At current prices, it's already worth fully solar individually... just expensive up front. Batteries and transmission are so expensive it's worth just installing MOAR solar. Connecting to the grid would be $1k/year so (depending on rate of return) it takes ~20years to pay off, which is right around the warrantee period.
Where I am there are ~5 peak solar equivalent hours in mid summer and ~0.5 hour on a rainy winter day. If I need 10kWh/day, then I need to install ~20kW at $500/kW, with 30kWh of battery for <$5k, and <$3k for dual 6.5kW inverters for 240V at 50A service. During the summer I charge my neighbors electric cars, but it's not worth paying the connection fee to hook up.
I think the grid tie solar fees are so high because the power companies would rather be getting the money for installing solar and batteries.
Where I am there are ~5 peak solar equivalent hours in mid summer and ~0.5 hour on a rainy winter day. If I need 10kWh/day, then I need to install ~20kW at $500/kW, with 30kWh of battery for <$5k, and <$3k for dual 6.5kW inverters for 240V at 50A service. During the summer I charge my neighbors electric cars, but it's not worth paying the connection fee to hook up.
I think the grid tie solar fees are so high because the power companies would rather be getting the money for installing solar and batteries.