Client: Arsan Energy
Installed Capacity 40 MW
Pondage In Tunnel
Unlined Long Tunnel
Kayakopru-I HEPP and Kayakopru-II HEPP are both diversion type hydropower facilities over Yagli Creek. These projects are in commercial activity since 2012.
Kayakopru-I HEPP makes use of the head between 853.55 m and 582 m of Yagli Creek and Kayakopru-II HEPP makes use of the head between 582 m and 500 m of Yagli Creek for energy generation. One of the most significant features of the projects is the long conveyance tunnels whose lengths are 6,770 m and 2,745 m for Kayakopru-I and II HEPPs, respectively. In these projects, tunnels are designed such that they can be used for daily storage by making use of the volume of the tunnels. The storage capacity is 42,300 m3 for Kayakopru-I HEPP, and 22,000 m3 for Kayakopru-II HEPP. Three different excavation cross-sections - 4.40 m diameter and 4.40 m height, 5.40 m diameter and 4.90 m height, 5.40 m diameter and 5.10 m height- have been used for conveyance tunnel of Kayakopru-I HEPP and a single excavation cross-section - 4.40 m diameter and 4.40 m height- has been used for conveyance tunnel of Kayakopru-II HEPP. The topography of the area is too steep which increases excavation amount significantly. In order to reduce the amount of excavation, circular forebays are designed in both projects. The penstock of Kayakopru-I HEPP was adapted by inclined pipe-jacking method at two regions with a length of 156 m and 101 m due to field conditions and expropriation restrictions. By taking the advantage of having daily storage, two Francis type units with equal capacity can be used effectively.