Capacity of supply is a crucial matter in electricity markets as it directly influences reliability of supply, price volatility and blackout risk. In this paper, we analyse the dynamics of capacity expansion in the Swiss electricity market and the impact of different policies such as nuclear phaseout and management of electricity exchanges - imports and exports - policies. This article develops the conceptualization model presented in [Ochoa, P., 2007b. Policy changes in the Swiss electricity market: a system dynamics analysis of likely market responses. Socio-Economic Planning Sciences 41 (4):336-349.]. We build a system dynamics model based on the dynamics of capacity expansion explained in the latter paper and present and analyse different scenarios. We conclude that international electricity exchanges are important for the Swiss market as they help to lower costs and to increase the income of the utility companies; however, we illustrate the need for explicit policies for managing imports and exports of electricity to avoid import dependence from neighbouring countries.