## 4 Case Study
### Simulation Analysis
#### 4.2.5 Comparison of the Proposed Mechanism with the Other Two Cases  
In order to prove the advantages of the hybrid electricity market trading mechanism and user-side consideration of carbon responsibility, this paper sets three comparison cases; the method proposed in this paper is set as Case II:  
* Case I: Open the pool market and consider carbon responsibility on the user side under the single pool market trading mechanism;
* Case II: Add a bilateral market and consider carbon responsibility on the user side under the trading mechanism of the hybrid electricity market;
* Case III: Add a bilateral market and consider carbon responsibility on the generation side under the trading mechanism of the hybrid electricity market. The sales of electricity by new energy generators in Case I, Case II, and Case III are shown in Figure 10. The electricity sold by new energy generators in Case II and Case III is significantly higher than that in Case I which means the hybrid electricity market mechanism significantly increases the market share of new energy generators. In addition, the electricity sold by new energy in Case II is closest to the maximum output of new energy generators. On the premise of not changing the user's demand for electricity, Case II transfers the carbon responsibility from the power generation side to the user side on  
Figure 9: Sensitivity analysis of carbon price. the basis of Case III which has a direct incentive effect on users, prompting users to adjust power purchase strategies so as to increase the electricity sales of new energy. In addition, as can be seen from Figure 11, the carbon emission in Case II and Case III are significantly reduced compared with Case I; Case II has the least carbon emission. In Case III, the reduction in carbon responsibility on the generation side leads to the power generators with high carbon intensity raising their quotation in order not to incur losses. As thermal power generator has the highest carbon intensity, their market competitiveness and their output decreases. In Case II, the reduction in carbon responsibility on the user side can directly stimulate users and promote the transformation of the users' power purchasing strategies to low-carbon. The carbon emission results verify the emission reduction effectiveness of this model. As shown in Figure 10, when both Case II and Case III open bilateral markets the electricity sold by new energy power generators in Case II is higher than that in Case III. In order to more accurately convey the enthusiasm of users to actively choose clean energy, the bilateral power purchase situation of users under Case II and III is analyzed. As shown in Figure 12, the amount of new energy power purchased by users in the bilateral market in Case II is greater than that in Case III. This is because under Case II users are motivated by carbon responsibility and purchase new energy power in the bilateral market to reduce carbon responsibility costs following wind power and photovoltaic output. In  
Figure 11: Carbon emission situation. Figure 10: Electricity sales of new energy power producers. Case III, in order to achieve the electricity cost objective function, users only consider the preferential transaction with the generator with the lower bid. However, due to the differences in pricing strategies of power generators at different periods, the proportion of users actively purchasing new energy cannot be guaranteed when there is no carbon responsibility constraint. The comparative analysis shows that, compared with the single price incentive, the double incentive of electric carbon is more conducive to tapping the user's emission reduction potential and promoting the consumption of new energy. Table 4 shows the economic comparison in each case.