thats ridiculous, and extortionate , if it were me though id create a small power bank(of batteries obv) that the panels fed into then invert that into a seperate mains loop to run folders on ,and as far as the elecy co go they wouldnt know about it or id have it removed either way id then pay less.
IMHO thats how solar and wind should be used anyway as local power , and just used to power low voltage lighting throughout the house plus a constant low power water conserve boiler on perma heat, plus whatever other houshold items it had the juice to feed then have mains just for the kettle and cooking