Battery Storage Glossary: 58 Technical Terms That Will Shape Every Decision
From AgNes to §118: Definitions for Ancillary Services, Grid Fees, Economic Efficiency, and Regulation — in Industrial and Commercial Use. With Legal Basis and Sources.
Which BESS terms are most relevant for industrial companies?
This glossary includes 30 core terms from the fields of battery storage technology, grid balancing power, grid fee optimization, and regulatory affairs. All definitions are tailored for industrial and commercial applications of 750 kW and above.
BESS decisions are made in industrial companies by decision-makers who often do not have an energy technology background – CFOs, investment managers, energy purchasers, operations managers. At the same time, the relevant terms are often technically overloaded or used inconsistently: FCR and aFRR are confused, §19 S.1 and S.2 are treated as a single regulation, MiSPeL is mistakenly classified as a grid surcharge instrument. This glossary focuses on precision – for people making investment decisions, not for energy specialists.
All definitions follow a uniform format: Term, definition in one sentence, explanation, and source citation. Terms that are regulatorily critical (§19 S.1 vs. S.2, BK4-22-089, AgNes) include an explicit reference to common confusions or misunderstandings.
Why is precise terminology crucial in BESS projects?
Errors in terminology lead to wrong decisions. A company that confuses §19 S.1 and S.2 plans on the wrong application basis. A company that considers MiSPeL a network fee instrument calculates savings that do not exist. A company that uses BK4-22-089 as an argument against §19 S.2 waives an instrument that remains valid until December 31, 2028.
The market for BESS consulting is opaque in 2025. Many providers use terms loosely to make products appear more attractive. This glossary is based exclusively on public legal sources, BNetzA procedures, and independent market reports—not on manufacturer representations. Those who decide based on precise terms decide better.
§
20-year grid fee exemption for battery storage systems commissioned by August 4, 2029. Not retroactively claimable. Not extendable. Strongest long-term individual lever in BESS economic calculations.
Empowers grid operators to implement time-variable grid fees for controllable loads (including battery storage systems). In effect since April 1, 2025. BESS with EMS connectivity can respond to grid signals and benefit from reduced grid fees during off-peak times.
Source: §14a EnWG (as of April 1, 2025)
Grid fee discount for companies with proven atypical grid usage. Condition: Falling below the grid average in all 15 peak load time windows (HLZ). Valid until December 31, 2028. Exclusively applies to Sentence 1 — not Sentence 2 (which was reformed by BK4-22-089). Independently applicable.
A
Automatic Frequency Recovery Reserve. Secondary Control Power. Battery storage must provide full power within 30 seconds. Strongest FTM revenue stream for industrial storage 2025.
Incentives for grid congestion management. BNetzA proceeding BGK-25-01-1#3. Successor regulation to Section 19(2) of the Electricity Network Charges Ordinance (StromNEV) effective January 1, 2029. Introduces dynamic, load-profile-based grid charge signals.
Source: BNetzA BGK-25-01-1#3
The period required to fully recoup the investment costs from ongoing revenue. For BESS purchases in multi-use operations: typically 2–4 years (KPMG AG, Feb. 2026, for 1 MW). Applies exclusively to the purchase model—not to Contracting models without equity investment.
Source: KPMG Investment Case Feb. 2026
Network charge reduction according to § 19 Para. 2 Sentence 1 StromNEV for companies whose consumption in the local grid operator's 15 peak load time windows (HLZ) is demonstrably below the network average. Valid until December 31, 2028.
B
Battery Energy Storage System. Stationary system for electrochemical energy storage. In an industrial context, from 750 kW / 1,500 kWh. CUBE CONCEPTS entry-level size.
Source: IEC 62933
Balancing deviations between forecasted and actual energy consumption within one's own balancing group. Battery storage buffers forecast deviations and avoids balancing energy costs.
Source: § 8 StromNZV
BNetzA Decision on the Calculation Methodology according to §19 Paragraph 2 Sentence 2 StromNEV (Bandlast). Exclusively concerns §19 Paragraph 2 Sentence 2 - not §19 Paragraph 2 Sentence 1 (Atypical Grid Usage). Expired December 31, 2025.
Source: Raue Rechtsanwälte, Dec. 2025 BNetzA BK4-22-089
Operational Dimension of the Battery Storage System in the Company's Internal Grid. BTM Applications: Peak Shaving, §19 Atypical Grid Usage, §118 Grid Fee Exemption, Self-Consumption Optimization.
Source: §19 Paragraph 2 Sentence 1 of the StromNEV · §118 para. 6 of the Energy Industry Act
C
Capital Expenditure. One-time investment costs: BESS hardware, grid connection, planning, installation, commissioning, CUBE EfficiencyUnit, prequalification. Under the CPFS model: CUBE CONCEPTS bears all CAPEX costs until ownership is transferred.
Source: CUBE CONCEPTS Project Experience
BESS operating model without own investment: CUBE CONCEPTS invests, operates, and markets — the site operator pays a usage fee from the agreed revenue share (CPFS structure). Distinction from purchase: no balance sheet asset, no CAPEX risk, shorter decision-making processes. Open-book terms and conditions before contract conclusion.
Source: CUBE CONCEPTS GmbH · Contracting Framework Agreement
CUBE Profit Flex Solution. Standalone BESS operating model: €0 CAPEX, full FTM market operation by CUBE CONCEPTS until ownership is transferred. Open-book, IFRS-compliant, off-balance-sheet option available. No Contracting.
Source: CUBE CONCEPTS GmbH
Charge or discharge rate of a battery storage system relative to its nominal capacity. 1C = full charge/discharge in 1 hour; 0.5C in 2 hours. Crucial for marketability: FCR requires 1C systems (1h discharge), aFRR requires 0.5C systems (2h discharge). The C-rate determines which ancillary service markets are accessible – and thus the revenue mix.
Source: regelleistung.net
Corporate Sustainability Reporting Directive. EU directive on mandatory sustainability reporting according to ESRS standards (from 2025). Battery storage systems provide auditable data points for ESRS E1 (Climate Change) - measurable Scope 2 reduction through self-consumption and renewable energy integration. CUBE CONCEPTS' monthly open-book reporting delivers CSRD-ready data as standard.
Source: EU Directive 2022/2464 · ESRS E1
CUBE CONCEPTS Analysis Tool. Calculates 250+ operating variants based on load profile data and determines optimal storage technology, capacity, and performance.
Source: CUBE CONCEPTS GmbH
CUBE CONCEPTS Control and Marketing Infrastructure for Battery Storage. Coordinates FTM marketing (FCR, aFRR, mFRR, Arbitrage) and BTM applications (Peak Shaving, §19, §118) in real-time. Multi-use operation.
Source: CUBE CONCEPTS GmbH
D
Capacity loss of a battery storage system over its operational lifetime. LFP technology: typically 2.1% capacity loss per year (KPMG AG, Feb. 2026).
Source: KPMG Investment Case Feb. 2026
Aggregates multiple BESS (Battery Energy Storage System) facilities < 1 MW into a virtual power plant and markets them jointly in ancillary services markets (pooling). Enables FTM (Fast Turnaround Market) revenues (FCR, aFRR, mFRR, arbitrage) even below the 1 MW direct access threshold. Minimum size for pooling participation: 750 kW.
Source: regelleistung.net · § 5 Electricity Grid Fee Ordinance
E
BESS Strategy: Self-generated PV electricity is temporarily stored in a battery and used later for self-consumption – instead of being fed into the grid. Reduces electricity consumption (energy price) and increases the PV self-consumption rate. MiSPeL (from mid-2026) enables simultaneous self-consumption and FTM marketing without loss of EEG remuneration.
Source: §15 EEG 2023 · BNetzA MiSPeL Determination
Control system that coordinates the battery storage system’s charging and discharging cycles in real time. Optimizes the BTM/FTM split daily: peak shaving dispatch, §19 atypical usage verification, FTM bid submission (FCR, aFRR, mFRR, arbitrage), and self-consumption simultaneously. CUBE EfficiencyUnit is CUBE’s proprietary EMS—the control infrastructure for multi-use operation.
Source: CUBE CONCEPTS GmbH
F
Frequency Containment Reserve. Primary Control Power. Battery storage systems react within seconds to frequency deviations in the European grid (±200 mHz). Hourly auctions on regelleistung.net.
Source: regelleistung.net
Operational dimension of battery storage in the wholesale market. FTM revenues: FCR, aFRR, mFRR, spot market arbitrage. Runs independently of company operations.
G
All investment costs for a BESS facility: Hardware (battery modules, inverters, containers), grid connection, planning, permitting, installation, commissioning, EMS, pre-qualification. Benchmark: ~€250/kWh (KPMG AG, Feb. 2026, LFP system). Initial investment cost (GIK) is the basis for the LCOS calculation and the payback calculation for purchases. For the CPFS model: CUBE CONCEPTS fully bears the initial investment cost (GIK).
Source: KPMG Investment Case Feb. 2026
H
The 15 time points per year at which the local network operator records its annual peak load. Basis for atypical network usage according to §19 Para. 2 Sentence 1 StromNEV. Battery storage systems discharge specifically during peak load times.
I
Formal time of the first grid-parallel operation of a plant. Relevant for §118 para. 6 EnWG: commissioning by August 4, 2029 secures a 20-year grid fee exemption.
Stationary battery storage for industrial and commercial use. CUBE CONCEPTS entry-level size: from 750 kW / 1,500 kWh. Typical project sizes in the CUBE portfolio: 1–10 MW.
Source: CUBE CONCEPTS Project Experience
Temporary electricity price relief for energy-intensive companies on the KUEBLL list (2026–2028). Target price: approx. 5 ct/kWh on 50% of consumption. Obligation to provide consideration: at least 50% of the aid must be reinvested in decarbonization or flexibility measures (48 months). Battery storage explicitly recognized (CISAF para. 121). Flexibility bonus: +10% for ≥80% reinvestment. → Page: Industrial electricity price
Source: Draft BMWE Funding Guidelines, Jan. 2026 · CISAF Para. 121 · BAFA (Implementing Authority)
Internal Rate of Return (IRR) — the discount rate at which the net present value of the investment equals zero. In practical terms: the return on investment as a percentage. For a BESS purchase in a multi-use facility: 10.5% IRR (KPMG AG, Feb. 2026, based on 1 MW / 40 MWh). Benchmark for investment decisions: higher than typical industrial investments with a 2–4 year payback period.
Source: KPMG Investment Case Feb. 2026
K
Option held by the site owner, enshrined in the CPFS contract, to acquire the BESS facility after market operation by CUBE CONCEPTS under previously agreed terms. Secures full control of the facility at a defined point in time without initial capital risk. The purchase option is explicitly recognized as ISP consideration (CISAF para. 121).
Source: CUBE CONCEPTS GmbH · CISAF No. 121
L
15-minute interval measurement data of the electrical consumption of a plant from the RLM meter. Basis for every BESS dimensioning and profitability analysis: identify load peaks (peak shaving potential), check §19 qualification (high-load behavior), calculate FTM revenue potential, optimize storage capacity. A load profile of 12 months is sufficient for a complete analysis.
Source: § 40 MessZV CUBE CONCEPTS GmbH
Levelized Cost of Storage. Total cost per kWh stored over the system’s lifetime, including CAPEX, OPEX, and degradation. Key benchmark for storage technologies. LFP reference value: €110/MWh (KPMG AG, Feb. 2026, 10 MW / 40 MWh / WACC 6% / 2 cycles/day).
Source: KPMG Investment Case Feb. 2026
Component of the grid fee according to §17 StromNEV. Calculated based on the annual peak load point – the highest 15-minute average value of the entire year. This one value determines the capacity price for the following 12 months. Peak shaving with BESS cuts precisely this peak and thus permanently lowers the capacity price – regardless of §19.
Source: §17 Electricity Ordinance
Lithium iron phosphate. Currently the most cost-effective technology after LCOS for stationary industrial storage. Advantages: high cycle life (~4,000–6,000 cycles), low degradation (2.1 % capacity loss per year, KPMG AG Feb. 2026), thermal stability, no reliance on cobalt.
Source: KPMG Investment Case Feb. 2026
M
Manual Frequency Restoration Reserve. Tertiary control reserve. Reaction time: full activation within 12.5 minutes (manual activation by TSO). For battery storage, secondary compared to FCR and aFRR - supplementary in certain market situations.
Source: regelleistung.net
Market integration of stationary storage. BNetzA regulation on EEG support and FTM market integration. From mid-2026: simultaneous BTM and FTM operation for EEG plants without EEG remuneration loss. No §19 grid surcharge instrument.
Source: BNetzA MiSPeL Specification
Simultaneous operation of FTM marketing and BTM applications using the same battery storage system. CUBE EfficiencyUnit coordinates both aspects in real time. No capacity goes unused.
Source: CUBE CONCEPTS GmbH
N
Connection point between a facility and the public power grid. The available grid connection capacity determines the maximum installable BESS capacity. From ≥ 1 MW: direct FTM market access (FCR, aFRR, mFRR). From 750 kW: pooling through a direct marketer is possible. Grid connection capacity is the most important site-specific planning parameter – it determines the entire business case.
Source: regelleistung.net · § 5 EnWG
Fee for the use of the power grid. Accounts for approximately 40% of the industrial electricity price (BMWE, August 2025). It consists of a time-of-use component, a capacity component (annual peak load point), and other surcharges.
Source: BMWE, August 2025 §17 Electricity Ordinance
Alternative lithium-ion technology: higher energy density than LFP, but higher thermal risk (fire hazard during overcharging), higher degradation, and cobalt dependency in the supply chain. Largely displaced by LFP in the commercial and industrial (C&I) storage market by 2026. CUBE CONCEPTS recommends LFP for multi-use battery energy storage systems (BESS) in industrial applications due to superior cycle life and thermal stability.
Source: KPMG Investment Case Feb. 2026
O
Balance sheet structuring where the asset does not appear as a liability—no impact on equity ratio, credit lines, or rating. Relevant for companies with active bank financing or IFRS reporting obligations. Possible with the CPFS model; prerequisite: IFRS 16 compliant contract structure.
Source: IFRS 16
Governance Principle in the CPFS Model: All revenue and cost items are fully visible before contract signing — no information asymmetry between CUBE CONCEPTS and the site owner. Basis for an auditable, IFRS-compliant accounting structure. Not: public price disclosure.
Source: CUBE CONCEPTS GmbH
Operating Expenditure. Running operating costs: Maintenance, monitoring, market connection, insurance, reporting. In the CPFS model: CUBE CONCEPTS bears all OPEX until ownership transfer.
Source: CUBE CONCEPTS Project Experience
P
Peak load capping in the industrial grid connection. Reduces the annual power component of the grid fee (§17 StromNEV), which is calculated at the highest annual load point.
Source: §17 Electricity Ordinance
Aggregation of multiple BESS units < 1 MW into a virtual power plant, jointly participating in ancillary services markets. Coordinated by a direct marketer. Minimum size: 750 kW. Pooling enables FTM revenues (FCR, aFRR, mFRR, spot arbitrage) even for smaller sites – without direct access to the ancillary services market.
Source: regelleistung.net CUBE CONCEPTS GmbH
Formal admission by the transmission system operator (TSO) for participation in ancillary services markets. Requirements: Minimum capacity of 1 MW, response times, smart meter for active energy measurement, proof of availability.
Revenue-sharing model under the CPFS model: As a site owner, you receive 25% of the net market proceeds—after deducting all OPEX (operations, marketing, IT)—with no upfront investment and no operating expenses. CUBE CONCEPTS receives 75% and covers all investment and operating costs.
Source: CUBE CONCEPTS GmbH · Related terms: Open-Book, CPFS, OPEX
R
General term for system services for frequency maintaining in the European interconnected network (target frequency: 50 Hz). Includes FCR (primary, seconds), aFRR (secondary, 30 seconds), and mFRR (tertiary, 12.5 minutes). Battery storage systems are particularly suitable due to their millisecond response time and flexibility. Tendered by the four German transmission system operators via regelleistung.net. Page: Control Energy
Source: regelleistung.net 50Hertz, Amprion, TenneT, TransnetBW
Registering power measurement. Metering method for large consumers from approx. 100,000 kWh/year. Provides 15-minute load profile data — basis for BESS dimensioning, §19 atypical load proof, and operational optimization.
Source: § 40 MessZV
Key metric for investment profitability: ROI = (Profit ÷ Investment Cost) × 100. For BESS purchase in multi-use operation: typical payback period of 2–4 years corresponds to a 25–50% ROI per year (KPMG AG, Feb. 2026). ROI applies exclusively to the purchase model—with CPFS, no CAPEX is required, and the relevant comparative figure is the profit share.
Source: KPMG Investment Case Feb. 2026
S
Current charge level of the battery storage system as a percentage of its rated capacity (0% = empty, 100% = full). The EMS optimizes the SOC daily: For FCR symmetry (bidirectional demand response), it typically maintains a SOC of 50%–60%. For peak shaving, it discharges completely in the evening to recharge overnight. SOC management determines availability for all FTM markets.
Source: IEC 62933 CUBE CONCEPTS GmbH
Trading of electrical energy on day-ahead (EPEX SPOT, daily auction) and intraday markets. Battery storage systems charge at low or negative prices and feed in at high prices. 457 hours of negative prices in 2024 (EPEX SPOT). Revenue potential structurally increases with a growing share of renewable energy in the grid.
Source: KPMG Investment Case Feb. 2026 EPEX SPOT SE
Ü
Operator of the high-voltage transmission grid (≥ 220 kV). In Germany, there are four TSOs: 50Hertz, Amprion, TenneT, TransnetBW. They tender for balancing energy (FCR, aFRR, mFRR), issue prequalifications, and activate mFRR manually. Each TSO is responsible for its own control area – with location-specific price differences.
Source: regelleistung.net § 12 EnWG
V
Key figure for usage intensity: Quotient of annual energy consumption (kWh/year) and connected load (kW). Relevant for §19 para. 2 sentence 2 StromNEV (base load privilege): Prerequisites were ≥ 7,000 operating hours per year and ≥ 10 GWh annual consumption. BK4-22-089 has terminated this sentence 2 as of December 31, 2025 — §19 sentence 1 (atypical grid usage) remains unaffected.
Source: §19 Para. 2 StromNEV · BNetzA BK4-22-089
A complete charge-discharge cycle (0–% → 100–% → 0–% state of charge). Key metric for lifespan calculation and LCOS modeling. LFP systems: typically 4,000–6,000 full cycles over the lifespan. KPMG LCOS basis: 2 full cycles/day.
Source: KPMG Investment Case Feb. 2026 · IEC 62933
W
Weighted Average Cost of Capital — the minimum required rate of return on equity and debt capital. Basis for the LCOS calculation: KPMG AG uses a 6% WACC in the February 2026 investment case (10 MW / 40 MWh). The lower the WACC, the lower the calculated LCOS. Companies with a lower cost of capital achieve a lower LCOS in mathematical terms.
Source: KPMG Investment Case Feb. 2026
Z
Zinc-bromine redox flow battery. Lowest LCOS in C&I comparison: €104/MWh (KPMG AG, Feb. 2026). Advantage: almost no capacity loss during deep discharge. Compared to LFP: lower power density, larger physical volume, more limited supply chain — significantly less often used in the C&I market in 2026.
Source: KPMG Investment Case Feb. 2026
CUBE CONCEPTS GmbH · /knowledge/glossary/ · v24.1 · 04/01/2026 · QA Framework v35
What are the legal deadlines until 2029?
For BESS decisions, five regulatory instruments are relevant until 2029—with varying deadlines, different mechanisms of action, and a critical risk of confusion.
The table below provides an overview. Two points are particularly frequent subjects of misunderstandings: Firstly, MiSPeL is not a grid fee instrument—it concerns EEG subsidies and FTM market integration, but has no direct influence on §19 or §118. Secondly, BK4-22-089 exclusively affected §19 para. 2 sentence 2 (load profile) and expired on December 31, 2025—§19 para. 2 sentence 1 (atypical grid usage) is completely independent of it and is valid until December 31, 2028. Anyone who is not aware of this distinction will make incorrect planning decisions.
| Instrument | Effect | First |
|---|---|---|
| §14a EnWG | Time-variable grid charges | As of April 1, 2025 |
| §19 Paragraph 2 Sentence 1 of the StromNEV | Atypical grid usage | Until 12/31/2028 |
| MiSPeL | EEG promotion + FTM (no NE!) | From mid-2026 |
| §118 Paragraph 6 of the Energy Industry Act | 20 J. grid charge exemption | IBN until Aug. 4, 2029 |
| Agnes | §19 Succession: Dynamic NE Signals | As of 01/01/2029 |
Frequent Misunderstanding: MiSPeL is not a grid fee instrument
MiSPeL (Market Integration of Stationary Storage) is often incorrectly classified as a network tariff reform in marketing materials. This is incorrect: MiSPeL is a BNetzA (Federal Network Agency) regulation for EEG (Renewable Energy Sources Act) promotion and FTM (Forward Trading Market) integration — not for network tariff optimization. MiSPeL has no direct connection to §19 para. 2 StromNEV (Electricity Grid Fee Ordinance) or §118 EnWG (Energy Industry Act). The confusion arises because MiSPeL allows simultaneous BTM (Balancing Energy Market) and FTM operation — which indirectly improves economic efficiency, but not via the network tariff mechanism.
§ 19 Para. 2 Sentence 2 vs. Sentence 2: The Difference That Changes Project Planning
§19 Para. 2 Sentence 2 of the StromNEV concerns the privilege for high-usage electricity consumers with ≥7,000 full utilization hours and ≥10 GWh annual consumption. BK4-22-089 (BNetzA) exclusively concerned this sentence — and expired on December 31, 2025. §19 Para. 2 Sentence 1 concerns atypical grid usage (HLZ windows) — a completely independent instrument, which is not affected by BK4-22-089 and is valid until December 31, 2028. Both sentences are frequently subjects of misunderstandings in consulting discussions and market materials — correct differentiation is a prerequisite for planning.
Source: §19 Para. 2 StromNEV · BNetzA BK4-22-089 Raue Attorneys at Law, December 2025
What distinguishes LFP, ZnBr, and NIB—the three relevant storage technologies in 2026?
The BESS market offers three technically mature alternatives for stationary industrial storage in 2026. The right choice depends on the usage profile, operating strategy, and site profile—not on manufacturer preferences.
LFP — Lithium Iron Phosphate
Standard technology for industrial storage systems starting at 750 kW. Advantages: low system costs (following the price decline in 2022–2025), high cycle life (~4,000–6,000 full cycles), thermal stability, widespread availability from Tier 1 manufacturers in Europe, South Korea, and China. Disadvantages: lower energy density than NMC, performance drop at low temperatures below -10°C. LCOS: €110/MWh — lowest value for 1–4-hour storage (KPMG AG, February 2026LFP is the first choice for multi-use operation (FCR, aFRR, Peak Shaving) with daily full cycles.
ZnBr — Zinc Bromide (Flow Battery)
Competitive for long-term storage applications (6–12-hour discharge duration). Advantages: no capacity loss during full discharge, no thermal management required, capable of withstanding 100 % deep-discharge cycles. Disadvantages: lower energy density, more complex system design, higher CAPEX per kWh than LFP for short-term storage. LCOS: €104/MWh for long cycles. Attractive for self-consumption optimization and arbitrage-heavy operating strategies (KPMG AG, Feb. 2026). Suitable for locations with large daily spreads between cheap nighttime and expensive daytime electricity.
NIB (Sodium-ion battery / Na-ion) — Sodium-ion
Emerging technologies based on low-cost and abundant raw materials (no lithium, no cobalt). Advantages: potentially lower raw material dependency, good low-temperature performance, no critical minerals in the supply chain. Disadvantages: not yet a series standard for large storage in 2026, cycle life not yet fully field-proven, few qualified Tier 1 suppliers. LCOS: €127/MWh (KPMG AG, Feb. 2026, limited field data). CUBE CONCEPTS is observing NIB — not a standard product currently.
The technology decision is a function of the operating strategy: A storage facility for dominant FCR/aFRR marketing with 2-3 full cycles per day has different requirements than an arbitrage storage facility with one daily cycle. CUBE BatterySizer calculates the optimal technology and capacity based on your site-specific load profile—manufacturer-independent and without prior commitment. The result is not always LFP. It is always the technology that achieves the lowest lifetime LCOS with the planned operating strategy in your load profile. For sites with high arbitrage potential and long discharge cycles, ZnBr may be the better choice—this results from the calculation, not from manufacturer preference.
Source: KPMG AG Investment Case, February 2026 · CUBE CONCEPTS Project Experience
Which glossary terms are most important according to your role?
Depending on your role in the company, different terms are crucial. This overview will help you get started.
If you are responsible for investment decisions
Priority: CPFS, Open-Book, IFRS 16, Off-Balance, LCOS, §118 para. 6 EnWG (IBN Deadline), CAPEX, OPEX. These terms form the basis for the economic feasibility study and the governance requirements that accompany a BESS investment decision.
§118 Planning Lead Time — Calculate Realistically
Existing network connection: 6-12 Months* Lead time to IBN. New network connection: on average 40 months*— August 4, 2029 is closer than it seems.
* ECO STOR / pv-magazine, February 2026.
If you are responsible for energy procurement and network charges
Priority: §19 para. 2, sentence 1, HLZ, atypical grid usage, peak shaving, §118 para. 6 EnWG, AgNes, §14a EnWG, MiSPeL (incl. differentiation from §19). These terms are directly relevant to action – errors in their usage will lead to planning mistakes.
If you are responsible for ancillary services and FTM revenue
Priorities: FCR, aFRR, mFRR, spot arbitrage, prequalification, CUBE EfficiencyUnit, multi-use, full cycles, FTM. An understanding of market mechanisms and remuneration structures is essential for revenue forecasting.
If you are responsible for ESG and CSRD
Priority: BTM, self-consumption, Scope 2 reduction according to GHG Protocol Location-Based Method, CO₂ equivalents, BESS, RLM. BESS provides measurable and auditable data points for ESRS E1-compliant reporting - if the plant is operated with appropriate documentation. CUBE CONCEPTS' monthly open-book reporting provides this data by default.
Realized Projects with Tier 1 Industrial Companies
CUBE CONCEPTS has successfully completed over 150 energy projects across Europe (exclusively in the PV sector). The methodology—open-book, manufacturer-independent, and load-profile-based—is the same one now being used for BESS.
What can you find out with your load profile in 30 minutes?
CUBE CONCEPTS analyzes your load profile and calculates concrete revenue potential — §118 exemption value, FTM revenues, peak shaving savings, §19 atypicality potential — in 30 minutes, free of charge, without commitment.
⚠ §118-IBN-Deadline: August 4, 2029 Planning takes 12–18 months.
Which further BESS pages are recommended?
Frequently Asked Questions about BESS Terms and Regulations
AgNes (BNetzA BGK-25-01-1#3) will replace Section 19(2) of the StromNEV as of January 1, 2029, with dynamic, load-profile-based grid fee signals. Battery storage systems with forecast-based control are structurally better positioned than uncontrolled consumption profiles.
The economic entry point begins at approximately 750 kW / 1,500 kWh. Above this size, there is an obligation for RLM metering, peak loads become significant, and FTM pooling is possible. From 1 MW, there is direct FTM market access. The FTM revenue potential is €200,000–€300,000/MW/year, independent of location and PV system (KPMG AG, Feb. 2026).
CPFS (CUBE Profit Flex Solution) is a standalone BESS operating model: €0 CAPEX, full FTM market operation until ownership is transferred. Contracting is a separate model—not Contracting with extras.
FCR (Frequency Containment Reserve) is primary control reserve — reaction in seconds. aFRR (automatic Frequency Restoration Reserve) is secondary control reserve — full capacity in 30 seconds. aFRR is the strongest revenue stream for industrial storage in 2025.
HLZs are the 15 times per year when the local network operator records its peak annual load. This is the basis for atypical grid usage according to §19 Paragraph 2 Sentence 1 of the StromNEV — battery storage systems discharge specifically during these windows.
Levelized Cost of Storage - Total cost per stored kWh over the plant's lifetime. Includes CAPEX, OPEX, and degradation. The only fair comparison indicator for storage technologies. LFP benchmark: €110/MWh (KPMG AG, Feb. 2026). LFP has the lowest LCOS for industrial storage.
MiSPeL is a BNetzA regulation for EEG funding and FTM market integration – not a grid fee instrument. From mid-2026, it will enable simultaneous BTM and FTM operation for EEG-funded plants without loss of EEG remuneration.
Open-Book means complete transparency of all revenue and cost flows within the CPFS business relationship. Not: public price disclosure. Basis for IFRS-compliant accounting structure and auditability.
The performance charge according to §17 StromNEV is determined at the annual peak load point for 12 months – a single unfavorable quarter-hour determines the costs for the entire year. The battery storage automatically caps this peak. §19 is an additional lever (until December 31, 2028), not the basis.
Metering of registered power. Metering method for large consumers from ~100,000 kWh/year. Provides 15-minute load profile data — prerequisite for BESS sizing, §19 atypicality proof, and operational optimization.
§19 Para. 2 Sentence 1 grants a grid fee discount for companies whose grid load is below the grid average in all 15 HLZ windows. Valid until 12/31/2028. Independent — not affected by BK4-22-089, which concerned §19 Para. 2 Sentence 2 (peak load) — not Sentence 1).
Section 118, Paragraph 6 of the German Energy Industry Act (EnWG) grants battery storage systems a full 20-year exemption from grid fees if they are commissioned by August 4, 2029. This cannot be acquired retroactively – the deadline is legally fixed.
How does CUBE CONCEPTS translate concepts into concrete numbers for your business?
A glossary explains terms. CUBE CONCEPTS translates these terms into a location-specific open-book calculation—based on your RLM load profile data, current regulations, and current market prices.
The difference between a BESS project that is economically viable and one that is not rarely lies in the concept itself—it lies in the quality of implementation. The CUBE EfficiencyUnit is the control infrastructure that coordinates §19 atypical verification, §118-compliant self-consumption, FCR and aFRR bidding, and peak-shaving dispatch in real time. Open-book costing is the tool that provides the CFO, audit, and energy procurement teams with the same data set—before the decision is made, not after the contract is signed.
What CUBE CONCEPTS specifically delivers
- Manufacturer-independent tender (min. 3 offers, LCOS-evaluated)
- Open-book calculation based on your load profile data
- LCOS Calculation for LFP and Alternatives
- Three revenue scenarios (Base / Conservative / Optimistic)
- IFRS 16 Compliant Accounting Structure + Off-Balance Sheet Review
- Full prequalification and TSO communication
- Monthly open-book reporting starting from IBN
What other providers often don't deliver
- Transparent calculation before the decision
- Site-specific LCOS calculation
- Manufacturer-independent tender
- Open-Book Billing per Asset
- IFRS 16 Structuring by Auditor Coordination
- Full Atypicality Detection Coordination
Most providers sell either hardware or electricity. CUBE CONCEPTS builds the system behind it — the governance, operational, and revenue structure that industrial companies need to make and own a BESS decision with conviction.
CUBE CONCEPTS Project Experience · KPMG AG Investment Case, February 2026
Citations
Section 118(6) of the Energy Industry Act (EnWG): IBN deadline August 4, 2029 · Section 19(2), sentence 1 of the Electricity Grid Regulation (StromNEV): Atypical grid use until December 31, 2028 · BK4-22-089: Only §19, sentence 2 (peak load) — not sentence 1 — expired Dec. 31, 2025, expired Dec. 31, 2025 — Raue Rechtsanwälte Dec. 2025 · AgNes: BNetzA BGK-25-01-1#3, effective Jan. 1, 2029 · MiSPeL: BNetzA EEG subsidies + FTM, mid-2026 · §14a EnWG: Since April 1, 2025 · BMWE: Grid fee share ~40 % of industrial electricity price, August 2025 · KPMG AG: Investment Case for Stationary Battery Storage, February 2026 · ISEA Battery Revenue Index: RWTH Aachen, 2025
CUBE CONCEPTS GmbH · /knowledge/glossary/ · v24.1 · 04/01/2026 · QA Framework v35