The short study examines how optimized grid connections for wind and PV can help reduce grid expansion costs, which are expected to rise significantly in the future, particularly due to the connection of renewable energy sources. Currently, renewable energy systems are connected to the grid almost at their nominal peak capacity, even though generation peaks rarely occur.
Until now, grid expansion costs related to renewable energy in €/kW have been unknown due to a lack of data. Distribution network areas in Germany are highly heterogeneous, which is why the optimized grid connection capacity depends on region-specific renewable energy-related grid expansion costs. The study shows that PV grid connections are particularly overbuilt compared to onshore wind, which can be explained by the high simultaneity of PV generation.
Optimizing grid connection capacity can lead to greater cost efficiency in renewable energy expansion. The efficiency gains result from savings in distribution grid expansion and the value of the additional curtailed electricity. However, these efficiency gains are counterbalanced by distribution effects. Operators of renewable energy systems lose potential revenue, while grid expansion costs and, consequently, network charges for end customers decrease.
