Solar system – Hesse
Legal basis
- EEG 2023 – feed-in tariff and funding (federal level)
- Solarspitzengesetz – smart meter and control box required for new systems from 7 kWp (since 25.02.2025); without a control box, the grid operator permanently limits feed-in to 60 % of installed capacity
- § 9a Hessisches Energiegesetz (HEG), passed in November 2022 – solar requirement for state-owned buildings and car parks; no solar requirement for private residential buildings
RECOMMENDED PROVIDERS
Solar requirement in Hessen
No solar requirement for private residential buildings – neither for new buildings nor existing buildings. An extension to private households is not currently planned in concrete terms, and there is no timetable.
A genuine solar requirement has existed since November 2022 under § 9a HEG, but only for state-owned buildings with more than 50 m² of usable floor area (new and existing buildings), as well as for new car parks from 35 parking spaces (state-owned) or from 50 parking spaces (not state-owned). Private owners are not affected.
Official requirements
| Step | Requirement | Threshold |
|---|---|---|
| 1 | Notify the grid operator | all systems |
| 2 | Register in MaStR | all systems |
| 3 | Smart meter + control box | mandatory installation from 7 kWp; voluntary at 2–7 kWp, otherwise 60 % feed-in curtailment |
| 4 | Tax office | from >30 kWp |
Planning permission: not required for rooftop systems. Exceptions: listed-building protection, ground-mounted systems.
PROVIDERS
Grid operators
| Region | Grid operator |
|---|---|
| Frankfurt / Rhine-Main | Mainova / Netzdienste Rhein-Main |
| Kassel | Städtische Werke Kassel |
| Wiesbaden | ESWE Versorgung |
| Darmstadt | ENTEGA Netz |
| Rural areas | E.ON / Westnetz (in part) |
Find your grid operator: postcode search at solar.red/netzbetreiber
Processing time: 4–8 Wochen | Statutory deadline up to 30 kWp: 4 Wochen (EEG 2024)
Funding in Hessen
WIBank – Hessian loan for PV
| Feature | Details |
|---|---|
| Type | Low-interest loan + interest subsidy from the state |
| Loan amount | 10.000 € – 50.000 € |
| Interest subsidy | 1,5 % p.a. from the state of Hessen for the 10-year fixed-interest period |
| Equity | At least 10 % required; loan covers up to 90 % of investment costs |
| Minimum term / fixed-interest period | 10 Jahre |
| Eligible | PV up to 20 kWp, storage, control/regulation technology |
| Requirement | Owner-occupied residential building, private builders/owners |
| Application | WIBank customer portal online |
Municipal grants (selection) – as at 07/2026
| City | PV system | Special features |
|---|---|---|
| Frankfurt | Klimabonus: 20–30 % of costs depending on the measure | Max. 50.000 €; the funding pot for balcony solar systems was temporarily exhausted in mid-2025, and has since been topped up again |
| Darmstadt | Balcony solar systems only: 200 € (1 module) or 400 € (2 modules), max. 50 % of purchase and installation costs | Tenants are also eligible to apply; no separate funding for large rooftop systems |
| Bad Homburg | 300 €/kWp, max. 6.000 € (permanently installed modules) | Solar roof tiles: 400 €/kWp, max. 8.000 €. Balcony solar system: 200 €/module, max. 50 % of equipment costs. Storage: 300 €/kWh usable capacity, max. 3.000 € |
| Kassel | Balcony solar system: flat rate of 150 € | For participants in the Stromspar-Check, up to 500 € after assessment |
| Wiesbaden | Check locally | – |
Municipal programmes change frequently – always check availability directly with the city.
New from June 2026: energy sharing
The new Energiewirtschaftsgesetz permits sharing self-generated solar electricity with neighbours from June 2026 – relevant for apartment buildings.
EEG feed-in tariff (Q2/Q3 2026)
| System size | Partial feed-in | Full feed-in |
|---|---|---|
| up to 10 kWp | 7,78 ct/kWh | 12,34 ct/kWh |
| 10–40 kWp | 6,73 ct/kWh | 10,35 ct/kWh |
| 40–100 kWp | 5,50 ct/kWh | 10,35 ct/kWh |
Valid: 01.02.2026 – 31.07.2026 | From 01.08.2026, reduction of 1 % (six-monthly reduction under § 49 EEG 2023). Systems already commissioned retain their tariff rate for 20 Jahre.
Installation steps in Hessen
- Check the roof (orientation, structural capacity)
- Apply for the WIBank loan (before placing an order)
- Check and apply for a municipal grant – check the offer in your city to see whether it funds a balcony solar system or a rooftop system
- Appoint a certified specialist firm
- Notify the grid operator – 4–8 Wochen lead time
- Register in MaStR, arrange smart meter installation
- Commissioning + acceptance report
Grid operator note: The table above lists common grid operators – it is not exhaustive. The grid operator actually responsible depends solely on the postcode . Find it using the postcode search: solar.red/netzbetreiber
How to submit applications
1. Feed-in application to the grid operator
- Identify the grid operator: postcode search at solar.red/netzbetreiber
- Online portal of the grid operator (a legal requirement since Jan. 2025)
- Complete the form: location, planned kWp capacity, feed-in type
- Wait for approval – 4 Wochen deadline (up to 30 kWp); automatically approved if no response after 1 month
- Tip: the installer often handles the notification – ask when requesting a quote
2. MaStR registration (Marktstammdatenregister)
- Portal: marktstammdatenregister.de
- Deadline: within 1 month of commissioning
- Required: system capacity (kWp), installation date, site postcode
- Tip: many installers also handle the MaStR registration – clarify this in the quote
3. WIBank loan (Hessen)
Submit the application before placing an order.
- Portal: WIBank customer portal – wibank.de
- Online application complete: investment amount, system size, proof of ownership
- Loan approved → then appoint the installer
- Interest subsidy (1,5 % p.a.) is automatically provided by the state of Hessen
4. Municipal funding (e.g. Frankfurt Klimabonus)
- Frankfurt: stadtplanungsamt.frankfurt.de → Klimabonus → 20–30 % of costs, max. 50.000 €
- Other cities: ask the municipal utility or city authority directly – clarify in advance whether a balcony solar system or rooftop system is funded
- Submit the application before installation
5. KfW 270 (federal level)
- Through your bank apply
- Portal: kfw.de/270