The Great Grid Debate: BNetzA Criticizes TSOs Over "Fictional" Assumptions in Germany’s 2037/2045 Power Plan

BERLIN – In a move that has sent shockwaves through the European energy sector, the German Federal Network Agency (Bundesnetzagentur, or BNetzA) has issued a scathing critique of the latest grid development proposals submitted by the country’s four Transmission System Operators (TSOs). The dispute centers on the second draft of the Grid Development Plan (Netzentwicklungsplan, or NEP) for the target years 2037 and 2045.

At the heart of the controversy is a fundamental disagreement over how Germany should prepare its high-voltage infrastructure for climate neutrality. While TSOs—Amprion, TenneT, TransnetBW, and 50Hertz—argue for a cautious approach based on cost-efficiency, the BNetzA and various industry stakeholders warn that the current plan relies on "pseudo-accuracy" and "fictional" operational realities that risk leaving Germany with an under-dimensioned power grid, potentially costing billions in future remedial measures.

Main Facts: A Planning Crisis in the Heart of the Energiewende

The conflict erupted following the BNetzA’s evaluation of the TSOs’ second draft for the NEP 2037/2045 (Version 2025). The regulator’s report, released in June 2026, took the unprecedented step of labeling the TSOs’ cost-benefit analyses as "practically unusable."

The primary points of contention include:

• Under-Dimensioning Risks: The BNetzA warns that the TSOs’ methodology creates a high risk of a grid that cannot handle the actual load of a fully electrified economy.
• Unrealistic Scenarios: Critics argue that "Scenario A" (Slowed Electrification), which the TSOs have labeled as "robust," actually fails to meet the legal requirements of the Renewable Energy Sources Act (EEG).
• Storage Undervaluation: The plan assumes a standard 2-hour duration for large-scale battery storage, a figure industry experts claim is already obsolete.
• Redispatch Costs: The current plan accepts a 15% to 30% increase in "Redispatch" (emergency grid interventions), which critics view as a "risky planning regression" that prioritizes low upfront investment over long-term operational stability.

Chronology: The Road to the 2026 Deadlock

The current friction is the result of a multi-year planning cycle that has struggled to keep pace with rapid technological shifts and legislative changes.

1. Early 2025: The first draft of the NEP 2037/2045 (Version 2025) is presented by the TSOs. It introduces three primary scenarios: A (Slow), B (Standard), and C (Ambitious).
2. Early 2025 (The "Solar Summit Law"): The German government passes the Solarspitzengesetz, significantly easing the market integration of prosumers and incentivizing flexible battery usage.
3. Late 2025: The TSOs release a second draft, incorporating updated data but maintaining a focus on Scenario A as the "robust" foundation for grid expansion.
4. June 2026: The BNetzA publishes its preliminary examination results, delivering a sharp rebuke of the TSOs’ methodology and their failure to account for the year 2045 in key cost-benefit metrics.
5. August 2026: Industry associations, led by the Association of Energy Market Innovators (bne), issue formal statements supporting the BNetzA’s criticism and demanding a pivot toward Scenario C.

Supporting Data: The Case for an Ambitious Expansion

The push for a more robust grid is supported by historical data and evolving market trends. In 2014, the BNetzA approved a grid plan that estimated 54.1 GW of solar PV by 2025. In reality, Germany reached approximately 110 GW by the end of 2025—nearly double the "ambitious" forecast.

The Scenario Gap

The TSOs’ preferred "Scenario A" assumes high hydrogen imports and slower domestic electrification. However, investment trends do not support this.

• Scenario C (Ambitious): Despite being more intensive, Scenario C is estimated to cost approximately €390 billion. Interestingly, due to intelligent control systems and the elimination of certain redundant projects (like the P609 decentralized booster), Scenario C is projected to be more cost-effective than the intermediate Scenario B.
• Battery Capacity: The TSOs assume a 2-hour storage duration for the 175 GW of battery capacity projected in Scenario C. Market data from 2026 shows that 4-hour and even 8-hour storage systems are becoming the industry standard. Using a 2-hour assumption leads to a massive underestimation of the grid-damping potential of batteries.

Regionalization and Offshore Wind

The BNetzA and industry experts have pointed out significant flaws in where the TSOs expect power to be generated:

• Brandenburg PV: The TSO model suggests only 3 GW of additional ground-mounted PV in Brandenburg between 2037 and 2045. Regional planners argue this is "unrealistically low" given current project pipelines.
• Offshore Reduction: The plan reduces the offshore wind expansion target from 70 GW to 60 GW without reallocating that 10 GW deficit to onshore wind, effectively planning for a shortfall in renewable generation.

Official Responses: "Fiction vs. Reality"

The language used by the BNetzA in its June 2026 report is unusually blunt for a regulatory body. The agency stated that the TSOs’ assumption that all grid components are available 100% of the time is a "pure fiction that has nothing to do with operational reality."

Furthermore, the BNetzA criticized the TSOs for focusing their cost-benefit analysis only on the year 2037, ignoring the 2045 climate neutrality deadline. "This makes the cost-benefit analysis of the transmission system operators practically unusable," the regulator noted.

In response, the Association of Energy Market Innovators (bne) issued a statement in August 2026, reinforcing these concerns. "Choosing Scenario A is an energy-policy blind flight," a spokesperson stated. "The TSOs are de facto planning for a failure to meet the EEG targets. This will lead to a permanent shortage of grid connections at both the transmission and distribution levels."

The TSOs, meanwhile, have defended their cautious approach, citing the immense financial burden on consumers. They argue that building a grid to handle every possible peak of renewable generation is "economically inefficient" and that some level of congestion management (Redispatch) is a necessary evil to keep grid fees manageable.

Implications: The High Cost of Planning Small

The outcome of this debate will determine the stability of the German economy for the next two decades. The implications of following the TSOs’ current path are twofold:

1. The "Redispatch" Trap

By planning for an under-dimensioned grid, the TSOs are effectively baking in a high level of Redispatch. This involves paying power plants to throttle up or down to prevent grid overloads. While this saves money on construction today, it creates recurring annual costs in the billions. These costs are passed directly to end-consumers via grid fees. Critics argue that investing in "physical assets" (lines and cables) creates long-term value, whereas Redispatch is "burnt money" used for emergency management.

2. The Prosumer Paradox

The 2025 Solarspitzengesetz was intended to turn German households into active participants in the energy market. By 2037, it will be standard for prosumers to use smart meters and price signals to shift their load. However, the TSOs’ plan assumes that "network-oriented control" (the ability of the grid to manage household load) only happens in the most ambitious scenario. If the grid is not built to integrate these decentralized flexibilities, the "smart home" revolution could be throttled by a "dumb grid."

3. Investor Uncertainty

For the hydrogen economy and large-scale battery developers, the NEP is the ultimate roadmap. If the roadmap is based on "Scenario A" while the market moves toward "Scenario C," developers will face years of delays in securing grid connections. This could drive energy-intensive industries out of Germany toward regions with more reliable infrastructure.

Conclusion: A Call for a "Climate Neutrality Grid"

As the BNetzA prepares its final confirmation of the 2025 NEP, the pressure is mounting to abandon the "slowed electrification" path. The consensus among regulators and market innovators is clear: Germany cannot afford to plan for failure.

To ensure a stable transition, the 2027 Scenario Framework—already in development—must mandate longer storage durations, realistic regionalization of PV, and a commitment to Scenario C as the "True Robustness Scenario." Without these changes, Germany’s path to 2045 remains obstructed by an infrastructure plan that looks backward rather than forward.