Impacts of renewable portfolio standards on multi-market coupling trading of renewable energy in China: A scenario-based system dynamics model

China implements brand new renewable portfolio standards (RPS) since 2020. Based on the newly issued RPS policy, this paper constructs the system dynamics (SD) model of the multi-market coupling trading system involving the renewable electricity market, the consumption above quota market, and the tradable green certificate (TGC) market. The simulation experiments based on six scenarios are conducted to explore impacts of policy parameters such as RPS quota planning goals, unit penalties, and TGC price ceilings. The results show that: (1) Not only does the new RPS affect the price and transaction volume of the multi-market, but it also promotes renewable power generation in China. (2) The RPS quota planning goals display significant influences on the multi-market stability and renewable energy production growth, but it's not that the higher the quota planning goal, the better its effects. (3) An appropriately higher unit fine compared to the TGC price cap is conducive to moderate market volatility and stimulate market consumer demand. (4) According to the current development of renewable energy in China, the 15% quota planning goal cooperates with a unit fine and a TGC price cap with a proper gap is favorable to achieve market equilibrium and moderately promote renewable energy power generation.