Soto de Ribera power plant, owned by the company EDP, is a
coal-and-gas-fired power station located next to the Nalón River
at a distance of about 7 km from Oviedo (Fig. 3). It has three conventional
units which use mainly coal as fuel and one unit with a
combined cycle in which gas is used. Unit 1 was decommissioned
in 2008; only units 2 and 3 and the combined cycle unit are currently
in operation. In the following research, the name ‘Soto de
Ribera power plant’ will be used to refer only to unit 3; subject
of study. This coal-fired unit has a nominal capacity of 360MW
and uses a closed-loop cooling system which transfers the waste
heat of the process to water taken from the River Nalón. This hot
water (at 35 C approximately) has to be cooled in the cooling
tower in order to return it to the river again; consequently the
waste heat goes into the atmosphere.