The Curtailed Renewable Energy Generation And New Approaches For Its Utilization

Concerns over climate change(global warming) are driving innovation for stabilizing and reducing greenhouse gas(GHG) emissions. Technologies like carbon capture and storage(CCS), electric vehicle as well as renewable energy sources including wind and solar have been increasingly used and integrated into existing energy systems. The global installed renewable energy capacity booms, but many problems regarding grid integration appear due to the variability and uncertainty in the output of renewable energy generation. It is common for wind farms, solar power plants and hydroelectric power stations to experience generation curtailment in the integration of large-scale renewable energy generation, resulting in a number of clean energy wastes. Therefore, it is of great practical significance to explore the the utilizations of curtailed electric energy(CEE) in consideration of the characteristics of renewable energy generation.Under the background of low carbon and environment friendly promoted in smart grid, potential new ways to make full use of CEE has become the focus of our research. The following researches are carried out in this paper.An estimation method for CEE based on real-time power balance is proposed in this paper. The method is based on the annual cumulative installed capacity, the actual power generation and the annual available power generation utilization hours of renewable energy. Then, the worldwide CEE from 2008 to 2013 is estimated, especially in China. Reducing the concertration of CO2 in the air is the key to addressing climate change. Moreover, to evaluate the potential utilization of various generation resources, the potential of reducing fossil fuel consumption, GHG emissions and air pollutants as well as the potential of capturing CO2 with CEE are analyzed.CO2 capture from ambient air can compensate for all CO2 emissions to the atmosphere, ultimately reducing CO2 concentrations on a global scale. A replacement of conventional energy by wind energy to power the existing systems of CO2 capture from air is proposed in this paper and its technical feasibility is validated. Fossil fuels are scarce and additional CO2 emits when CO2-intensive fossil fuels are used to drive the systems of CO2 capture from air. Intermittent and volatile wind and solar power which have great potential for development and will not emit additional CO2 directly, are the ideal power sources to drive the systems of CO2 capture from air. The intermittency and volatility of wind power supply in seasonal variations are considered when wind power is used to meet the energy requirements for CO2 capture. Energy requirements for each device in the system of CO2 capture from air are specified and the characteristics of all devices are also analyzed. In order to investigate how flexible CO2 capture regarding the variations in wind power supply, an optimal operation model is established. Each device in the system of CO2 capture is considered as a separate load, thus devices are dispatched separately rather than as a whole to improve the acceptance of intermittent and volatile wind power and reduce CO2 concentration in the air.In conclusion, focusing on the CEE, the corresponding researches are conducted. An estimation method for CEE based on real-time power balance is put foreword and then a potential new approach to make full use of CEE is proposed through a replacement of conventional energy by wind energy to power existing systems of CO2 capture from air. The work of this paper can provide guide for further development of large-scale renewable energy and new ideas for addressing climate change.