No they aren't a scam BUT like so many following the green dream they haven't done their homework to ensure it is a good investment for them. I installed a 5 kW system about 9 years ago now and it has more than paid for itself. You are right though so much energy is pumped out to the grid at low tarrif rates to only be bought back a few hours later at multiples of that. Batteries aren't financially justified for most yet - though if the grid becomes more unstable with the suicidal green push currently going on by the ALP a battery may be worth investing in to secure your energy needs as a risk mitigation.
