The volatility of the new energy industry in China, especially with the background of the global energy transition toward the so-called Dual Carbon strategy, has become a major challenge to the old approach to investing in China. This paper empirically examines how ESG constraints affect new energy investment portfolio optimization. The research samples, which are 10 major enterprises within the industry, such as CATL and BYD, will provide their weekly trading data and Huazheng ESG rating indicators in 2024-2026. Using the Markowitz mean-variance model and solver programming, it identifies risk-minimizing efficient portfolios. According to the empirical findings, the variance of the investment portfolio following the imposition of the ESG ≥ 85 constraint decreases by 36.61 percent as compared to the equal-weight benchmark portfolio. Nonetheless, the research also finds that there are important implementation issues, such as a green allocation paradox (high-ESG assets with high volatility are left out) and excessive concentration (the two largest holdings constitute 88.35%), which can negatively affect diversification returns. This paper suggests optimization strategies, such as the creation of a dynamic ESG monitoring system, the establishment of weight caps in subdivided industries, and improved active governance participation, in order to address these pain points. This paper adds a quantitative model of including ESG in portfolio development, providing not only a risk-management perspective to green investors but also practical suggestions toward the high-quality, capital-markets-appropriate development of the new energy sector in China.
Research Article
Open Access