Photosynthesis is ca. 2% to 5% effective while even common off the shelf PV panels reach 20% easily. Assuming an efficient light source in the desired spectral

Photosynthesis is ca. 2% to 5% effective while even common off the shelf PV panels reach 20% easily. Assuming an efficient light source in the desired spectral range that'd make it more efficient to grow plants under solar panels with such light sources using the generated power than growing them under glass or out in the open.