Connection to the grid

Updated: 07.02.2019

Author: Stefan Ćetković

RES-E plants (except wind power plants) are not obliged to follow any special procedure or special provisions for grid connection. Renewable energy is not given priority.

The exact procedure of grid connection is governed by the General Electricity Supply Conditions. The technical details of grid connection are governed by the Grid Code. 

According to the grid operator HEP-OPS, wind power plants must follow a different procedure when being connected to the grid. This procedure is governed by the Criteria for the Registration of Wind Power Projects and the Procedural Rules for Wind Power Plants. 


Process flow

Procedure for the connection of RES-E plants in general:

The operators of RES-E plants (except wind power plants) are required to apply to the grid operator for authorisation. The application is processed by the grid operator, which first issues preliminary authorisation, which a prerequisite for obtaining planning permission for the power plant (Art. 3 General Electricity Supply Conditions).

The plant operator must submit the following data in his application: 

  • the entry capacity of the plant
  • the date of connection
  • the rated power and features of major appliances and facilities for power generation
  • the technology used to produce electricity;
  • the expected annual production of electricity 
  • other information (technical details etc.)

(Art. 7 General Electricity Supply Conditions).

A preliminary authorisation is valid for 2 years (Art. 9 General Electricity Supply Conditions).

Based on the data given in the preliminary authorisation, the grid operator and the plant operator conclude a contract in which they set down the terms and conditions of power supply (Art. 27 General Electricity Supply Conditions).

Procedure for the connection of wind power plants:

The connection procedure for wind power plants is slightly different. The operator of a wind power plant is first required to apply for registration on a list of wind power plants. Such an application shall also be made in case of changes to the grid connection (e.g. an increase in the output of the wind power plant) (Art. 1 Criteria for the Registration of Wind Power Projects). 

The grid operator keeps a list of wind power plants. Project holders need to be placed on the list in order to request connection. The request must be sent to the grid operator along with: 

  • an extract from the register of plants,
  • an energy permit for the building,
  • a (preliminary) authorisation,
  • a legally valid planning permission
  • a signed contract for grid connection

(Art. 4 Criteria for the Registration of Wind Power Projects). 

The plant operator is required to submit further documentation (e.g. that he is holding the status of a qualified producer, has a signed a power purchase agreement, etc.) within 6 months from the registration on the list (Art. 6 Criteria for the Registration of Wind Power Projects).

Competent authority

Grid Operator (HEP – OPS)


Usually, the deadline for a connection to the low-voltage grid is 30 days from the day on which all conditions for connection have been met (Art. 28 § 6 General Electricity Supply Conditions). For medium or high-voltage grid connections, the deadline is set in the agreement (Art. 28 § 8 General Electricity Supply Conditions).

For wind power plants, the deadline for the decision on registration on the list is 15 days from the day of submission of the application. Project that have been registered on the list, will be connected on a first-come first–served basis (Art. 5 Criteria for the Registration of Wind Power Projects).

Obligation to inform

The mutual obligation to inform is set down in the connection agreement. In any case, both parties are obliged to report to the other party any changes regarding the power output of the power plant, any damages/irregularities concerning the measuring devices, damage to the connection line, etc. (Art. 19, 35, 80 and 81 General Electricity Supply Conditions). 

Priority to renewable energy

  • Priority to renewable energy
  • Non-discrimination

Non-discriminatory and transparent use of and access to the transmission and distribution system is guaranteed to all registered grid users (Art. 29, No. 8 and Art. 40, No. 9 Electricity Market Act).

Capacity limits (quantitative criteria)

If grid capacity does not allow any new RES-E plants to be connected to the grid, the grid operator will refuse connection. There are no obligations for the grid operator to expand his grid in order to enable an RES-E plant to be connected (Art. 3 General Electricity Supply Conditions).

Distribution of costs

Plant operator

The costs of the connection are borne by the plant operators (Art. 1 § 2 Connection Fee Rulebook). 


Further information

  • Hrvatska Elektroprivreda Operator Prijenosnog Sustava (HOPS) – Croatian Transmission System Operator
  • +385 1 45 45 111
  • HOPS website
  • kontakt(at)
  • Hrvatska Elektro Privreda Operator Distribucijskog Sustava (HEP ODS) – Croatian Distribution System Operator
  • +385 1 63 22 111
  • HEP ODS website