A tethered aerial system includes an on-board fuel cell for powering on-board electronics and a tether cable which is less conductive than air. The tether cable includes a pipe for carrying a flow of gas to the fuel cell and/or maintain the gas level in a lighter-than-air platform, so that the tethered aerial system can remain operational for an extended period of time. The system is particularly applicable for maintaining communication links in remote areas, agriculture and applications in the IoT (Internet of Things), event coverage, interactive marketing, for post-disaster situations in rural areas and at mining sites or construction sites in remote environments. The system also is immune to rays.