Electrodynamic tethers can be used to generate power onboard spacecraft orbiting the Earth (or any other planetary body with a magnetic field), essentially "harvesting" energy from the orbital energy of the spacecraft. A key benefit of an electrodynamic tether is the high peak power generation capability for a small impact in spacecraft mass and volume. Reciprocally, the same system can be used to provide orbit-raising propulsion, or change of any other orbital parameter if power is applied to the tether. In this work, the research goal is to develop a better understanding of the power generation capabilities of EDT systems on various scales, and to develop system concepts, key elements, and technology roadmaps for their use. This paper reports on preliminary results for large-to-small, nano-, and picosatellite scales. The results show that EDTs are viable devices for providing power to spacecraft and worthy of further investigation.