Excellence should indicate how the project is innovative and new. Impact should include information on how the research findings would influence society and markets. In implementation, the way to deploy the project with attention to its feasibility.
It is recommended to consult with experts who have written proposals before in order to be successful. Calls are very competitive in Horizon 2020 and proposals need to be prepared very meticulously. Please note that it is usually the coordinator in Europe that takes the lead in developing the proposal.