A group of concerned property owners enlisted the help of ioMosaic to provide engineering support in their case against the proposed location of a Battery Energy Storage System (BESS) facility. The client needed to demonstrate that the risk posed by locating the facility in close proximity was unacceptable to the surrounding community
ioMosaic was able to demonstrate that the proposed BESS facility has the potential for a thermal runaway event, which could lead to fires or explosions and the release of toxic and flammable gases such as hydrogen fluoride.
ioMosaic used its proprietary software Process Safety Office® SuperChems® to model how the generated gases would disperse through the air under atmospheric and wind conditions common to the local area. Using the design specifications of the BESS facility, ioMosaic performed a hazard analysis study to determine whether the risk of thermal runaway was acceptable to the surrounding community and environment.
Our team is experienced in preparing expert opinion reports and white papers to assist attorneys in responding to interrogatories, including Root Cause Analysis, Verification of Physical Evidence, and Structural Analysis.
The ioMosaic team completed a hazard analysis study on the proposed Battery Energy Storage System (BESS) facility with dispersion analysis. The primary scenario evaluated was a thermal runaway with the combustible concentration reduction (CCR) system failing for any cause. The NFPA 855 Standard supported this scenario as credible. For onsite consequences, a safeguard was added for the project not being normally occupied. For off-site consequences, that safeguard was not available.
The dispersion analysis demonstrated that concentrations above recognized exposure levels for carbon monoxide and hydrogen fluoride could reach ground level beyond the property fence line.
In addition, the other models showed that concentration levels above recognized exposure limits for carbon monoxide and hydrogen fluoride could extend for large distances beyond the project fence line, even at reduced emission rates, but at elevations above ground level. These clouds would still be of concern for properties and structures at higher elevations than the project.
Because of the risk of toxic exposure to the public, ioMosaic recommended that this BESS facility not be built at this location.
The ioMosaic team provided written and oral expert testimony during the evidentiary hearings regarding the siting of the BESS project and the impact on areas outside the proposed facility. The testimonies from this project are in the public domain and can be viewed at https://eeaonline.eea.state.ma.us/dpu/fileroom/#/dockets/docket/12515. This information is also available from ioMosaic upon request.
Our client was pleased with the results of the testimony. Agreements regarding the project were still under discussion and negotiation as of early February 2026. The Energy Facilities Siting Board (EFSB) is finalizing new regulations that may affect how projects like this are evaluated.