This work builds a comprehensive North West European Electricity Market model for the year 2020 and uses it to quantify the impacts of ambitious national renewable electricity targets. The geographical coverage of the model comprises Germany, France, Belgium, Netherlands, Luxemburg, Great Britain and Ireland. The model simulates the electricity market operation for the entire region at half hourly resolution and produces results in terms of electricity prices, cross border flows, emissions and associated total system costs. The impact of two carbon prices is examined within the model. Results highlight the policy challenges that arise when individual Member States formulate renewable energy plans in isolation in the absence of integrated modelling of interconnected regions as cross border power flows play a more significant role in market dynamics especially in the presence of geographically dispersed variable renewable generation sources such as wind and solar. From a policy perspective results suggest that based on these national plans, congestion will be present on a number of key lines at long periods during the year. (C) 2015 Elsevier Ltd. All rights reserved.