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Changes in 2021

The Electricity ATB provides a transparent set of technology cost and performance data for electric sector analysis. The update of the 2020 ATB to the 2021 ATB includes general updates to all technologies as well as technology-specific updates—both of which are described below. Use the following charts to explore the changes from 2020 to 2021.

Parameter value projections by ATB projection year

Compare the 2020 ATB and the 2021 ATB. Click "more details" above the chart to select a parameter (LCOECAPEX, fixed operation and maintenance O&M [FOM], capacity factor, and fixed charge rate [FCR]) and other filters.

General Updates to All Technologies

  • The assumptions in each of the two financial assumptions cases are modified to reflect current assessments.
  • Fixed O&M costs have been updated to ensure property taxes and insurance costs are included for all technologies.
  • The Base Year is updated from 2018 to 2019 using new market data or analysis where applicable.
  • The dollar year is updated from 2018 to 2019 with a 1.8% inflation rate (BLS, 2020).
  • Historical data are updated to include data reported through year end 2019.

Renewable Generation Updates Summary

  • Land-Based Wind: Projections are based on bottom-up technology analysis and cost modeling plus learning rates, with innovations that increase wind turbine size, improve controls, and enhance science-based modeling.
  • Offshore Wind: Projections are based on experiential learning curves derived from market data and cost reductions associated with economies of size and scale.
  • Photovoltaics: Projections are based on bottom-up techno-economic analysis of effects of improved module efficiency, inverters, installation efficiencies from assembly and design, all attributable to technological innovation. Resource categorization is split into 10 resource classes by irradiance instead of by representative location.
  • Concentrating Solar Power: Component and system cost estimates for Base Year reference a 2017 industry survey, and a 2018 cost analysis of recent market developments.
  • Geothermal: New data are consistent with GeoVision Study.
  • Hydropower: Non-powered dam data are based on new, 2020 cost analysis.
  • Battery Storage: Cost data are available broken down by grid scale, commercial, and residential technologies, and are updated with bottom up cost modeling for current costs.
  • Pumped-Storage Hydropower: This technology is new to the 2021 ATB.

Technology-Specific Updates

Land-Based Wind

  • Base Year: Capital expenditures (CAPEX) associated with wind plants installed in the interior of the country are used to characterize CAPEX for hypothetical wind plants with average annual wind speeds that correspond with the median conditions for recently installed wind facilities based on the 2019 Cost of Wind Energy Review (Stehly et al., 2020). The operations and maintenance (O&M) cost of $43/kW-yr is estimated (Stehly et al., 2020); no variation of FOM with wind speed class is assumed. Capacity factors align with performance in Wind Speed Classes 2–7, where most installations are located.
  • Projections: Specific technology innovations are associated with each scenario. In the Moderate Technology Innovation Scenario (Moderate Scenario), large, segmented blades are transported by truck, enabling larger rotors. Segmentation enables higher hubs and larger turbines, and advanced controls enable higher capacity factors and lower CAPEX. In the Advanced Technology Innovation Scenario (Advanced Scenario), even larger turbines and advanced rotor configurations increase turbine capacity, on-site manufacturing further increases hub heights, and high-fidelity modeling and advanced controls are fully implemented.

Offshore Wind

  • Base Year: CAPEX and O&M costs are calculated with a combination of bottom-up techno-economic cost modeling (Beiter et al., 2016) and experiential learning effects with economies of size and scale from higher turbine and plant ratings (Beiter et al., 2020). Bottom-up estimates from the 2020 ATB are brought forward one year (2018 to 2019) using the learning methodology. Capacity factors are determined using a representative power curve for a generic NREL-modeled 6-MW offshore wind turbine (Beiter et al., 2016), and they include geospatial estimates of gross capacity factors for the entire resource (Musial et al., 2016).
  • Projections: Instead of projecting costs with literature estimates of cost reductions induced by specific technological innovations in each future year (Valpy et al., 2017)(Hundleby et al., 2017), the 2021 ATB uses experiential learning curves derived from empirical market data (Musial et al., 2019) along with economies of size and scale to project future costs (Beiter et al., 2020). As the learning curve predicts future costs as a function of future offshore wind deployment, future costs in each of the ATB technology innovation scenarios are driven by different levels of deployment based on literature estimates.

Photovoltaics (PV): Utility-Scale, Commercial, and Residential

  • Base Year: CAPEX for 2019 and 2020 are based on new bottom-up modeling and market data from (Feldman et al., 2021), which focuses on larger systems to align with market trends. The O&M costs are based on modeled pricing for a 100-MWDC, one-axis tracking system (Feldman et al., 2021).
  • Projections: Projections that were based on literature surveys are now based on bottom-up CAPEX benchmarks. The Moderate Scenario is based on module efficiency gains consistent with PERC (passivated emitter and rear contact) n-type mono modules, improved inverter systems, and installation efficiencies that are due to automation, preassembly, and improved design. The Advanced Scenario assumes additional innovations, such as continuation of the historical rate of module efficiency improvement, simplification of inverter design and automation of inverter manufacturing, and greater installation efficiency from preassembly, automation, and materials innovations. Estimates for energy yield gain for utility-scale and commercial PV systems are also included.

Concentrating Solar Power (CSP)

  • Base Year: Estimates are based on bottom-up cost modeling from (Turchi et al., 2019) for the updates to the System Advisor Model (SAM) cost components. Future year projections are informed by the literature, NREL expertise, and technology pathway assessments for reductions in capital expenditures.
  • Projections: The Moderate Scenario assumes a transition to a supercritical CO2 cycle in the powerblock, advanced coatings on the receiver, improved tanks, pumps, and component configurations for the thermal storage unit, and improved heliostat installation and learning that are due to deployment in the solar field. The Advanced Scenario assumes higher temperature supercritical CO2 , higher temperature receiver, advanced storage compatible with higher temperatures, and low-cost, modular solar fields with increased efficiency.


  • Base Year: As before, estimates are based on bottom-up cost modeling using the Geothermal Electricity Technology Evaluation Model (GETEM) and inputs from the GeoVision Business-as-Usual (BAU) scenario (DOE, 2019).The Base Year is updated to 2019$ dollar year based on the consumer price index and producer price indices.
  • Projections: The projection of future geothermal plant CAPEX for the Advanced Scenario is based on the Technology Improvement scenario from the GeoVision Study ((DOE, 2019) and (Augustine et al., 2019)). The Moderate Scenario is based on the Intermediate 1 Drilling Curve detailed as part of the GeoVision report to 2030, and a minimum learning rate to 2050 which is implemented in AEO2015 (EIA, 2015) as a 10% CAPEX reduction by 2035. The Conservative Technology Innovation Scenario (Conservative Scenario) retains all cost and performance assumptions equivalent to the Base Year and assumes a minimum learning rate to 2050.


  • Base Year: The 2021 ATB data for non-powered dams (NPD) are based on a bottom-up modeling of reference sites using site-specific data (Oladosu, G. et al., 2021), whereas the 2020 data were based on econometric cost equations with assumed capacity factor estimates (DOE, 2016); thus, NPD categories for the 2020 ATB and the 2021 ATB are not directly comparable. NSD is updated to 2019$ dollar year based on the consumer price index.
  • Projections: New cost analysis is used to update NPD data in the 2021 ATB. The analysis involved identification of 20 reference sites for U.S. NPD hydropower and detailed bottom-up design and cost simulations under baseline and near-term innovation cases. The near-term innovation case is judged to be applicable in the next 5–10 years. (Oladosu, G. et al., 2021). New stream-reach development (NSD) data in the 2021 ATB retain previous years data, which are based on projections developed for the Hydropower Vision study (DOE, 2016) using technological learning assumptions and bottom-up analysis of process and/or technology improvements to provide a range of future cost outcomes (O'Connor et al., 2015). The NSD projections use a mix of U.S. Energy Information Administration (EIA) technological learning assumptions, input from a technical team of Oak Ridge National Laboratory researchers, and the experience of expert hydropower consultants.

Utility-Scale PV-Plus-Battery

  • This technology is new to the 2021 ATB.
  • Base Year: CAPEX for 2019 is based on new bottom-up modeling and market data from (Feldman et al., 2021). The chosen configuration reflects recent and proposed utility-scale PV-plus-battery projects. Capacity factors and tax credits assume 75% of the energy used to charge the battery component is derived from the coupled PV.
  • Projections: PV-plus-battery projections in the 2021 ATB are driven primarily by CAPEX cost improvements, but also by improvements in energy yield, operational cost, and cost of capital (for the Market+Policies Financial Assumptions Case).

Battery Storage

  • Base Year: CAPEX for 2019 is based on new bottom-up modeling and market data from (Feldman et al., 2021).
  • Projections: Battery projections in the 2021 ATB are represented for utility-scale, commercial-scale and residential-scale battery systems. Cost improvements are driven by a literature survey as described by (Cole et al., 2021).  This literature survey incorporates more-rapid reductions in battery pack and cell costs while soft costs and costs related to other factors decline more slowly.

Pumped-Storage Hydropower (PSH)

  • This technology is new to the 2021 ATB. Resource characterizations including capital costs are forthcoming and will accompany the national closed-loop PSH resource assessment.

Natural Gas and Coal

  • The 2021 ATB represents the first time the U.S. Department of Energy (DOE) Office of Fossil Energy and Carbon Management directly contributed to an ATB update. One notable change is the inclusion of assumptions for property taxes and insurance (PT&I) as a component of fixed operation and maintenance costs. PT&I are not included in prior ATB cost and performance estimates matched to EIA's Annual Energy Outlook (AEO).

Nuclear and Biopower

  • Cost and performance estimates are updated to match AEO2021 (EIA, 2021).
  • Information about current published costs in the literature is updated.


The following references are specific to this page; for all references in this ATB, see References.

Beiter, Philipp, Walt Musial, Patrick Duffy, Aubryn Cooperman, Matt Shields, Donna Heimiller, and Mike Optis. “The Cost of Floating Offshore Wind Energy in California between 2019 and 2032.” NREL Technical Report. Golden, CO, November 2020.

Feldman, David, Vignesh Ramasamy, Ran Fu, Ashwin Ramdas, Jal Desai, and Robert Margolis. “U.S. Solar Photovoltaic System and Energy Storage Cost Benchmark: Q1 2020.” National Renewable Energy Lab. (NREL), Golden, CO (United States), January 27, 2021.

Cole, Wesley, Will A. Frazier, and Chad Augustine. “Cost Projections for Utility-Scale Battery Storage: 2021 Update.” Technical Report. Golden, CO: National Renewable Energy Laboratory, 2021.

Oladosu, G., George, L., and Wells, J. “2020 Cost Analysis of Hydropower Options at Non-Powered Dams.” Oak Ridge, TN: Oak Ridge National Laboratory, 2021.

EIA. “Annual Energy Outlook 2021.” Energy Information Administration, January 2021.

Stehly, Tyler, Philipp Beiter, and Patrick Duffy. “2019 Cost of Wind Energy Review.” Technical. National Renewable Energy Laboratory, December 2020.

Turchi, Craig, Matthew Boyd, Devon Kesseli, Parthiv Kurup, Mark Mehos, Ty Neises, Prashant Sharan, Michael Wagner, and Timothy Wendelin. “CSP Systems Analysis: Final Project Report.” Technical Report. Golden, CO: National Renewable Energy Laboratory, May 2019.

O’Connor, Patrick W., Scott T. DeNeale, Dol Raj Chalise, Emma Centurion, and Abigail Maloof. “Hydropower Baseline Cost Modeling, Version 2.” Oak Ridge, TN: Oak Ridge National Laboratory, 2015.

Musial, Walter, Philipp Beiter, Paul Spitsen, and Jake Nunemaker. “2018 Offshore Wind Technologies Market Report.” Technical Report. Golden, CO: National Renewable Energy Laboratory, December 2019.

DOE. “GeoVision: Harnessing the Heat Beneath Our Feet.” Washington, D.C.: U.S. Department of Energy, May 2019.

BLS. “CPI for All Urban Consumers (CPI-U).” U.S. Bureau of Labor Statistics, 2020.

Beiter, Philipp, Walter Musial, Aaron Smith, Levi Kilcher, Rick Damiani, Michael Maness, Senu Sirnivas, et al. “A Spatial-Economic Cost-Reduction Pathway Analysis for U.S. Offshore Wind Energy Development from 2015-2030.” Technical Report. Golden, CO: National Renewable Energy Laboratory, 2016.

Augustine, Chad, Jonathan Ho, and Nate Blair. “GeoVision Analysis Supporting Task Force Report: Electric Sector Potential to Penetration.” Technical Report. Golden, CO: National Renewable Energy Laboratory, 2019.

Musial, Walt, Donna Heimiller, Philipp Beiter, George Scott, and Caroline Draxl. “2016 Offshore Wind Energy Resource Assessment for the United States.” Technical Report. Golden, CO: National Renewable Energy Laboratory, September 2016.

Hundleby, Giles, Kate Freeman, Andy Logan, and Ciaran Frost. “Floating Offshore: 55 Technology Innovations That Will Have Greater Impact on Reducing the Cost of Electricity from European Floating Offshore Wind Farms.” KiC InnoEnergy, and BVG Associates, 2017.

Valpy, Bruce, Giles Hundleby, Kate Freeman, Alun Roberts, and Andy Logan. “Future Renewable Energy Costs: Offshore Wind: 57 Technology Innovations That Will Have Greater Impact on Reducing the Cost of Electricity From European Offshore Wind Farms.” KiC InnoEnergy, and BVG Associates, 2017.

DOE. “Hydropower Vision: A New Chapter for America’s Renewable Electricity Source.” Washington, D.C.: U.S. Department of Energy, 2016.

EIA. “Annual Energy Outlook 2015 with Projections to 2040.” Annual Energy Outlook. Washington, D.C.: U.S. Energy Information Administration, 2015.

Developed with funding from the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy.

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