Hi @cawilson
I don’t know much about the PowerStore specifically, but the concept has been around for a while and is a very good one. It just makes sense to store your excess energy from solar as hot water if you can.
The reviews on Product Review are a bit concerning https://www.productreview.com.au/listings/solahart - these aren’t for the product itself, but for the company.
Hopefully there are other people on here with experience with different products, and installers that integrate hot water and solar PV.
Cheers
Marty