Congestion income between Finland (FI) and Estonia (EE).
Congestion income is published on ENTSO-E's Transparency Platform, which can be founded here: https://transparency.entsoe.eu/transmission/r2/dailyImplicitAllocationsCongestionIncome/show . There are historical values to be found from Open Data until the beginning of February 2017. After February 2017 updated data as well as historical data can be founded from ENTSO-E's Transparency Platform.
Congestion income is calculated as follows: congestion income [€/h] = commercial flow on day ahead market [MW] * area price difference [€/MWh]
Congestion originates in the situation where transmission capacity between bidding zones is not sufficient to fulfill the market demand and the congestion splits the bidding zones into separate price areas. Congestion income arises from the different prices that the sellers receive and the buyers pay when electricity flows from the higher price area to the lower price area. The power exchange receives the difference, which it then pays to the Transmission System Operators (TSOs). The TSOs spend the received congestion income on increasing the transmission capacity on its cross-border interconnectors according to the EU regulation.