I messaged the bloke who had installed it, but time was pressing, so I tried the manufacturer’s website. It was all big and glossy, banging on about a green future, sustainability, solar this, inverter that. I was invited to visit support. Click. Sorry, page doesn’t exist. Great. Deep down, hidden in the base rock of one of the pages, I found a precious relic from a bygone age – a phone number. Murmuring prayers of thanks and hope, I made the call.