The German Renewable Energy Federation (BEE) has called for Germany’s future electricity grid planning to give a greater role to battery storage, demand-side flexibility and other tools capable of reducing congestion and limiting the need for additional grid infrastructure.
The federation submitted its position on 24 August on the second draft of Germany’s Electricity Grid Development Plan (NEP) 2025–2037/2045. While it acknowledges progress in some of the assumptions used by transmission system operators, BEE argues that the scenarios remain too conservative regarding future electricity demand, onshore wind deployment, domestic electrolysis and, particularly, the future expansion of energy storage.
One of BEE’s main criticisms is that the plan assumes no further expansion of large-scale battery storage after 2037.
“A future-proof electricity system needs all available flexibility options in addition to grid expansion. Storage and flexible consumers will help avoid grid bottlenecks, reduce redispatch and thereby limit additional grid expansion,” said Christine Falken-Großer, Managing Director of BEE.
The federation also considers the assumptions used to model large-scale battery energy storage systems (BESS) insufficient. The current NEP draft assumes that large batteries will continue to have a two-hour storage duration through 2045.
BEE argues that this configuration is already too short for unrestricted market access, optimising photovoltaic generation and improving the operation of hybrid storage systems. It therefore expects storage durations to increase from two hours to three or four hours over the coming years.
The association proposes that the NEP assume 50% of new large-scale battery capacity will have a four-hour duration, 25% a three-hour duration and the remaining 25% the current two-hour configuration.
For smaller battery systems, the NEP currently assumes a 2.5-hour duration. BEE proposes increasing the duration of part of future additions to three hours, particularly as the share of marketed rooftop photovoltaic generation increases.
BEE is also proposing an adjusted “Scenario C+” to assess how Germany’s grid expansion requirements could change if large-scale storage systems were operated specifically to support the electricity network.
The analysis should consider both charging and discharging behaviour, as well as mechanisms that could influence the regional deployment of large-scale batteries.
The objective would be to determine how much grid expansion could be avoided if battery storage were located and operated primarily to reduce congestion.
BEE also proposes allowing eligible large-scale battery systems to participate in upward redispatch, increasing their electricity injection when required by the grid.
BEE’s criticism extends beyond battery storage. The federation considers that the potential of demand-side management across industry, businesses and households is modelled too conservatively.
It also argues that Germany should consider higher domestic electrolyser capacity, both to produce green hydrogen and to use electrolysers as flexible loads capable of absorbing periods of surplus renewable generation.
Another area highlighted by BEE is data centre electricity consumption. The federation argues that the assumptions through 2045 do not sufficiently reflect the expected increase in electricity demand associated with digitalisation and the growing use of artificial intelligence.
More broadly, BEE warns that conservative electrification assumptions could result in Germany underestimating both future electricity consumption and the grid infrastructure required to accommodate it.
Regarding renewable generation, BEE supports the photovoltaic deployment pathways included in the plan and welcomes the increase in assumed full-load hours for onshore wind to 2,600 and 2,700 hours per year, depending on the scenario.
However, the federation maintains that the assumed onshore wind expansion pathways remain below the levels required for a cost-efficient and resilient electricity system.
For offshore wind, BEE considers the assumed full-load hours plausible but warns that deployment expectations remain highly ambitious given uncertainties surrounding site availability, investment conditions, supply chains and increasing wake effects between wind farms.
BEE is also calling for the NEP to incorporate the potential effects of Germany’s planned reform of the grid tariff system, known as AgNes, which is intended to create stronger incentives for generators, storage facilities and consumers to operate in ways that support the grid.
The federation argues that planners should examine how these incentives could influence the location and operation of battery storage and other flexible assets, potentially reducing congestion, redispatch costs and the amount of additional grid infrastructure required.
While BEE supports the NEP’s economic assessment of the trade-off between grid expansion and congestion management, it is calling for greater transparency over the criteria used.
In particular, the federation wants Germany to quantify more clearly how much battery storage and flexible demand could contribute to avoiding grid bottlenecks before determining how much additional grid expansion is actually necessary.
Sé el primero en comentar…

source