Chaira Hydro Power Plant

{{Short description|Hydroelectric power plant in Bulgaria}}

{{Infobox dam

| name = Chaira Pumped Storage Hydro Power Plant

| name_official =

| image = PAVECChaira.jpg

| image_caption = Belmeken Dam

| image_alt =

| coordinates = {{coord|42|9|32|N|23|52|15|E|region:BG_type:landmark|display=inline,title}}

| country = Bulgaria

| location = Pazardzhik Province

| status = Not operational since April 2022 following turbine failure in Unit 4[https://bankwatch.org/blog/pouring-millions-from-empty-into-the-void Pouring millions from empty into the void] {{webarchive|url=https://web.archive.org/web/20220703083745/https://bankwatch.org/blog/pouring-millions-from-empty-into-the-void |date=2022-07-03 }}

| construction_began =

| opening = 1995 (units 1 and 2)
1999 (units 3 and 4)

| demolished =

| cost =

| owner = NEK EAD

| operator =

| res_name = Belmeken reservoir

| res_capacity_total=

| lower_res_name =

| lower_res_capacity_total=

| plant_hydraulic_head =

| plant_turbines =

| plant_pumpgenerators =

| plant_pumps =

| plant_capacity= 864 MW

| plant_capacity_factor=

| plant_annual_gen=

| ps_cooling_source =

| website =

| extra =

}}

Image:PAVECChairawall.jpg

The Chaira Pumped Storage Hydro Power Plant (Chaira PSHPP) was built in the Rila mountain range, about {{convert|100|km}} southeast of Bulgaria's capital city, Sofia. Part of the major Belmeken–Sestrimo–Chaira Hydropower Cascade, Chaira has generating capacity of {{convert|864|MW}} and a pumping capacity of {{convert|788|MW}}. The power plant is equipped with four reversible Francis pump-turbines, each rated at {{convert|216|MW}} in the generating mode, and {{convert|197|MW}} in pumping mode.

Units 1 and 2 have been in operation since 1995, and at that time Chaira was the largest pumped-storage plant in southeast Europe with the highest head in the world for a single-stage pump turbine ({{convert|690|m}} generating and {{convert|701|m}} pumping). Units 3 and 4 came online in 1999.

The pump-turbines and motor-generators were supplied by Toshiba, and three of them were manufactured under Japanese supervision in Bulgaria. The upper basin for Chaira is formed by the Belmeken Dam which connects to the pumped storage plant by two headrace tunnels with a diameter of {{convert|4.2|m}} and two penstocks with diameter {{convert|4.4|m}}, reducing to {{convert|4.2|m}}.[http://www.nek.bg/cgi?d=1432 Chaira PSP] {{webarchive|url=https://web.archive.org/web/20110721073049/http://www.nek.bg/cgi?d=1432 |date=2011-07-21 }} Outflow from the Belmeken reservoir supplies the Sestrimo Hydro Power Plant