I spoke at a ‘green’ strata conference last year where other speakers seemed to be of the opinion that there are lots of other energy saving steps you should take before you even look at solar panels for strata buildings.
Water conservation and getting a water audit done to see how much if any is being wasted is actually also a big energy saver in may buildings because of the cost of pumping water up above anything higher than three storeys.
Low consumption lighting, reduced lighting and motion sensors for lighting in common areas (especially car parks) can be another big money saver. Solar powered external lighting can also save money.
Have a look at the Green Strata website which suggests lots of ways you can save energy and money before you even think of spending it on infrastructure.