Inverters (that's the technical name for a gadget that turns DC into AC) are no problem at all. Many are marketed specifically for computer users. Just make sure you get one with at least the power output capacity that your adapter needs (I think it's 65W for a MacBook). More capacity is better for a number of reasons, and there are a number of 90W and 100W units on the market that are both inexpensive and effective.