The paper discusses the potential advantages of operating a microwave power-generating solar power satellite demonstrator in low equatorial orbit. Advantages include being able to deliver power to receiving antennas in a dozen countries around the equator many times/day, and enabling progressive growth to become a large scale system, including geo-stationary satellites. Solar power satellites operating at progressively higher altitudes can deliver power to cities at progressively higher latitudes: within 24 degrees of the equator there is potential demand for several hundred GW of power. Planning an international conference to discuss such a project is recommended.