SEPTEMBER 24, 2021
Energy Storage Safety Hazard Analysis Part 2 – Project Design, Installation, Commissioning and O&M
In the first post of this two-part blog series on energy storage system safety, I talked about our approach to evaluating energy storage product design and safety, including Borrego’s risk assessment methodology and a brief discussion of an early flaw within one of the benchmark standards, UL 9540A. In this second installment, I’ll provide insight into the three other components of our safety approach: project design, installation and commissioning, and operations and maintenance (O&M).
Project Design – Utility-Scale Energy Storage Projects
When it comes to ensuring safety stays at the top of the priority list during project design, early and accurate product documentation is essential. It is not uncommon for ESU suppliers to have insufficient documentation on their products. This is the equivalent of Apple telling you that your new iPhone will run on iOS but omitting the details around Face ID and storage space. You wouldn’t buy the phone, so why buy a BESS that costs many orders of magnitude more and has far more severe safety implications?
Standard product documentation is a must and if it’s not available for your organization during the design phase, it likely won’t be available when you go to permit and convince the AHJ that your project is safe. Proceeding in this manner puts your organization, your stamping engineers, and anyone in proximity to the project at risk, not to mention the project schedule and preconstruction funding you’ve deployed.
In addition to robust product documentation and on time delivery, establishing design standards for your deployments can be a great way to account for common mode failures while reducing design process time. Our standards include general spacing requirements for adequate access, standard foundation details by product type, grounding systems and metering. Removing some design elements from a project sprint better enables your team to think clearly and comprehensively about the safety, installation and cost of your installations.
Of course, close coordination with the local fire department must be maintained from permitting until closeout, including product review and training on the emergency response plan (ERP). I recommend reaching out to new AHJs prior to permitting to ensure you understand their needs and can provide the appropriate documentation and education. This can be particularly helpful in maintaining your project schedule if additional hazard mitigation analysis or project design requirements will be necessary.
New York City forces this conversation during the development stage of a project through their Building Department’s OTCR and FDNY’s TM approval processes, but not all entities have the same resource availability to review products. They may also lack the know-how to state what will keep their community safe and ensure that their first responders can safely and sufficiently respond to a worst-case incident. Fire reporting, dry pipe suppression and emergency response planning are all topics that are best broached early.
Installation and Commissioning
Keeping safety first during BESS installation and commissioning is where the rubber meets the road. Through the due diligence of our hazard analysis, we identify the greatest or at least most frequent possible safety threats during installation in addition to mitigating actions that we can utilize to reduce risk during operation. Since energy storage products are constantly evolving, the team approach to safety during install and commissioning will need to evolve as well. It’s important to ensure that the components and system that you receive on site are in good condition, with verification of complete factory acceptance testing and inspection of the equipment to verify there is no mechanical, thermal or other damage.
While it’s extremely important to employ visual inspections as a first line of defense against installing damaged products, the inspections can only take you so far. Two additional measures that Borrego employs are performing module-level open circuit voltage and insulation resistance testing. While these additional measures, if not already required by your battery OEM, do add cost, they can help ensure installed capacity meets design capacity, and that there are no underlying issues with a module that may lead to a downstream safety event. On utility-scale applications, this may not always be possible, however additional measures deployed in factory acceptance testing and in the delivery logistics can help maintain an acceptable level of risk and project performance.
Operations and Maintenance
Once the storage system is commissioned, the EPC team hands the baton to the system’s operations and maintenance (O&M) service provider. It will be their responsibility to understand and implement the ERP, if needed, in coordination with first responders and to ensure that all primary, secondary and tertiary safety systems remain in good working order. Temperature and humidity monitoring can be done remotely, and the energy management system (EMS) can help expedite emergency response. Since prevention is the preferred strategy, early detection and isolation of any problematic cells or battery packs is essential.
O&M safety isn’t all about monitoring and response, however. Many aspects of design standardization and installation safety that we previously discussed are also applicable in asset management. Module replacement will need to occur on sites, fire suppression and detection will need to be tested and recommissioned, and arc flash hazards are always present. At Borrego, we recommend a process in which your team reflects on the ongoing maintenance of a project at an early stage and involves the O&M provider as early as feasible to ensure a seamless and safe handoff. This ends up being less effort than backtracking and providing re-education once a project closes out.
Safety Is Foundational
A keen focus on safety is foundational to how Borrego deploys energy storage. The depth of our due diligence process creates value and risk mitigation for the customer and gives the system vendors confidence, making for more efficient system design, construction, commissioning and operations.
Stay tuned for more upcoming blogs on energy storage. In case you missed it, here’s the link to the first safety post. You can also check out our team’s recent webinar on energy storage augmentation or read about the pros and cons of augmentation in our summary of the webinar.