Electric Energy Consumption in Portugal
The electric energy consumption in Portugal has consistently increased in the last years, in about 120.000 tep. /year. Most of that energy is thermoelectric origin, produced in thermoelectric plants (50%) and in combined heat and power generation (11%).
What remains of the electricity production is rectified by the production from hydro sources (16,6%) and production by wind energy and geothermal energy (14%).
Portugal has typically a deficit in electric energy production, resorting to an annual net import of electricity (8,8% in 2009).
The Paper Industry was, in 2009, responsible by the production of 4, 2% of the electricity consumed in Portugal.
Cogeneration is a production technology that combines the heat production, used in an industrial process or in heating processes, with the electricity productions. It is an energetic process and environmental interesting because it is much more efficient than the simple electricity production that wastes a bigger fraction of thermal energy contained in fossil fuels.
Nationally, the paper industry is the sector that contributes the most for the total of electric energy from this way of production, with 35% of the total, remaining, through new investments, as the main cogenerating sector and growing its self-sufficiency, compared with consumption needs.
In European terms, the average self-sufficiency of the paper sector in electric energy was of 48% (CEPI, 2009), much lower than Portugal, where the sector remains surplus in electricity production, with the production exceeding the consumption by 18%.
Fuels Profile in the Thermal Production
The thermal production in dedicated central structures is, in Portugal, practically based in fossil fuels, particularly coal and fuel oil.
The cogeneration production (except in the paper industry) is based mainly by oil products, mostly fuel oil and, more recently, natural gas.
The cogenerations of paper industry are different than the others industrial sectors concerning the fuels used. Most of the fuels consumed in cogeneration by this sector, has origin in biomass (70% in 2010).
Global Fuel Consumption
The industry consumes fuels in the production of thermal energy used directly in the process, in intern transportation and in cogeneration, with simultaneous production of heat (through steam or hot water used in the industrial process) and electricity.
In the paper industry case, the strong investment in cogeneration systems represents the reduced fraction of fuels with direct utilization for thermal energy and/or in internal transportations.
Of the about 30% of fossil fuels used by this industry, the dominant is natural gas (77%). All the biomass is used in cogeneration processes.
When it is compared with the fuels profile of paper industry in Europe (CEPI, 2010), it is observed that the sector in Portugal presents a bigger proportion in the use of biomass (69% national versus 54% European, the absence of the use of coal and a bigger one of fuel oil ( 5% versus 3,8%).
Data referred to “National energy balances”, made by the General Direction of Geology and Energy for the period 1990 to 2009 and CEPI, 20010.