Impacts of Carbon Tax Policies on Low-Carbon Technology Investment in the Electricity Supply Chain Under Peak–Valley Pricing

This article investigates low-carbon technology (LCT) investment strategies within the electricity supply chain, employing a hybrid decision-making framework that considers both decentralized and cooperative approaches. By integrating a peak–valley pricing mechanism, the article examines the impact of carbon tax policies (CTPs) on LCT investment. It analyzes the competitive and cooperative interactions between power generation and electricity retail (ER) enterprises, focusing on how the CTP influences investment decisions, electricity pricing, and the profitability of the electricity enterprise under a wholesale electricity pricing discount strategy. The findings are as follows: 1) Surprisingly, CTPs may not always incentivize LCT investment under peak–valley pricing. When unit carbon emissions are low, CTPs promote greater LCT investment, stimulate electricity demand during peak and valley periods, and enhance the profitability of the ER enterprise. However, when unit carbon emissions are high, the absence of CTPs more effectively drives LCT investment, increases electricity demand, and yields higher profits for the ER enterprise. 2) Under a wholesale electricity pricing discount strategy, compared to the case without CTPs, when unit carbon emissions are low, CTPs lead to lower initial wholesale electricity prices during peak and valley periods, thereby increasing marginal profits for the ER enterprise. Conversely, when unit carbon emissions are high, CTPs lead to higher initial wholesale electricity prices in both periods, reducing the ER enterprise’s marginal profits. 3) Under a CTP, higher unit carbon emissions increase retail electricity prices during peak and valley periods, which reduces electricity demand, LCT investment, and the profitability of electricity enterprises. Furthermore, an increase in the unit cost of electricity generation raises retail electricity prices during peak and valley periods, further exacerbating declines in demand, investment, and profits.