Power of efficiency : international comparisons of energy efficiency and CO2 emissions of fossil-based power generation

The thesis looks at developments in capacity, energy efficiency and CO2 emissions of fossil power generation. Fossil fuel combustion for power generation is responsible for 27% of total greenhouse gas emissions emitted globally in 2005. It is estimated that by implementing best available technology for fossil power generation and thereby improving energy efficiency, greenhouse gas emissions of power generation could be reduced by 29%. This is if all fossil power plants would be replaced by best available technology and power generation would remain the same. With continuing trends however, greenhouse gas emissions from fossil power generation would grow by 95% in 2030. Energy efficiency improvement of fossil power generation alone is therefore not sufficient to compensate for the growth of fossil power generation, in case the current trend continues. This is confirmed by a case study for the EU. Despite climate targets, a large amount of new fossil capacity has been built and is planned. By placing new efficient production capacity, the efficiency of gas-fired generation in the EU increased from 34% in 1990 to 50% in 2005. For 2015, a further rise to 54% is expected. The efficiency of coal-fired power generation increased from 34% in 1990 to 38% in 2005 and is expected to increase to 40% in 2015. Despite these efficiency improvements, it is expected that greenhouse gas emissions in 2020 will have increased by 10% compared to 2005, due to an increase of fossil-fired electricity generation. It is also shown that a large portion of new capacity is not suitable for CO2 capture technology. It is estimated that CO2 capture can be applied to only 15-30% of power plants in 2030 in EU. The large amount of new fossil capacity makes it difficult to achieve greenhouse gas emission objectives. This is not only due to the limited ability to capture CO2 but also due to the long lifetime of these plants, which reduces the opportunity for renewable energy. Renewable energy is one of the main options for greenhouse gas emission reduction from electricity generation in addition to energy savings. This thesis shows the important role energy savings should play. Global electricity consumption in a business as usual scenario grows from 17 PWh in 2005 to 47 PWh in 2050. In a scenario where technical measures for energy efficiency improvement in demand sectors are implemented, electricity consumption would only grow to 22 PWh. This is a reduction of 53% in comparison to reference electricity consumption in 2050, but still a growth of nearly 30% in comparison to the 2005 level. Due to the limited potential of different options to reduce greenhouse gas emissions, it follows that a menu of options is needed to cut greenhouse gas emissions from electricity generation, including energy efficiency improvements, renewable energy and CCS