We had ours installed in 2019 and it has been a great addition to our home solar (Suncommon). GMP installs it for free and you get on demand backup power with no interruption when the service goes out. We live in Colchester so its rarely out for more than 12 hours , but the two batteries we have totally cover all of our needs for about 24 hours (within reason). GMP makes a point not to draw them down leading up to storms where a power outage is more likely so its the perfect alternative to a generator. So overall, a great experience.

Its interesting to watch how GMP draws the power from them to balance peak demand (primarily in the summer). They then fill them back up when demand is not high. It seems too good a deal to be true but it really is as advertised.