weve been on stand alone for 16 years, just done an upgrade last year, all good and highly recommend, we are very lucky to have a mad scientist, mate and solar pioneer, wouldn't trust anyone else as there are plenty of horror stories fly by nighters selling shit component and putting together shit systems, the price has come down a lot, can jump on the Tig whilst in the upper limits of the bell curve, can run the refridge a/c in cloud lifes good