RTG

The RTG is a late-game power item that provides a constant source of electricity when placed on a platform. It is one of the most efficient portable power sources in Astroneer, making it especially useful for bases, outposts, and mobile setups that need uninterrupted output without relying on sunlight, wind, or fuel.

RTGs are built around a real-world radioisotope thermoelectric generator, reflecting their role as compact, long-lasting power producers. In practice, they are prized for stability rather than raw scale: an RTG produces a steady 4U/s and can keep devices and networks powered continuously as long as it is connected to the grid.

Shelters and Field Shelters include built-in low-power RTGs that cannot be removed. These embedded units provide 1U/s and 0.5U/s, respectively, giving each shelter a small but permanent trickle of power even when no other generation is available.

Because the RTG is a high-end item, its crafting requirements are deliberately extreme. Producing one requires multiple advanced materials and gases, and the full production chain generally forces players to visit at least two planets just to gather the needed gases for the component metals. If all crafting materials are purchased through a Trade Platform and all required gases and processing machines have already been acquired, the effective Scrap cost of a single RTG is 12 Scrap, with 1 Graphite and 1 Hematite left over.

• RTGs are best used as always-on backbone power for important machines, rather than as burst power for short tasks.
• They can be placed on platforms like other power sources, making them easy to integrate into a base layout.
• The item can be shredded in a Large Shredder or Extra Large Shredder for 4 Scrap.
• Since the RTG is based on a real radioisotope thermoelectric generator, its in-game function matches the idea of a compact, dependable power source for long-duration use.
• The embedded RTGs in Shelters and Field Shelters are permanent and cannot be removed, so those structures always retain their minimal power output.

Overall, the RTG is a premium endgame convenience item: expensive to make, but unmatched for providing reliable power anywhere it is needed.