Designing Energy Harvesting Cyber Physical Systems (EH CPS) with real-time capabilities requires a sophisticated approach that integrates energy aware scheduling policies, predictive modeling, and dynamic task allocation. By effectively managing energy resources, these systems can adopt an energy neutral behavior: they ensure perpetual operation even in environments with intermittent energy availability and real-time requirements. This paper provides a brief overview of the state of the art about energy harvesting aware scheduling under realtime constraints. It describes the optimal scheduler called ED-H. Then, it highlights technical issues in the actual implementation of such a scheduler, particularly with regard to measurement of energy consumption and prediction of environmental energy production.