Feasibility Study of China's Electric Power Sector Transition to Zero Emissions by 2050

Abstract:

The study explores the potential transition of China’s electric power sector to zero emissions by 2050. Using a capacity expansion model (CEPRO) with 31 regions, hourly time resolution, and 39-years of historical reanalysis weather data (MERRA-2), we simulate the expansion and operation of the power sector. Instead of confronting alternative electricity-generating technologies based on costs, we consider China’s abundant solar and wind energy as the primary source of generation, and study conditions for reaching a high-renewables power system, complementarity, and substitutability of alternative balancing options: hourly energy storage, long-distance grid, back-up capacity (bioenergy), and flexibility on the demand side. In total, we consider 68 scenarios with different settings of balancing options; each scenario describes the state and operation of a nearly 100% VER-based power system in 2050. The optimization is undertaken from scratch, assuming that most of the current capacities will be retired by 2050 (except hydro and nuclear). The base year of weather information is 2018; sensitivity analysis is conducted for the six selected scenarios on 39 years of historical weather data.

The results suggest that zero-emissions power generation can be achieved with mostly wind and solar energy and alternative sets of balancing technologies. The expansion of expensive energy storage, the primary technology to balance intermittency, can be significantly reduced or entirely substituted by a combination of the long-distance power grid, partially responsive demand, and optional back-up generation. We show that a high-renewables power system can operate without significant storage and provide a high level of reliability. The balancing can be achieved by some flexibility of demand, expansion of power grid, and some back-up capacity. The four balancing options and the level of reliability of the system are substitutes for each other, making at least storage or back-up generation optional. Most importantly, a high-renewables power system may be very affordable with the supply-side system-wide costs as low as 0.2–0.3 CNY/kWh (3–4 US cents per kWh).