Since installation the system has probably performed better than we anticipated. We didn't set out to be living off the grid but pretty much by accident that's where we ended up. We were ideally hoping to reduce our electricity bill but now we don't have an electricity bill at all... we recently had a major power outage and the house was fully powered right through the evening until the power was reconnected. So it's not just the savings, it's the fact that you can actually store power for when you really need it.