Chapter 6: Decommissioning and End-of-Life Management for Battery Energy Storage Projects

BESS Handbook Index
Home Page
1. Introduction and RACI Tables
2. Planning
3. Procurement
4. Deployment and Integration
5. O&M
6. Decommissioning and EOL

Chapter 6: Decommissioning - Outline and RACI Matrix	Project Mgmt.	Engineering	Safety	Operations	Legal	IT / OT Cybersecurity	Land / Environment	Corporate Sustainability	Site Manager
Plan for Decommissioning
Determine roles and scope for decommissioning	A/R	C	C	C	I	I	I	I	R/C
Develop decommissioning plan	A	R	C	C	I	I	C	C	R/C
Determine material value and cost of decommissioning at EOL	A/R	R/C	I	I	I	I	C	C	C
Maintain documentation for decommissioning	A/R	C	C	C	C	I	I	I	A/R
Onsite preparations	A	C	C	C	C	I	I	I	R
Disconnect and Decommission
Determine end of life condition has been met	A	C	C	R	I	I	C	C	R
Execute decommissioning plan	A	C	C	I	I	I	I	I	R
Transport to End Destination
Package for transport	A	C	C	I	I	I	I	I	R
Transportation to next destination	A/R	I	I	I	C/I	I	C/I	I	I
Additional Resources

RACI Role	Definition
Responsible (R)	Does the work to complete the project activity
Accountable (A)	Delegates and reviews project activity, and ensures activity completion per schedule
Consulted (C)	Provides input on work being done and should be consulted prior to project activity
Informed (I)	Needs to be kept in the loop on specific project activity, as outcome likely impacts the Informed party’s work.

Introduction to Decommissioning and End-of-Life Management

Typically, decommissioning is the process which occurs after a battery energy storage system (BESS) project is determined to have met an end of use (EOU) or end of life (EOL) condition. EOU or EOL can be thought of as a decision point for repurposing, recycling, repowering, or disposal. The specific condition(s) associated with EOU or EOL may be specified in a utility’s asset plan, and/or it may be guided by the BESS vendor’s warranty conditions.

When a BESS is decommissioned or repowered, some or all components of the BESS may be removed from service at its current location, potentially including, but not limited to, the battery modules, enclosures, thermal management systems, fire suppression, power electronics, and so forth.

Determining a battery’s EOL point lacks an industry-wide standard definition. Up until present day, many systems that have been decommissioned were relatively small research systems or pilot projects and did not serve any critical grid purpose. Due to this, and rather than rebuilding a new system, many sites have been returned to a greenfield condition or empty gravel lot after decommissioning. However, the majority of the site infrastructure beyond the BESS components will have a design life far exceeding that of the BESS or inverter. Interconnections, infrastructure, land, and operating permits are not likely to get any cheaper or easier to obtain in the long-term. Therefore, in cases where the service(s) provided by the BESS are still desired, it may be economically and environmentally preferable to retain the site, infrastructure, interconnection etc. and simply replace the EOL components such as batteries, inverters, or converters.

This chapter will predominantly follow the planned decommissioning scenario, where a system’s capacity gradually fades to its minimum state of health (SOH)—this being the EOL trigger for decommissioning or a site repower. Other common EOL conditions are discussed later in the chapter. In this scenario, ample time is given for decommissioning or repower planning and preparation prior to the EOL condition being reached. For scenarios where the BESS has experienced thermal runaway or a large scale fire, decommissioning may require additional risk reduction steps for dismantling and handling -- consult Decommissioning Strategies for Damaged, Defective, and Recalled Lithium Ion Batteries [EPRI, 3002031225].) (Note that for this document, the scope of “decommissioning” will extend solely to BESS equipment, leaving the future of the site to a separate post-process.)

Figure 6-1 provides a high-level view of the steps involved in the typical case of decommissioning and models the approach of a utility engaging a third party to coordinate onsite work, transportation logistics, shipping, and disposal upon determination of an EOL condition or other need to decommission and recycle.

Figure 6-1 Stages of Energy Storage: Key Steps for Energy Storage Decommissioning - Source: EPRI

EOL planning should begin at installation, as early attrition of modules and electronic components is expected and requires clear pathways for recycling or return-to-vendor (RTV). This early planning sets the foundation for eventual large-scale decommissioning.

The decommissioning process begins well before the asset is considered at its end of life or use. The time needed to plan and execute a successful decommissioning may take months and should therefore be addressed while the asset is still in operation. The process begins with a comprehensive review and update of the existing decommissioning plan, which should be created during the Deployment and Integration phase of a project and updated, as necessary, during the subsequent Operations and Maintenance phase. Plan review is followed by coordination and engagement with recycling and decommissioning partners to outline the scope of work, procedures, equipment title transfer, finances, and site resource plans necessary to execute the decommissioning plan.

Once the decision has been made to proceed with decommissioning, operations staff may need to de-register the BESS from the pool of operational assets and proceed with the pre-developed decommissioning plan. The BESS may need to be charged or discharged to arrive at a final resting state of charge (SOC) specified in the plan or in guidance from a recycling vendor, battery OEM, or regulatory body. After this step, the BESS may be electrically disconnected, and then prepared for removal from the site. The system, or appropriate portion of the system, is then dismantled, components are packaged, and then transported to recycling or disposal partners per applicable federal, state, and local rules and regulations.

While this approach simplifies the utility portion of the effort, other divisions of responsibility, such as the utility performing the majority of labor and logistics work before shipping to a recycling partner, may take advantage of any existing internal site expertise. The emergence of new roles and responsibilities for decommissioning/recycling partners is discussed later in this chapter.

Decommissioning may also be required post-emergency if a fire suppression discharge or thermal event occurs, and the system is considered unsafe to operate. There are other scenarios where a system may no longer be required to perform service in its current location, and the asset would be decommissioned without reaching any EOL conditions. Both of these scenarios require case-specific modifications to the typical decommissioning process. Handling of any damaged modules from thermal events, fires, physical damage, water, or other fire suppression requires additional planning to account for the heightened threat of reignition during handling and transport. It may be necessary to directly involve the manufacturer to resolve such situations. It may also be necessary to fully discharge or take other precautions with damaged modules prior to transportation. Prior to taking such steps, the manufacturer and the destination recycling entity, if different from the manufacturer, should be consulted.

Ensuring site and personnel safety is key for any decommissioning process. Discharging and removing batteries involve potentially hazardous conditions that utility or third-party personnel will need to pay particular attention to, in order to maintain safety. Ensure the appropriate training and personal protective equipment is provided beforehand.

Project Stakeholder Focus

There are numerous stakeholders within an electric utility that would benefit from being knowledgeable about decommissioning and EOL issues for energy storage projects. Table 6-1 provides a list of such utility departments and their prospective role in supporting the end of a utility-scale energy storage project.

The various steps of the decommissioning process may involve a wide range of business functions, including (in part) system operations, legal, engineering, corporate sustainability or management, safety, environmental compliance, and site/land management. It is advisable to designate a lead project manager for the decommissioning process who is responsible for coordinating the diverse group of stakeholders. A utility might decide that the BESS asset or site manager should be the decommissioning project manager. Alternatively, a separate party may act as the project manager for the decommissioning process, though closely coordinated with the BESS asset or site manager.

Table 6-1 Utility Stakeholders and Their Roles in Decommissioning of an Energy Storage Project

Utility Stakeholder Group	Summary of Decommissioning Involvement
Project Management	Integrate input from all other functions/stakeholders into overall decommissioning plan and execution. Ensure cross-coordination among all functions and parties.
Engineering	Re-review and execute the decommissioning plan - originally developed and funded early in the project - to guide electrical disconnection and site disassembly. Work may be performed directly or supervised through external contractors. The site or landowner must determine if removal of all site structures and any environmental remediation of the site is desired and necessary.
Safety	Engage closely on electrical disconnection, termination of conduits, and disassembly site works.
Operations	De-register BESS from asset pool and update operational plans accordingly.
Legal	Ensure clarity of responsibility/liability for asset and hazards at each stage of decommissioning and site disassembly. This is a re-review of the plan set during commissioning, not a new plan. Review needs for compliance with relevant safety, hazmat, environmental and transportation regulations.
IT/OT/Cybersecurity	Ensure proper termination of external communication access as needed.
Corporate Sustainability	Partner with Project Management to ensure that disposal plan in accordance with ESG policy to the fullest extent possible.
Asset Recovery / Asset Management	Track the final disposition and associated costs or profit of key equipment.
Environmental Compliance	Advise on jurisdictional regulations relating hazardous materials retention and disposal that are applicable to the BESS. Prepare any required regulatory documentation of compliance.
Site Manager	Review plans, coordinate onsite activities, and interface with third parties during decommissioning. May own & update decommissioning plan.

Each utility department’s potential role in EOL activities can be further illustrated via a responsibility assignment (RACI) matrix, which is used to clarify and define roles and responsibilities in cross-functional or departmental projects and processes. The RACI matrix defines, generally the specific roles for each stakeholder group involved in each phase of an energy storage project. Groups can use this RACI matrix to understand how the 'average' utility may assign roles and responsibilities to an energy storage project. The RACI matrix, provided at the beginning of the chapter, could prove useful to utilities in addressing decommissioning and EOL activities for energy storage projects. (For resources, references, and guide materials, see the Decommissioning Resources section with brief annotations and links.)

The RACI matrix has been constructed for decommissioning a utility project with a third party to execute the pre-developed plan onsite. This can involve tasks such as disconnecting the system, dismantling components, packaging for transport, shipping, removing enclosures, and site remediation. Although a third party may be handling the majority of the onsite work, input will be needed from the internal utility stakeholders to generate and execute a safe and successful decommissioning.

Plan for Decommissioning

It is important for a utility to consider decommissioning and EOL during early BESS project phases, specifically during facility design, procurement, and operations. In doing so, a utility should be able to reduce risks and positively influence options for asset management, including potential sale, life extension, repowering, and retirement. Table 6-2 provides more details on decommissioning and EOL considerations that are advisable to take during earlier project stages.

Table 6-2 Considerations for Decommissioning in Prior Project Phases

Project Phase	Considerations for Decommissioning
Planning	During the planning phase, the project team should also hold a briefing/coordination on the project’s decommissioning plan. It is important to ensure that all stakeholders have provided the necessary input and are aligned on the various requirements and processes expected for decommissioning and EOL prior to a final decision. During the planning phase, a utility should estimate a decommissioning cost which incorporates the net salvage value. This could involve engaging professional engineers, who can accurately break down work scope; and potentially researchers or service providers who are projecting markets and costs out to the time of expected end of system life. A utility could also consider selecting technologies, manufacturers, and/or project management/engineering firms that have demonstrated or are developing EOL management processes rather than those that leave this up to the utility to determine. It is also important to consider what types of decommissioning and EOL financial assurance mechanisms are required or desired by the financier, regulatory commission, insurance firm, parent company, or other project partners. This supports the fact that decommissioning plans typically delineate the decommissioning and EOL responsibilities of the asset owners, including eventual removal, restoration, and disposition processes to be conducted at the end of a system’s operational lifetime or should a system be moved to another location. See Guidelines for Assessing End-of-Life Management Options for Renewable and Battery Energy Storage Technologies (EPRI, 3002020594) and End-of-Life Management for Lithium Ion Battery Technologies: Issues, Uncertainties, and Opportunities (EPRI, 3002020006) for details on EOL management processes.
Procurement	During the procurement of a BESS, a utility would be advised to consider including contractual terms prior to project award that clearly define decommissioning and EOL responsibilities for relevant parties as well as penalties for non-performance. Related to this effort, a utility should request information on management processes from both the battery vendor or integrator, and from the developer or engineering firm that will design and construct the site. Among the key questions to ask are: Is a decommissioning plan included in the project deliverables? What EOL options are available for the project? Is manufacturer takeback recommended or available? Does the firm have relationships/recommendations for certain EOL service providers that have experience with their technology? What is the product bill of materials? When will each piece of equipment meet EOU or EOL?
Operations and Maintenance	Once a BESS is operational, the utility should conduct reviews of relevant codes, standards and regulations, decommissioning and EOL cost estimates and update them accordingly. Consider conducting the review midway through project life and as a project nears its decommissioning date or EOL. Taking these steps can provide useful insights on final costs. For example, process efficiency improvements and buildouts of new recycling infrastructure may reduce costs as the industry gains more experience and becomes more mature. Where EOL is concerned, recent federal domestic investments in recycling infrastructure in many countries will shift demand and supply availability and costs for EOL services. Reuse or repurpose (aka “second life”) markets for batteries may expand, and even established markets will be affected by global changes in mineral demand and material recovery developments. The relative costs of different EOL options may change as recycling processes for batteries improve and/or as investments are made in dedicated recycling facilities. Environmental and transportation regulations for battery modules, which are almost always classified as hazardous materials (e.g., Class 9 Dangerous Goods during transport), are major cost drivers for decommissioning energy storage systems whether at EOL or not. A utility should periodically review existing and pending regulatory requirements as changes in hazardous material or hazardous waste management (such as landfill bans), packaging and transport requirements could alter previously set plans. A utility could also preferentially consider EOL service providers that hold certifications for environmentally responsible recycling. For example, e-waste recyclers may hold Sustainable Electronics Recycling International (SERI) Responsible Recycling (R2) Standard or e-Stewards certifications. Currently there are no lithium ion battery-specific certifications.

Determine Roles for Decommissioning

For utility owned systems, the division of responsibilities and labor can take multiple paths. The physical dismantling, de-energization, and demolition of the site could be performed by utility personnel, a recycler offering this service, the original installer, integrator, and/or an entirely new contractor. Communication and demarcation of equipment to be decommissioned, and which party has that equipment within their scope, is key throughout the decommissioning process. If onsite equipment is not sufficiently audited and clearly assigned to scopes and destinations, it is probable that delays, unnecessary work and contractual discrepancies will occur.

The transportation logistics for decommissioning can also be coordinated among various parties, including utility staff, a contractor, the original integrator, or through a decommissioning or recycling company. Ensuring that all equipment being transported is clearly assigned to each party’s scope is important, as is confirming that each party understands the full dimensions and requisite order for the removal of each piece of equipment.

Lessons Learned: Forgetting Site Upkeep While Waiting for Decommissioning

Project Context	BESS project awaiting decommissioning.
Project Experience	Site sat for over a year without proper thermal management, leading to concerns about temperatures exceeding the safe storage range. Modules were damaged when evaluated by the recycling partner, presenting a safety risk and far greater cost for handling and transportation.
Root Cause	Decommissioning was not planned in advance, and site responsibility/accountability was not established.
Advice for Future Projects	Maintain clear site responsibility and upkeep, even if awaiting decommissioning. Damaged modules are more expensive and dangerous to handle and transport.

Battery recycling vendors and associated logistics providers already offer a variety of services, ranging from simply accepting module shipments to going on site and handling the dismantling, shipping, logistics, and end recycling of the systems. As BESS decommissioning becomes more common, the potential roles of recyclers and logistics providers are likely to expand.

Bottom line, as with system installation, defining the roles, responsibilities, process interdependencies and destinations for every piece of equipment is critical to ensuring a smooth decommissioning experience.

Develop a Decommissioning Plan

A decommissioning plan should be created as part of the project planning and procurement processes. The National Fire Protection Association Standard 855 requires stationary storage projects approved for construction or installation after August 25, 2019, to provide the authority having jurisdiction with a decommissioning plan as part of the commissioning process and prior to final inspection and approval for commercial operation.

Even if not required by regulators or other external parties, a decommissioning plan may be a useful internal reference and may help communicate requirements among different business groups. It may also aid in developing cost estimates when selecting potential partners for decommissioning and recycling.

Common elements of a decommissioning plan include:

• Descriptions of the project, decommissioning work, and site
• Expected facility lifetime
• Cost estimates for decommissioning and EOL activities
• Plan for notification of relevant authorities, partners, and emergency response agencies
• Summary of relevant regulatory and permit requirements
• Typical removal and demolition elements
• Disposition of battery modules and other components (e.g., housings, electronics, fire suppression system, etc.)
• Plans for site restoration

Decommissioning plans can vary in depth and detail, as they might range from a few pages of descriptive text to lengthy, detailed guidebooks complete with engineering drawings and tabulated cost estimates. For practical management of the decommissioning process some entities find it useful to include detailed items such as job safety assessments, lift plans, and de-energization plans as the decommissioning approaches. For one example, see Cedartown Battery Energy Storage System Decommissioning Case Study: Lessons Learned from Decommissioning an Early-Stage Utility-Scale Lithium Ion Project (EPRI, 3002027944).

As discussed previously, this plan will require revisitation and updates throughout the life of the system—not just when the system reaches an EOL condition. Keeping this plan up to date provides a strong contingency in the event of an emergency, allowing for easier adaptation to the situation. In the typical case of decommissioning, this plan should be reviewed by the project team and can guide the selection of recycling/decommissioning partners, as well as the end scope of work. Coordination and selection of these partners can take months. Additionally relevant standards, rules and regulations impacting decommissioning need to be monitored as they may have evolved during the preceding operational period and may impact or require modifications to the decommissioning plan. When the EOL condition is finally reached, a thorough plan is already in place to implement. For more information on developing decommissioning plans, see Holistic Decommissioning Planning for Lithium Ion Battery Modules and Energy Storage Facilities (EPRI, 3002021775). EPRI's End-of-Life Regulatory Actions for Lithium Ion Battery Energy Storage (EPRI, 3002031206) also compiles relevant regulatory and policy activities across the globe to prepare lithium ion battery owners for potential upcoming requirements.

Consequently, a robust decommissioning plan may assist in the following areas:

1. Inform project development, including choice of battery technology as decommissioning costs can vary by chemistry.
2. Meet safety and decommissioning requirements imposed by authority having jurisdiction, landowners, and project partners.
3. Support permitting and compliance with applicable regulations, codes, and standards.
4. Guide the decommissioning process itself – in planned situations, emergency situations and at EOL.

Maintain Documentation for Decommissioning

Over the years, maintaining the decommissioning plan and documentation essential to the decommissioning plan is critical. A risk inherent in older BESS is a potential loss of useful institutional knowledge due to personnel changes, incomplete or lost documentation, and obstacles in contacting the original manufacturer, installer, or integrator.

The lack of standardization in many early products also presents challenges in understanding true specifications of the installed system, which may or may not match the generalized documentation provided by the vendors and integrators upon installation. Best practice for utilities is to have a detailed internal handoff when individuals change roles to resist the loss of enterprise knowledge. Although it may be difficult to retroactively document existing equipment onsite, requiring decommissioning plans for all future systems can assist in combating such long-term documentation and communication challenges.

It is important to ensure site documentation, commissioning and decommissioning plans, integrator contacts, and internal handoffs age properly to avoid challenges from loss of information during decommissioning.

Determine Material Value and Cost of Decommissioning at EOL

Final decommissioning costs at EOL will be impacted by the recovery value of recycled materials and minerals – values that are highly speculative in advance. As such, projecting EOL costs in the future remains very difficult. Factors such as current supply chain challenges, national incentives for recycling and domestic cell production, shifts away from nickel and cobalt chemistries, and the future decommissioning of growing numbers of EVs and BESS all will impact the future market for recycled materials. The market price of the recovered materials will also impact the potential value or cost of decommissioning systems at EOL.

In 2017, EPRI estimated the net future costs of decommissioning at EOL, including recycling or disposal of the component parts of a 1MWh NMC BESS in a 40’ ISO container to be $91,500 in 2030 dollars. In 2022, the cost of decommissioning, including recycling and disposal of a 20MW/10MWh NMC system was $1,185,000 in 2030 dollars. At the same time the cost was estimated for a smaller, mixed technology system comprised of a 100kW/400kWh lithium ion battery system and 100kW/400kWh vanadium flow battery system. The total for the mixed system was $168,200 in 2030 dollars. (The updated 2022 assessment is included in Investigation of Battery Energy Storage System Recycling and Disposal: Industry Overview and Cost Estimates [EPRI, 3002023651].)

It is important to consider dynamic BESS design features (e.g., chemistry, energy density) as well as recycling trends and policies, in determining accurate decommissioning costs at EOL. EPRI's Novel Advances in Lithium Ion Battery Recycling and Pretreatment (EPRI, 3002029517) reviews the state of the lithium ion battery recycling industry, commercially available recycling methods, and promising recycling innovations and advancements that could be commercialized by 2030.

Onsite Preparations

Decommissioning requires a thorough review and documentation of site conditions, equipment dimensions, hazardous material transportation and waste labelling and handling prior to actual field activities, preferentially through an on-site visit by the recycler or logistics provider. While the decommissioning plan should cover the intricacies of system dimensions, site layout, and access conditions, a confirmation and check of the plan may be important if it was not kept up to date over the years.

Allocating time to familiarize all parties with the conditions on the ground is essential to streamlining the onsite effort with lift plans, truck staging, work staging, and cost estimates—both in the event of a planned and expected end of life effort, or in the event of an emergency clean up effort. Ensuring all parties are certain of the equipment included in their scope of responsibilities will also streamline the efforts.

For an onsite visit, a checklist can be made to verify key elements of the decommissioning plan, such as:

• Number of modules or units
• Keys and entrance to containers
• Tools and equipment required for disassembly
• Road conditions and vehicle access
• Critical dimensions for equipment
• Estimates of equipment condition and health
• Site layout, staging areas, maneuverability for cranes or heavy equipment

Prior experiences with the decommissioning of energy storage systems have served as reminders to anticipate logistical delays and build that time into the project schedule and costs. More learnings, experiences, and information can be obtained in Energy Storage Decommissioning Case Study: Lessons Learned from the Energy Storage Implementation Practices Collaborative (EPRI, 3002022301), ESIC: Battery End-of-Life Case Study (EPRI), and Cedartown Battery Energy Storage System Decommissioning Case Study: Lessons Learned from Decommissioning an Early-Stage Utility-Scale Lithium Ion Project, (EPRI 3002027944).

Disconnect and Decommission

Decommissioning can be a time-consuming process. Because large, utility-scale BESS are a relatively new product and asset class, many processes and regulations have yet to be standardized. In addition, a wide range of stakeholders are involved in the process – both internally and externally (such as regulatory authorities and recycling partners). In addition, a variety of BESS sizes, designs, and ancillary equipment exist, meaning that while the overall dismantling and salvage steps from different types of BESS remain the same, the labor effort and cost for disassembly, details of packaging and logistics, ability to bring cranes and large trucks on site, quantity of materials to be removed and other details will vary substantially by site.

Determine End-of-Life Condition is Met

At this time, there is no industry standard definition for the EOL of a battery, though certain ratios of observed parameters to nominal ones, such as capacity (Ah), energy (kWh), and internal resistance are typically used to form an estimate for the State of Health (SOH) of the BESS. SOH is used as a metric for performance and degradation over the system life, though it can also inform safety cut offs for lithium ion BESS. As lithium ion batteries age, they can form internal defects like lithium plating or dendrites, which dramatically increases the safety risk of the system. For this reason, batteries are typically given an EOL SOH, which demarcates the lowest recommended SOH level that is permissible, and once reached, the system should be retired.

Referring to the specific battery manufacturer’s guidance and/or warranty provisions related to defining the operational end of life for the battery is the most common method of defining EOL conditions.

Battery cell manufacturers often specify that their warranty coverage extends for a specific remaining energy capacity (e.g., “70% SOH”); a specified calendar life (e.g., “10 years”); or a specified energy throughput (e.g., “10 GWh”). Furthermore, the warranty typically includes the caveat to these three metrics by stating whichever of these comes first completes the warranty. However, performance and workmanship warranty coverage may end before performance EOL conditions arise. If a BESS is infrequently used and well maintained, it may run out of the warranty period before reaching an EOL SOH. As with automobiles, exceeding a 36-month, 36,000-mile warranty does not necessarily indicate that the vehicle is at its true EOL.

A battery that experiences failure may also be deemed to be at EOL. If a battery failure occurs in a large BESS with multiple battery enclosures, the failure may only affect a small number of them, leaving the other battery units fully operational. In such a case, the battery module or enclosure that experienced the failure may be deemed to be at EOL and removed from operation. Other (unaffected) battery modules/enclosures may continue in normal operation (if they are assessed to be safe), perhaps at reduced capacity until replacements arrive. Note that damaged, defective, or recalled (DDR) modules must be decommissioned with different protocols than functional modules, and it may be wise to account for these protocols in the decommissioning plan. Consult Decommissioning Strategies for Damaged, Defective, and Recalled Lithium Ion Batteries, (EPRI 3002031225) for planning considerations for handling damaged or hazardous BESS assets during decommissioning.

Operators may be tempted to push systems beyond projected eol, as seen with generators running past original design life. Some chemistries may need early retirement. Planning should anticipate EOL conditions and enable smooth decommissioning to prevent idle time for degraded systems

Circular strategy analysis can help to determine whether assets should be retired, repurposed, or refurbished rather than fully decommissioned. For guided frameworks and examples in assessing whether systems or components have reached end-of-life thresholds, refer to:

• EPRI Research Activities on Renewable and Battery End-of-Life Management and Circularity (EPRI, 3002033798)
• Comparisons of Different Circular Economy Strategies for the Energy Industry (EPRI, 3002030233)
• Program on Technology Innovation: Energy System Circularity Case Study - New York Power Authority Takes a Comprehensive Path (EPRI, 3002033959)

Execute Decommissioning Plan

Typical steps for a BESS decommissioning are listed below.

• Audit all onsite equipment to determine its final disposition, whether reuse/repurpose, recycling or disposal, as well as the location they will be delivered to upon removal from the site. This will, in part, determine the status of the material as a “waste” vs. a “material”, which will trigger different handling, labeling, transport, and storage practices under environmental regulations.
• Determine any other equipment with special needs for packing and shipping (e.g., determine if container size requires lowboy and/or wide-body flatbed trucks), ensuring that proper transportation equipment is available and aligned with the project schedule.
• Charge/discharge the BESS to its final state of charge (SOC). The system manufacturer may have guidance on the desired SOC.
• Record the status of the battery modules, including last status, state of health, SOC, and other system parameters prior to taking the system offline.
• Electrically disconnect the BESS from grid, auxiliary power, transformers, and inverters (if possible, for AC integrated BESS) with proper lock-out tag-out procedures in place. Note that auxiliary power may be required for some decommissioning activities and care needs to be taken in timing auxiliary power disconnects.
• Ensure job safety leading practices are followed, including job hazard analyses, safety briefings, identification and use of proper PPE, development of emergency procedures and muster points; likewise, maintain communication and prepare coordinating with local emergency response agencies and the site AHJ.
• Follow relevant environmental and safety regulations for the handling, storage/accumulation and other management of undamaged lithium ion batteries which are classified as universal waste – a subcategory of hazardous waste under the U.S. Environmental Protection Agency Resource Conservation and Recovery Act 40 Code for Federal Regulation (CFR) § 273.
• Package BESS components and ship materials to reuse/repurpose, recycling and/or disposal partners. See the following section for more information on Equipment Packaging and Transport.

An example project decommissioning plan with an accompanying Gantt chart is also provided in Cedartown Battery Energy Storage System Decommissioning Case Study: Lessons Learned from Decommissioning an Early-Stage Utility-Scale Lithium Ion Project, (EPRI 3002027944).

Onsite Safety

Few utility-scale BESS have been decommissioned due to the industry’s relative immaturity. Early projects coming due for decommissioning may have been small capacity pilots, R&D efforts, or simply projects that reflect the state of the industry at the time of their installation. As such, they were generally designed to have walk-in lithium ion architectures, as well as potentially outdated fire suppression systems. It is important to anticipate that safety challenges due to the specific system’s unique risks will need to be addressed in the decommissioning plan.

Many older systems do not meet NFPA 855 compliance, and current fire safety standards did not exist at the time of installation. During decommissioning, any thermal management, fire suppression, gas management and detection, and explosion prevention systems that exist may end up being disabled or switched offline, resulting in unmonitored batteries with offline safety systems. Decommissioning activities may also remove the capability of interfacing with controls and the BMS. Thus, it is crucial to focus on safe and precautionary approaches to the de-energization and disassembly of a BESS during decommissioning.

For example, a 2 MWh NMC BESS that was commissioned in 2014 and decommissioned in 2022 was housed in a 53-foot, custom-built walk-in container that was equipped with a gaseous fire suppression system, smoke detectors, and an HVAC system. All of these were taken offline by the contractor during the battery module removal and decommissioning process. Figure 6 2 shows the inward facing battery cabinets and the walk-in corridor; such an architecture typically is no longer used. Modern BESS unit designs have increased modularity, are smaller in footprint and capacity, and with direct access to the battery modules from doors that open to the outside. Humans cannot enter the unit. For systems that ship with battery modules inside such a modular enclosure, one option for decommissioning may be to remove the unit in its entirety. This could occur in the event the manufacturer is taking the system back for refurbishment and reuse, or repurposing, or final disposition. However, it is also possible that such modular enclosures will be dismantled on site and the materials and components sent to different recyclers or end points.

Figure 6-2 Interior of a Walk-in Battery Energy Storage System Enclosure - Source: EPRI

Equipment Packaging and Transport

Pre-planning and early preparation are common themes for the Decommissioning Phase, and packaging and transportation are no exceptions. The regulatory requirements for packaging and transport of batteries destined for recycling and disposal can be complex. As mentioned earlier, a strong decommissioning plan will identify relevant standards, codes, and regulations, and ensure that the plan adapts with any regulatory changes. Balance of plant, power electronics, enclosures, and other non-battery equipment has separate transportation regulations that are more common for logistics teams and drivers. EPRI's End-of-Life Regulatory Actions for Lithium Ion Battery Energy Storage (EPRI, 3002031206) also provides insight on transportation regulations applicable to lithium ion batteries.

Packaging for Transport

The typical process for the packaging and transport of equipment is outlined below.

• Package BESS components according to all relevant regulations for later transportation (e.g., the U.S. Department of Transportation regulations for packing, labeling, notification, shipping, and overall safety of hazardous materials under 49 CFR § 172 and 173.185). Special packaging and labeling are required as per the CFR.
• Ship materials to recycling, reuse/repurpose, waste handling, and/or disposal partners. Multiple destinations may be appropriate. Ensure paperwork appropriately declares any hazardous materials, hazardous and/or universal wastes, and the transportation and/or logistics partners are aware of and follow all associated requirements for retention, handling, transportation, disposition, and documentation.
• Obtain certifications of final disposition once processing is complete.

In a decommissioning of a 2 MWh lithium ion BESS, EPRI observed lack of understanding by field personnel of UN/DOT Class 9 hazardous material labelling and EPA Universal Waste labels. After battery modules were packaged on pallets for transport (see Figure 6-3), the contractor required a reminder of proper labeling practice. It is important for utility personnel to be informed on regulatory requirements as a doublecheck on vendor practices.

Figure 6-3 Ensure Labeling of Battery Modules Complies with Regulatory Requirements - Source: EPRI, U.S. Department of Transportation

Damaged, defective, or recalled (DDR) battery modules require special packaging and documentation to ensure awareness to all handlers and safety during transport. Determination of the status of DDR modules should be done with input from the owner/operator, the logistics provider and the recycler. Best practice is to assume that some fraction of modules on site may have DDR status, and to bring the appropriate packing materials just in case they are needed, or if modules are damaged during the disassembly and removal.

Transportation to Next Destination

Whether the energy storage system is leaving the site for final recycling or is being relocated to a new, second life, it is critical to manage the transportation safely and effectively. This includes the enclosures, power electronics, and other onsite equipment.

In field decommissioning experiences, EPRI has observed challenges with the transport of BESS containers, PCSs, and other equipment due to insufficient communications, documentation, and/or record-keeping by vendors regarding equipment dimensions. Figure 6-4, for example, illustrates an instance where the lifting eyes on an enclosure exceeded the permitted truck dimensions, requiring a scramble to remove the enclosure. In a separate instance, a container’s lifting eyes had been welded in place and had to be cut off before the driver could accept the container for transport. Both situations could have been avoided if proper accounting of equipment and container dimensions were handled before ordering trucks for their removal and transport. This includes not just the standardized container or enclosure dimensions, but any ancillary equipment (such as HVAC units) or the support structure (such as the lifting eyes).

Figure 6-4 Problem: Lifting Eyes Exceed Permitted Truck Dimensions - Source: EPRI

Decommissioning Resources

Resource	Application to Decommissioning
End-of-Life Management for Lithium Ion Battery Technologies: Issues, Uncertainties, and Opportunities	This white paper, which focuses on stationary storage applications, introduces leading battery chemistries and key technology attributes from an end-of-life perspective and identifies management options, project life-cycle considerations, and applicable policies and regulations.
Second Life for Large-Format Lithium Ion Batteries	This paper assesses the viability of reusing or repurposing large-format EV LIBs at EOFL for BESS applications.
Decommissioning Strategies for Damaged, Defective, and Recalled Lithium Ion Batteries	This report documents the “state-of-the-science” for managing damaged, defective, or recalled lithium ion batteries; identifies novel methods for managing these batteries; and presents considerations for known practical risk reduction measures— such as de-energization with salt solutions or load banks prior to transportation.
Energy Storage Decommissioning Case Study: Lessons Learned from the Energy Storage Implementation Practices Collaborative	This report summarizes lessons learned from the decommissioning and disposal of a lithium ion battery energy storage system (BESS).
Holistic Decommissioning Planning for Lithium Ion Battery Modules and Energy Storage Facilities	This white paper presents findings and recommendations reflecting a review of decommissioning plans for U.S. stationary energy storage facilities based on lithium ion battery modules, as well as related literature.
EPRI Research Activities on Renewable and Battery End-of-Life Management and Circularity	This fact sheet summarizes the range of current and prior EPRI research deliverables on EOL management topics. It is intended as a resource for EPRI members and public stakeholders interested in specific research projects and is a starting point for further reading.
Guidelines for Assessing End-of-Life Management Options for Renewable and Battery Energy Storage Technologies	Compilation of guidelines for decommissioning renewable and battery energy sites.
Lithium Ion Battery Energy Storage End-of-Life Management Infographic	This infographic summarizes a variety of metrics for the End-of-Life management of lithium ion batteries.
Recycling and Disposal of Battery-Based Grid Energy Storage Systems: A Preliminary Investigation	Reports on the characteristics of lithium ion batteries as well as existing options for and challenges to removing, reusing, and recycling these types of systems and associated electronic and auxiliary parts. Also examined is the potential impact of evolving state and federal safety and environmental regulations on end-of-life battery management.
Investigation of Battery Energy Storage System Recycling and Disposal: Industry Overview and Cost Estimates	This report develops cost estimates for end-of-life management of two different BESS designs: (1) a large BESS (20MW, half hour) lithium ion system, and (2) a smaller mixed chemistry system incorporating both lithium ion (100kW/400kWh) and vanadium flow batteries (100kW/400kWh).
Circular Economy Considerations for Transformer Refurbishment	This report describes the valuation process, cost differentials, revenue and schedule implications, and the value of sustainability when deciding to refurbish a transformer or purchase a refurbished transformer.
Energy Storage Integration Counsel (ESIC) Energy Storage Implementation Guide	Provides insights on planning, procurement, deployment & integration, operation & maintenance, and decommissioning of Energy Storage Systems.
Energy Storage Integration Council (ESIC) Energy Storage Request for Proposal Guide	Use elements of RFP Template and guidance for decommissioning/EOL.
ESIC BESS End-of-Life Case Study Webcast Presentation; Recording	Decommissioning case study of a 250 kW, 750 kWh battery. It includes lessons learned from the decommissioning contractor and recycling and shipping requirements from a recycling company.
Energy Storage Relocation and Decommissioning Project Lesson Learned	This report summarizes a project intended to relocate and recommission a battery to another site, but ultimately resulted in final decommissioning of the system. The system being relocated had been in service from 2017-2018, and due to a change in ownership of the site, the battery energy storage system (BESS) needed to be moved. The system owner identified another site that could use the BESS to support peak load reduction.
Cedartown Battery Energy Storage System Decommissioning Case Study: Lessons Learned from Decommissioning an Early-Stage Utility-Scale Lithium Ion Project	This report summarizes the preparation, process, and lessons learned from the decommissioning and recycling of a lithium-ion battery energy storage system (BESS) purchased by EPRI through a research project funded by Southern Company. This project involves one of the first utility-scale lithium-ion systems to be decommissioned by a utility and thus provides important insights into the end-of-life planning and environmental and safety considerations for future generations of BESS.
Carnegie Road Energy Storage System Failure Response, Recovery, and Rebuild Lessons Learned	This report conveys the lessons learned from the Carnegie Road energy storage system (ESS) failure event, including aspects of emergency response, root cause investigation, and the redesign and rebuild processes.