How often are you in the shed working? If you are in the shed a few hours a week, it would be quite possible to run your shed on solar/wind, as it is charging the batteries even if you are not in the shed. If you are in the shed a few hours a day, to get the charging capacity you need may start to get expensive.
Of course it is all going to depend on:
1) What is your expected load? Running LED's and charging cordless tools is one thing, running heaters/AC, compressors, beer fridge etc. is something else.
2) How much power can you put back into the battery bank? This will depend on light conditions such as direct sunlight/overcast, hours of sunlight, and how the panels are oriented to the sun. The more direct the sun hits them, the better.