The objective of this paper is to examine the importance of independent arrays in the offshore renewable energy farms. In this context, several scenarios have been contemplated for a floating offshore renewable energy farm: a farm only using floating wave energy; a farm only using floating offshore wind energy; and a farm composed by floating wave energy and floating offshore wind energy installed in independent arrays. The article proposes a method to calculate the main economic parameters and decide their economic feasibility. A hypothetic offshore renewable energy farm located in the Galicia region (Spain) has been studied as case of study. Results show which of the scenarios has the best economic results. This method is worthwhile to compare different floating offshore renewable energy technologies in economic terms and help in the decision making of this new emerging sector that can help to rebuild Europe in the post-pandemic period.