The 1.2GW Ilisu storage hydropower plant in southeast Turkey is expected to start up in May, state-run hydraulic works administration DSI said.
One of six 200MW units is planned to be commissioned next month, with the plant due to reach full capacity by next winter. Ilisu was most recently expected to come on line in June, having faced several delays since 2018.
Ilisu is expected to generate 4.12 TWh/yr and will be Turkey's fourth largest storage hydropower unit after the Ataturk, Karakaya and Keban plants, which are all located in the Firat-Dicle basin.
The unit started building reserves last summer. Reservoir levels rose above 6,000 hectometres³ (hm³) earlier in April, nearly 3,000hm³ higher than the minimum threshold required for the start of commercial operations, DSI data show.
Turkey's large-scale hydropower projects are all expected to be commissioned by 2021 at the latest. The 500MW Asagi Kalekoy storage hydropower plant, also in southeast Turkey, came on line partially earlier this month and is planned to reach full capacity before the end of this year. The 420MW Cetin storage hydropower plant was partially commissioned in the first week of April.
Asagi Kalekoy was initially scheduled to come on line last year, while Cetin was expected to be commissioned by the end of the first quarter, having been postponed since 2018. But Cetin's eventual commissioning was three months ahead of its operator Limak's latest estimate.
And the 558MW Yusufeli storage hydropower plant, located in northeast Turkey, is planned to come on line in 2021. Construction at the site is continuing, despite the Covid-19 crisis, with the plant on track to be commissioned next year, Limak said earlier this week. The company is developing the project for DSI.
These developments suggest a combined 2.12GW of storage hydropower capacity can come on line by the end of this year. Higher storage hydropower output has pushed gas-fired generation to the margins of the Turkish power mix since last year.
Gas-fired output fell to 6.26GW in 2019, with generation in averaging below year-earlier levels in each month of the year. Gas burn partially recovered in January-February this year as a result of higher demand, but has fallen to new lows owing to a combination of higher hydro output and declining demand. Output at gas-fired plants has averaged just 1.78GW so far in April, putting it on track to fall to a record low.
Large-scale hydropower plants could also offset declining solar power capacity additions this year. Turkish solar capacity expanded by 110MW in the first quarter of this year, down from 253MW a year earlier. At the same time, wind power capacity grew by 170MW, up from 70MW in January-March last year.
