Solar panels

Just had a long winded conversation from someone claiming to be with EDF. Apparently they are campaigning to get solar panels installed on as many eligible houses as possible to make up for a forecast shortfall in generation capacity due to various power stations being closed in the future and as a result, install the panels at no cost to you, the energy generated is deducted from your bill etc etc. we all know the script..
Has anyone else had the call and if so how did it pan out? I seem to remember a while back someone posted on this forum that their parents had been royally stiffed by some panel installation outfit, so I am naturally very suspicious of the whole thing. Anyway, EDF are going to send someone round to assess the house so we'll see what happens. Is it just my suspicious nature or does it all wiff of "con"?
Opinions please Frenchies.

Alas my son answered and he takes great delight in baiting them for as long as possible. My first action is also to hang up immediately. Anyone experienced the hilarious Indian call centre scam where someone who can hardly speak English claims to be from Microsofts trouble shooting technical department and tries to get you to hand control of your computer over to them. Excellent value and well worth keeping them going for as long as possible with lots of feigned computer ineptitude. Their frustration is almost palpable!