Among the different individual factors considered (market prices of coal, gas and C02, change in electricity demand, electricity import/exports, investments in new conventional plants and phase-out of nuclear units in Germany, availability factors of nuclear and hydro plants), the deployment of variable renewable energy has been the largest individual contributor to the price drop: -24% in Germany and -35% in Sweden. However, because of the intrinsic complexity of such analysis, most of the studies focus only on one or two components of system costs and, to the knowledge of the authors, a complete and comprehensive analysis of the system effects has yet to be performed. Also, many studies analyse and describe the impacts of large VRE penetration on the system, but do not explicitly calculate the system costs. The only attempt in this respect has been performed by the NEA publication (2012) in which the system costs of different conventional power plants have been compared with those of VREs.