Coordinated Generation Expansion Planning for Transmission and Distribution Systems

This paper presents a coordinated approach to investments in a wide range of generation and storage technologies on the transmission and distribution system levels by coupling two generation expansion planning models. This coupling allows to account for both the centralized decision maker's perspective as well as the end consumer's perspective. We provide the location, type and capacity of new assets and account for the increased need for flexibility in case of investments in intermittent RES. The capabilities of the developed methodology are demonstrated using Swiss system data for the period 2020-2050. We show that the phased-out nuclear power will be gradually substituted by high shares of distributed PV and investigate the impacts of the replacement on the Swiss electricity exports/imports, electricity prices, investment costs and endconsumers' savings as well as the hourly dispatch.