From Open Energy Information


Solar+Storage: Reducing Barriers through Cost-optimization and Market Characterization

As interest in solar and battery storage increases, building owners and decision-makers need information about the cost-effectiveness of these technology in their buildings and locations. The information provided in these webpages help stakeholders understand where solar and storage may provide cost savings, and how technology prices, utility rates, and other factors impact the economics.

  • Building owners and energy managers can use the results to learn about typical system sizes for different building types or load profiles, and how utility rate structures impact economics costs.
  • Policy makers and regulators can understand the impact of existing incentives, such as the investment tax credit (ITC) and net metering (NEM), on solar+storage economics. They can determine the cost at which solar+storage becomes economically viable, and design incentive and policies that encourage deployment in their location.
  • Industry can use the results to explore where solar+storage markets may develop over time, as technology costs drop.
  • Utilities can get a better understanding of how rate structures and load profiles impact customer decisions regarding behind-the-meter solar and/or storage investments.

Questions answered by this research include:

  • Are solar and/or storage economical in my location?
  • Which commercial building types are most likely to see cost-savings from solar and/or storage?
  • Where are the emerging markets for solar and/or storage?
  • Which utility rate structures encourage solar and/or storage deployment?
  • How do cost-optimal system sizes vary across buildings and locations?
  • What is the role of policies and incentives in solar and/or storage economics?
S+S-TechResults.pngExplore the results

Summary of Results

  • Combining solar with storage may increase the number of cases in which storage is economical.
  • While savings from storage-only projects are largely derived from demand charge reductions, solar combined with storage also provides significant energy charge savings.
  • A common assumption is that load profiles with peaks are likely candidates for savings from storage, due to the opportunity for demand charge reduction. Our results indicate that potential for savings from combining solar with storage is independent of building load variability, likely due to the energy cost reductions from the solar.
  • Systems are more often economical under time of use and demand charge rates, particularly when demand charges are >$10. Where systems were found to be economical, expected lifetime savings averaged between 7% – 10%, with savings of 30% in numerous cases.
  • Near term markets exist for solar+storage in locations such as California and New York.
  • As technology prices drop, the number of building types that can benefit increase, and additional markets appear in Colorado, New Mexico, and Alaska.
  • At the lowest price point modeled, systems also become economical in Florida and Minnesota.

Explore the results using the "Menu" button above.

Potential for Savings from Solar and/or Storage in Commercial Buildings

The map below summarizes the results for all buildings and locations modeled. The darker-shaded states were found to have higher potential for savings. The pie charts indicate the degree to which each technology combination contributed to the cost reduction. Savings were highest in California, New York, New Mexico, and Alaska. Solar alone was economical for some of the building types in every location, while solar combined with storage provided cost savings in more than half of the locations. Some states, such as Georgia and Washington, had few cases in which solar and/or storage was found to provide savings potential.

Solar+Storage Tableau charts.pdf

Impact of Technology Cost Declines on Solar + Storage Economics by Location

As solar and battery costs decline, solar with storage projects become economical in 10 of 17 locations modeled.

Solar+Storage Tableau charts.pdf

Cost Effective Technology Combinations by Location and Building Type

At the higher technology cost point, solar-only systems are already economical in many locations and building types. As technology costs decline, solar combined with storage becomes economical in more locations and building types.

Solar+Storage Tableau charts.pdf

Explore the Results

About this Research Project

Solar+Storage: Reducing Barriers through Cost-optimization and Market Characterization was a two-year research effort to elucidate the emerging market for distributed solar paired with battery energy storage in commercial buildings across the United States. The results provide insight into the near-term and future solar and solar-plus-storage market opportunities as well as the variables that impact the expected savings from installing behind-the-meter systems. The project was funded by the Department of Energy’s Solar Energy Technologies Office and conducted by the National Renewable Energy Laboratory, with assistance from the Clean Energy Group.

About NREL

NREL is the only federal laboratory dedicated to the research, development, commercialization, and deployment of renewable energy and energy efficiency technologies.

NREL analysis informs policy and investment decisions as energy-efficient and renewable energy technologies advance from concept to commercial application to market penetration. With objective, technology-neutral analysis, NREL aims to increase the understanding of energy policies, markets, resources, technologies, and infrastructure and connections between these and economic, environmental, and security priorities.

NREL is managed for the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy by the Alliance for Sustainable Energy, LLC, a partnership between Battelle and MRI Global.


Joyce Mclaren (bio)
Senior Energy Analyst
National Renewable Energy Laboratory

Todd Olinsky-Paul
Project Director
Clean Energy Group