The Role of Natural Gas in Electricity Generation and the CO2 Forest Ecosystem Balance in Clean Sustainable Development
Authors: Bahia R.R. 
Published: March 2010

Abstract
Recent energy industry privatization and/or deregulation is a worldwide phenomenon derived from technological and economical developments and ecological pressures causing changes in the structure of primary energy and electric energy generation matriced. In Brazil, the capital costs associated with hydraulic sources from primary energy are 38% compared against 3% worldwide. This high concentration, results from the 93% share of this source in electricity generation, as compared to the 3% share in the world. There are not enough state financial resources currently available to finance a suitable expansion of electric energy to supply the increasing electricity demand in the Brazilian energy market. This explains the need for a quick and accelerated change in the Brazilian electric generation matrix, with the expected thermal share to increase from 18% in the year 2000 to 42% in 2010, and 51% in 2020, supported by natural gas (NG) as the main source for thermal generation. By the year 2020, the potential of NG demand for thermal electricity generation will be about 160 million cubic metres per day (Mcmd); that is, 66% of the total NG demand of 240 Mmcd, from which 58% (140 Mcmd) will be imported from Bolivia, Argentina, Peru, Trinidad-Tobago, and/or Venezuela.
Brazil is in the small group of countries with low CO2 Emissions, mainly due to limited coal consumption in electricity generation and the large use of hydroelectricity. An increased NG use in thermal electricity generation is still the better option in regards to this emission. Recent carbon fluxes measurements from the Long Range Biosphere and Atmosphere Experiment (LBA) in the Amazonian region have demonstrated the possibility of both young and mature forests being able to sink the 2.1 Gt/yr (3 t/hectare/yr) of CO2, and compensate for all of the CO2, and compensate additional emissions from the NG consumption increase in primary energy (with the NG demand, growing from 10 Mcmd in 2000, to 150 Mcmd in 2010, to 240 Mcmd in 2020). Finally, Brazil, even with a reduction in hydroelectricity generation and an increase of NG use in the primary energy matrix is in a very favourable position to maintain a clean, sustainable, economical, and ecological development.

Introduction
Natural gas (NG) in the primary energy and the electricity generation matrices is analyzed in relation to the energy sources ill Brazil as compared to the rest of the world. The long-term world primary energy demand matrices are revised in both tendential and ecological scenarios from the years 1850 to 2100. The Brazilian primary energy matrix, the hydroelectricity (HE), and thermoelectricity (TE) generation matrices are reviewed in relation to NG shares during the 1990 - 2000 and 2000 - 2020 periods. NG financial economical and ecological advantages are evaluated, in addition to some energy improvement indicators of boe/inhab and kWh/inhab as a result of the increasing annual growth rates of oil and NG in the Brazilian primary energy matrix for the years 2000 to 2020. The supplies of NG and LNG from domestic and external sources are estimated based on conventional gas pipelines and cryogenic ocean transportation.