In the study, 10 electricity generation companies on the Fortune 500 list were examined using nine criteria. These companies are listed in the top 40 in terms of installed power. The aim of the study was to determine the financial performances of the companies with the entropy-weighted Grey Relationship Analysis (GRA) method by obtaining the 2021 data of the criteria from the websites of the relevant companies. As a result of the weighting made by the entropy method, it was determined that the most important criterion was the export income. These criteria were determined as equity, total assets, net sales, asset turnover, equity turnover, profit before interest/tax , change in profit before interest/tax, and as change in net sales respectively. After the weights of the criteria were calculated with the entropy method, the GRA method was used to rank the alternatives. Çelikler company was determined to be the best electricity generation company with the highest degree of relationship. This company was followed by Odaş, Gama, İçdaş, Limak, Akenerji, Zorlu, Enerjisa, Aksa and Enka respectively.