Behind-the-Meter Storage Analysis

NREL's behind-the-meter storage (BTMS) analysis helps identify opportunities to minimize the grid impacts of electrification by integrating energy storage, electric vehicle (EV) fast charging, photovoltaic (PV) generation, and building demands.

A woman plugs a charger into a red electric vehicle.
NREL's behind-the-meter storage analysis research focuses on technologies that minimize the costs and grid impacts of electrification for consumers by balancing peak energy demands, integrating EV chargers, and generating electricity on-site. Photo by Werner Slocum, NREL

NREL's analysis experts work alongside the BTMS Consortium to develop technologies for stationary applications below 10 MWh that increase the energy efficiency of buildings, optimize high-power EV charging systems, and reduce the costs associated with installation and system use.

BTMS analysis plays a crucial role in these projects by visualizing energy flows by comparing potential trade-offs between system upgrades, such as battery and thermal energy storage footprint, PV size, EV charging or building energy demands, and use of grid energy. These models inform component developments and optimize system designs for different climates, building types, and utility rate structures.

In addition, NREL researchers explore how BTMS systems impact stakeholders at all scales to advance nationwide decarbonization goals. Using NREL's flagship BTMS tool, EVI-EDGES, analysts work with businesses and industry partners to design optimal, cost-effective BTMS solutions tailored to specific sites.

Behind-the-Meter Storage Benefits Clean Energy Adoption

Several fundamental and watershed changes in the transportation, electrical, and building sectors are happening simultaneously. Understanding the intersection of these changes is essential for optimizing the economic, social, and climate benefits of BTMS systems.

  • Buildings must serve significantly more energy needs—such as grid services, EV charging, electric generation, space conditioning, energy storage, and resiliency—than before.
  • Rapid EV adoption, if unassisted, could have significant and potentially negative effects on grid infrastructure and buildings operations.
  • High penetration of solar photovoltaic generation installed on buildings is leading to new challenges for building interactions with the electric grid.
  • New wind and solar installations are market-competitive, creating new challenges for utilities.
  • Energy storage costs are rapidly declining, enabling greater use of clean energy.

A BTMS system provides energy directly to homes and businesses without passing through an electric meter or interacting with the electric grid. The system acts as a load during a battery's charging period and as a generator during discharging periods. As a result, BTMS systems can help manage demand charges, provide continuous energy supply during power outages, enable EV fast charging, and more.

To learn more about BTMS, read Behind-The-Meter Battery Energy Storage: Frequently Asked Questions, USAID-NREL Technical Report (2021).

Featured Projects

In 2019, the Army successfully deployed a behind-the-meter battery energy storage system (BTM BESS) at Fort Carson. The battery, along with an existing solar photovoltaic system, was dispatched to reduce demand charges and is projected to shave an estimated $500,000 off Fort Carson's utility bill each year. Interested in replicating this success, the Army tasked NREL with identifying additional opportunities across 80 U.S. installations.

To identify sites with high potential for cost-effective deployment of BTM BESS without conducting an in-depth assessment at each one, NREL developed a novel phased analytical approach. This methodology could be applied by other federal agencies and organizations interested in identifying BESS opportunities across a large number of sites.

To learn more, read Behind-the-Meter to Front of the Line: Prioritizing Battery Storage Opportunities Across a Portfolio of Sites, NREL Fact Sheet (2021).

Dallas Fort Worth (DFW) International Airport aims to be the first carbon-neutral airport in the Americas and has set an ambitious goal to reach net-zero emissions by 2030. One aspect of the efforts to curb DFW's carbon emissions and operational costs will include BTMS systems.

NREL has already successfully demonstrated an advanced control method to optimize the operation of DFW's central plant with thermal storage, resulting in considerable savings in power consumption and power demand. Next, as the airport plans flexible EV charging, NREL is using EVI-EDGES to evaluate the impact of and optimally size on-site generation and storage to reduce electric infrastructure needs. Current work uses NREL’s EVI-EDGES model to design the stationary battery and PV system to reduce costs of charging rental car vehicles.

The methodologies developed will be fine-tuned and de-risked through hardware demonstration and experiments at NREL's Advanced Research on Integrated Energy Systems (ARIES).

As e-commerce continues to grow, parcel delivery companies are considering replacing existing fleets with battery-electric vehicles. The U.S. Postal Service (USPS) plans to replace more than half of its 160,000 existing vehicles with alternative fuel vehicles by 2026.

NREL, together with Argonne National Laboratory, is assessing charging requirements (e.g., power demand) and the impacts of various charging management and grid integration strategies for several illustrative sites. Based on the analysis, the laboratories will develop an estimate of energy and power requirements for USPS fleets, ultimately informing charging strategy recommendations.

Should the USPS choose an electric vehicle design, the impacts to the U.S. power grid would be significant. Follow-up analyses may investigate integrating on-site storage and solar generation.

Featured Articles

Integrated Data and Analysis Tools

Bolstered by high-performance supercomputing and innovative data visualization technologies, BTMS researchers leverage an integrated suite of data and analysis tools to design, model, and optimize electric vehicle infrastructure.

EVI-EDGES: Electric Vehicle Infrastructure - Enabling Distributed Generation Energy Storage

REOPT: Renewable Energy Integration and Optimization

SAM: System Advisor Model



EVI-PRO: Electric Vehicle Infrastructure — Projection Tool

EVI-EnSite: Electric Vehicle Infrastructure — Energy Estimation and Site Optimization Tool


Check the Storage Stack: Comparing Behind-the-Meter Energy Storage State Policy Stacks in the United States, NREL Technical Report (2022)

An Overview of Behind-the-Meter Solar-Plus-Storage Program Design: With Considerations for India, NREL Technical Report (2022)

Impact of Electrode Thickness and Temperature on the Rate Capability of Li4Ti5O12/LiMn2O4 Cells, Journal of The Electrochemical Society (2021)

An Overview of Behind-The-Meter Solar-Plus-Storage Regulatory Design: Approaches and Case Studies to Inform International Applications, NREL Technical Report (2020)


Margaret Mann

Lead, Clean Energy Supply Chain and EV Storage Analysis