1. Line a large bowl with thin kitchen towel or cheesecloth. Grate the zucchinis into the towel.
2. Twist the towel into a pouch and squeeze out excess liquids.
3. Transfer to a large bowl. Add salt, pepper, garlic powder, green onions, flour and beaten eggs. Mix until well combined.
4. In a large skillet heat oil over medium-high heat. Spoon 2-3 tablespoons of zucchini mixture to the hot oil, flatten slightly.
5. Fry 3-4 minutes on each side or until golden brown. Transfer to paper towels to drain.
6. Serve with sour cream.