If you are considering batteries, you're in the right place. Many homeowners in Maine are frustrated by the constant power outages. Maine is actually #1 in the nation for them. A new SolarEdge 10kW battery system is an awesome solution. You will need to have an Energy Hub inverter and also consider a subpanel of the panel that will have all the critical loads like well pumps, refrigerators, internet, lighting and possibly other critical loads. Another part of the system will be the SolarEdge BUI or backup interface. This unit will shift power from the battery to your home in a matter of 3 seconds or so. The system will also alert you when it is turned on. How many batteries do you need? It really depends on your needs. Most homes can do fine with 1-2 batteries, but with each inverter, you can install up to 3 batteries. Each backup interface can handle three inverters, so you potentially could have 90 kW of batteries in theory. This would be overkill, but it is possible. In my own home, I have a single battery, but I am considering another for 20kW total.