Given demographic changes, it is wholly appropriate for Germany to run current account surpluses because, put simply, there is a shrinking number of us to generate national product and proportionally there are more and more who consume it.
A current account surplus allows external assets to grow, and these can be run down at a later point in time as more and more employees retire and draw on their savings. Also, when a country reduces its debt ratio, it implicitly improves the sustainability of statutory pensions.