[![enter image description here][1]][1][![enter image description here][2]][2]I have a breaker panel with one open breaker. Problem is I was going to add a heat pump to my seasonal cottage but it requires 220. Will I need to replace entire panel to accommodate this heat pump?  It's a 100 amp max box as well. Cottage is 1200 square feet. Don't know the code for this rural town in Maine. Will need to get this. 
Thanks


  [1]: https://i.sstatic.net/NxebX.jpg
  [2]: https://i.sstatic.net/JQQTi.jpg