Before installing solar panels on your roof, check with your home owners association. Some associations have restrictions on what you are allowed to do to the outside of the property, and this might mean solar panels are not an option for you. It is better to have this information up front than to purchase the panels and be forced to remove them at a later time.
Minimize the upfront costs of solar panels by considering a lease instead of a purchase. This spreads the payments over a long-term period into monthly installments, so you could actually start saving money immediately. Still, consider how long you will be in that building, as the long-term periods usually run a decade.