Grid-Tie Solar Systems

These use a solar string inverter connected to the mains 230v and the solar panels. There are no batteries involved. The household loads are supplied by a combination of mains AC and inverter-generated AC. This is a system that's tied to the grid in the full sense of the word, without the grid voltage present at the meter box there's no power for the house, not even when the sun is blazing. 

This system is very good where heavy daytime demands are made on your power, such as a home industry or for charging an EV during the day.  Any excess solar energy is usually fed back into the grid and there is a buy-back payment made to your power bill.  This seems to be why it's so popular in Australia, the typical system has an oversized (compared to home requirements) solar array and the owner is banking on making more money on selling energy than would be lost by buying power for overnight use.  Plus the fact that these installations are subsidised by the government, but not (up until very recently) batteries. Many owners don't even worry that they're purchacing energy for hot water when they're generating way in excess themselves because the power bill is so small.  But for those who do there's a hot water diverter available to re-direct solar energy into the hot water element. In effect this acts as a sort of battery, where excess pv energy is stored in the water cylinder. It's not a system for energy security

There is no power available from the inverter when the sun goes down or the grid fails.  With the grid down you're without power even if the sun is shining,  because the unit shuts down to prevent the feed of power into the grid (anti-islanding)  a potentiallly lethal danger for line technicians. 

These systems are sometimes sold as ‘battery-ready’ indicating the possibility of adding batteries at a later time, but it's not actually as straightforward as that as you can’t simply add a battery pack and hook it up to what you’ve got. In this situation you need to integrate another, battery-compatible inverter into the system, turning it into a DC or an AC coupled system.  

basic schematic diagram of a typical grid-tie solar inverter installation