  Offshore wind power in the North Sea is considered a main pillar in Europe's
future energy system. A key challenge lies in determining the optimal spatial
capacity allocation of offshore wind parks in combination with the dimensioning
and layout of the connecting high-voltage direct current grid infrastructure.
To determine economically cost optimal configurations, we apply an integrated
capacity and transmission expansion problem within a pan-European electricity
market and transmission grid model with a high spatial and temporal
granularity. By conducting scenario analysis for the year 2030 with a gradually
increasing CO2 price, possible offshore expansion paths are derived and
presented. Special emphasis is laid on the effects of weather uncertainty by
incorporating data from 21 historical weather years in the analysis. Two key
findings are (i) an expansion in addition to the existing offshore wind
capacity of 0 GW (136 EUR/tCO2), 12 GW (159 EUR/tCO2) and 30 GW (186 EUR/tCO2)
dependent on the underlying CO2 price. (ii) A strong sensitivity of the results
towards the underlying weather data highlighting the importance of
incorporating multiple weather years.
