In a large saucepan over medium heat, sauté onions in oil until translucent, about 5 minutes. Add ginger, salt, pepper, and carrot slices. Sauté until carrots are slightly soft. Add orange pulp, 5 cups water, and orange juice. Bring to a boil, then reduce and simmer until vegetables are tender, about 30 to 45 minutes, adding more water as needed to keep vegetables covered. Puree soup with an immersion blender adding more water to reach desired consistency. Serve warm.