Solar Panels, cold callers and increased performance

[toastyhamster]

Had some panels fitted around 3 years ago, generally quite happy with them, had a great first year of payments followed by a couple of average ones, long term investment etc etc

Yesterday had a doorstop cold call claiming they can change the inverter and add a new "thing" which would increase output by around 25%.

Had a bit of a google and it would appear to be real (depending on what i already have), but it would need to be pretty cheap to justify it, 25% on a poor year is only about 150 quid and as they have to replace the entire inverter as well I guess it's going to be well north of 1k (my current inverter looks to be about £950).

Anybody looked into this further?

[toastyhamster]

The googling I did suggested that the entire system runs to the lowest panel output? Is this also a scam?

i was going to call the original installers who were very good but I guess you saved me a job - thanks.