There are no insuperable obstacles, although measures need to be taken to ensure the stability of the system, the study points out.
In the EU's high-renewables scenario, the contribution from all renewables - currently around 30% - will rise to 45% by 2020 and to 60% by 2030.
The current contribution of the variable renewables — wind and solar photovoltaic (PV) — to European electricity supplies is about 10%, and this could rise to around 27-30% by 2030.
The study used 30 years of weather observations to set up an hourly time series of wind and solar generation data. This showed that aggregating the outputs at the European level enabled the fluctuations — in percentage terms — to be reduced. There were, however, still significant excursions that would need to be managed.
The extreme hourly fluctuations in wind and PV output were estimated to be 70GW (10% of the total capacity).
This compares with the maximum hourly change for wind in western Denmark (as derived by the author), which is around 18% of the country's total capacity.
Aggregation at the European level is only possible if there are adequate cross-border transmission connections, and the study investigated the economic viability of several undersea routes. The basis of the cost-benefit analysis was that reinforcements were worthwhile if the reduction of generation investment and operation costs was higher than the cost of the reinforcement.
The principal connections found to be viable were links from Great Britain to north-west France, Norway and Germany.
A connection going from Germany to Norway was also judged viable.
Capacity credit for wind
The energy generated by 700GW of solar PV and wind corresponds to the energy generated by 160GW of thermal plant.
However, 60GW of additional backup capacity is required, and so the study suggests that the capacity credit of wind plant — or the conventional generation that can be replaced — is 100GW (160 minus 60).
No capacity credit is assigned to the PV plant as it will not be generating at times of peak demand in most of northern and central Europe.
Costlier nuclear gives wind advantage
A European Commission working document produced for the Economic and Social Committee gives insight into the rising costs of nuclear electricity. It aims to quantify the size of the required investments and, although it does not quote generation costs, it gives the latest data on construction costs of plant now being built or planned. As the capital cost repayment is the largest component (over 80%) of generation costs, the latter can be inferred with reasonable accuracy.
A survey in 2007-12 revealed construction costs were in the range of €3,145-5,379/kW. Those now planned or being built are around €4,500-6,755/kW.
The lowest price is subject to some uncertainty as the reactor type has not yet been chosen.
The highest price is for the UK's Hinkley Point power station, for which the electricity price has been agreed and is now – allowing for inflation – around €124/MWh.
The average construction cost quoted in the report is €5,290/kW and the corresponding electricity price would be around €101/MWh, assuming identical financial and operating costs to Hinkley Point.
At its median cost of around €1,500/kW, wind can undercut nuclear's average cost of€101/MWh at wind speeds down to about 6.5 m/s, while the Hinkley Point electricity price can be beaten by wind at higher construction costs — up to around €1,800/kW.
AT A GLANCE - THIS MONTH'S REPORT CONCLUSIONS
Commission Staff Working Document: Nuclear Illustrative Programme presented under Article 40 of the Euratom Treaty for the opinion of the European Economic and Social Committee, April 2016 The average construction cost for nuclear is €5,290/kW, with a corresponding electricity price of around €101/MWh. At its median cost of around €1,500/kW, wind can undercut nuclear's average cost of €101/MWh at wind speeds down to about 6.5 m/s.
Technical and economic analysis of the European electricity system with 60% RES, Burtin, A and Silva, V, EDF R&D, 2015. Europe's electricity network could operate with 60% renewables if cross-border transmission connections are built. Viable links are as from Great Britain to France, Norway and Germany, and Germany to Norway. It would still need 60GW of thermal backup.