Yunuslar Hydropower Project

As a result of these revisions, expropriation costs of the project has been reduced significantly as well as the negative social and environmental effects.

Project Information

Client: HES Energy

Location: Kastamonu

Status: Completed 


Key Features

Diversion Type

Total Installed Capacity 9 MW

Pressurised GRP Pipeline

Transient Analysis

Pressure Relief Valves (PRV) 



Yunuslar Regulator and HES project is a diversion type hydroelectric power station that is located in West Black Sea region, inside the borders of Çatalzeytin district of Kastamonu province over the creek of Akçay. Project is planned to make use of the energy potential of Akçay Creek between the altitudes of 240 m and 30 m.

Initially, Yunuslar HES project was planned as two staged. In both stages, currents that are converted by regulator structures are transmitted to the head ponds through canal facilities. In this case, the total canal length of the project is around 14 km. Since in the district where the project will be conducted, the construction of such a long canal line, headpond  and transportion line would be hazardous to environment and also too costly, project formulation was revisioned by Prosem Engineering.

As a result of the land and office works of Prosem Engineering, the project is reduced to a single stage and its tranmission line is planned as a pressurised GRP pipeline that will be constructed in a  closed station next to the stream bed. Also, it is been agreed to be more economic and feasible to have the water that is converted by the regulator to be transmitted directly to the turbines through this pipeline. A revised feasibility report has been prepared after the project formulation is converted in this way. As a result of these revisions, expropriation costs of the project has been reduced significantly as well as the negative social and environmental effects.

The transission line of the project is 12 km long, thus, the water hammer effect affects the design of the project significantly. For this reason, Prosem Engineering has performed a transient analysis. According to the calculations, in order to maintain the pressure rise in GRP pipe line at a reasonable level, pressure reducing valves (PRV) will be constructed in the powerouse and along the transmission line.