EPC Engineering, Procurement and Construction for BESS
Looking for EPC Engineering, Procurement and Construction for BESS and grid connection? Monsson delivers safe, maintainable, bankable EPC solutions—built for harsh climates
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EPC Engineering, Procurement and Construction for BESS
At Monsson, we deliver an advanced Battery Energy Storage System (BESS) solution built for quality, durability, and long-term reliability. Designed for harsh climates—both extremely hot and extremely cold—our systems maintain stable operation by keeping the battery environment tightly controlled.
Unlike typical container-based solutions, Monsson ESS units are housed in custom-built, well-insulated enclosed structures that enable precise temperature management, keeping the batteries consistently in the optimal range (around 20–24°C)—a level of control not easily achieved by standard approaches. Maintaining this stable thermal window over time reduces stress on the cells, helps preserve performance, and significantly supports long-term battery life and reliability.
The system is modular and scalable, with total MW/MWh capacity and the number of block units configured to match each client’s needs. Each block unit includes a thermally insulated battery area, a dedicated ORS (Oxygen Reduction System) room, and a control room, supported by specially developed control software to deliver robust performance for grid services, arbitrage, balancing, and peak shaving.
Performance & Grid Services Capabilities
MONSSON HALL-TYPE STRUCTURES
• It supports continuously deep-discharge operation and the full range of ancillary service categories, including FCR. Monsson system is specifically engineered to perform these services safely and reliably, even under repeated high-stress operating conditions.
• Very high efficiency AC to AC of 89%-90% including internal energy consumption due to well insulated enclosures and innovative low consumption energy of cooling or heating system.
• Very low energy consumption during battery stand-by.
CONTAINERIZED SOLUTION
• The ESS cannot operate continuously.
Many containerized solutions need time to cool down between cycles and cannot participate to all TSO services, as FCR.
• Low overall efficiency due to high cooling/ heating demand during hot summers or cold winters.
• Relatively high energy consumption due to poor container isolation.
Maintenance, Accessibility & OPEX
MONSSON HALL-TYPE STRUCTURES
• Low workload and low cost for scheduled and unscheduled maintenance including the spare parts and logistic.
• High thermal stability and high reliability, easy to operate in all climate conditions.
• The cooling equipment in the primary circuit is strategically designed and located to allow easy cleaning during periods when agricultural work is being carried out
•
24/7 intervention capability, easy maintenance in any season, with full accessibility to all equipment.
CONTAINERIZED SOLUTION
• High volume of works and costs due to larger number of containers and their related equipment.
• Medium-thermal stability, challenging to operate.
• Very limited accessibility for maintenance (cleaning) due to space constraints.
• Limited intervention capabilities, restricted by season, weather conditions and very tight space constraints.
Safety, Monitoring & Fire Protection
MONSSON HALL-TYPE STRUCTURES
Multiple monitoring and alarm systems:
o Detection of toxic gas emissions: CO, CO₂;
o Detection of flammable gas emissions: H₂;
o Smoke, fire and rising temperature trends;
o Measuring continuously of oxygen content in the battery room;
Very efficient and versatile dual fire suppression system with N2, able to maintain the oxygen reduced atmosphere for day in case of hazards
Multiple integrated temperature monitoring systems:
o Battery-integrated system within the Battery Management System (BMS);
o Water outlet temperature sensor for each battery module.
o Thermal camera measurement of battery module
temperatures in all other components inside the battery block.
o Ambient and humidity sensors in each enclosure.
The capacity of maintaining during operation, inside the battery blocks the atmosphere with oxygen concentration of 14.5%, below of the ignition limit.
The Monsson BESS battery blocks are isolated IP66, avoiding humidity and water penetration
The liquid cooling system (intellectual property of Monsson) for the batteries provides thermal stability and precise temperature control for each battery module, along with excellent hydraulic balancing across the battery rows.
All Power Conversion Systems have shelter for sun and
Band weather, reducing the potential exposure at humidity of critical equipment.
CONTAINERIZED SOLUTION
Monitoring and alarm systems are limited due to restricted space.
A single fire suppression system with no redundancy, which cannot keep the fire suppressor flooded longer period of time, extremely important in case of Lithium-Ion batteries.
Limited temperature monitoring systems (only within the BMS).
Containers are only IP54 or IP55, with all potential issues deriving.
Moderate temperature control for both air-cooled and liquid-cooled systems due to low container isolation and resulting in high energy consumption year-round.
Longevity, Degradation & Repowering
MONSSON HALL-TYPE STRUCTURES
Increased repowering capabilities due to the modular design (replacement of only the modules at the end of their lifespan).
Reduced repowering costs.
Long battery lifespan with minimal degradation.
CONTAINERIZED SOLUTION
Very limited repowering capability – battery modules are embedded in racks welded to the container structure.
High repowering costs.
Average battery lifespan with increased degradation, depending on the operating temperature conditions.
Additional Advantages of Monsson BESS solution
Alongside the technical benefits highlighted above, the Monsson hall-type ESS delivers these practical advantages preserving all key conveniences typically associated with standard containerized solutions, ensuring a smooth and familiar implementation experience for the client:
- Standard permitting pathway – follows the typical approval process used for utility-scale ESS projects.
- Familiar installation workflow – deployment and commissioning remain straightforward, with no added complexity.
- Full interoperability with market platforms, SCADA/EMS systems, and standard grid-service applications.
Battery control, lifetime strategy, and superior thermal management
The BESS integrates an advanced Battery Management System (BMS) that collects and consolidates information from all String Management Units (SMUs). By continuously monitoring the critical parameters—voltage, temperature, and current—the BMS ensures optimal operation of the battery modules in each rack and instantly activates internal and external protection and safety systems whenever required.
To maximize long-term value, the Energy Storage System is sized using a declining-capacity strategy: the battery capacity is dimensioned for beginning-of-life, then managed throughout the BESS lifetime in line with real annual usage. This approach supports flexible operation while maintaining predictable performance over time.
On top of the BMS, the Monsson Energy Management System (MEMS) continuously monitors the key drivers that define battery performance and lifetime: energy throughput, average state-of-charge across multiple time domains, C-rate, temperature, and calendar life. MEMS also compares the planned capacity trend with the actual measured capacity, validated through an annual capacity check, enabling proactive optimization and transparent lifecycle tracking.
Where Monsson clearly differentiates is our battery cooling system—Monsson intellectual property—engineered to protect the cells and preserve performance year after year. The Primary Cooling Circuit (PCC) includes a chiller unit, heat pump, dry cooler, and heat exchange system, each with dedicated piping, pumps, monitoring, and safety systems, ensuring optimal battery temperature regardless of ambient conditions or load. The Secondary Cooling Circuit (SCC) uses special frequency-controlled pumps, comprehensive flow/temperature/pressure sensing, and a dedicated cooling network to each rack and module, complete with expansion and safety components.
The entire cooling system is fully automated via PLC control, with continuous adjustment of both circuits. Any deviation in temperature, pressure, or flow is immediately transmitted to the dispatch center through SCADA, using multiple alarm levels for rapid response. Most importantly, the ESS automation logic is focused on maintaining battery temperature in a tight optimal window around ~22°C, preventing temperature rise during normal operation and significantly reducing battery wear—one of the key reasons Monsson systems deliver superior durability and reliability in the long term.
Our BESS uses an advanced BMS collecting data from all SMUs to optimize each rack and activate protection systems in real time. MEMS continuously monitors the parameters that drive battery lifetime (throughput, SOC, C-rate, temperature, calendar life) and verifies actual capacity via an annual capacity check, while sizing follows a declining-life strategy aligned with real usage.
Monsson’s proprietary cooling architecture (primary + secondary circuits) is fully automated (PLC) and monitored via SCADA to maintain battery temperature in a narrow window around ~22°C, significantly reducing degradation over time.
Advanced Control & ~22°C Thermal Management
The BESS includes a high-performance BMS that aggregates data from all SMUs, monitors voltage/current/temperature, and triggers protection and safety systems instantly. Capacity is sized for beginning-of-life and managed through a declining-life strategy based on real annual operation.
The MEMS tracks the key lifetime indicators (throughput, SOC, C-rate, temperature, calendar life) and confirms actual capacity via an annual check. Monsson’s edge is our proprietary, fully automated cooling system, designed to keep batteries around ~22°C and preserve performance for the long run.
Battery Safety,Monitoring & Grid-Ready Control
Monsson ESS is built with a multi-layer safety architecture and best-in-class monitoring. Battery temperature is supervised through four independent systems: cell-level BMS sensing, module cooling outlet sensors, bi-spectral thermal CCTV monitoring every module/cable/cabinet with automatic alarms, plus ambient room temperature and dew point measurement and control.
For early hazard detection, each battery room includes gas, smoke and fire monitoring, tracking CO, CO₂, H₂ and smoke, supported by state-of-the-art detection and alarm systems compliant with applicable regulations. Fire protection is designed with redundancy: ORS (Oxygen Reduction System) continuously inerts the room with nitrogen to keep oxygen around ~14.5%, preventing combustion, while a dedicated nitrogen flooding suppression system can maintain safe inert conditions for extended periods if required. Mobile 50 kg extinguishers and G5 extinguishers for electrical installations are positioned at entrances for additional response capability.
The Power Conversion System (PCS) is delivered as a compact, customizable MV-ready skid integrating bi-directional inverters, MV step-up transformer, MV switchgear and all related components—factory-wired and tested, pre-assembled for fast site connection, and protected by a dedicated shelter to reduce humidity impact.
Each inverter is individually controllable via SCADA, and the skid MV switchgear interfaces directly with the connection point/substation MV switchgear.
The solution is fully SCADA-enabled: BMS control (battery functionality + PCS coordination), plant-level ESS EMS control, and grid-connection SCADA (TSO/DSO dependent).
Monsson also offers MEMS (optional) for advanced commercial operation and performance/lifetime optimization—Monsson intellectual property.
OPTIONAL SERVICES
At the specific request of the Client, Monsson can provide the following services:
1. Development, Asset Management & Off-take of Electricity based on Tolling Agreements
• Wind, PV and ESS Development Service
• 3-10 years Tolling agreement for off-taking the BESS electricity
• Commercial Operation Services for ESS
• Grid Solution Studies
• EPC for transformer stations and grid connection stations including Electrical Design up to 400KV
• Grid Connection support services
• Conformity test for commission for RES and ESS
• TSO Ancillary service qualification tests
2. O&M Service
• Up to 10 years LTSA Technical Operation Services for ESS with backed warranty
• Authorized dispatching services according to ANRE, RED and RET legislation and remote monitoring services
• Engineering and health check services for RES Assets
• Degradation reporting tool (SOH trending)
3. Training & Education
• Training in BESS Operation
• GWO & Solar Europe International Trainings
• Local Skills & reskilling Trainings
• Digital Learning & Mobile Training Centers
4. Software & Digitalization
• Energy management system (EMS) software
• Electricity trading software for BESS applications
• Digitalization for RES Assets & Integration
• Software for BMS, ESS, Third party ESS
• On-demand software
Utility-Scale BESS Performance Guarantees
Monsson provides bankable performance guarantees for utility-scale Battery Energy Storage Systems (BESS), supporting financing, predictable revenues, and compliant grid operation. Our guarantee structure covers the key metrics that matter in real projects: availability, usable energy over time, efficiency, power delivery, thermal stability, safety performance, and SCADA/communications reliability.
Availability guarantee
High BESS availability for commercial operation, with standard exclusions such as scheduled maintenance, grid-side outages/curtailments, force majeure, owner-caused outages, and TSO/DSO communication or control issues.
Capacity retention guarantee
Guaranteed usable energy over time, aligned with the battery module supplier specification and the agreed operating envelope (cycling intensity and depth-of-discharge limits).
Capacity test methodology
Capacity verification under clearly defined test conditions (ambient environment, charge/discharge rate, state-of-charge window, and measurement accuracy) for consistent and transparent results.
Response and incident management SLA
Structured remote alarm acknowledgement and escalation based on event severity, ensuring fast intervention and stable operations.
Round-trip efficiency guarantee
Guaranteed minimum AC-to-AC efficiency at medium voltage, enabling strong economics for arbitrage, balancing, and grid services.
Power capability and grid services guarantee
Rated charge/discharge capability, fast active-power response, and AC output quality compliant with local grid code requirements, with support for frequency response and ancillary services where requested..
Thermal performance guarantee
Battery temperature maintained within a tightly controlled operating range to reduce degradation and protect long-term performance.
State-of-the-art fire detection, continuous fire prevention via inerted battery-room atmosphere during operation, and inert-gas suppression designed to maintain safe conditions until the event is fully neutralized.
SCADA and communications reliability guarantee
High data availability and accurate telemetry to the grid operator, with cybersecurity maintenance and updates, excluding external factors outside the system’s control.
Talk to Our EPC Team
If you are planning a utility-scale BESS or a hybrid renewable-plus-storage project, Monsson can deliver a complete EPC (Engineering, Procurement and Construction) solution—from design and procurement to construction, commissioning, and long-term support.
Contact us to discuss EPC scope, grid connection strategy, guarantees structure, and project delivery schedule:
Email: office@monsson.eu
Phone: +40 241 550 353
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