The main environmental impacts of aquaculture include eutrophication, chemical pollution and harm to sensitive marine ecosystems. At the same time, the required energy leads to high emissions of greenhouse gases. Offshore wind turbines are a sector of renewable energy that grows rapidly. Offshore wind turbines can be combined with aquaculture units to meet their energy needs, saving fuel and reducing their carbon footprint. However, there are many difficulties in installing aquaculture units in existing offshore wind parks (e.g. small water depth). A new paradigm is to deploy floating wind turbines and aquaculture at open sea. Open sea aquaculture is more environmentally friendly, but has not been developed due to increased supply chain cost and harsh sea state conditions. The aim of this study is to propose a renewable energy system that can cover the energy needs of an open sea aquaculture unit. The system consists of a multiuse floating structure that accommodates wind turbine, photovoltaic panels, batteries, energy management system, fish monitoring devices and automatic feeding system. In this way the frequency and cost of in-situ visits, will be reduced. The above combination makes open sea aquaculture development more attractive and at the same time improves its environmental footprint.