The goal of this paper is to achieve sustainable development. The most important way to achieve sustainable development is increasing the penetration rate of distributed energy resources (DER). A novel approach is presented in this paper for DER expansion planning problem considering multifarious support schemes. The intermittent nature as well as different uncertainties which are associated with the DER resources would cause investors to encounter risk in their investment decisions. Therefore, considering the supporting policies for increasing the penetration rate of DERs are known as an inevitable issue. The supporting policies for each of DERs technologies have remarkable impacts on investment strategy of other rivals. Under this condition, the system dynamics approach is employed in this paper for modelling of this multidimensional complex problem. System dynamics approach is known as an appropriate method for simulating the dynamics of power system and studying the effects of various factors on each other. Here, the supporting policies are contemplated in combined heat and power, wind turbine, PV and demand response resources. By using this method, the impacts of regulatory policies on market dynamics are modelled, which effect on market dynamics and investment policies of resource owners. Also, the robustness of achieving to sustainable development could be evaluated.