This paper proposes a novel approach for distributed energy resource (DER) expansion planning from investors' viewpoint based on a combination of dynamic programming algorithm and game theory. An innovative framework is proposed in this paper to consider different aspects of distributed energy resource planning. Wind turbines, gas engines and demand response (DR) programs are considered as DERs in this study. The intermittent nature and uncertainty of wind power generation and also uncertainty of demand response programs will cause the investors to consider risk in their investment decisions. In order to overcome this problem, a modified model has been derived to study the regulatory intervention impacts on wind expansion planning and implementing DR programs. Support schemes were contributed to both wind and DR programs to determine an optimum penetration level of these sources in distribution power system. A model based on intermittent nature of wind power generation and uncertainties of DR programs is developed which can calculate optimal investment strategies. The effectiveness of the proposed model is proved through implementing on a test system. (C) 2012 Elsevier Ltd. All rights reserved.