As to possible improvements (it's both a house and a vehicle, so there's plenty to keep one busy if that's the choice): Solar panels are much better these days

As to possible improvements (it's both a house and a vehicle, so there's plenty to keep one busy if that's the choice): Solar panels are much better these days and a bus has obviously tons of space to put them. AGM batteries are also the way to go. If there were an raspberry pi + app to remotely report battery charge level on a mobile, that would be awesomesauce.