Overview

National Spatial Planning

For the Kozjak pumped storage hydropower plant project on the Drava River and the 2 x 400 kV transmission line connection to the existing international transmission line Maribor-Kainachtal, the Decree on the national spatial plan (DPN) for the pumped storage hydropower plant on the Drava River and the PSP-TS Maribor transmission line connection (Official Gazette of the Republic of Slovenia, No. 12/11) was adopted in 2011on the basis of the elaborated conceptual design (IBE) from 2005 and the positive environmental assessment in the environmental report (VGB, 2007, supplemented June 2010). The national spatial planning determined the spatial layout of the Kozjak Pumped Storage Hydropower Plant, the national spatial planning area, the spatial implementation conditions for the design and the guidelines for the determination of the intended use of space in the municipal implementation acts for the area.

The DPN covers an area of approximately 280 hectares. Of this area, we can distinguish the following segments:

• The area of the upper storage basin and the permanent landfill covers - approximately 58 hectares;
• The area of the lower platform with the inlet-outlet structure - approximately 9 hectares;
• Area of mitigation measures - approximately 5 hectares;
• Transmission line route area - approximately 180 hectares;
• Discharge tunnel area - approximately 4 hectares.

The remaining 24 hectares consist of access roads and the intersection area planned for reconstruction in Spodnja Selnica.

The figure below shows a graphical representation of the area of the Decree on the national spatial plan for the Kozjak pumped storage hydropower plant on the Drava River and the PSP-TS Maribor transmission line connection and its spatial layout. 

 

Kozjak PSP project and local self-government (municipalities)

As can be seen in the figure above, the Kozjak pumped storage hydropower plant project and the 2 x 400 kV transmission line link geographically extend across three municipalities: Selnica ob Dravi, Maribor and Pesnica.

The largest construction works will be carried out in the Municipality of Selnica ob Dravi, where all key components of the pumped storage hydropower plant are to be built (upper storage basin, penstock, transformer and powerhouse cavern, discharge pipeline, access and service tunnel, surge tank, inlet-outlet structure, and part of the transmission line) and the necessary reconstruction of the access roads to the upper storage basin.

In the Municipality of Maribor, the construction of the transmission line and the creation of a mitigation area is planned. In the Municipality of Pesnica, the construction of the termination of the transmission line and the connection into the existing Maribor-Kainachtal transmission line is planned.

The total length of the transmission line is 21.7 kilometres and includes 70 standpoints, of which:

• Selnica ob Dravi: 7.2 kilometres (24 standpoints);
• Maribor: 10.5 kilometres (34 standpoints);
• Pesnica: 4 kilometres (12 standpoints).

The project affects approximately 542 properties in the Municipality of Selnica ob Dravi, 424 in the Municipality of Maribor and 145 in the Municipality of Pesnica. The lands where permanent occupation is foreseen are scheduled for acquisition. These are mainly lands in the area of the upper storage basin and the lower platform with the inlet-outlet structure and in the area of mitigation measures.

The easements will be acquired on the road surfaces and the standpoints of the transmission line.

Project Investors

The project for the construction of the Kozjak PSP and the 2 x 400 kV transmission line has two investors. They are two well-known and trusted Slovenian companies: Dravske elektrarne Maribor, d.o.o. and ELES, d.o.o., the operator of the combined transmission and distribution electricity network.

Project implementation plan

Project phases

The Kozjak PSP project is divided into four phases:

• The pre-investment phase covers the activities of preparing the project and technical documentation, investment documentation, conducting surveys, studies and monitoring for the Environmental Impact Assessment (EIA) up to and including the obtainment of the building permit;
• The investment or the implementation phase covers the preparation of project and technical documentation, the construction phase of the facilities and the installation of the equipment, including commissioning of the power plant, training of personnel and obtaining the usage permit;
• The operational phase of the facility takes place after the commissioning of the facility has been completed and the usage permit has been obtained, and the facility is handed over for use and maintenance for the lifetime of the facility;
• The decommissioning phase follows after the end of the facility's working life.

Pre-investment phase

The pre-investment phase covers all activities in the period leading up to the award of the building permit under the integral procedure (IGD), including the preparation of project documentation, obtainment of the environmental consent (OVS), and the building permit procedure. The key activities of the pre-investment phase are:

• Establishment of the appropriate organisational structure on the part of the client and the engineer for the implementation of project activities and provision of appropriate contractors;
• Preparation of project and technical documentation (DPP, DGD, revised IDP, RD);
• Preparation of investment documentation (DIIP, PIZ, IP);
• Land acquisition (land purchases and/or easements);
• Establishment of appropriate communication with stakeholders and the public;
• Preparation of an Environmental Impact Assessment (EIA) with all related technical documents;
• Preparation of technical bases and studies;
• Preparation of the IGD application and participation and support in the administrative process of obtaining the IGD for the Kozjak PSP and the connecting 2 x 400 kV transmission line;
• Coordination between the two investors.

Implementation phase

The implementation phase covers all the activities necessary for the realisation of the project after obtaining the integral building permit. The implementation phase consist of: preparatory works, access roads, construction works on all parts of the Kozjak PSP facility (I-O facility, switchyard, all tunnels and pipelines, both caverns, surge tank, storage basin), supply and installation of all electrical, mechanical and hydromechanical equipment, construction of the 400 kV transmission line, provision of mitigation measures, all testing, trial operation, elimination of faults within the warranty period and all activities until the facility is granted an usage permit.

Project schedule

Overview of key activities already carried out: 

• 2003: Preparation of the pre-investment concept and conceptual solutions
• 2005: Preparation of the conceptual design (powerhouse in the shaft in the area under Kozjak)
• 2006: Peer-review of the conceptual design (Lahmeyer International Frankfurt - positive)
• 2008: Preparation of the investment program and supporting documents for the DPN
• 2011: Adoption of the Decree on the DPN for the Kozjak PSP together with the 400 kV transmission line
• 2012: Optimisation of the project to ensure better technical characteristics (revised IDP)
• 2012: Peer-review of the revised conceptual design (Lahmeyer International Frankfurt - positive)
• 2021: EKC study - Techno economic assessment of PSP Kozjak and other potential projects in HSE group in terms of wholesale market operation and ancillary services provision, EKC, Belgrade
• 2022: Verification of the validity of the DPN Decree and elaboration of the Proposal for the selection of the appropriate technology to ensure flexibility (IBE, December 2022)

Key activities planned until the building permit is obtained

The timetable foresees the obtaining of the integral building permit by the end of 2026. In 2027, the implementation phase of the project will start with preparatory works. The following are the more important activities until the end of 2026.

2024:

• Revised and reviewed conceptual design (IDP);
• Preparation of project documentation for the obtaining of design and other conditions (DPP);
• Start of preparation of tender documentation (DZR);
• Preparation of the Investment Project Identification Document (DIIP);
• Start of land acquisitions and easements;
• Hydraulic models of both inlet-outlet structures developed and adopted.

2025:

• Preparation of Documentation for Obtaining a Building Permit (DGD);
• Tender documentation for the LOT TGD;
• Preparation of the Pre-investment Study (PIZ);
• Preparation of all technical documents and Environmental Impact Assessment (EIA);
• Alignment of the EIA and the DGD;
• Hydraulic studies of the bifurcation and the surge tank;
• Electrical parameter studies.

2026:

• Start of preparation of the Design for Execution (PZI) documentation;
• Tender documentation for the LOT A1, A2, EO, MT;
• Preparation of the investment program for the IP;
• Completion of land acquisition activities;
• Submission of application for building permit and acquisition of building permit for preparatory works.

Current project phase and current activities

The project is currently in the pre-investment phase, which means that all the activities necessary to obtain the integral building permit are being carried out.

The main ongoing activity of the project, which is important for the client, the client's engineer, and the external designer, is the revision of the conceptual design. The conceptual design is an update of the preliminary concept and further specifies all the elements of the civil engineering works. Based on the conceptual design, the preparation of project documentation for the obtaining of design and other conditions (DPP) and the preparation of documentation for obtaining a building permit (DGD) will start this year.

All the technical bases to be prepared for the Environmental Impact Assessment (EIA) are in progress or in the procurement phase. The necessary content of the technical bases and the analyses, which examine the impact on the environment and people in more detail, are defined by the adopted Decree on the national spatial plan.

The most important activities include those related to land acquisition or the right to build. Valuations of the real estate to be purchased by DEM as investor for the purpose of the pumped storage hydropower plant are being obtained. On the basis of these valuations, purchase contracts will be concluded with the land owners this and next year.

The aim of Dravske elektrarne Maribor and the state is to build a strategic hydropower facility that will allow the storage of electricity in anticipation of the deployment of solar and other power plants that harness intermittent, renewable resources.