the short answer to your question is yes, that type of inverter does exist, they are very rare. The Delta model H6 (Thailand) is one example. A battery less grid tie inverter that is also advertised as a backup inverter for power outages, up to its full rated 6kw output, provided the solar array is sized for the load and in direct sun, no clouds. This unit also costs much less than similar sized grid tie units and has a full 1 month warranty, you can derive your own conclusions from that. Most battery less models that had backup capabilities are not on the market long because as your question states,are components in the system at risk of damage? Yes. There are a number of grid tie battery bank models that operate as backup power as well with proven track records. Our Trace (Xantrex now) SW-4024 is one example, it’s been running non stop at our property for over 20 years now.
It’s worth mentioning that a battery bank can be expensive, or cheap. We use 4 Trojan T-105 golf cart batteries for ours, so for a few hundred dollars we have reliable grid tie solar and solar/battery backup. The components never seem to have any trouble going from one mode to another and back again, mainly because the inverter has two fairly solid voltages to anchor to, 24 VDC batteries, and 120 VAC grid to synchronize with. Either one is sufficient, but the batteries are required in either mode, and any available solar power is simply dumped into the homes existing AC wiring. In most cases when our power goes out here, we are not aware of it until a neighbor calls and asks if we have power, because they don’t.
The few batteryless, grid tie/backup power inverters that are available are purely computer generated sine waves driven entirely by the variable output of your array, which accounts for why most companies making them stop making them after a time, or offer short warranty periods. A battery based grid tie “hybrid” unit has a much higher incidence of reliability.
