Yes. Cleaning your roof can save you money in more ways than one...
First, the algae and fungus that grow can cause premature roof granule loss, and shorten roof shingle life. So you save money because your roof lasts longer
Second, when the algae turn your roof black, it becomes less reflective, and it retains heat; If you use an air conditioner it has to work harder to overcome the increased heat load, costing money in electric bills.
Third, the aesthetics of cleaning your roof when it comes to selling your home can not only save you money but can make you money too.