[en] The goal of the paper is to quantify the impact of increasing renewable energy sources (RES) especially (wind generation and the photovoltaic feed-in) on the electricity prices in Germany, in order to investigate the well-known merit-order effect. To explore this effect, we carry out an empirical analysis based on hourly historical data for the Germany electricity market between 2012 and 2016. Our main empirical findings suggest that the increasing share of wind generation and photovoltaic feed-in induces a strong decrease of electricity spot price level. This merit order effect can have a negative impact on neighbouring electricity system. Moreover, the insufficient dispatching of the flexible gas-fired plants jeopardises their profitability and the fact that back-up is mainly done by coal plants creates a big challenge for Germany in its progress towards decarbonizing its energy mix. (authors)