Dynamic transformer rating (DTR) can be used to load power transformers above nameplate rating, while respecting contingency loading limits and ensuring an acceptable risk level. Purchase of power transformers is a major contributor for high costs of building new substations. Application of DTR allows to postpone the investment in new power transformers in old substations, thus DTR has a potential to become an economically beneficial technology. A quantitative risk and economic evaluation of DTR application is performed for a wind farm connected transformer and thus for a highly variable load scenario. The risks analyzed in this project are increased loss of insulation life and the risk of dielectric failure, based on the Arrhenius-Weibull model. A comparative net present value calculation has been performed to investigate the profitability of replacing a 19.4 MVA transformer with a 16 MVA dynamically rated transformer. The feasibility of DTR application is analyzed and a methodology is developed to support both transformer manufacturer and potential customers, such as distribution system operators, in the decision-making process of purchasing of dynamically rated transformer for wind energy applications.