The entry of companies dealing with renewable energy sources into the market will be analyzed firstly, in addition to the companies dealing with fossil-based energy production, which are still strongly present. Here the game-theoretic stylization of the competition between two types of companies is in scope, while the incumbents determine the energy prices, and those entering the market can respond with quantitative adjustments. After that, the cyber security issues of the market-leading energy companies are under revision. Nowadays, due to the widespread use of computer control systems, a possible cyber-attack is a big risk for a power plant, as it can result in a complete system shutdown or, in the worst case, even irreparable damage. In light of these, risk networks are analyzed in three layers, reflecting normal and extreme market conditions. Ultimately, we will analyze the strategic steps of companies' restructuring and withdrawal. In the current economic situation, many dominant companies have a diversified portfolio, which on one hand promises beneficial profit opportunities and financial stability due to the parallel presence of diverse investment and production directions, but also makes it necessary to abandon the given route and to reallocate resources to another sector if necessary. Based on these points, by the end of the analysis, we will have a clearer picture of the struggle for market dominance of large energy companies and the steps necessary for success.