This is my fourth question in the series Saturnian Cloud Cities. Click to see the previous question
The diagram of the cloud city is given below, but I will try to describe it in a nutshell. The cloud city is essentially a large rigid-hull zeppelin that is lifted by heated hydrogen, and the heat is derived from harvesting Saturn's geothermal heat, by means of long graphene cables that plunge deep into the atmosphere, well below the water-ice deck. Massive wind turbines are used to harvest the wind energy of Saturn, and use it power lighting and heating systems, meant for sustaining the algae-oxygen generators and the farms.
However, although I have come up with a diagram, I cannot explain how to deploy the cloud cities. More specifically, when the cloud cities are being made by future colonists, the materials (graphene cables, algae cells, turbines etc) are carried by rockets, and the cloud city is made in orbit, but the problem arises, when the cloud cities are taken to Saturn's atmosphere. Since the geothermal cables do not immediately start heating up after being deployed, the cities would immediately sink as the normal, unheated hydrogen is not sufficiently buoyant enough to lift in Saturn's mainly hydrogen atmosphere.
How do I heat up the lift-gas as fast as possible, so that the cloud city is now lifting itself up?