The wrong storage system doesn’t just burn — it costs you returns, uptime and trust.
Together with our specialized battery analytics partner, we qualify every manufacturer before the tender—with a 6-stage testing process. No system without complete certification evidence. No contract without a trial operation.
all addressable preventatively
IEC 62619 · UL 9540A · VDE-AR-N 4110
state-of-charge estimation*
20 years of grid fee exemption
Check system selection — Get an assessment of your manufacturer documents in 30 minutes →
BESS is no longer a question of if. It's a question of when.
BESS stands for Battery Energy Storage System — a stationary facility for electrical storage. Safety, fire protection, and certification are central requirements for planning and operation.
Most providers sell either hardware or electricity. CUBE CONCEPTS builds the system behind it.
„Lithium burns – we don't want any risk on the premises.” This objection is valid. But it's misdirected. BESS fires are not an incalculable fate. In the overwhelming majority of cases, they are the result of decisions made months before commissioning: in component selection, supplier qualification, and contractual agreements.
Those who only address the risk in the fire suppression concept are too late. Those who address it in the tender are in control. This is doubly true for co-location setups with PV: fire and heat barriers for BESS containers and PV inverters must be dimensioned on the same foundation — otherwise a local defect will propagate throughout the entire system.
- Up to −17 % return due to coarse state-of-charge estimation in LFP storage systems*
- If modules cannot be switched off, the total failure of a single module paralyzes the entire storage system
- Warranty conditions that are tied to manufacturer specifications are effectively worthless.
- Certification gaps = Exclusion from balancing energy prequalification
- Full certification documents for FCR, aFRR, and §118 operation
- State-of-charge determination < 5 % Inaccuracy — Yield remains stable over the entire term
- Warranty conditions anchored independently of manufacturer specifications
- 1 month trial period before acceptance — production defects claimable under warranty
* Battery Analytics partner based in Dresden, analysis covering 2014–2025. Refers to LFP batteries with coarse state-of-charge (SoC) estimation (SoC error > 5 %).
Why Battery Storage Catches Fire — and What That Has to Do With Your Tender
Thermal runaway is an uncontrolled chain reaction: a cell overheats, releasing energy that triggers neighboring cells - thermal propagation. What's special about BESS fires: oxygen is produced by the decomposition of the cathode material directly within the fire. This makes it difficult to interrupt the classic fire triangle from the outside.
The most common causes are documented—and all addressable during the planning and selection phase:
Source: CUBE CONCEPTS BESS-Webinar 2.0 — Battery Fires: Causes of Fire and Failure. Recording in the knowledge area
What does a BESS fire really cost in an industrial operation?
Safety risks don't only affect the storage system. They affect buildings, people, operations — and the bottom line.
| Damage dimension | Concrete consequences |
|---|---|
| Direct damages | Total loss of containers and racks · Toxic contamination (HF, CO) · Site closure · Damage to neighboring facilities (PV, buildings) |
| Operational consequences | Storage failure → Loss of all FTM revenues · Consumption peaks without buffer → Demand charges rise back to initial level · Operating interruption and repair costs |
| Regulatory consequences | Liability and insurance disputes · Loss of reputation with customers and authorities · Regulatory audits · Delays in approval for follow-up projects |
| §118 loss in the event of failure | Anyone who misses the commissioning date due to damage forfeits the 20-year grid fee exemption. §118 para. 6 EnWG is not retroactive and cannot be postponed. |
A fire suppression concept reduces damage. Thorough supplier qualification prevents the fire. Both are necessary — but only one determines the project's return. Have manufacturer documents reviewed →
What certifications must an industrial battery storage system have – and why?
Certifications are not a formality. They are the only solid basis for guarantees, insurability, and balancing energy prequalification. A storage system without complete proof is not approved for FCR and aFRR — and thus disqualified for any FTM use. mFRR as a supplementary channel requires the same proof.
| Norm | What it checks | Why it is mandatory |
|---|---|---|
| IEC 62619 | General safety testing for stationary Li-ion applications | Basic standard — without it, no operating permit in Germany |
| IEC 62620 | Performance and lifetime tests, aging behavior | Basis for LCOS calculation and degradation planning |
| UN 38.3 | Transport safety — mechanical, thermal, electrical load capacity | Mandatory for Delivery and Replacement of Cells and Modules |
| UL 1973 | Safety Standard and Stress Testing for Stationary Systems | Requirement of many industrial insurers |
| UL 9540A | System Safety — System-Level Thermal Runaway Propagation Test | Requirement for balancing energy prequalification and §118 approval |
| EU Battery Regulation 2023/1542 | EU-wide product requirements, carbon footprint, supply chain | Mandatory for all storage systems on the European market |
| VDE-AR-N 4110:2023 | Application Rule Medium-Voltage Connection — Technical Connection Conditions | Mandatory for every BESS connection to the medium-voltage grid in Germany |
Data sheets for cells, modules, and containers must be consistent. Aging curves must be substantiated with test conditions—not just manufacturer specifications. Known fires involving specific cell types can be researched publicly. As part of our partnership, this check will be performed for every project. Request document audit
How should a thorough supplier qualification process be structured?
The more thorough the supplier qualification, the better the subsequent return. This is not a rule of thumb – it is the core of ten years of battery analytics experience from our partner, NOVUM engineering from Dresden. Together, we apply this process to every CUBE project.
Especially with LFP batteries, manufacturers' State of Charge (SoC) estimations are often inaccurate. The result: the battery can offer less power on the market after a short time than originally planned — because the system operates conservatively to avoid overcharging. For a 1 MW battery, this means measurably less FCR and aFRR revenue over its entire operating life. Request for evaluation of your manufacturer data
* CUBE CONCEPTS battery analytics partner (founded 2014, Dresden): 9.7 GWh under contract, 11,246 battery fires prevented.
What to do when prevention is not enough?
The basic principle for BESS fires is: prevent thermal runaway — limit propagation — do not extinguish at all costs. BESS fires are difficult to fight due to self-ignition, toxic gases, and contaminated extinguishing water.
- Automatic Fire and Gas Detection (Smoke, CO, H₂, Temperature)
- Water, gas, and/or aerosol extinguishing systems
- Automatic venting and pressure relief devices
- Automatic and mechanical emergency shutdowns
- Containment basins and fire water treatment
- Fire protection concept according to state building code and Ordinance on Industrial Safety and Health
- Risk assessments for construction, operation, maintenance, and emergencies
- Operational plans for the plant fire department documented and practiced
- Operating instructions and emergency plan documented in writing
Sufficient distance to the building, cooling in case of fire spread, and protection of neighboring plant components are planning topics – not emergency topics. CUBE CONCEPTS handles the fire protection concept as part of full-service project management.
Stationary battery storage systems are classified as „of overriding public interest” according to §11c EnWG. This speeds up approvals and strengthens the position in location and connection issues. In conjunction with §35 BauGB (outdoor privilege since January 1, 2026), clear planning and building law frameworks are created for industrial operations from 1 MW.
The CUBE CONCEPTS BESS Webinar 2.0 covers fire suppression concepts, extinguishing agent selection, and fire propagation in detail, including practical case studies. Recordings and documents in the knowledge area
What risks does BESS safety affect at your decision-making level?
A BESS fire means production downtime, site shutdown, and liability risks. CUBE CONCEPTS handles all maintenance and ongoing monitoring—no disruption to production, no internal effort required. The CUBE EfficiencyUnit continuously monitors operational data.
Peak Shaving and Production StabilityThermal runaway prevention begins with documented risk assessments, certified components, and a comprehensive fire protection concept. CUBE CONCEPTS provides the safety documentation as part of every project — audit-proof and CSRD-compatible.
ESG Benefits and CO₂ ReportingA faulty storage system not only incurs repair costs. It costs FTM revenues, the §118 deadline, and in the worst case, the insurability of the site. An auditable decision-making basis protects you – before signing, not after.
Open-book
„Did you ever see all the numbers before signing the contract?”
Our open-book pricing is not a bargaining chip—it is the foundation on which a true partnership is built. Every assumption, every line item, every revenue stream: transparent. CUBE retains 75% of net market revenue after OPEX, and the customer retains 25%—with no upfront investment required.
Open-book means transparency within the business relationship — no public disclosure of project data.
Realized Projects with Industrial Companies
currently under construction
Industrial companies with strict IFRS and governance requirements choose this model. Anonymized project example: Industrial supplier, 2 MW / 4 MWh, §118 exemption secured, commissioning Q4 2024.
Check system selection — get an assessment of your manufacturer documents in 30 minutes
You will receive an initial, solid assessment: What certification gaps exist? Which contract clauses do not protect you? Where is the greatest return risk? Free of charge, no commitment.
Check system selection — 30 minutes, free →§118 para. 6 EnWG — commissioning deadline: August 4, 2029 · Planning takes 12–18 months · Not retroactive
§118 Planning Lead Time — Calculate Realistically
Existing grid connection: 6–12 months lead time to commissioning. New grid connection: on average 40 months — August 4, 2029 is closer than it seems.
Further Topics at a Glance
BESS Safety FAQs — in the language they are asked
Thermal runaway is an uncontrolled exothermic chain reaction in lithium-ion cells, where released heat triggers further cells. In BESS fires, oxygen is generated by cathode material decomposition internally, making firefighting operations particularly difficult and external extinguishing agents often ineffective against the actual cause.
Mandatory requirements in Germany: IEC 62619 (general safety), IEC 62620 (performance and lifetime), UN 38.3 (transport), UL 1973 (stress testing), UL 9540A (system safety), EU Battery Regulation 2023/1542, and VDE-AR-N 4110:2023 for medium-voltage connection. Missing certifications are grounds for exclusion from balancing energy prequalification and the §118 permit.
Rough estimates of the state of charge for LFP batteries can reduce returns by up to 17%—simply because the capacity is less marketable on the balancing energy market. This is determined during the supplier selection process, not during operation. Rules of thumb: State-of-charge determination with less than 5% inaccuracy, balancing within 10 hours for a 1% charge difference.
Warranty conditions based on manufacturer specifications (SoH, SoC from the storage BMS) are effectively worthless; only the manufacturer collects and provides these values. Meaningful warranties are tied to independently measurable cell parameters. Acceptance only after a one-month trial period provides the opportunity to claim manufacturing defects while still under warranty.
Direct damages: Total loss of container, toxic contamination (HF, CO), site shutdown. Operational consequences: Storage failure, consumption peaks without buffer, higher demand charges. Further consequences: Liability disputes, loss of image, approval delays. And: whoever misses the §118 commissioning deadline due to damage permanently loses the 20-year grid fee exemption.
The BMS (Battery Management System) monitors cells and modules at the cell level—voltage, current, and temperature. The EMS (Energy Management System)—at CUBE CONCEPTS: CUBE EfficiencyUnit—coordinates all power sources and loads at the site and controls operations across all use cases. For safety monitoring, you need cell-level data at the EMS level, not just aggregated BMS data.
One month of trial operation allows for an independent safety check: production defects are identified right at the beginning and can still be claimed under warranty. Without trial operation, the operator bears the risk of hidden manufacturing defects—which often only appear after weeks, but are then outside of the warranty period.
Yes — it should be possible to disconnect a defective module without taking the entire system out of operation. Systems without this functionality experience total failures due to individual cell problems: no FTM operation, no §19 atypical grid usage, no peak shaving effect — and thus direct revenue loss and uncapped demand charges.
For prequalification in the balancing energy market, complete certification evidence is a prerequisite. Missing UL 9540A or IEC certificates will lead to direct rejection by the transmission system operator—without exception. This examination is carried out for each project as part of our partnership with specialized battery analytics experts.
Besides direct repair costs, operational downtime means the loss of all FTM revenues, a return to uncapped demand charges, and potential liability claims. For a 1 MW storage system with §118 exemption, a multi-month outage results in five- to six-figure damages—in addition to all repair costs.