No entiendo

You may have noticed this garage doorway on the way down into the town where they put orange peel out to dry. Two questions:-

1. How do they manage to get through so many oranges?
2. What are they drying the peel for?

One couple told us that they use dried orange peel to make fireworks. That seems absurd. I've never read anywhere about orange peel being an explosive. Maybe they use it to light the fire - no sé. Please send any sensible suggestions to keith@bigastro.es.