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.
Carefully consider the types of solar panels you plan on having installed. Long ago, if you didn't have enough roof space, you'd need very expensive high efficiency mono-crystalline panels. There are now more advanced polycrystalline panels and even thin film panels. If you've got enough roof space, you might wish to look at the size of the panels in relation to their output capacity to avoid having insufficient panels that you need more of later.
Once your panels are in place, keep an eye on them and monitor them regularly. Get to know what you daily output of energy is, what everything looks like when operating optimally and even keep a record of such things. This can help you quickly notice when something isn't working correctly and help you ascertain where the problem is.