Go Power - RETREAT-E, Retreat Expansion 100WGo Power RETREAT E, Retreat Expansion 100W SKU: RETREAT E 100W Retreat Expansion Kit. All Go Power! Solar Expansion kits are compatible with one another using 80 watts or higher. As your need for power grows, so can your RV solar system by adding additional modules to your existing Solar Kits or even to the Weekender ISW and Solar Elite charging system. Each Go Power! expansion kit includes a solar module, mounting hardware and expansion connections