The Positioning of Coal-fired Power Plant during Energy Transformation and The Effect of CO2 Emission
No.: PR2025
Author: Jheng, Ruei-He
Price: Not for Sale
Publication: 2019.03
Abstract:
Greenhouse Gas Reduction and Management Act of Taiwan was passed in June 2015. The law aims to reduce 50% greenhouse gas emissions of Taiwan by 2050 and it requires power sector to reduce 132.63 MtCO2e. In addition, according to the latest version of Power Development Planning in Taiwan, thermal generator capacity will increase and part of the old coal-fired generators will be replaced by Ultra-Supercritical Combustion (USC) generators. However, the CO2 emission coefficient of coal-fired generator is higher than that of other generator so the replacement just can mitigate greenhouse gas emission of Taiwan.
Moreover, the government announces coal-fired generators will be 30 percent in electricity mix by 2025 and we estimate the idle capacity of coal-fired generators will be at least 3,300 MW. Furthermore, Germany’s Energiewende was beginning in 1980 that for the purpose of changing energy structure and reaching the goal of greenhouse gas reductions through energy savings, electricity supply, grid strength, power market, environmental regulation, and so on. The trend of power capacity and generation in Germany, nuclear and coal-fired generators are decreasing, renewable energy (especially onshore-wind power and PV) is increasing.
Besides, they retrofit coal-fired generators to be stand-by units for the sake of power supply security. On the other hand, CO2 emissions of Germany were 502 MtCO2e in 2016 which reduced 23.76% comparing to 1990 and the CO2 emissions is rigidity recently. In terms of power system reliability, the System Average Interruption Duration Index (SAIDI) and System Average Interruption Frequency Index (SAIFI) are improvement.
The experience of Energiewende in Germany that we can refer including: (1) coal-fired generators should be retrofitted and transferred to stand-by units; (2) the traditional power dispatch plan would be change to meet the variation of renewable; (3) levying carbon tax or energy tax to reduce coal-fired generation and electricity comsumption; (4) it design reward-compensation mechanism for stand-by units which are coal-fired generators or CHP (cogeneration, combined heat and power); (5) continuing improve power grid construction and considering grid-level energy storage system.
According to energy transformation plan of Taiwan, elextricity mix of renewable energy, gas-fired and coal-fired will be 20 percent, 49 percent and 29 percent respectively by 2025. However, in the past two years, in addition to the roof type PV system, the ground–mounted PV system and wind power are far lower than original plan. It is worthy of observing the development of renewable in the future. In addition, the estimation of peak load growth rate may be too low to fit the reality and in the future that will lead to the power shortage. We suggest that the growth rate should be 2 percent per year. In addition, the government should not only focus on supply side but also enhance the measures of Demand Response Management (DRM) in power development and plans such as Demand Response (DR), demand bidding, Time for Use (TOU), and promotion of energy storage system in order to maintain security of power supply and quality of energy transformation roadmap. The study estimate the electricity mix of transformation roadmap that plan by the government. We construct an electricity model under the condition of minimum generation cost.
The result shows that the coal-fired, gas-fired and renewable energy will close to 30 percent, 50 percent, and 20 percent when the generation cost of coal-fired, gas-fired, renewable energy and nuclear are NT$2.4 per kWh, NT$4 per kWh, NT$1.4 per kWh and NT$12.5 per kWh respecitvely. Furthermore, the electricity carbon emission coefficient will decrease from 0.461 kgCO2e/kWh to 0.429 kgCO2e/kWh by 2025 under energy transformation roadmap which is differen from the goal of greenhourse gas reduction (0.394 kgCO2e/kWh).