WHAT WE DO
Our areas of activity
Hydroelectric Business
XEAL operates in the Galicia-Costa Hydrographic Demarcation a number of hydroelectric developments in the basins of the Grande do Porto river, in the municipality of Vimianzo, and the Xallas river, in the municipality of Dumbría.
In the first, a flow-type hydroelectric power plant is operated and, in the second one, a series of cascade hydroelectric power plants. Between them, they have a total installed capacity of 167 megawatts (MW).
Rio Grande do Porto
Furaqueira reservoir with the Carantoña power plant.
Xallas River
Fervenza reservoir, with the Fervenza I and Fervenza II power plants.
Ponte Olveira reservoir, with the Ponte Olveira I and Ponte Olveira II plants.
Castrelo reservoir, with the Novo Castrelo and Castrelo power plants.
Santa Uxía reservoir, with the Santa Uxía I, Santa Uxía II and Novo Pindo power plants.
XEAL is also responsible for the management of two dams and 3 weirs that allow the regulation of the flows of both rivers, and the safe and efficient management of their water resources.
In addition,XEALmanages an important electrical network up to its connection with the national electrical grid at the Dumbría substation. The maximum voltage of its owninternal networkis 220 kV.
Grande do Porto river catchment area
Rio Grande do Porto
On the Grande do Porto river there is a dam that creates the Furaqueira Reservoir, from which the Carantoña Power Plant is fed with a diversion channel for its subsequent return to the river. This is a flowing type of hydroelectric exploitation.
| Reservoir | Basin area (km2) | Accumulated basin area (km2) |
| FURAQUEIRA | 226,9 | 226,9 |
Xallas River
The hydroelectric exploitation in the Xallas river covers the final 16 kilometers of its course, before it flows into the sea.
It basically consists of a regulating reservoir at the headwaters, whose regulation is transferred to all downstream uses, and which directly feeds the Fervenza I and Fervenza II power plants.
Downstream of it rises the Ponte Olveira dam, which generates the reservoir of the same name. This reservoir feeds the Ponte Olveira I and Ponte Olveira II power plants.
The tail of the Castrelo reservoir begins at the restitution of the Ponte Olveira power plants.This reservoir feeds the Novo Castrelo power plant, which discharges into the tail of the Santa Uxía reservoir; and the Castrelo power plant, which, after a 7 km-long diversion channel, returns its waters into the Ézaro inlet.
The Santa Uxía dam is located at the end of the river, forming its associated reservoir. This reservoir provides additional regulation to that offered by the Fervenza headwater reservoir to the three hydroelectric developments that are fed from it: Santa Uxía I, Santa Uxía II and Novo Pindo.
As mentioned above, the river is regulated principally by means of the Fervenza (98.376 hm3) and Santa Uxía (18.053 hm3) reservoirs.
There are also two other small reservoirs in operation formed by the Ponte Olveira and Castrelo dams.
| Reservoir | Basin area (km2) | Accumulated basin area (km2) |
| FERVENZA | 320,5 | 320,5 |
| PONTE OLVEIRA | 107,0 | 427,5 |
| CASTRELO | 13,6 | 441,1 |
| SANTA UXIA | 57,9 | 499,0 |
Sub-basins of the Xallas river that flow into each of the reservoirs.
The Fervenza I and Fervenza II hydroelectric power plants correspond to the type of power plant with regulating reservoir.
The Fervenza reservoir regulates the flow of the Xallas river to maximize the electricity production of the downstream plants: Ponte Olveira I, Ponte Olveira II, Novo Castrelo, Castrelo, Santa Uxía I, Santa Uxía II and Novo Pindo.
The Ponte Olveira I and Ponte Olveira II hydroelectric power plants benefit from the regulating effect of the Fervenza reservoir. Through the dam, part of the flow of the Xallas river is diverted to be turbined in the two plants.
The water, once turbined, is returned to the river and is once again used for hydroelectric purposes.
The Ponte Olveira I plant is a free sheet bypass plant with a channel excavated in a tunnel and the Ponte Olveira II plant is a pressure bypass plant with a conduit excavated in a tunnel.
The Novo Castrelo power plant benefits from the regulating effect of the Fervenza reservoir. It is a pressure diversion power plant with a tunnel excavated conduction and a balancing chimney.
The Castrelo plant also benefits from the regulating effect of the Fervenza reservoir.
It is a free-flowing diversion power plant with mid-slope canal sections, tunnel sections and aqueducts.
It returns water downstream of the Santa Uxía dam, so that the turbined water can no longer be used by the Santa Uxía I, Santa Uxía II and Novo Pindo power plants, which use this reservoir.
Downstream of the Castrelo weir is the Santa Uxía reservoir, from which the Santa Uxía I, Santa Uxía II and Novo Pindo hydroelectric power plants are fed. This reservoir allows the additional regulation of the river flows, increasing the effect achieved with the Fervenza reservoir.
The Santa Uxía I and Santa Uxía II plants are hydroelectric power plants with load diversion by means of a tunnelthat crosses the mountain to feed the penstock of each plant. The Novo Pindo plant was built later, grafting the penstock of the Santa Uxía II plant and thus increasing the power installed in the final section of the river.