Fratel Dam

Fratel Dam (Portuguese: Barragem de Fratel) is a concrete gravity dam on the Tagus, where the river forms the border line between the districts of Portalegre and Castelo Branco. It is located in the municipality Nisa, in Portalegre District, Portugal.

Fratel Dam
Location of Fratel Dam in Portugal
Official name	Barragem de Fratel
Location	municipality Nisa, Portalegre District, Portugal
Coordinates	39°32′34.1″N 7°48′10.4″W
Purpose	Power
Status	Operational
Opening date	1973
Owner(s)	Companhia Portuguesa de Produção de Electricidade
Operator(s)	Energias de Portugal
Dam and spillways
Type of dam	Concrete gravity dam
Impounds	Tagus
Height (foundation)	48 m (157 ft)
Height (thalweg)	43 m (141 ft)
Length	240 m (790 ft)
Elevation at crest	87 m (285 ft)
Dam volume	124,000 m^3 (4,400,000 cu ft)
Spillway type	Dam body
Spillway capacity	16,500 m^3 (580,000 cu ft)
Reservoir
Total capacity	92,500,000 m^3 (75,000 acre⋅ft)
Active capacity	21,000,000 m^3 (17,000 acre⋅ft)
Surface area	10 km^2 (3.9 sq mi)
Normal elevation	74 m (243 ft)
Operator(s)	Energias de Portugal
Commission date	1974
Hydraulic head	28.8 m (94 ft) (max)
Turbines	3 x 45.6 MW Kaplan-type
Installed capacity	132 MW
Annual generation	357.9 GWh

The dam was completed in 1973. It is owned by Companhia Portuguesa de Produção de Electricidade (CPPE).[1] The construction of the dam meant the flooding of most of the tens of thousands of petroglyphs found in the Tagus valley rock art area.[2]

Dam

Fratel Dam is a 48 m tall (height above foundation) and 240 m long gravity dam with a crest altitude of 87 m. The volume of the dam is 124,000 m³. The spillway is part of the dam body (6 radial gates with a maximum discharge capacity of 16,500 m³/s).[1]

Reservoir

At full reservoir level of 74 m (maximum flood level of 76 m) the reservoir of the dam has a surface area of 10 (7,3)[3] km² and its total capacity is 92.5 mio. m³. The active capacity is 21 mio. m³. Minimum operating level is 71 m.[1]

Power plant

The run-of-the-river hydroelectric power plant went operational in 1974.[4] It is owned by CPPE, but operated by EDP.[5] The plant has a nameplate capacity of 132[3][5][4] (130)[1][6] MW. Its average annual generation is 357,9[4] (327,[3] 347.5[1][5] or 382[6]) GWh.

The power station contains 3 Kaplan turbine-generators with 45.6 MW (50 MVA) each in a dam powerhouse. The turbine rotation is 150 rpm. The minimum hydraulic head is 17.8 m, the maximum 28.8 m. Maximum flow per turbine is 250 m³/s.[4]

See also

• List of power stations in Portugal
• List of dams and reservoirs in Portugal

References

1. "FRATEL DAM". APA Barragens de Portugal. Retrieved 2015-02-21.
2. Arcá, Andrea (2001). "Damned dams again: the plight of Portuguese rock art" (PDF). Rock Art Research. 18.
3. "DECLARAÇÃO AMBIENTAL 2012" (PDF) (in Portuguese). Energias de Portugal. pp. 50 (48). Retrieved 2015-02-07.
4. "Fratel Informação Técnica" (in Portuguese). Energias de Portugal. Retrieved 2015-02-21.
5. "Fratel Hydroelectric Power Plant Portugal". Global Energy Observatory. Retrieved 2015-02-21.
6. "Hidroelectricidade em Portugal memória e desafio" (PDF) (in Portuguese). Rede Eléctrica Nacional, S.A. p. 29 (27). Retrieved 2015-02-05.