That's not how it works. The $16/month is a fee. The $10/month is a minimum. So, to take an extreme example, if you signed up for this plan, but used no electricity at all, and you did not have solar generation, you'd only pay $16/month. (I think this minimum is part of net metering, so it's doubly-contrived example.)
SDG&E has a very strange and confusing way of accounting for the $10/month minimum on your bill, but it's just a minimum. If your bill is above $10/month, it doesn't make any difference.