One roof. Several homes. A shared plan.

Section 42a of the EnWG sets out specific protections for tenant electricity within the meaning of the EEG. For ordinary residential tenancies, the electricity contract is separate from the tenancy agreement. The label “Mieterstrom” alone does not tell you whether an offer falls under this model. Ask for the model to be named explicitly.

GGV generally requires a building electricity use agreement. Section 42b(6) provides a specific option based on an owners’ association resolution for a system operated by that association. The detailed arrangements and individual users’ rights must still be taken into account.

A system that exports all its electricity is another option. The apartments then retain their normal electricity supply. Compare export revenue with investment and operating costs, as well as the other possible uses of the roof.

One discussion concerns roof use, installation, financing and system operation. Another concerns which households receive electricity and on what terms. Interest in the roof project does not itself create an individual electricity agreement.

Where privately owned apartments are rented out, the owner and the electricity user are often different people. Record who is expected to invest and who will actually receive the electricity. Have the resolutions, cost allocation and contracts needed for your owners’ association reviewed.

Other agreed keys can distribute unused shares differently. Allocation is limited by the available amount and actual consumption in the same time interval. This example explains a fixed key only; it does not assess a particular system or annual savings.

Ask for a sample bill and an explanation of how the key is adjusted when participants join or leave. A share of the investment costs and a share of the electricity used are different quantities.

Ask which support applies to the offered model and planned commissioning date, and who receives it. A tenant electricity premium is not an automatic payment to tenants. Treat unconfirmed support as a separate scenario and check eligibility before placing an order.

Explore programmes, the status of Ulm funding and the right steps →

Clarify who reports changes, how participation and billing start or end, and how vacancies are handled. Include deadlines, meter readings, responsibility for the final bill and adjustments to the allocation.

Record who receives fault reports, resolves metering errors and informs users. Ask how a change of operator, roof work or the end of a service contract would be handled.

These loads change demand and consumption times. Define which metering point they belong to and how electricity amounts and costs are allocated. A battery needs its own transparent assessment of additional benefits; it does not automatically follow from a shared roof project.

Plan several projects together → · Prepare shared charging infrastructure → · Compare battery storage →

No. Section 42c of the EnWG describes shared use involving electricity passing through the public grid. GGV under Section 42b, as explained here, stays within the building or an associated ancillary structure without that grid transit. A project spanning several buildings or grid connections therefore needs a separate assessment of the appropriate model.

Further reading: EnWG: Section 42b building supply and Section 42c shared use

“In our building with eight apartments, we would like to explore using solar electricity from the shared roof. There is interest, but no participation agreements yet. We would like to compare GGV with a tenant electricity offer. Which documents do you need, who clarifies metering and billing, and what costs arise during the initial assessment?”

This is an illustrative conversation example. Add only details that actually apply to your building.

Participation in the electricity model and financing the rooftop system must be clarified separately. First establish interest and ask what level of participation the offer assumes. Any required association resolutions and their cost implications must be reviewed independently for your owners’ association.

You remain free to choose the supplier for supplemental grid electricity. Whether your existing contract and billing can continue unchanged must be clarified through the specific metering and supply process. Do not cancel your current contract pre-emptively.

Further reading: EnWG: Section 42b building supply and Section 42c shared use

The model’s name alone cannot tell you that. Compare the total annual cost, including fixed charges, supplemental electricity and a realistic solar allocation. Where values are uncertain, use several scenarios instead of a seemingly precise savings figure.

Electricity for individual apartments under a tenant electricity model must be distinguished from shared building operating costs. Supplying apartments requires the appropriate electricity contracts and billing. Ask for common-area and apartment electricity to be explained separately in the offer.

Further reading: Federal Network Agency: tenant electricity for consumers

Editorial status: 19 September 2026. This page supports orientation and preparation. The specific metering design, economic assessment, resolutions and contract documents must be reviewed for each building.

• EnWG: Section 42b building supply and Section 42c shared use
• Section 42a EnWG: tenant electricity contracts
• Federal Network Agency: tenant electricity for consumers
• Federal Network Agency: solar on multi-unit buildings
• BSW/GdW: building supply guide (2024 edition, PDF)
• Regional Energy Agency Ulm: building energy advice
• Ulm Netze: generation systems and storage

The EnWG was checked in its current consolidated version. The BSW/GdW guide is identified as the 2024 edition; its statements at that time about practical market processes do not confirm availability in Ulm in 2026. The allocation example is illustrative and is not an annual forecast.