This item allows you to change the appearance of your Barn and increases your animal limit by 5. This item is available for 1000 MC from October 4-18, 2011. The description reads "Go green with this eco-friendly barn and increase your harvestable animal limit by five!"
You will only see the Solar-Powered Barn in the shop if you have your Barn fully upgraded.
Once you purchase the Solar-Powered Barn it shows up in your storage. To use it go to your storage and click the Use button. This will change the skin of your barn to look like the Solar-Powered Barn. If you want to go back to the old style Barn simply click Use on the old Barn in your storage. Removing a barn skin or keeping it in storage will not affect your animal limit.