Costa Rica’s multiuse Proyecto de Riego Arenal-Tempisque (PRAT) scheme was developed between 1975 and 1978 and is administrated by the Servicio Nacional de Aguas Subterráneas, Riego y Avenamiento (SENARA). PRAT channels water from the Arenal Lake, which originally used to flow down the Caribbean basin, towards the Pacific basin through a hydroelectric complex of three power plants built in cascade: Arenal, Corobici, and Sandillal (ARCOSA), illustrated above from left to right. Once the waters pass through these facilities, they enter two irrigation canals. Construction started on Arenal in 1974. The plant has three 52.5-MW Fuji Francis turbines driving Mitsubishi generators. Average annual generation is about 640 GWh. Corobici is the second of the three ARCOSA plants and has three 60-MW Mitsubishi Francis turbines with Hitachi generators. The plant went into service in 1982 and supplies about 730 GWh/yr to the Costa Rican grid. Sandillal is the last of three hydroelectric plants in the scheme. The plant has two 16-MW Kaplan turbines from Voest driving Siemens generators. Construction on Sandillal started in 1987 and it went into operation in November 1992.

Photographs courtesy of Instituto Costarricense de Electricidad
Posted 23 Dec 2003

Angostura (left) is the newest -- and largest -- hydro station in the Rio Reventazon basin in Cartago province after Cachi (center) and Rio Macho (right). Angostura is in Turrialba canton and came on-line in 2000 and has three 70-MW Francis turbines from Voest equipped with Mitsubishi generators in a powerhouse on the right bank. Angostura uses water from the Reventazon, Tuis and Turrialba rivers. Cachi is in Jimenez canton and its 34-MW turbines were twice the size of the 15-MW machines at La Garita and Rio Macho, then the largest in Costa Rica. The three 34-MW Francis T/G sets were supplied by Toshiba, the first two entering operation in 1966 and 1967, respectively, and the third in 1978.  Cachi's arch dam in Valle de Ujarraz is unique in the country and uses water from the Macho and Reventazon rivers. Rio Macho is the oldest of the three plants. It is in Valle de Orosi, Paraiso canton. The first phase of the plant was built between 1959 and 1963 and has two 15-MW Pelton turbines and generators from Toshiba. Subsequent expansion of the water collection system culminated in 1972 in the addition of two 30-MW Pelton machines from Toshiba, this time with Mitsubishi generators, and a third 30-MW machine was added in 1978. Rio Macho operates with a head of 460 m, the highest in the country. The plant uses water from the Blanco, Macho, and Pejibaye rivers.

Photographs courtesy of Instituto Costarricense de Electricidad
Posted 26 Dec 2003

The first hydroelectric plant at the Alberto Echandi site in San Ramon Canto, Alajuela Province, was built in 1909.  It has been rebuilt several times, most recently in 1990 with a 4.7-MW horizontal Francis turbine from Bell and a BBC generator.

Photograph courtesy of Instituto Costarricense de Electricidad
Posted 29 Dec 2004

The Toro hydroelectric complex consists of two plants built in the Rio Toro basin cascade in Valverde Vega canton in Alajuela province. Studies on hydroelectric development in the area were completed from 1981 to 1983 and construction of the project began in 1990. Toro-1 (above left) has two 11.6-MW vertical Francis turbines which went into operation in 1995 and 1996, respectively. Toro-2 (above right) use a regulation dam which also harnesses flows from the Rio Claro and Quebrada Gata. The powerhouse has two 32.6-MW Francis turbines which went online in the fall of 1996. Brazil’s Sade-Vigesa and Hydro Inepar supplied the generating equipment. Costa Rica's Grupo Saret was the main construction contractor.

Photographs courtesy of Instituto Costarricense de Electricidad
Posted 26 Dec 2004

The Tres Rios complex consists of three minihydro plants on the Rio Tiribi in La Union Canton, Cartago Province. These were privately-developed and acquired by ICE in mid-1975. All three sites are at elevations ranging from 1,565-1,750 m. The plants are Avance (240 kW, left), Los Lotes (375 kW, center), and Puerto Escondido (184 kW, right).  Avance was completed in 1938 and has a horizontal Pelton turbine from Escher-Wyss driving an Ideal generator. Los Lotes was completed in 1940 and rebuilt in 1956.  It has a horizontal Francis turbine from Voith driving a generator from Schorch-werke AG.  Puerto Escondido was completed in 1940 with a single 184-kW horizontal Francis turbine from Escher-Wyss driving a Dornhoff generator.

Photographs courtesy of Instituto Costarricense de Electricidad
Posted 29 Dec 2004

Cariblanco
Location: Alajuela
Operator: ICE
Configuration: 2 X 40 MW Francis
Operation: 2007
T/G supplier: Litostroj, Koncar
Quick facts: In Feb 2007, the first set was commissioned at this plant on the Rio Sarapiqui. The $170mn project was financed by Banca de Inversion del Banco Nacional de Costa Rica (BNCR).

Photograph courtesy of Dirección Sectorial de Energía
Posted 19 May 2007

Don Pedro
Location: Heredia
Operator: Enel Latin America LLC
Configuration: 1 X 14 MW Pelton
Operation: 1996
T/G supplier: Sulzer Escher Wyss, Canadian General Electric
EPC: Ingendesa, Jose Cartellone Construcciones
Quick facts: Don Pedro is a peaking hydro plant in Sarapiquí 45km north of San José. Water is diverted from the Rio San Fernando by means of a concrete gravity dam and flows through a siltation basin and then 3km of open canal and tunnel. Water is stored in a small geomembrane-lined reservoir designed to store about 5hr worth of water which is delivered to the powerhouse by a 3km penstock. Water then flows through a tailrace canal to the Rio Volcán. A 14km, 34.5kV overhead transmission line connects to ICE’s Toro Substation.

Photograph courtesy of Enel Latin America LLC
Posted 20 May 2008

La Joya
Location: Cartago
Operator: Union Fenosa
Configuration: 3 X 17 MW Francis
Operation: 2006
T/G supplier: Alstom
EPC: Alstom, Union Fenosa, Ghella, Seli
Quick facts: This site is downstream of the Cachi plant on the Rio Reventazón. It was first used by Cia Nacional de Fuerza y Luz SA for a minihydro plant in 1915.Union Fenosa is a 65% owner of the €61mn BOT project. The €49mn civil work was subcontracted to Seli and Ghella. Construction started in Feb 2003 and included a 7.9km long, 6.18m diameter tunnel, drilled using a double shield Robbins TBM.

Photograph courtesy of Union Fenosa
Posted 9 Sep 2006

Rio Volcan
Location: Heredia
Operator: Enel Latin America LLC
Configuration: 1 X 17 MW Pelton
Operation: 1998
T/G supplier: Sulzer, Canadian General Electric
EPC: Sulzer, Jose Cartellone Construcciones
Quick facts: This complex small hydro project is in Sarapiquí, 45 kilometers north of the city of San José and uses water from the Volcán and Volcancito rivers. Water is diverted via concrete gravity dams to a degraveler downstream of the Volcán dam. From there, a 1.4km tunnel runs to a siltation basin, from which a 600m tunnel conveys water to a small geomembrane-lined reservoir. A 4km penstock conveys the flow from the regulating reservoir to the powerhouse with a 3-jet, horizontal Pelton turbine. Power is transmitted through a 14km, 34.5kV overhead transmission line to ICE’s Toro Substation. The Don Pedro and Rio Volcan projects were originally developed by Covanta Energy.

Photograph courtesy of Enel Latin America LLC
Posted 21 May 2008

Ventanas-Garita
Location: Alajuela
Operator: ICE
Configuration: 2 X 48.7 MW Francis
Operation: 1987
T/G supplier: Fuji, Marelli
EPC: ICE
Quick facts: This plant is on the Rio Ciruelas and was an extension to the La Garita project.

Photograph courtesy of Instituto Costarricense de Electricidad
Posted 19 May 2007