It has come to our attention that a number of domestic solar owners have been approached by pushy companies using hard sales tactics, such as offering "free health checks" to get through your door, and once inside pushing them to have unnecessary and sometimes expensive work carried out. One such example is the installation of high quality solar inverters from the SolarEdge. The design of this system incurs additional labour costs over a conventional string inverter replacement as panels on the roof need to be lifted to install “power optimizers” behind each panel. It is in my view a top notch bit of kit with several benefits and worth the extra effort in several scenarios. Increased yields from SolarEdge systems are real, but usually only marginal over a well sited and designed string inverter system. If anybody promises vaguely couched promises of "upto 25% more solar yield" then you'd be right to raise a suspicious eyebrow.
If you have encountered pushy "sign up today" sales tactics, backed up by impressively high performance promises, please proceed with caution. If you want a second opinion we are here to help.