Typical solutions for indoor horticulture involve the use of HID / MH lamps, which, consume a large amount of electricity and generate a lareg amount of waste heat.
Similar levels of incident radiation can be acheived with laser irradiation, for much lower input power; at the expense of spectral distribution.
Back-of-the-envelope calculations, coupled with absorbtion profiles of chloroplasts suggest non-optimal, but workable, efficiencies with commercially available lasers. Specific sepctral bands not accessible with lasers to be filled in with LED lighting. Overall high a net reduction in requried power is exepcted.