Eagle Energy Storage - Answers to Questions and Clarifications Raised at Greenburgh Town Board Meeting 12/9/20 1. Estimated Property Tax/Benefits to Town Supervisor Feiner and many other parties asked about the financial benefits to the town, and how much property tax the energy storage system would ultimately pay. Property taxes applicable to the project will ultimately be determined by the tax code and the judgement of the Town Assessor. Our team estimates that the project may ultimately pay $30k-$50k per year in property taxes over the life of the project (up to $1.5mm over 30 years). The actual number will be determined in coordination with the Town Assessor. 2. Storms/Trees Causing Line Outages A Town Councilperson asked what would happen if the lines between the battery and the Elmsford substation went down. We wanted to confirm that the battery project could in no way negatively impact the Town’s power supply. In the event of an outage between the battery system and the Knollwood substation the battery would safely be placed into a non-operational mode, and Con Edison’s grid would function (or not function) exactly the same as if the system were not present. When the battery is operational, it should help to stabilize the grid and increase reliability on a grid-wide level. The proposed overhead electrical lines will generally be located away from branches which could impact the lines. Where the project proposes to connect to existing poles, the branches will be trimmed, in-line with other local utilities. 3. Selling Energy to the Public A member of the Planning Board stated that “[the project] has no intention of selling energy to the public.” This is not accurate. The proposed project would sell energy into the NYISO energy, capacity and ancillary services markets. The public buys energy from these markets, either through Con Edison or through a third-party energy supplier. The proposed project would operate identically to virtually all power generating facilities in the state of New York which sell into the wholesale energy markets. The project would be regulated by the Federal Energy Regulatory Commission (FERC) in the same way as other wholesale power generators in New York State. 4. Availability of Other Locations A member of the Planning Board as well as other parties asked for additional analysis around whether the project could be located in another location that was not zoned residentially. The project must be located near the substation so that it can interconnect to the substation. Strata has been in discussions with all other landowners directly adjacent to the Con Edison substation (see diagram below; blue outline is the substation, red outlines are parcels of land that Strata approached). We were not able to reach agreement for the use of any of these other plots of land due to lack of interest from the landowner, previous engagements that precluded the landowner from leasing or selling the property to the project, or due to offers from other interested parties (e.g. the expanding car dealership). Many of these other locations were located closer to residences than the proposed site at the Knollwood Country Club. It should also be noted that the alternative locations that were reviewed and approached are closer to residential areas. Specifically, the Kimco Parcel is less than 400 feet to the nearest residential house with the other alternative locations situated even closer. The Knollwood Country Club was selected as it represented the only available and the best suitable site near the Elmsford substation which could accommodate the BESS Facility. While there may be available parcels outside of the area, they would be located significantly further from the Elmsford substation, making the Interconnection Route infeasible. Figure 1 - Land Near Elmsford Substation 5. Conditions in the Planning Board’s Recommendation Chairperson Simon referenced a list of recommended conditions that the Planning Board included in their recommendation to the Town Board. As we have discussed with the Town Board and Town Attorney, we can accept almost all of the recommended conditions, including secondary containment and a decommissioning bond. Many of the concerns that have been raised have been previously addressed in memos and submissions to the various Town entities and review Boards. To simplify the collection of documents, please refer to the below list of documents, included in the Appendix to this document, which were previously submitted (or, in the case of the Viewshed Profile, are being submitted now). This list is not comprehensive. For further information, please reference the original application & submission submitted to the Town on 9/11/20, as well as the revised application materials submitted on 10/28/20. • 9/29/20 – Letter of No Effect from SHPO • 10/28/20 – Planning Board Question & Answers • 11/18/20 – Letter of Review and Support from Fire Chief • 11/18/20 – Letter to Planning Board & CAC • 11/25/20 – Planning Board Letter & MSDS Sheets • 12/17/20 – Viewshed Profile 6. Length of fire event A member of the Planning Board and other parties stated that Tesla claims that a fire could take a day or more to be extinguished. While Tesla may have stated this previously, it is not accurate for the Megapack system being proposed. The most recent emergency response guide is Tesla’s “Lithium-Ion Battery Emergency Response Guide, For Tesla Energy Products including Powerwall, Powerpack, and Megapack – TS-00004027 – REV 2.1 from August 28, 2020. This document states that “a battery fire may continue for several hours and it may take 24 hours or longer for the battery pack to cool.” (page 13 of 21). It does not state that a fire would continue for 24 hours and in fact explicitly states that the fire would continue for only “several hours”. In fact, the fire would be extinguished in no more than 3.5 hours, though the system could remain hot for a full 24 hours. This is detailed in a separate document from August 2020 specifically applicable to the proposed Megapack (as opposed to the more general emergency response guide that also includes the Powerpack and Powerwall) which states “External suppression is not required as the system performs in a safe and controlled manner, fully consuming itself slowly over a period of 3.5 hours without explosive busts, deflagrations, or unexpected hazards.” This document can be shared under a Non-Disclosure Agreement (NDA). In considering the Tesla Megapack, there are multiple benefits to the approach taken to allow the single enclosure to fully consume itself in a fire situation. An enclosure on fire is actually safer than one where potentially explosive gas is allowed to build up. The Megapack also has a sparker system that burns the gases before they can accumulate, thereby mitigating the danger of explosion. By allowing the enclosure to fully consume itself the danger of cell re-ignition cells hours after the system has stopped burning is mitigated. This has the added benefit of making decommissioning safer since the stranded energy remaining in the battery cells is removed during the fire. Nationally recognized testing according to the UL9540a method has shown that a fire in one enclosure will not spread to adjacent enclosures, even when they are only 6 inches apart. Tesla has tested the Megapack against the most rigorous version of the UL9540a test methods (Version 4). In sum, allowing the fire to burn itself out is the safest way to handle a fire event inside a Megapack container, and the system would burn itself out in no more than 3.5 hours. 7. Battery Safety Events A member of the Planning Board referenced an article in the Wallstreet Journal around a recall of Tesla’s electric vehicles. We believe that this comment was referring to an October 19th, 2020 article discussing a recall by Chevy of their Bolt electric vehicles1. We are not aware of any recall of Tesla’s electric vehicles. A member of the public presented several safety incidents that have occurred at battery installations including an incident in Arizona and in South Korea. None of these safety incidents involved Tesla energy storage systems, which have never had an incident. The fires in South Korea are due to improperly integrated systems; the Tesla system comes fully integrated so that cannot be a problem. 1 https://www.wsj.com/articles/auto-makers-grapple-with-battery-fire-risks-in-electric-vehicles-11603099800 In addition, the incidents in Arizona and South Korea took place in Walk-In Energy Storage System Units, as opposed to the Tesla Megapack which is an Energy Storage System Cabinet. As per NYSERDA’s definition of ESS Cabinets it is a “cabinet containing components of the energy storage system that is included in the UL 9540 listing for the system. Personnel are not able to enter the enclosure, other than reaching in to access components for maintenance purposes.” Cabinet type systems are significantly safer than walk-in type systems. 8. Chemical-Based Fire Suppression A member of the Planning Board asked for data regarding why a chemical fire suppression system would not be effective in this type of system. NFPA 855 – Standard for the Installation of Energy Storage Systems specifically addresses suppression methods to be used with lithium-ion BESS. Annex C-5 addresses firefighting considerations and states, “Fire-fighting dry chemical powders can eliminate visible flame. However, they also lack the ability to cool burning battery components. Quite often, even if visible flame is removed, the thermal runaway inside the battery will continue resulting in reignition. Carbon dioxide and inert gas suppressing agents will also eliminate visible flame but will likely not provide sufficient cooling to interrupt the thermal runaway process.