Quality issues.
This one was on test and for sale from a UK, England, and retailer of RE products. GTI connected to the main utilities grid.
I called in every 6 months or so to pick PV rails/clamps up, as it was on my travel route, and it saves postage.
Ran well for the first 6 months, but output down on what the manufactures said.
After a year taken down from this mounting pole and put on the roof of the main 3 storey building. Maintenance issues.
2 years later, I called for some more RE stuff and said, "crikey what's up with that", "It fell apart " said the company spokesman, “ and we had to disconnect from the utilities grid not long after it went upâ€.