First, plants lose about half the energy because of spectrum. There's lots of other losses (e.g. light falling on parts of the plant other than chloroplasts) but they apply to artificial light, too. And then, plants use only about 10% of the mid-day energy after all of these losses, because of saturation effects, but more the rest of the day-- we'll call it like 25% here. So that 50% factor and 25% factors multiplied are what you can try to exceed == 12.5%.
Cheap solar panels are about 15% efficient. So you're not going to beat direct sunlight by much.
First, plants lose about half the energy because of spectrum. There's lots of other losses (e.g. light falling on parts of the plant other than chloroplasts) but they apply to artificial light, too. And then, plants use only about 10% of the mid-day energy after all of these losses, because of saturation effects, but more the rest of the day-- we'll call it like 25% here. So that 50% factor and 25% factors multiplied are what you can try to exceed == 12.5%.
Cheap solar panels are about 15% efficient. So you're not going to beat direct sunlight by much.