New Energy Investment Strategies in the Electricity Supply Chain Under Subsidy Mechanism

This paper investigates new energy investment strategies in the electricity supply chain (ESC) in the context of the global energy transition. A noncooperative–cooperative (nonco–co) biform game framework is used to construct a two-tier ESC model comprising an electricity generator and a retailer. By integrating upstream carbon quota mechanisms, Grandfathering (GM) and Benchmarking (BM), with downstream green certificate subsidies, the study reveals the logic of collaborative new energy investment through cost-sharing and price competition, and clarifies the effects of carbon quota mechanisms on investment decisions, carbon emissions, and corporate profits. The findings are as follows: (1) The BM provides stronger incentives than the GM for generators to expand new energy investment, whereas the GM is more effective in controlling total carbon emissions, keeping them below BM levels. (2) Under the BM, a higher unit carbon quota drives generators to expand new energy investment, along with a rise in total carbon emissions. From a profit standpoint, when the unit carbon quota is relatively low, both generators and retailers achieve higher profits under the GM; conversely, when the quota level is relatively high, both attain higher profits under the BM. (3) Under both mechanisms, an increase in the green certificate subsidy coefficient raises the cost-sharing ratio of new energy investment, stimulates higher investment volumes, and expands electricity demand. At the same time, the profits of both generators and retailers increase, while total carbon emissions decline; however, it also pushes up both wholesale and retail electricity prices.