The Infrastructure Gap: German Energy Innovators Warn of "Outdated" Grid Planning for 2040

BERLIN – As Germany accelerates its transition toward a climate-neutral industrial base, the blueprint for its future power grid has come under intense scrutiny. On September 28, 2026, the German Transmission System Operators (TSOs) released their draft for the Scenario Framework Electricity 2040/2045 (Version 2027). While the document is intended to serve as the foundational architecture for the nation’s grid expansion over the next two decades, the Association of Energy Market Innovators (bne) has issued a sharp critique.

The bne argues that while the TSOs have made methodological strides, the current draft risks "planning past reality." The association warns that by underestimating the speed of market developments—specifically in battery storage, prosumer flexibility, and solar integration—Germany may end up building the wrong infrastructure, leading to billions in stranded costs or, conversely, a grid that cannot handle the 100% renewable reality of the 2040s.

Main Facts: A Blueprint Under Fire

The Scenario Framework (Szenariorahmen) is the first step in the biennial Network Development Plan (NEP) process. It defines various "pathways" or scenarios (usually labeled A, B, and C) that describe how much electricity Germany will consume and how much wind, solar, and storage will be installed by the target years of 2040 and 2045.

In their 2027 version, the TSOs (Amprion, TenneT, TransnetBW, and 50Hertz) presented a framework that the bne acknowledges as "solid" in its basic methodology. However, the bne’s formal response to the Federal Network Agency (BNetzA) highlights several critical failures:

1. The "Narrow Funnel" Problem: Scenarios B and C are nearly identical, failing to provide policymakers with a range of distinct transformation paths.
2. Missing the 100% Target: None of the current scenarios model a 100% renewable energy supply for the year 2045, despite this being a probable and legally relevant target.
3. Storage Blind Spots: The framework fails to adequately account for "co-location" (solar parks paired with batteries) and underestimates the grid-serving potential of decentralized storage.
4. Digitalization Deficits: The TSOs are accused of projecting today’s digital bottlenecks into the 2040s, ignoring the mandatory rollout of smart meters (iMSys) and dynamic tariffs.

Chronology: From Draft to Concrete in the Ground

The development of the German power grid follows a rigid legal timeline, and the Scenario Framework is the "domino" that sets everything else in motion.

• Mid-2026: TSOs begin drafting the Scenario Framework based on current energy laws and market trends.
• September 28, 2026: The official draft for Version 2027 is published, triggering a public consultation phase managed by the BNetzA.
• Late 2026 / Early 2027: Stakeholders, including the bne, environmental NGOs, and industrial consumers, submit technical feedback.
• Spring 2027: The BNetzA is expected to approve or mandate revisions to the Scenario Framework.
• 2027–2028: Based on the approved framework, the TSOs will calculate the "Network Development Plan," identifying exactly which high-voltage lines need to be built or upgraded.
• Post-2028: These requirements are codified into the Federal Requirement Plan Act (Bundesbedarfsplangesetz), giving them the force of law for construction.

The bne emphasizes that if the "input data" in the Scenario Framework is wrong today, the physical grid built ten years from now will be fundamentally mismatched with the needs of the market.

Supporting Data: The Cost of Underestimation

To illustrate the danger of conservative planning, the bne points to a historical precedent from 2014. In that year’s Scenario Framework, the "ambitious" Scenario C predicted that Germany would have 54.1 GW of solar photovoltaics (PV) by 2025. In reality, Germany surpassed 110 GW by the end of 2025—more than double the "ambitious" forecast.

"When a scenario path is robust, it is usually Path C, not Path A," the bne noted in its statement. The association argues that the TSOs are repeating this mistake by being overly cautious regarding the following technical areas:

The AC/DC Modeling Error

A technical but vital point of contention is how solar power is measured. TSOs often look at the "DC" (Direct Current) capacity of solar modules. However, the grid only "feels" the "AC" (Alternating Current) output from the inverters. In modern "co-location" plants (Solar + Battery), the AC connection is often much smaller than the solar peak to save on grid connection costs. By simply adding up DC solar power and battery power, the TSOs overstate the peak load on the grid, leading to inefficient planning.

Co-Location and Storage Potential

The bne demands that co-location batteries be regionalized with the same logic as solar parks. Furthermore, they argue that by 2040, it will be standard for solar park batteries to not only store solar energy but also draw power from the grid when prices are low (grid-serving behavior). The bne suggests that at least 25% of a storage system’s capacity should be modeled as available for grid intake, a regulatory possibility that already exists under the Renewable Energy Sources Act (EEG).

Prosumer Flexibility

By 2040, millions of electric vehicles (EVs), heat pumps, and home storage systems will be active on the German grid. Under Paragraph 14a of the Energy Industry Act (EnWG), these devices are already required to be controllable by grid operators to prevent local overloads. The bne argues the TSOs are ignoring this "flexibility potential," treating these loads as static "problems" rather than dynamic "solutions."

Official Responses: The Call for a 100% Scenario

The bne’s position is clear: the Federal Network Agency (BNetzA) must intervene and force the TSOs to broaden their horizons.

"At least Scenario C must reflect a 100% supply from renewable energies," the bne stated. The association argues that failing to model a 100% renewable system in the 2040s is a "systematic planning error." If the TSOs do not plan for a world where renewables provide the bulk of the power, the grid will remain tethered to the logic of large, centralized fossil-fuel or hydrogen plants, ignoring the decentralized reality of the future.

Furthermore, the bne is calling for a more explicit description of how storage is modeled. They propose that by 2040, 15% of all onshore wind farms should be equipped with co-location batteries. This would significantly smooth the feed-in profile of wind energy, reducing the need for massive "over-dimensioning" of the transmission grid.

The Distribution System Operators (VNBs), who manage the lower-voltage local grids, are also affected. Since their regional planning interacts with the TSO scenarios, a flaw at the top of the planning hierarchy trickles down to every local substation in Germany.

Implications: Beyond the German Border

The debate over the Scenario Framework is not happening in a vacuum. The bne highlights two major pieces of EU legislation that the TSOs must anticipate: the European Grids Package and the Network Code on Demand Response.

1. Stranded Assets and Economic Efficiency

If the TSOs overestimate the need for traditional grid expansion because they ignore the "cushioning" effect of local batteries and flexible loads, German consumers will pay the price through higher grid fees. Conversely, if they underestimate the speed of the solar rollout (as they did in 2014), the grid will become a bottleneck, forcing "curtailment" (throwing away green energy because the wires can’t carry it), which also drives up costs.

2. The Digitalization of the Distribution Grid

The bne’s critique strikes at a sensitive point: the "digitalization deficit" of German grid operators. By 2040, the association expects that today’s gaps in smart meter deployment and control-room automation will be a thing of the past. The grid of 2040 will be a "Smart Grid" by necessity. Planning for 2040 based on the "digitalization bottlenecks of the 2020s" is, in the eyes of the bne, a recipe for obsolescence.

3. Market-Oriented vs. Grid-Oriented

The TSOs currently apply a rigid separation between "market-oriented" behavior (buying/selling when prices are right) and "grid-oriented" behavior (helping the grid stay stable). The bne argues this is a false dichotomy. Modern software can ensure that a home battery or a solar park serves the market and the grid simultaneously. Acknowledging this dual-use would drastically reduce the projected need for new physical power lines.

Conclusion: A Critical Juncture for the "Energiewende"

The consultation on the Scenario Framework 2040/2045 is more than a technical exercise; it is a battle over the vision of Germany’s energy future. On one side, the TSOs represent a cautious, traditional approach to infrastructure, prioritizing "worst-case" safety margins. On the other, the bne represents the "New Energy Economy," pushing for a grid that is as dynamic and digital as the technologies it connects.

As the BNetzA reviews the TSOs’ draft and the bne’s scathing response, the stakes could not be higher. The decisions made in the coming months will determine whether Germany’s grid becomes a high-speed highway for the energy transition or a multi-billion-euro monument to the planning logic of the past. For the bne, the path forward is clear: the BNetzA must demand a Scenario C that is truly ambitious, 100% renewable, and fully digital.