— Designing reliable ocean energy devices with reduced costs is crucial for the sector’s development. This development of renewable energies should also be implemented in a sustainable manner and not cause additional environmental stress and related damage. In order for the ocean energy sector to consider environmental impacts at the earliest stage of concept creation, the Environmental Assessment (EA) module was developed and included in an integrative suite of design and assessment tools (namely DTOceanPlus) to support technology innovation processes. Several complementary features were developed in the EA module which provides insight into impacts at different levels. At local scale, environmental impacts are assessed in relation to the different design choices that cover various potential pressures induced by the ocean energy array. Moreover, surveys and mitigation measures are provided regarding endangered species potentially present. At global scale, a life cycle assessment is conducted to evaluate the carbon footprint of a project in terms of its contribution to global warming and the cumulative energy demand. The present paper describes the integration of EA into DTOcean+ and two case studies were used to exemplify the use and relevancy of the EA’s features to evaluate environmental impacts of a wave and a tidal ocean energy projects. Overall the EA module provides insight and support to the ocean energy sector to achieve sustainable development of marine renewable energies.