These seminars are run by the same types of people who
* sell retirement investment plans
* rental "investment" housing interstate
* resort holidays
* time share stuff.
Solar can work for many people (may as well get in myself soon), but the big players, who hold seminars are typically making more out of it than you.
I'd keep an eye out for Tesla and Solar City, which are not far off having small levels of storage with their systems...from a few 18650s on the panel to ride through a cloud, to a couple hundred to provide some peaking capacity...lets you use your power BEFORE it gets to the meter.
People I know with (or going to) solar.
* FIL installed 5KW at a ridiculously generous taxpayer sponsored tarrif (60c/KWHr feed-in, versus 20c retail power rate, and 4c wholesale at the time)...tax office is after retirees with "offsets" much greater than their consumption
* Mother, installed 3KW, predominantly so that she didn't have to pay for her air conditioning and heat pump load during the day as a retiree...she's home when the sun shines, and it works.
* bloke next door. 2.5KW. Gets about 6c during the day while he's at work, buys it back at 27c after work. Still works for him.
* bloke at work, put in 3KW. His wife is at home part of the day, and they put in an energy minder, monitors the import/export (need two meters on current install)...has trained his family (easily, it's green light export, red light import) to cook a baked dinner, wash the clothes etc. to minimise red (import)...will pay his $4,500 back in 3 years.
* bloke at work who is a few years from retirement, who is setting him and wife up for it. Full battery storage (in suburbia), $30k, sized such that he will export on 90+% of days without import, and that will get better as he replaces home items with more efficient...payback 12 years, however, he's paying it off while working
All different answers to different questions, answered by smaller companies that each of them contacted, rather than companies that try to sell their generic "one cheap size fitz all"