In a large bowl, combine flour, salt to taste, baking powder and baking soda. Add club soda and olive oil, mixing well.
Fill deep fryer halfway with oil and heat to 350°F.
Dip green beans in batter mixture. Fry green beans for 2 minutes or until golden brown. Use a metal slotted spoon to transfer to paper towels to drain. Serve immediately with sauce.
To make the chipotle dipping sauce, in a food processor, blend together sour cream, mayonnaise, lime juice, chipotle peppers, garlic and chili powder until smooth.