Foreign Power Connections
From Workers & Resources: Soviet Republic Official Wiki
Foreign power connections are buildings situated next to some customs houses. These resemble a power switch or transformer. Foreign power connections can be used to import or export electricity. Electricity prices start at 0.98 Rubles per MWh from Soviet Bloc connections or 1.20 Dollars per MWh from a NATO connection.
Foreign power connections can only import or export up to 18 Megawatts of power. The amount of power imported or exported fluctuates with demand: Demand inside your republic for import, and Demand outside of your republic for export. Demand outside of your republic is randomized an fluctuates at no specific rate.