Besides hardware damages that can be caused by power fluctuations, there are software damages that can occur when the electricity goes off suddenly. The typical problem is the loss of documents that you are working on when the power goes off. You should save your work frequently. Never be caught with an hours work lost because you did not save it. Saving your work every 10-15 minutes is good practice. Another perfect time to save your work is just after you have performed a task which you do not wish to recreate.