Not so free if and when you wish to sell your house. The legalities, etc likely cost the vendor thousands. These rented roofs are a minefield for potential house purchasers. Far better to install your own kit and avoid the third party renters of equipment.
Both my neighbours had the panels fitted by A Shade Greener shortly after I had mine installed & both subsequently sold on. The first had a bit of a gripe from the Halifax BS, but A Shade Greener put an additional clause in the contract that allowed, in the event that HBS re-possesed the house, that ASG would remove the installation without charges if requested to do so – a "backstop" in current parlance, I suppose. Neither my original or new neighbours suggested that this had cost them any extra. With so many of this type of installation (ASG had over 10,000 at the time I saw a TV report about them moving out of their original area into ours & got in touch with them), arrangements will be made to accomodate them when properies get sold.
At the time of installation, the arrangement we have would have cost around £18K so, for me at the time, an outright purchase of my own installation was not possible. Installation costs did come down a lot as numbers of installations increased, so several years later owning my own may have been an option. As it is I generate around 4500 kwh a year, for which ASG receive (IIRC) 42p per kwh FiT & I get to use the electricity FOC – what I can't use at the time it is generated feeds back into the mains.
Nigel B