Community Q&A
Responses to questions submitted by community members during and after the March 11, 2026 webinar.
Safety & Emergency Response
How do lithium iron phosphate (LFP) batteries catch fire, and what is done to prevent that?
LFP batteries are the safest commercially available battery chemistry for grid-scale storage. Unlike the lithium-ion batteries found in consumer electronics, LFP batteries do not contain cobalt or nickel, which are the materials most associated with thermal runaway in other battery types. LFP chemistry has a significantly higher thermal stability threshold, meaning it requires much more extreme conditions to reach a dangerous state.
To prevent fires at Battery Energy Storage Systems (BESS) facilities, several measures are implemented, including:
Adherence to Updated Safety Standards: Compliance with modern safety codes such as NFPA 855 and UL 9540A ensures that newer BESS installations are equipped with fire safety features designed to limit fire initiation and propagation.
Improved System Design: Advancements in BESS technology include enhanced thermal management systems, integrated fire safety systems, and containment enclosures to reduce the likelihood of fire incidents.
Rigorous Testing and Quality Control: Modern BESS units undergo comprehensive testing and quality assurance during system integration, construction, and assembly to minimize risks associated with early lifecycle failures.
Firefighting Strategies: Fire suppression tactics emphasize containment and cooling of targets rather than active suppression efforts, reducing the risk of environmental contamination and improving safety.
Controlled Burn Approach: In cases of deep-seated battery fires, fire departments often allow the BESS container to consume itself in a controlled manner, minimizing the use of water and reducing potential environmental impacts.
Continuous Research and Development: Ongoing research and advancements in technology aim to further enhance the safety and reliability of BESS systems.
These measures collectively contribute to reducing the risk of fires and their potential environmental and safety impacts.
Have fires occurred at other battery storage sites? If so, how many and what was the impact on the community?
There have been a small number of fire incidents at battery storage facilities in the United States, and it is important to understand the context. The vast majority of those incidents involved older nickel manganese cobalt (NMC) battery chemistry, not the lithium iron phosphate (LFP) chemistry proposed for Monarch Grid. LFP is a fundamentally different and more thermally stable chemistry. The battery storage industry has also evolved significantly in recent years, with improved safety standards, container-level suppression systems, and enhanced monitoring protocols that did not exist when earlier facilities were built. Eolian incorporates all current best practices and safety standards into every project.
Real-world data and environmental monitoring indicate that BESS fires have minimal long-term environmental and public health impacts. Toxic emissions and contamination risks are localized and short-lived, and modern safety measures further mitigate potential harm to communities.
Localized Impact: Toxic gases such as CO, CO₂, VOCs, HF, HCN, and HCl are released during BESS fires, but their concentrations are confined to the immediate vicinity of the fire.
Rapid Dissipation: In an open-air site like Monarch Grid, gases disperse quickly, reducing the risks of widespread toxic exposure.
No Public Health Risk: Air sampling from past incidents (e.g., Escondido, CA, and Lyme, NY) found no hazardous concentrations in nearby communities. Shelter-in-place and evacuation orders were lifted shortly after measurements were taken.
Soil and Water Contamination
Minimal Risk: Firefighting water runoff and soil contamination risks are low due to the limited solubility of chemical byproducts in water and standard stormwater management practices.
Environmental Sampling Results: Past incidents showed no hazardous contamination levels in soil or water requiring remediation.
If these batteries are safe, why are you training 12+ fire departments?
At this early stage we are offering educational sessions to those fire departments that are interested in learning more about energy storage. The fire departments in the region are an exceptional group and curious about this technology and learning current strategies being employed for the prevention and response to emergency situations associated with it. As the site specific comprehensive emergency response plan (ERP) is finalized, only the involved agencies that need to respond will be involved in the development of the ERP and the initial and annual training for provided for the life of the project. To that end, we will work with this group of first responders to ensure they understand the technology, the facility layout, and the specific response protocols for battery storage. This is responsible planning. The goal is to make sure first responders are prepared and confident, not because we expect an emergency, but because preparedness is a core part of how we operate.
What is the fire response plan? How are firefighters expected to respond?
The specific response protocols will be developed in close collaboration with the Nunda Rural Fire Protection District and mutual aid groups and documented in a comprehensive site-specific Emergency Response Plan (ERP) prior to the facility becoming operational. The ERP will be developed based on national best practices that are customized for the facility. These best practices include extensive collaboration with first responders to address emergency situations that might be encountered at the site, including extreme weather, fires, security incidents and more. They also address emergency response roles and highlight the importance of coordinating with first responders—particularly during planning—to ensure there is a complete and detailed shared understanding of potential emergencies and the proper safety responses. Emergency response plans also include contact details for facility experts who can advise first responders on appropriate actions for each situation.
How long does it take for a battery container to burn itself out if there is a fire?
The duration depends on the specifics of the situation, but the modern energy storage facility is designed, installed, and certified to self-contain and minimize a thermal event. This is accomplished through strict conformance to NFPA 855 which dictates where and how systems are placed (spacing, ventilation, suppression). Stringent testing for all systems that are used within the facility, including certification to UL1973 (battery cells) and UL9540 (entire system), with UL9540A large scale fire testing to prove the that the thermal event will on spread between units. The modular outdoor design also ensures that the event is contained to one container. Typical durations for a thermal event range from several hours to approximately 24 hours depending on the scenario. During this time, the container is isolated from all other units, and the event does not spread. The Emergency Response Plan developed with local fire departments will include detailed protocols for monitoring and managing any such event.
What happens to the air quality if a battery fire occurs? What about toxic emissions?
In the rare case where fires do occur, they may be managed without endangering broader communities. The average level of toxicity is similar to that of plastics fires involving materials such as sofas, mattresses, or office furniture. Toxic gases such as CO, CO₂, VOCs, HF, HCN, and HCl are released during BESS fires, but their concentrations are largely confined to the immediate vicinity of the fire. Gases disperse quickly, reducing the risk of widespread toxic exposure. This has been shown during air sampling from past incidents (e.g., Escondido, CA, and Lyme, NY) found no hazardous concentrations in nearby communities. Modern safety standards and evolving firefighting strategies have significantly mitigated these risks compared to legacy systems. The code-required site-specific Hazard Mitigation Analysis developed for the site will summarize how risks beyond the site boundary will be prevented. The HMA will be utilized in the development of the site-specific comprehensive Emergency Response Plan.
How would families on Behan Road evacuate in an emergency? Behan Road has no other exit.
We understand this is a real and personal concern for families on Behan Road. The safety of the community and its residents is a primary concern, and we recognize that this concern exists for residents in this area whether the proposed facility is constructed or not. A storm or other weather-related event, a brush fire or structure fire, a motor vehicle accident, or any number of scenarios could affect access on Behan Road for a period of time. We encourage residents to work with local officials to understand what plans and contingencies are currently in place for the community in the event Behan Road is closed for any reason. The project will work closely with emergency services and the fire department throughout the development of the project. Prior to commercial operation, a comprehensive site-specific Emergency Response Plan will be finalized in close collaboration with the fire department and emergency services. The first step is meeting with the fire department and emergency services to review detailed project site maps for potential hazards and align the facility’s capabilities with their response tactics, plans, and procedures. During operation, the ERP will be a living document kept up to date for the life of the project and will include mandatory initial and annual refresher training for facility operators and first responders.
What emergency response time can residents expect? Will there be someone on site at all times?
The facility will be monitored 24 hours a day, 7 days a week through remote monitoring systems that track every container in real time. First responders will be in touch with someone immediately by phone and a site technician will be dispatched to the site within 30 minutes for alarms. The Emergency Response Plan will address emergency response roles and highlight the importance of coordinating with first responders—particularly during planning—to ensure there is a complete and detailed shared understanding of potential emergencies and the proper safety responses. Emergency response plans also include contact details for facility experts who can advise first responders on appropriate actions for each situation.
How close is the facility to the nearest school? What protections are in place for students?
The proposed facility is located approximately two-thirds of a mile or 3,500 feet from the nearest school property. The Incident Commander as defined in the Emergency Response Plan developed in collaboration with the local fire department and emergency services will include steps for coordinating with the school district on notification protocols to determine if shelter-in-place or other procedures would be appropriate for the area during an event. This decision will be based on the specifics of the incident and planned through a collaborative effort with the local fire department and emergency services. A shelter in place order could also occur if a house or a commercial and industrial site currently located within 2/3 of a mile of school were to catch fire now. The smoke from a house or structure or substation would have similar localized toxicity to the air quality of the area. The safety of students and families near the facility is something we take extremely seriously, and we welcome direct conversation with school officials as planning progresses.
You can’t fly with lithium batteries. Why is it okay to have them in a neighborhood?
The restriction on lithium batteries in airline cargo holds relates specifically to the conditions inside a pressurized aircraft cabin at altitude, the inability to respond to an incident mid-flight, and the specific battery chemistries commonly found in consumer electronics. Grid-scale lithium iron phosphate (LFP) batteries are a fundamentally different technology. They are housed in engineered steel containers with built-in fire suppression, continuous monitoring, and are accessible to first responders at all times. Commonly used consumer batteries used are also not subject to the same stringent testing that is used for all systems within the proposed facility. These include certification to UL1973 (battery cells) and UL9540 (entire system), with UL9540A large scale fire testing to prove the that the thermal event will on spread between units. The comparison to airline restrictions does not apply to stationary, ground-based battery storage facilities with dedicated safety systems.
What about lightning strikes?
The facility will be designed and constructed to meet all applicable electrical codes, which include comprehensive lightning protection and grounding systems. Battery containers are enclosed in steel housings that act as effective shields. Lightning protection is a standard and well-understood component of electrical infrastructure design.
What happens if a tornado or severe storm damages the facility? Who cleans up?
Eolian is responsible for the facility and its maintenance for the life of the project, including response to any damage from severe weather. The Emergency Response Plan will also address protocols for emergency situations that might be encountered at the site, including extreme weather, fires, security incidents and more. In addition, the facility will carry comprehensive insurance, and Eolian is contractually and legally responsible for any cleanup, repair, or remediation required. Battery containers are engineered steel enclosures designed to withstand significant weather events and earthquakes. In the event of catastrophic damage, Eolian bears full responsibility for cleanup and restoration. Additionally, State law requires the posting of a decommissioning bond to further ensure that, in any event, the site is restored to its former use.
What is the source of water for fire suppression?
The facility will maintain dedicated on-site water storage for emergency use. The site would store enough water in holding tanks or ponds, similar to the Snap-On facility located to adjacent to the facility. In the event of a thermal event, water is primarily used to cool adjacent containers as a precautionary measure to prevent heat from spreading, not to extinguish the affected container directly. Because of this, the water use requirements are very limited for these modular outdoor cabinets compared to a traditional structure fire that could be occupied and present an immediate threat to human life within the structure. The specific sourcing and replenishment plan for on-site water storage will be detailed in the site engineering plans and shared as part of the permitting process.
Please provide a history of any battery farm fires in Eolian installations over the past 10 years. What changes have been made to ensure these situations never happen again?
In five years of operating battery energy storage facilities, Eolian has had zero fire or thermal incidents at any of its projects. Eolian’s safety record reflects the company’s commitment to using the safest available battery chemistry available, incorporating multiple layers of monitoring and suppression technology in every container, and working closely with local fire departments to develop comprehensive emergency response plans before any facility becomes operational.
Will there be signs listing emergency contact numbers and an evacuation plan for residents?
Yes. NFPA 855 requires specific signage and labeling to ensure first responders and facility staff can quickly identify hazards and shut down the system during an emergency. As part of the Emergency Response Plan developed in collaboration with local fire departments and emergency services, Eolian will work with local officials to ensure that emergency notification and communication procedures are in place and well understood.
Environmental Protections
How will the facility be cooled? Will it use groundwater?
The battery containers are cooled using self-contained HVAC systems, essentially the same technology as standard air conditioning units. This is not the type of intensive water-based cooling associated with data centers or large industrial operations. The cooling systems are closed-loop, air-based, and do not draw from or discharge into local groundwater or waterways. There is no industrial-scale water consumption associated with this facility.
How will the project protect the Fox River, local lakes, and residential waterways?
Protecting local water resources is a central part of the project’s design. As discussed in the webinar presentation, the facility will include a comprehensive stormwater management system designed to meet or exceed all county and state requirements. This system is engineered to ensure that stormwater runoff from the site is properly managed and does not impact adjacent waterways, including the Fox River. The facility does not discharge heated water or any process water into the environment at any time. For additional detail on groundwater protections, please refer to the groundwater section of the webinar presentation, which is available on the project website.
How much water will the facility use from the aquifer?
The facility’s cooling systems do not require any water draw from the aquifer. This is fundamentally different from water-intensive operations like data centers or heavy industrial facilities. Water stored onsite would be supplied by groundwater but would not require a constant draw from the aquifer as the tanks or pond would store enough water for use in the event of an emergency only. As covered in the groundwater section of the webinar presentation, the project has been designed specifically to avoid impacts to local groundwater resources.
What about impacts to endangered species, like Blanding’s Turtle? Have environmental surveys been conducted?
Environmental surveys are a required component of the permitting process. Eolian is committed to conducting thorough environmental assessments, including coordination with the Illinois Department of Natural Resources (IDNR) and the McHenry County Conservation District. Survey results and any required mitigation measures will be made available to the public as part of the permitting process. Protecting the ecological character of the surrounding conservation areas and waterways is a priority for the project.
How many trees will be removed?
The project site is primarily a previously developed commercial/industrial property. It was the site of a former mink farm. The detailed site plan, including any impacts to existing vegetation and the landscaping plan for the facility, will be part of the public permitting process. Eolian is committed to working with the community and local officials on landscaping and screening the facility from the surrounding environment.
The landscaping renderings showed non-native plants. How does that protect the local environment?
We appreciate that feedback. Eolian is open to working with the community, the McHenry County Conservation District, and local officials to develop a landscaping plan that incorporates plantings that are both disease and drought resistant while prioritizing native species appropriate to the area. The renderings shown during the webinar were conceptual, and the final landscaping plan will be developed as part of the site plan review process.
Will environmental studies be shared with the public?
Yes. Eolian is committed to transparency and will make environmental studies available to the public as they are completed through the permitting process.
What is the stormwater management plan? Is it just a retention pond?
The stormwater management system will be engineered to meet all county and state requirements and will be designed based on detailed site hydrology. The specific design, which may include retention, detention, and other best management practices, will be part of the public permitting process and subject to review and approval by the relevant authorities.
Can landscaping be only native Illinois plants, bushes, and trees? Can fencing allow for all species (animals, birds, amphibians, etc.) free movement?
Eolian is committed to working with the community, the McHenry County Conservation District, and local officials to develop a landscaping plan that incorporates plantings that are both disease and drought resistant while prioritizing native Illinois species. Regarding fencing, the facility requires a secure perimeter barrier for safety and security given the presence of high voltage equipment on the site. This perimeter barrier will be solid to prevent wildlife from entering the facility for their own safety. The project will only develop approximately half of the total 50 acres and allows buffer areas for the movement of wildlife around the facility without needing to cross roads or other physical barriers.
What is the stormwater plan? Specifically, removal of toxins.
The battery containers are sealed, self-contained steel enclosures. Under normal operations, there is no release of any chemicals, toxins, or hazardous materials into the environment. The stormwater management system is designed to manage rainwater runoff from the site, not to treat industrial discharge, because there is no industrial discharge. In the unlikely event of an incident, the facility’s containment systems are designed to prevent any release from reaching stormwater systems or adjacent waterways. The stormwater management plan will meet all county and state requirements and will be part of the public permitting process.
Community Benefits & Economics
What are the tax benefits to the community? Can you provide projections over time?
The Monarch Grid project is expected to generate approximately $5 million in property tax revenue in its first year of operation, with an average of approximately $3.5 million annually over the life of the project. This revenue is distributed to local taxing bodies, including school districts, fire protection districts, road districts, the county, and other local services. The percentage allocated to each taxing district is determined by the existing property tax levy structure established under Illinois law, not by Eolian. Eolian does not control or influence how tax revenue is distributed among local taxing bodies. This represents a significant, stable, long-term source of revenue for the community that does not require any public investment.
How will this affect property values? Can you cite specific studies?
Independent research on the impact of battery energy storage facilities on nearby property values is still an emerging area of study. The available evidence to date, including analyses from assessors and appraisers in communities with operating BESS facilities, has generally not shown a measurable negative impact on surrounding property values. It is also worth considering that the benefits the project brings to the community, including millions of dollars in annual tax revenue supporting local schools and services, contributions to grid stability and reliability, and support for long-term energy affordability, are the types of factors that contribute positively to the overall desirability and value of a community. The visual screening, setbacks, and low-profile design of the facility are all intended to minimize any visual or noise impact on neighboring properties.
Will homeowners be compensated if property values decrease?
Eolian is committed to being a good neighbor and takes property value concerns seriously. The project is being designed with significant setbacks, visual screening, and noise mitigation specifically to protect the character and value of the surrounding community. We are open to continuing this conversation with residents as the project progresses.
How does Eolian get paid? What is in it for the company?
Eolian is a private energy company that invests in, builds, and operates energy infrastructure. Monarch Grid would generate revenue by participating in the PJM wholesale electricity market, storing energy when supply is high and prices are low, and delivering it back to the grid when demand is high and supply is tight. This is a market-based business, and Eolian bears the financial risk of the investment. The community benefits through tax revenue, local spending during construction, and improved grid reliability, without bearing any of the financial risk.
How many permanent local jobs will this create? What are the titles and salary ranges?
Battery energy storage facilities are not labor-intensive operations once constructed. The facility will require a small number of permanent positions for on-site operations and maintenance, so there is little disruption to the surrounding community or drain on resources.
As a result of the project we estimate the creation of;
- 110 new local jobs during construction for McHenry County,
- 410 new local jobs during construction for the State of Illinois,
- 4-5 new local long-term jobs for McHenry County, and
- 10-11 new local long-term jobs for the State of Illinois.
Who pays to build this project? Is there any cost to taxpayers?
Eolian funds the construction and operation of Monarch Grid entirely with private capital. There is no cost to local taxpayers. The community receives tax revenue from the project without contributing any public funds to its construction or operation.
What happens at end of life? Who pays for decommissioning? Will a trust be established?
Eolian is fully responsible for decommissioning the facility at the end of its operational life, including removal of all equipment and restoration of the site. A decommissioning plan and financial assurance mechanism will be established as part of the permitting process to ensure that funds are available for decommissioning regardless of the future financial condition of the company. This is required by law for energy storage projects of this type in the state of Illinois and ensures the community is protected.
What about the batteries after 40 years? Is that not terrible for the environment?
Battery materials, particularly lithium iron phosphate, have significant recycling value. The battery recycling industry is an established industry, driven by both the value of the materials and regulatory requirements. At end of life, battery modules are expected to be reused, recycled or repurposed and cannot be displaced in landfills or incinerators due to state and federal laws. Eolian’s decommissioning plan will include responsible handling and recycling of all battery materials.
What specific benefits would Prairie Grove see if it annexes the project area?
If the project were annexed into the Village of Prairie Grove, the Village would have direct land use authority over the project and could negotiate a development agreement or host community agreement that provides specific, direct benefits to the Village and its residents. These could include direct payments, community investment funds, infrastructure improvements, or other negotiated benefits in addition to the property tax revenue the project would generate. Eolian welcomes that conversation with Village officials and residents.
What benefit is there to residents of Oakwood Hills?
While the project is not located within Oakwood Hills, all residents of the area benefit from the property tax revenue that flows to shared taxing bodies such as school districts and the fire protection district. Additionally, the grid reliability benefits of battery storage serve the broader region, not just a single municipality.
How does the ‘helping families stay in their homes’ program work?
This project would require very little municipal services. Once operational, the site would have 1 or 2 car trips a day, it would not require daily water usage, no sewer, and no additional students would be added into the school system. This means that all taxes and community benefit funds provided to the community would go towards the collective benefit of the community. In the long term, this project would reduce energy costs and increase reliability. All of this adds up to near-term savings on monthly bills and long-term stability in energy prices.
Have energy bills decreased at Eolian’s Massachusetts project?
Eolian’s project in Massachusetts recently reached commercial operation, so it is too early to measure specific energy bill impacts for that community. However, the principle behind how battery storage reduces energy costs is well established and has been demonstrated in other markets. In Texas, for example, battery storage has played a measurable role in reducing price spikes during periods of peak demand by adding supply to the grid exactly when it is needed most. As discussed in the webinar presentation, this is the same mechanism through which Monarch Grid would contribute to energy affordability in the PJM market. In Illinois, the Clean and Reliable Grid Affordability Act (CRGA), signed into law in January 2026, uses energy storage as a tool to stabilize electricity prices and provide direct financial returns to households. By storing cheap energy during off-peak times and releasing it when demand is high, the state can avoid using expensive "peaker" plants that drive up utility rates. The state has mandated the procurement of 3 gigawatts (3,000 MW) of battery storage by 2030. This build-out is expected to save Illinois consumers $13.4 billion over 20 years by suppressing high market prices.
Source: https://dailyenergyinsider.com/news/50814-new-illinois-law-poised-to-provide-more-clean-energy-save-consumers-more-than-13b-over-20-years/
What is Eolian’s initial investment, and what would the potential revenue stream be?
An exact cost of the project has not yet been determined, but the project could represent up to a $700 million investment. Eolian’s revenue comes from participating in the PJM wholesale electricity market. The final investment will be known once the final design and procurement contracts are in place, but the key point for the community is that Eolian bears all of the financial risk while the community receives the benefits of tax revenue, grid reliability, and local economic activity during construction.
What will be the source(s) of Eolian’s revenues? Who pays Eolian? Will the renewable energy royalty structure be put in place? Can you explain how it works?
Eolian’s revenue from Monarch Grid comes from participating in the PJM wholesale electricity market. The facility stores energy when supply is high and prices are low, and delivers it back to the grid when demand is high and supply is tight. Eolian is compensated at prevailing wholesale market prices set by PJM through a competitive, FERC-regulated process. No individual ratepayer or community member pays Eolian directly. The State of Illinois is also implementing an energy storage procurement program run through the Illinois Power Agency, but Monarch Grid has not applied to that program, and may or may not choose to participate. At this time, Eolian does not anticipate any revenue coming from a royalty structure or any other additional revenue stream outside of the PJM market.
Please explain how energy savings will occur and be validated. Will you receive legally enforceable commitments from providers like ComEd before dropping a shovel?
Battery energy storage contributes to lower energy costs by reducing price spikes during periods of peak demand. When the grid is under stress and prices surge, battery storage adds supply at exactly the moment it is needed most, which helps bring prices down for all consumers in the market. This is a market-level effect, not a direct billing arrangement between Eolian and individual households. Eolian does not have a contractual arrangement with ComEd regarding consumer savings. The savings mechanism works through the PJM wholesale market. By adding supply during high-demand periods, battery storage helps moderate the capacity and energy prices that ultimately flow through to consumer bills. This effect has been documented in other markets, including Texas, where battery storage has measurably reduced price volatility during peak periods.
What is the anticipated staffing during construction?
Construction of the Monarch Grid facility is expected to employ approximately 110 workers at peak construction activity. These jobs include a range of skilled trades and construction disciplines. Once construction is complete, the facility will transition to a smaller permanent operations and maintenance team.
Perhaps you guys can pay the property taxes for the homes within a few mile radius of building site while it is in operation. That would change people’s minds.
We appreciate the directness of this suggestion, and we understand the underlying point: residents want to see tangible, direct benefits, not just abstract tax revenue numbers. That is exactly the kind of conversation a host community agreement is designed to address. A host community agreement between Eolian and the local government can include direct community benefits beyond standard property tax revenue, such as community investment funds, infrastructure improvements, or other programs negotiated between Eolian and local officials on behalf of residents. Eolian welcomes that conversation.
How the Project Works
What is PJM, and how does battery storage fit into the grid?
PJM Interconnection is the regional transmission organization that coordinates the movement of wholesale electricity across 13 states and the District of Columbia, including Illinois. PJM ensures that the power grid has enough supply to meet demand at all times by regulating the connection of generating projects to the grid and managing the power markets. Battery energy storage facilities like Monarch Grid participate in the PJM market by storing electricity when there is excess supply on the grid and releasing it when demand is high. This helps balance the grid, reduces the need to run expensive and less efficient power plants during peak demand, and supports overall grid reliability.
We have never had blackouts or brownouts here. Why do we need this?
The fact that McHenry County has enjoyed reliable power is a testament to the existing grid infrastructure, and the goal of projects like Monarch Grid is to help ensure that reliability continues as conditions change. Electricity demand across the PJM region is rising significantly, driven by economic growth, electrification, and new large-scale demand sources. This increasing demand is reflected in rising capacity prices in the PJM market, which is the market signal that additional supply resources are needed. As shown in the webinar presentation, capacity prices have increased substantially in recent years, which means the cost of maintaining grid reliability is going up. In its most recent capacity auction, PJM fell over 5 gigawatts short of its reliability requirement, signaling the strong need to add supply resources in order to maintain the reliability the people in this region have enjoyed. Battery storage is one of the most efficient ways to meet that growing demand and help manage those costs without building new fossil fuel power plants. The point is not that blackouts are happening today, but that proactive investment in grid infrastructure is what ensures they do not happen in the future.
How do the batteries get charged? Who pays for the electricity used to charge them?
The batteries charge by drawing electricity from the grid during periods when supply exceeds demand and prices are low, typically overnight or during mild weather when less energy is being consumed. Eolian purchases this electricity at wholesale market rates through PJM. The batteries then discharge that stored energy back to the grid during peak demand periods. Eolian bears all costs associated with purchasing electricity to charge the batteries. There is no cost to local residents or ratepayers.
What is the markup when you sell energy back to the grid? Who decides the price?
Electricity prices in the PJM wholesale market are set by supply and demand through a competitive market process regulated by the Federal Energy Regulatory Commission (FERC). Eolian does not set the price. When the batteries discharge energy to the grid, that energy is sold at the prevailing market price at that time. The difference between the cost to charge and the revenue from discharging is how the project generates revenue. This market mechanism benefits all consumers by helping to reduce the price spikes that occur during peak demand.
Are the batteries powered by solar panels?
No. Monarch Grid is a standalone battery energy storage project. It charges from the existing electrical grid, not from on-site solar panels or wind turbines. The project connects to the grid through the existing Silver Lake substation.
You say this is a generation source, but you did not create the energy. That does not make sense.
That is a fair point, and the terminology can be confusing. Technically, battery storage is classified as a generation resource in the PJM market because it can deliver electricity to the grid when called upon, just like a power plant, and primarily because it sells capacity, energy and ancillary services in the same power markets as more traditional generation. But it is more accurate to think of it as a grid resource that stores and delivers energy when it is needed most. The energy itself comes from the grid, but the ability to store it and deploy it at the right time provides real value to grid reliability and helps manage costs.
Why doesn’t ComEd build their own battery storage if it is so beneficial?
ComEd is a regulated utility that delivers electricity to homes and businesses. Under Illinois’s deregulated energy market structure, the delivery of electricity (ComEd’s role) is separated from the generation and storage of electricity, which is provided by competitive market participants like Eolian. That said, ComEd has been involved in smaller-scale battery storage pilot projects, including a DOE-funded solar-plus-storage pilot in Rockford and a microgrid project in Chicago’s Bronzeville neighborhood. These are test and research projects, not the type of large-scale, grid-connected storage that the PJM market needs to meet growing demand. The competitive market structure is designed to minimize ratepayer costs through competition and attract private investment in projects like Monarch Grid so that the cost and risk of building new supply resources is borne by private companies, not utility ratepayers.
How long can the batteries hold a charge? What is the self-discharge rate?
Battery energy storage facilities like Monarch Grid are designed to charge and discharge daily as part of normal grid operations. The self-discharge rate of LFP batteries is very low, typically less than 2-3% per month under normal conditions. In practice, the facility operates on a daily cycle, so long-term charge holding is not a primary operational consideration.
How long have LFP batteries been in use?
Lithium iron phosphate battery technology has been in commercial use for over 15 years. It is one of the most well-established and widely deployed battery chemistries in the world, used in electric vehicles, commercial applications, and grid-scale energy storage. The technology is mature and well-understood.
What is the expected lifespan of the facility? What happens when the batteries degrade?
The facility is designed for an operational life of 20 years or more. LFP batteries do degrade gradually over time, similar to any rechargeable battery, but they are designed to maintain effective capacity over their expected service life. As individual battery modules reach the end of their useful life, they can be replaced with new modules without replacing the entire facility. The containers, electrical infrastructure, and grid connection are designed to last well beyond the life of any single set of battery modules. At end of life, the entire facility will be decommissioned and the site restored at Eolian’s expense.
Project Details & Siting
Is the property already purchased?
No, the property is under contract to be purchased.
Is this just a proposal or is the project already moving forward?
The project is in the early development and community engagement phase. It has not yet received any land use approvals or permits. The webinar was part of Eolian’s commitment to engaging with the community early in the process, before formal applications are submitted. No construction can begin without the required local approvals.
Why was this site chosen? Why next to a conservation area, a school, and residential properties?
The site was selected based on several technical and practical factors: proximity to the existing Silver Lake substation (which provides the grid connection necessary for a battery storage facility and which is a critical node in the regional transmission system), the availability of a previously developed commercial/industrial property, and the overall suitability of the site for this type of infrastructure. The project is being designed with significant setbacks, visual screening, and safety systems specifically because of its proximity to residential areas and conservation land. Eolian takes the surrounding context seriously and is designing the project accordingly.
Why not put this in an industrial area instead of in the middle of a residential community?
Battery storage facilities must be located near existing high-voltage electrical infrastructure, specifically substations, because that is where they connect to the grid. The Silver Lake substation is the grid connection point that makes this location viable. Moving the facility to an industrial park that is not near a suitable substation would require building miles of new high-voltage transmission lines, which would create greater impact on the community and landscape than the facility itself.
How far will the fence line be from the road and from neighboring properties?
The current design places the fence line approximately 163 feet from Behan Road and 254 feet from the closest neighboring property.
What type of fencing or wall will surround the facility? How tall is it?
The current site plan includes a visual screening wall designed to minimize the visual impact of the facility on surrounding properties and roadways. The wall height is designed to be a maximum of 26 feet and is designed to screen the battery containers from view and reduce any noise generated from the project site. The screening wall will be a solid material like precast concrete or PVC, which are low-maintenance and resistant to rot, rust, or storm damage, ensuring the community’s investment remains effective for decades. Eolian is open to community input on the design and appearance of the screening and has expressed willingness to work with residents and local officials on landscaping and buffering that fits the character of the area.
What are the noise levels? How loud is the facility at peak operations?
Battery storage facilities generate modest noise primarily from the HVAC cooling systems, similar to commercial air conditioning units. Noise levels at the property line are designed to meet all applicable local noise ordinances. The Illinois Pollution Control Board (IPCB) sets legally binding property-line noise limits (35 Ill. Adm. Code 901) based on land classification to prevent unreasonable interference with life and activities. This is a strict standard that sets limits for the life of the project, to which we must comply. A detailed noise study will be part of the permitting process, but preliminary analysis shows full compliance with the IPCB limits.
How much light pollution will the facility produce at night?
The facility is designed to minimize light pollution. Operational lighting is focused on security and safety requirements, with all lighting designed to be downward-directed and shielded to prevent light spillage onto neighboring properties. The facility does not require the type of continuous high-intensity lighting associated with commercial or industrial operations.
What about vibration impacts on wildlife, pets, and human health?
Battery storage facilities do not produce significant vibration. The primary operational components are static battery containers and HVAC cooling systems, neither of which generates the type of vibration associated with heavy industrial equipment or manufacturing.
Are the houses on the south side of Behan Road being torn down? What about asbestos at 2517 Behan Road?
Yes, the homes within the property boundaries would be torn down and removed. Before physical demolition begins, Monarch Grid must secure a demolition permit and adhere to certain safety and environmental protocols for potential asbestos and hazardous materials, well and septic abandonment, and other site safety and restoration standards.
Why are you purchasing properties under the stormwater management area if no containers are going there? Are you planning to expand?
The properties within the stormwater management area are part of the overall site plan necessary to support the facility’s required stormwater infrastructure. There are no plans to expand the battery storage footprint beyond what has been presented. The stormwater management system is an essential component of the project’s environmental design and is required to meet county and state regulations.
Will there be on-site security to prevent vandalism?
Yes. The facility will include comprehensive security measures including perimeter fencing, 24/7 monitoring and surveillance systems, and controlled access.
Does Eolian plan to build wind turbines or solar installations at this site?
No. Monarch Grid is proposed solely as a battery energy storage facility. There are no plans to build wind turbines or solar panels at this site, nor is the site a suitable location for either of those uses.
Does Eolian have any plans or relationships with data centers?
Monarch Grid is solely a battery energy storage project, and Eolian has no plans, agreements, or involvement with any data center development at this site or in the surrounding area. Eolian does work on energy storage projects in other regions of the country that are located near existing or planned data center developments, as data centers are among the large-scale electricity consumers driving demand for grid infrastructure nationwide. However, Monarch Grid is not associated with any data center project. A reference to data centers in a prior public communication reflected a topic that came up as Eolian was conducting diligence on other development interest in the area, not an Eolian initiative or plan. The sole purpose of this project is battery energy storage.
Is Silbrico Corporation involved in this project?
The specific contractors and suppliers for the project have not yet been selected. That said, we were not familiar with Silbrico Corporation prior to receiving this question and it has been not involved in the Monarch Grid project in any way. Upon doing research into Silbrico, we found they make perlite, which is a volcanic mineral used in products like potting soil, pool filters, and masonry insulation. Perlite has no application in a lithium-ion battery energy storage system. While final contractor and supplier decisions will be made during the detailed engineering and procurement phase, Silbrico would not be under consideration at any point in that process.
Do you buy your batteries from Gotion?
The specific battery supplier for Monarch Grid has not yet been finalized. Eolian evaluates multiple suppliers and selects the battery technology and manufacturer that best meets the project’s safety, performance, and reliability requirements. All battery systems will use lithium iron phosphate (LFP) chemistry.
Is your system better than a flywheel energy storage system?
Flywheel storage and battery storage serve different purposes. Flywheels are well suited for very short-duration applications, providing power for seconds to minutes in order to participate in the frequency regulation market. Battery storage provides longer-duration energy storage, typically 4 hours or more, which is what the grid needs to manage daily demand peaks and ensure reliability over extended periods. For the grid-scale application proposed at Monarch Grid, battery storage is the appropriate technology.
Are there other battery storage facilities already operating in McHenry County?
Yes. McHenry County is already home to multiple operating battery energy storage facilities that have been part of the community without incident. The McHenry Storage Project, a 20 MW battery storage facility originally developed by GlidePath and now owned by Cordelio Power, has been operating in McHenry County since 2015, making it one of the longest-operating battery storage facilities of its size in the country. It connects to the PJM grid through ComEd infrastructure and participates in the frequency regulation and capacity markets. Additionally, the Marengo Battery Storage facility, a separate 20 MW project also located in McHenry County, has been operating since 2018. Both of these facilities use containerized battery systems similar in concept to what is proposed for Monarch Grid, and both have operated safely within their communities in even closer proximity than Monarch Grid will be.
Will there be a person on site at all times for monitoring?
The facility will be monitored 24 hours a day, 7 days a week through sophisticated remote monitoring systems that track every container in real time. On-site personnel schedules will be finalized as part of the operational planning process.
What is the planned density? How many units will be on the proposed site?
The detailed site layout, including the specific number and arrangement of battery containers, is still being finalized as the project works through the local permitting process. The density of the site is dictated by NFPA 855. NFPA 855 requirements apply to the design, construction, installation, commissioning, operation, maintenance, and decommissioning of energy storage systems. The site will deliver 600MW of power to the grid for the life of the project and current design for the site calls for 876 battery containers on site through the life of the project. The final engineering and design of the site will determine the final total number of containers to be located onsite, as this number can vary depending on the specific technology utilized for the site. The final configuration will be part of the site plan submitted for public review during the permitting process, and residents will have an opportunity to review the layout at that time. The site must leave 50% of its acreage permeable to comply with county regulations around the Strategic Aquifer Recharge Area (SARA).
Can lighting be amber color (less glare) or motion-detected?
Eolian appreciates this suggestion and is open to incorporating amber-toned and motion-activated lighting into the facility design where it is consistent with safety and security requirements. Reducing light spillage and glare on neighboring properties is a priority, and these types of design choices are exactly the kind of input we welcome from the community as the site plan is developed.
What are the facility’s hours of operation? How will lighting, noise, and activity impact residents’ livelihood, expected anxiety, and sleep?
The battery storage system operates continuously as part of normal grid operations, charging and discharging in response to grid conditions. However, this is not the type of 24/7 operation associated with industrial manufacturing, trucking, or shift-based labor. There is no regular truck traffic, no outdoor work crews, and no production activity. The primary source of any sound is the cooling system, which operates at modest levels comparable to commercial air conditioning. Dark sky regulations require outdoor lighting to be designed to reduce light pollution, requiring any lighting to be fully shielded and directed downward.
Is it possible to build your facility elsewhere? Galt Airfield in Wonder Lake is for sale, 173 acres.
We appreciate that you took the time to research and suggest an alternative location. Battery storage facilities must be located in close proximity to high-voltage electrical substations because that is where they physically connect to the grid. The Galt Airfield is approximate 10 miles from the nearest transmission line. The Silver Lake substation adjacent to the proposed site is what makes this location technically viable. Relocating to a site that is not near a suitable substation would require constructing miles of new high-voltage transmission infrastructure, which would be both significantly more expensive and more disruptive to the surrounding area than the facility itself. Eolian evaluated multiple potential sites before identifying this location, and proximity to existing grid infrastructure was the primary determining factor.
Community Input & Approval Process
Will this be put up for a vote? Do residents get a say?
The approval process for a project like Monarch Grid is governed by local and state land use and zoning authority. Depending on whether the project is annexed into the Village of Prairie Grove or remains in unincorporated McHenry County, the applicable governing body (the Village Board or the County Board) would review the application through a public process that includes public hearings, opportunities for community comment, and a vote by the elected officials who represent the community. Residents have a direct voice in this process through public comment, participation in hearings, and communication with their elected representatives. In addition, the State of Illinois has established statewide siting standards for energy storage projects under the Clean and Reliable Grid Affordability Act, signed into law in January 2026. These standards set baseline requirements that apply statewide, reflecting the state’s recognition that energy storage is critical infrastructure needed to maintain grid reliability and manage energy costs for all Illinois residents. The local approval process operates within this broader state framework.
If the community does not want this, does that matter? Will you just proceed anyway?
Community input matters to Eolian, and it is also built into the formal approval process. The project cannot be constructed without land use approval from the relevant local government, and that process includes public hearings where community voices are heard. Eolian does not have the ability to override local government decisions. At the same time, energy infrastructure siting in Illinois is governed by both local and state law. The State of Illinois has established statewide siting standards for energy storage facilities that set the framework within which local governments make their decisions. This reflects the state’s determination that energy storage is essential to meeting Illinois’ growing energy needs and managing costs for consumers. Eolian’s goal is to present the project honestly, listen to community concerns, address them where possible, and work constructively within the established approval process.
If Prairie Grove rejects the project, will you just go to the county for approval on unincorporated land?
The project site includes areas that may fall under different jurisdictions, and the appropriate approval process will depend on the specific land use framework that applies. Eolian is engaging constructively with all relevant local government bodies. The company is not seeking to circumvent any community or its elected officials. The goal is to work within the established local and state approval processes, wherever that leads.
Why was the community not told about this project when discussions started in 2021?
Early-stage development activities such as site evaluation, engineering assessments, and initial conversations with local officials are a normal part of the project development process. These preliminary steps occur before a developer has enough information to present a meaningful project proposal to the community. Eolian chose to host this public webinar to share project information and hear community feedback well before submitting any formal applications, specifically to ensure the community is informed and engaged before any decisions are made. As the webinar noted, the period from 2021-2024 was spent primarily waiting for PJM to reform and restart its interconnection process, so the project did not have enough feedback from PJM to warrant approaching the public during that time period.
Who in our community told you that we want you here?
Eolian has not claimed that the community has asked for this project. The project was identified based on technical factors, including the location of existing electrical infrastructure and the needs of the regional power grid. Eolian’s approach is to present the project to the community, listen to concerns, and work through the public approval process. The purpose of the webinar and ongoing outreach is to give residents the information they need to engage in that process.
Does this project require Illinois Commerce Commission or other state approval?
Battery energy storage projects of this type are primarily governed by local land use and zoning authority, operating within the statewide siting standards established by Illinois law. The project connects to the PJM grid through existing infrastructure and is subject to PJM interconnection requirements. The Clean and Reliable Grid Affordability Act, signed into law in January 2026 and taking effect June 1, 2026, establishes statewide standards for energy storage project siting that apply alongside local approvals. Primarily, battery energy storage is governed by a variety of nationally and internationally recognized codes for energy storage systems that are incorporated into Illinois state building code. The main fire and electrical codes are developed by the International Code Council (ICC) and the National Fire Protection Association (NFPA), which work in conjunction with expert organizations to develop standards and regulations through consensus processes approved by the American National Standards Institute.
Below are the most relevant codes that apply to stationary energy storage systems:
- NFPA 1 Fire Code. Covers the hazards of fire and explosion, life safety and property protection, and safety of firefighters.
- International Fire Code (IFC). Similar scope to NFPA 1 contains high-level requirements only, mandating compliance with NFPA 855.
- NFPA 70 National Electrical Code (NEC). Covers practical safeguarding of persons and property from hazards arising from the use of electricity.
- NFPA 855 requirements apply to the design, construction, installation, commissioning, operation, maintenance, and decommissioning of energy storage systems.
Are energy storage systems subject to an Agricultural Impact Mitigation Agreement (AIMA)?
AIMAs are typically associated with solar and wind energy projects on agricultural land and are administered by the Illinois Department of Agriculture. The applicability of an AIMA to a battery energy storage project depends on the specific characteristics of the site and the applicable regulations. Eolian will comply with all state and local requirements applicable to the project.
Does Eolian publish an ESG report?
Eolian does not publish an ESG report, but please visit our website for additional information on the company, its accomplishments and structure.
www.eolianenergy.com
One such accomplishment we are most proud of is our Community Impact Fund. Eolian has invested a total of $2.5 million over the past three years in 44 nonprofit organizations across the U.S., investing $500K in 2023, $1M in 2024, and $1M in 2025.
Our Community Impact Fund is all about backing the local organizations that help communities thrive, especially in the places where we develop and deliver critical energy infrastructure. These partners expand opportunity, strengthen local capacity, and reflect the unique priorities of each community we serve.
The Community Impact Fund has also made additional donations to causes our employees are passionate about, including Nine Lives Foundation, Hope For The Heart, NRDC, BlinkNow, and many others; because community impact starts with personal connection. Our employees volunteered 382 hours and Eolian amplified employee donations by four times for a total of $388,952 in 2025.
Have any formal proposals been made for any McHenry County facilities? If yes, to what entities and when? If not, when do you anticipate submitting a proposal and to what entities?
Eolian has not submitted a formal application for the Monarch Grid project to any governmental body. The project is in the early development and community engagement phase. Eolian anticipates submitting a formal application this summer but the specific approval pathway will depend on whether the project is annexed into the Village of Prairie Grove or remains in unincorporated McHenry County.
Please share the following with the public on your website: (a) A recording of the March 11 Zoom meeting. (b) Copies of any formal presentations made to McHenry County governmental bodies in the past 24 months.
The recording of the March 11 webinar and the presentation materials, as well as the presentation delivered to the Prairie Grove Village Board in December 2025 are all available on the Monarch Grid project website (www.monarch-grid.com).
I noticed all of the Q and A from last night’s webinar were just pre-recorded and you did not answer any of our questions.
To clarify, the questions and answers during the webinar were not pre-recorded. The team addressed as many questions as possible during the live session, but the volume of questions submitted was substantial and not all could be answered in real time, so we attempted to summarize groups of questions that were asking about the same topic. That is exactly why we committed to providing this comprehensive written Q&A document, which addresses every question received during the webinar and in follow-up correspondence. We want every resident to have a thorough response to their concerns, and this document is that commitment.
Will all McHenry County and Prairie Grove ordinances, codes, and standards be followed? Including FPA 855, IFC 2021-24, NFPA, SARA, endangered species acts (IL and Federal), McHenry County UDO, EPA regulations, etc.
Eolian is required by law to fully comply with all applicable federal, state, and local regulations prior to the issuance of its building permit.