Does a sunlight sensor for solar panels exist?

I have a solar panel system installed at my house with three strings connected to a SunnyBoy SB7 inverter. Our home is two stories and is set at a 45-degree angle off cardinal directions, giving us both southeast and southwest roof options. Living in coastal California means we deal with morning clouds, making the southwest roofs more advantageous. Unfortunately, many of our southwest roofs are shaded due to trees, so most of our panels are on the southeast roofs. Recently, the HOA removed a large tree that was causing foundation issues for our neighbor, leaving an ideal section of southwest roof on the first story. However, during the morning, part of it gets shaded by the second story. If I were starting from scratch, I'd go for micro-inverters, which wouldn't let the shaded panel affect its neighbors. But since I'm looking to expand on the newly exposed southwest roof, my plan is to add these panels to the existing string with the second-story southwest panels. What I need is a simple device that can tell if a panel is in sunlight and disconnect it from the circuit if it's not. Does such a device exist and what is it called? Or is there a better approach to this situation? I'm under NEM2 with 22 panels currently and aiming to add 2 more without exceeding the 10% limit.