Fuels, together with water, make up the main natural resources used by electricity generation processes at thermoelectric power stations and by the vehicle fleet.

The sustainable growth strategy adopted by EDP, reflected in the growth of renewable energies, the gradual decommissioning of fuel oil and diesel oil-fired power stations, and the investment in more efficient natural gas power stations, has led to a significant drop in the consumption of primary energy associated with fuels: -18% between 2008 and 2011.




In addition to these resources, electricity generation involves the use of chemical products whose yearly consumption in 2011 is summarised in the table below.

Consumption of chemical products in thermal power stations in 2011 (t)

(1) The result increased significantly in Portugal in 2011, due to entry into industrial production of the denitrification unit of Sines powerplant.

The main impact originating from burning fossil fuels by thermoelectric power stations is the atmospheric emission of carbon dioxide (CO₂), sulphur dioxide, nitrogen oxides and particles. EDP has invested in monitoring and minimising the impact, namely by using fuel oil with a lower sulphur content, desulphurisation, and reducing NO_x and particle emissions.

The gaseous effluents produced by the facilities are continuously monitored and minor pollutants, e.g. heavy metals and volatile organic compounds, are regularly measured.

Currently all EDP Group coal fired thermal power stations have desulphurisation and denitrification systems which have ensured a significant reduction in specific SO₂ and NO_x emissions respectively over the past years.


Trend of SO₂ emissions (kt)
 













Trend of NO_x emissions (kt)














Trend of particles emissions (kt)



Specific emissions from thermal facilities NO_x, SO₂ and particles (g/kWh)
 
  

EDP’s thermoelectric power plants have treatment facilities for liquid effluent in order to guarantee the quality of the water disposed of in water resources. 


Effluent treated as a result of the electricity generation activity (m³)



EDP’s thermoelectric power plants continuously monitor and regularly analyse specific parameters of the treated liquid effluent, in accordance with the methods and frequency defined in their environmental permits and legislation. In the particular case of Soto Ribera, the discharge is in the river Nalón, which is declared Place of Community Interest, and their effluents are subject to conditions of temperature and chemical-physical parameters that guarantee no change in the receiving environment.

View detailed information on the quality of effluent treated and disposed of by EDP’s thermoelectric power plants:

> 2011

> 2010

> 2009

The thermal impact of cooling water from EDP’s thermoelectric power stations is regularly monitored in accordance with the specific characteristics of each plant and their environmental licences. Aerial thermographs and measurements taken allow EDP to check compliance with the established temperature limits.

Water is an essential resource for EDP operations and is used to produce steam in power plants, electricity production through water turbination, and for other uses such as irrigation and human consumption.

The reduction of water consumption is an overall objective of the EDP Group and has been included in the environmental programs of thermoelectric power plants. The use of cooling towers in all new projects has substantially reduced this impact, as it significantly reduces the amounts of water released into water resources.

The greater withdrawal of water is for use in the thermal plant cooling process. In open circuits, practically all the water is returned. In closed circuits, the withdrawn water is primarily needed to replace the water evaporated in cooling towers. 

The variations that occur in water withdrawals are mainly due to higher or lower production levels of the different thermoelectric power plants at certain periods.


Water withdrawn by source (x10³ m³)



Consumption of cooling water (x10³ m³)




In 2011, the operation of the facilities of the EDP group involved the capture of a volume of water corresponding to 1,452,958 x 10³ m³. The water withdrawal sources are different, however approximately 98% of water extracted comes from the ocean and is aimed at thermoelectric power plants in Sines (Portugal) and Aboño (Spain).

A percentage greater than 99% of the water withdrawal by EDP Group was destined for use in cooling circuits, and only 0.6% was consumed in the production of electricity.

In 2011, EDP answered, for the second time, the Water Disclosure Project, reporting in detail on its management and performance in terms of water consumption and use. This questionnaire identifies the strategy, water management plans, risks and opportunities, and it also identifies which sites/processes are in water resource stress areas. View EDP’s answers to the CDP Water Disclosure Project 2010 here. 

EDP operates a waste management programme that continuously strives to recover waste and reduce its production at the source.

Industrial waste generated by EDP’s activities is collected and stored separately. It is then sent to licensed waste management operators hired to carry out waste recovery processes as the preferred final disposal method.

The European Parliament and the Council Directive 2008/98/EC on waste, introduced several changes to the management of waste, emphasizing the definition of byproduct and what are the underlying reasons for this classification. Within the framework of energy production by the EDP Group, in 2010 were recognized by the competent authority as byproducts coal ash, coal slag (in Spain), and Gypsum from desulfurization. Thus, in line with current legislation from the year 2011 EDP reports distinctly waste and byproducts.


Total amount of waste sent for final disposal (t)
 


Total amount of hazardous waste sent for final disposal (t)




Total waste sent for recovery processes (%)




According to the Basel Convention, EDP limits the cross-border movement of wastes. Its export is restricted to PCB waste or accidental situations, where the country where the waste is generated does not have the technical capability/facilities required for disposal. There was no record of any cross-border movement in 2011.

Equipment contaminated with PCBs at concentrations below 500 ppm shall be kept until the end of its useful life, according to legislation. EDP, though, anticipates its disposal by giving priority to this type of equipment in replacement plans.


Total of PCB waste sent for final disposal (t)


 

EDP carries out sporadic noise measurement campaigns in order to check compliance with legislation in force.
 The evaluation and control of the quality of environmental noise has been an area of special focus in distribution, given that such facilities are often located close to residential areas.

EDP has been implementing acoustic insulation measures in the construction of new infrastructures.

In addition to fully complying with the applicable legislation and regulations, EDP systematically follows the development of national and international scientific studies. It also adopts the recommendations of global reference entities, especially those of the World Health Organization (WHO).