the first plan is American and would be unlikely to work on the 230V AC single phase UK power system without extensive modification. the second seems a bit fishy as its from a Yank but his picture shows what is probably an Australian setup (they still state the mains voltage as 240V)
In this country, feeding electric back into the grid needs approval from both your electric supplier and your distributor (such as Western Power Distribution, EDF or SSE) as well as a part P qualified sparky to do the work because of to the safety issues and it has to be co-ordinated with the distributor so the service fuse can be pulled to get your meter/tails/changeover kit/inverter connected safely. (this is all complicated and expensive, more so due to the bureaucracy and conflicting commercial interests at play here)
that said, if you google “home made solar panel” various genuinely free resources exist, and you could build enough kit to power maybe a laptop or PC, router and some loudspeakers from solar/non-grid power – you get “free” electric and the benefits of a UPS this way…
(these posts ought to be split into a separate thread)
