Every expedition costs energy to start, and your energy tank caps out at 200. Starting an expedition into any chamber costs a full tank (200 energy), so you'll need to wait for your energy to refill between expeditions rather than running several back-to-back instantly.
Energy refills gradually over time on its own. If you're subscribed to Chillverse Pro, your energy refills at a faster rate than a free account, meaning less time spent waiting between expeditions and more time actually exploring.