Power plants have lifetimes, and every plant has (or should have) a decommissioning plan. That is true for nuclear, wind, and solar plants, among others. And it is true for battery energy storage systems (BESS), as well. But relatively few jurisdictions require an owner/operator to have a BESS decommissioning plan. This is for many reasons, including the youth of the energy storage industry and the often componentized nature of energy storage plants. If you can put them together like building blocks, you can undo them in the same way—at least that is the way people view it.
Going forward, it is safe to say that more jurisdictions will require decommissioning plans in project applications.
DNV considers the development of a decommissioning plan and the estimation of its cost together to be an industry best practice. A decommissioning plan should describe how the BESS owner proposes to dismantle the infrastructure and restore the site to a condition suitable for future land use. Because much of a plant is recyclable—the cells themselves, but also the metal in the structure—recycling and salvaging of component materials can reduce the price tag for the entire system.
There are several general considerations in creating a decommissioning plan and cost estimate. Some key considerations are discussed below.
- Project size and footprint. Larger MW projects require more acreage for installation. For example, the main component of a 10 MW commercial BESS may be a 53-foot container, 9 feet wide and 10 feet tall. (The footprint could vary, depending on the technology and vendor.) In this case, a 150MW project might have 14 or 15 containers, which usually are connected to each other by an underground collection system. As one would imagine, the costs for decommissioning larger systems are greater when compared to small systems.
- Type of enclosure or facility. Outdoor, modular/block enclosures are fairly recent and increasingly popular, with the most important improvements related to safety, installation time, O&M efficiency, and transportation. Less common indoor, racked BESS require a more traditional building enclosure. Containerized batteries, whether in traditional large containers or in modular/block enclosures, require complete removal from the project site. Depending on the agreement with the landowner, the decommissioning plan might not include the building, retaining its value for future use (e.g., farming equipment storage).
- Weight. Batteries are heavy. Transportation of BESS can require large trucks and cranes, if containerized. Other solutions may require smaller equipment. It’s important to understand the equipment requirements and how they affect the decommissioning cost estimate. One consideration, helpful in general project planning as well as decommissioning cost estimates, is non-battery material salvage. Selling steel, aluminum, and copper as scrap material can help offset some of the decommissioning cost.
- Zoning regulation. Local zoning regulations, landowner agreements, and other applicable regulations can address key land use considerations. Usually all above-ground facilities and equipment must be removed, and the destiny of underground components can vary. The depth at which concrete foundations and underground collection cables are required to be removed is commonly set to three feet. As some projects will bury cables lower than three feet, some owners/operators may decide to abandon them if no other requirements for removal apply. Cables contain salvage material, so depending on the scrap market value, it may be profitable to remove the cables even if not required.
- Reassessment. The decommissioning plan and costs are likely to evolve over time, so it’s common for the owner/operator to negotiate the frequency of updates to the decommissioning study. Updates to the plan three years before the end of operations of the project shall provide an accurate estimate of the decommissioning costs to the project stakeholders.
While these are some key considerations, owners/operators of BESS need to incorporate decommissioning plans and cost estimates into their overall project development—not only will it increasingly be a requirement, it’s also good business practice.
If you’d like to learn more, please contact me.