tim.... wrote:

Expected output 2928 kWh per year.

And the company is demanding close to £20,000 for the installation? The
panels required (14 x 210W) retail for £4,200. The grid tie inverter
required for the feed-in costs £1000, retail.

So the company are charging somewhere around £14,000 for installation.

That's a rip off of impressive magnitude IMO. If they got that down to
£5K, with an installed price of £10-£11K it would be worth it.

It would certainly be better to DIY.