Assessing the impact of electricity interconnectors on the Great Britain’s power supply in 2030

The transition from the current CO2 emitting power production to a renewable-rich power system requires various types of energy storage options to capture the surplus renewable energy and/or increasing the interconnection capacity to trade power and secure electricity supply during peak demand times in addition to export surplus power at low demand periods. In this study, the function of power interconnectors between Great Britain (GB) and the neighboring countries within 2030 is investigated. Two interconnection links with a total capacity of 17.7 GW were assumed, i.e. a one-way import-only interconnector (IC1) and a two-way trade link between GB and France (IC2). The IC2 link was assumed to transmit power from cheaper country to the more expensive one. A linear programming (LP) merit order dispatch model was used to find the economic power production over 2030. The results indicate that the share of generating technologies in 2030 depends on the IC1 import price and the IC2 capacity. The capacity factor of the IC2 link reduces as the IC2 capacity goes up at constant IC1 import price. In addition, at constant IC2 capacity, the capacity factor of the IC2 link increases as the IC1 import price increases. For each IC1 import price, increasing the IC2 capacity reduces the percentage of times that IC2 is fully loaded and the load of IC1 is zero. The IC1 import price affects the quantity of electricity trade between GB and France. For example, assuming an IC1 electricity import price of £20/MWh results in about 9 TWh electricity export to France and 88 TWh electricity import to GB which is over 7x of the total electricity traded in 2016. At a fixed IC1 electricity import price, the power import via the IC2 link with capacity of 11 GW is ca. 5 times higher than the case with IC2 capacity of 2 GW. At any IC1 import price, higher IC2 capacities reduce the number of occasions that the IC1 is loaded. For the case that the IC1 import price is £20/MWh and IC2 capacity is 2 GW, there will be 990 half-hours that GB acts as an electricity corridor.