MiSpeL explained: Germany’s new rules for PV & BESS

Germany's Federal Network Agency (BNetzA) adopted MiSpeL on October 1, 2026. The rules establish a framework under which eligible co-located storage projects can charge from the grid while retaining the Renewable Energy Sources Act (EEG) treatment for the qualifying renewable share of their electricity exports. That share is determined using the applicable MiSpeL formulas and metering data. Until September 30, 2027, using MiSpeL requires consent from grid and metering operators.

Arbitrage or subsidies. For years, developers of solar photovoltaic (PV) plants with battery energy storage systems (BESS) in Germany had to pick one revenue stream. MiSpeL, short for Marktintegration von Speichern und Ladepunkten (market integration of storage and charging points), creates a route for eligible storage projects to combine grid charging with continued EEG treatment for the qualifying renewable share of their exports. 

The benefit is conditional on the selected MiSpeL option, the project’s metering configuration, direct-marketing arrangements and the applicable support scheme.

What do you need to prepare? This article walks through MiSpeL’s timeline, how the allocation works, and what it means for project design. And if you’re looking for an easier way to assess how the new metering and energy-flow rules could affect your project, RatedPower can help you compare the possibilities.

When does MiSpeL take effect?

The BNetzA adopted the final MiSpeL determination on 1 October 2026. 

A transition period runs until September 30, 2027. During this period, projects can use the MiSpeL options only with the agreement of both the grid operator and the metering-point operator. From October 2027, the framework is intended to be implemented as part of the operators’ standard processes.

MiSpeL follows the Stromspitzengesetz, which introduced amendments to the EEG and EnFG intended to facilitate more active and bidirectional use of storage and charging infrastructure alongside renewable-energy installations. MiSpeL provides the accounting and allocation framework for applying those changes.

Old EEG treatment vs. MiSpeL: what changes?

Before MiSpeL, the main route for a co-located battery to preserve EEG treatment for stored renewable exports was the exclusivity option (Ausschließlichkeitsoption). Developers effectively faced two operating approaches:

●      Green-only mode: Charge only from the solar plant to keep EEG payments on stored renewable electricity, but give up grid trading.

●      Gray mode (Graustromspeicher): Charge from the grid during low-price periods and sell when prices rise, but accept that grid charging can affect the project’s eligibility for EEG treatment under the previous exclusivity route.

The allocation option provides a route around that previous limitation. Depending on the project’s configuration and commercial arrangements, a co-located battery may be able to combine three potential sources of value:

●      Market-based arbitrage: Charge from the grid during low-price periods and discharge when prices are higher, subject to the project’s operating and commercial arrangements.

●      EEG treatment: Retain the applicable EEG treatment for the qualifying renewable share of exported electricity.

●      Charge and levy treatment: Apply the relevant reduction or netting of charges associated with grid electricity that is stored and later returned to the system, where the applicable rules permit it.

For background on the current support scheme, see our initial overview of EEG 2023 and the German solar market.

How does the MiSpeL allocation option work?

The main MiSpeL route for utility-scale solar and BESS projects is the allocation option (Abgrenzungsoption). It uses 15-minute meter data and fixed BNetzA formulas to split exports into a renewable share and a grid share.

The formulas rest on these rules:

●      Storage priority: When the site imports from the grid while the battery charges, the battery is deemed to charge from the grid first. When the battery discharges while the site exports, the export is deemed to come from the battery first.

●      Monthly settlement: The 15-minute values are allocated per calendar month, then added up for annual billing.

●      Negative-price periods: The applicable EEG treatment depends on the plant’s support regime, the relevant market-value rules and the MiSpeL allocation formula. Developers should therefore test how dispatch during negative-price intervals affects the renewable share that remains eligible for support.

To use the allocation option, every generator and battery behind the connection point must be in direct marketing (Direktvermarktung), all exports must be balanced in one separate balancing group, and the market premium is calculated on the annual market value. Both new and existing plants are eligible. The exception is projects that won support in an innovation tender (Innovationsausschreibung), the auction format for combinations such as solar plus storage. These projects can still only use the exclusivity option.

MiSpeL also introduces a flat-rate option (Pauschaloption) for solar installations of up to 30 kilowatt-peak (kWp). It uses statutory assumptions and simplified measurement requirements. Its application remains subject to the required European Commission state-aid approval, and it is not the relevant route for utility-scale projects.

What type of metering setup does MiSpeL require?

BNetzA doesn’t prescribe one universal setup. Instead, each formula set comes with a matching metering concept, and your site must use the one that fits its configuration (Section 3.2.2 of Annex 1).

For a solar plant with a battery and other on-site consumption, the applicable metering concept depends on the site configuration. The Abgrenzungsoption generally uses two meters with 15-minute resolution, but the final rules also provide simplified or special-case arrangements in which one meter may be sufficient. All meters must comply with German measurement and calibration law.

For utility-scale sites, the following points require early technical review: 

●      Strict separation: Nothing behind the battery meter may count as other consumption or other generation. Battery cooling can sit behind it only if it serves the battery exclusively.

●      Single-meter option: Sites where the battery is co-located with the renewable plant and there is no other consumption can use a simplified formula set that needs only the grid connection meter. Once you choose between the simplified and full formulas, you can only switch from the next calendar year.

●      Multiple generators: Many sites have more than one renewable plant behind the connection point. For plants of the same type, such as two PV sections, eligible exports are split in proportion to each plant's installed capacity, so no extra meter is needed. For different types, such as wind and solar, you need an additional meter and a fixed ranking order between the generators, which applies after the storage-priority rule. The periods where the applicable value falls to zero can also differ between plants, because the rules depend on each plant's commissioning year.

●      DC coupling: In some DC-coupled configurations, the selected MiSpeL formula set may require separate measurement of battery flows. Developers should confirm at an early stage whether calibrated DC measurement is required, available and economically practical for the proposed architecture.

How will MiSpeL change utility-scale BESS operation? 

With MiSpeL, an eligible co-located battery may be able to support solar output management while also participating in market-oriented charging and discharging. Your PV+BESS project may be able to import power during low-price periods and discharge during higher-price periods while retaining EEG treatment for the qualifying renewable share of its exports. The outcome will depend on dispatch rules, price assumptions, network limits, degradation, metering and the project’s marketing arrangements.

That flexibility brings new operating trade-offs:

●      Negative-price hours: Negative-price periods may affect the support treatment of exported electricity. Dispatch modelling should therefore test whether charging or discharging during those intervals changes the qualifying renewable share or project economics.

●      Arbitrage margins: BNetzA tightened the formulas after consultation to stop renewable electricity from being counted as netting-eligible. Its own review notes this narrows arbitrage margins compared with the draft, so the model returns against the final rules.

●      Grid fees: Do not treat grid-fee savings as a guaranteed MiSpeL benefit. The interaction between storage, electricity charges and the future network-charge framework remains a separate issue under the BNetzA’s AgNes process. Model any potential saving as a scenario until the relevant rules are final and applicable to the project.

How might MiSpeL change project design?

Designing a hybrid site for dual-source charging introduces technical trade-offs that don’t typically affect solar-only storage. Here are some of the design choices most likely to need another look as you update your plan around MiSpeL requirements:

Planning a PV+BESS project in Germany? Download our guide to permitting PV+BESS projects in Germany to plan the approvals that sit alongside your MiSpeL design decisions.

How can RatedPower help you prepare for MiSpeL?

Grid charging touches more than the battery. It changes sizing, import capacity, metering, and the business case at once, so most projects will need a fresh look at the full design.

MiSpeL makes the battery's charging source a design decision. Before you commit to grid charging, you'll want to know how it changes battery size, coupling choice, grid import needs, and project returns. RatedPower lets you compare PV+BESS configurations technically and economically using your own project assumptions for sizing, layout, energy yield, dispatch, degradation, auxiliary consumption, capital expenditure (CAPEX), and operating expenditure (OPEX). These are the MiSpeL questions it can help you work through:

RatedPower does not calculate official MiSpeL allocations, determine EEG eligibility or replace the settlement calculations performed by the relevant market participants and network operators. It can help teams compare the technical and indicative economic implications of alternative PV+BESS configurations. Use those outputs alongside legal, metering, market-access and network assessments when developing the final project design.

Once you settle on a configuration, generate the reports, layouts, bills of materials (BOMs), and SLDs you need directly from your project design. When you update the model, the related project outputs can be regenerated to reflect the revised design assumptions.

Schedule a demo to see how RatedPower can help you compare PV+BESS configurations under Germany’s new MiSpeL rules.