be evaluated using charging cost, round-trip efficiency, storage duration, capacity value, grid-service revenue, and levelized cost of storage. It should not be compared directly with the LCOE of a conventional river-fed generator.

The Hidden Cost of Financing

The most overlooked hydropower cost is often the time between initial development and commercial operation. Large projects can spend years in site investigation, licensing, engineering, financing, and construction.

During that period, the project may accumulate:

• Development salaries and consulting fees
• Geotechnical investigations
• Environmental studies
• Legal and licensing expenses
• Interest during construction
• Inflation and material escalation
• Contractor delay claims
• Community commitments

Consider a proposed 20 MW project:

• Construction and generating equipment: $100 million
• Development and environmental work: $8 million
• Grid interconnection: $7 million
• Interest during construction: $18 million
• Mitigation and community commitments: $10 million
• Contingency: $12 million

The complete project reaches $155 million, or $7,750 per kW.

If it generates 87,600 MWh per year, annual capital recovery of $12.4 million plus $1.5 million in O&M produces a simplified cost of approximately $0.159 per kWh.

Environmental and Community Costs

Hydropower does not burn fossil fuel during normal generation, but dams and water-control structures can alter rivers, sediment movement, fish migration, water temperature, dissolved oxygen, shoreline habitat, and community land use.

Project costs may include:

• Fish ladders and bypass systems
• Fish-friendly turbines or screens
• Minimum-flow releases
• Habitat restoration
• Water-quality monitoring
• Sediment management
• Cultural-resource protection
• Recreation facilities
• Property acquisition and relocation
• Dam-safety improvements

FERC’s Hydropower Licensing Primer explains that project licenses can contain measures for fish passage, aquatic habitat, instream flows, recreation, and other affected resources.

Some mitigation measures require large capital projects, while others reduce annual generation by requiring water to bypass turbines. Both can increase the effective cost per kWh.

Drought and Hydrology Risk

A hydropower plant has no conventional fuel bill, but water availability functions like a variable production resource.

Low precipitation, reduced snowpack, upstream withdrawals, reservoir operating rules, and climate variability can reduce generation. Fixed debt and staffing expenses then have to be recovered from fewer kilowatt-hours.

For example, a plant with annual fixed costs of $20 million and production of 400 million kWh has a fixed-cost burden of $0.05 per kWh.

If drought reduces generation to 250 million kWh, the same fixed costs rise to $0.08 per kWh before variable expenses are included.

Hydropower also competes with drinking-water supply, irrigation, flood management, navigation, recreation, and ecological requirements. A reservoir cannot always be operated solely to maximize electricity revenue.

How Much Water Does Hydropower Use?

Water use must be defined carefully.

Water passing through a turbine is usually discharged downstream and is not consumed in the same sense as fuel or evaporative cooling water.

Water stored or withdrawn may support electricity generation along with irrigation, flood control, navigation, recreation, or drinking-water supply.

Water consumption commonly refers to reservoir evaporation that would not otherwise have occurred. Allocating that evaporation to electricity is difficult when the reservoir serves several purposes.

Argonne National Laboratory has estimated generation-weighted U.S. hydropower reservoir water consumption at approximately 8.2 gallons per kWh under one allocation method. The estimate is reported in its life-cycle water analysis.

Other methodologies and individual reservoirs can produce much lower or higher figures. Run-of-river systems with little storage are fundamentally different from large reservoirs in hot, dry climates.

The original claim of 100,000 to 300,000 gallons per MWh would equal 100 to 300 gallons per kWh, not 0.1 to 0.3 gallons. The prior conversion was incorrect by a factor of 1,000.

Three Hydropower Cost Scenarios

Existing large plant: A long-operating facility has no remaining original construction debt. Routine O&M and annual compliance cost $12 million, while generation reaches 1 billion kWh. The operating cost is approximately $0.012 per kWh.

Existing-dam retrofit: A 15 MW project costs $75 million and produces 65 million kWh annually. Annual capital recovery and O&M total $6.5 million, producing a simplified cost of $0.10 per kWh.

Micro-hydro installation: A 20 kW system costs $180,000 and generates 61,320 kWh per year at a 35% capacity factor. Simplified annual capital and maintenance costs of $12,000 equal approximately $0.196 per kWh.

These are illustrative calculations. A complete financial model would include taxes, depreciation, financing terms, inflation, replacements, escalation, residual value, and project-specific revenue.

Hydropower vs Solar and Wind

IRENA’s 2025 global weighted-average costs were approximately:

• Onshore wind: $0.033 per kWh
• Solar photovoltaic: $0.044 per kWh
• Hydropower: $0.062 per kWh
• Offshore wind: $0.078 per kWh
• Geothermal: $0.089 per kWh

These values compare plant-level generation cost, but they do not capture every difference in grid value.

Reservoir hydropower can provide dispatchable generation, rapid ramping, voltage support, reserves, and energy shifting. Solar and wind can often be constructed faster and at lower capital risk, but their output depends on weather and time of day.

Natural gas plants may have lower construction cost and dispatchable output, but they require continual fuel purchases and face fuel-price and emissions exposure.

The correct comparison depends on the power system’s need for energy, capacity, flexibility, storage, transmission, and environmental performance.

When Hydropower Makes Sense

Makes sense if:

• The site has dependable flow and useful elevation difference.
• Existing infrastructure can be reused.
• Environmental and community requirements are identified early.
• The project has affordable long-term financing.
• Transmission access is practical.
• Annual generation justifies the civil construction cost.

Does not make sense if:

• Water flow is uncertain or highly seasonal.
• The estimate ignores interest during construction.
• The project requires extensive new transmission.
• Fish passage, sediment, or relocation costs are omitted.
• A low O&M figure is mistaken for total LCOE.
• Pumped storage is evaluated as if it produces free net energy.

What We Verified

• Checked IRENA’s 2025 weighted-average hydropower LCOE.
• Reviewed DOE’s capital-cost data for recent U.S. projects.
• Separated existing-fleet O&M from new-project LCOE.
• Confirmed DOE’s typical hydropower lifespan of approximately 65 to 85 years.
• Verified the capacity-factor calculation and corrected the 500 MW example.
• Distinguished conventional generation from pumped-storage economics.
• Reviewed FERC licensing and environmental mitigation categories.
• Corrected the water-use conversion by a factor of 1,000.
• Cross-referenced reservoir evaporation estimates through Argonne.
• Removed unsupported expert quotations and unreliable dam case studies.

Related Energy Costs

Property owners and energy planners can compare hydropower with the cost of solar energy, the price of a home windmill, and the cost of replacing an electrical panel.

Answers to Common Questions

How much does new hydropower cost per kWh?

New utility-scale hydropower commonly costs approximately $0.03 to $0.15+ per kWh. The 2025 global weighted average was about $0.062 per kWh.

Why is electricity from old dams so cheap?

Many existing plants paid off their original construction debt decades ago. Their current costs are concentrated in operation, maintenance, licensing, mitigation, and equipment upgrades.

How much does a hydropower plant cost to build?

Current projects can cost approximately $3,000 to $10,000+ per installed kW. A 100 MW project at $6,000 per kW would cost about $600 million.

How many kWh can a water turbine generate?

A 500 MW turbine or generating group operating at a 50% capacity factor produces approximately 2.19 billion kWh per year, or an average of 6 million kWh per day.

How much does micro-hydro electricity cost?

Micro-hydro commonly costs $0.15 to $0.60+ per kWh. Strong year-round flow and existing civil infrastructure can reduce the price.

Does hydropower consume water?

Water passing through turbines is generally returned downstream. Reservoir hydropower can consume water indirectly through evaporation, but the amount allocated to electricity varies greatly by climate, reservoir design, and methodology.

Is pumped-storage hydropower cheap electricity?

Pumped storage is primarily an energy-storage system. It buys or uses electricity to pump water uphill and returns part of that energy later. Its economics depend on storage value and grid services rather than generation cost alone.

How long does a hydropower plant last?

DOE gives a typical hydropower facility lifespan of approximately 65 to 85 years. Major civil structures can last longer, while turbines, generators, controls, and other equipment may need earlier refurbishment.