The study helps the System Operator Company to create a market monitoring system - corresponding to the legal obligations and the meeting the challenges of the current economic reality - that adequately reflects the ongoing market changes in the electricity industry. The goal is not the description of the technological processes but the demonstration of economic and market analysis. The first part includes a summary of the current international practice and the newest economic techniques of measuring market power. The second part includes a daily, a weekly and a quarterly report based on real market data, and proposed market power indices.