<p>Demand response (DR) has become a key tool for reliable energy management and peak load reduction in distributed energy resource systems (DERSs). Significant uncertainties in DR arise from varying energy prices and users’ willingness. However, the correlation between these two uncertainties has rarely been discussed, potentially leading to misevaluation of operational costs and reliability. To accurately capture DR uncertainties, this study proposes a dual DR uncertainty model incorporating the correlation between stochastic energy prices and users’ willingness. Frank and Gumbel copula functions are employed to construct the correlated DR uncertainty model. Furthermore, this study proposes a two-stage chance-constrained method to evaluate the influence of correlated uncertainties on operational performance. The results indicate that there is a strong correlation between response loads caused by two DR uncertainties. The correlated uncertainty model reduces extreme scenarios during valley and peak periods by 30.5% and 22.8%, respectively. Additionally, compared with the single-factor uncertainty model, reserve resources increase by 8%–35% under different confidence levels. Compared with independent dual DR uncertainty model, operating costs are reduced by 2.1% in the correlated uncertainty model. The proposed methodology provides a balanced operational strategy that compromises between economy and reliability.</p>