Is this, or could, LED gardens be more efficient per sqft than leaving crops directly in the sunlight? Since a lot of spectrum is unused for photosythesis [1][

Is this, or could, LED gardens be more efficient per sqft than leaving crops directly in the sunlight? Since a lot of spectrum is unused for photosythesis [1][2], the conversion of {full spectrum -> electricity -> required spectrum} seems potentially more efficient. Another interesting idea would be to create solar panels that only convert the lost spectrum into {electricty -> required spectrum} [3] [1] http://bernardkatz.com/wp-content/uploads/2012/07/spectrum-of-sun.jpg http://bernardkatz.com/wp-content/uploads/2012/07/spectrum-o... [2] http://www2.estrellamountain.edu/faculty/farabee/biobk/pigment.gif http://www2.estrellamountain.edu/faculty/farabee/biobk/pigme... [3] http://mitei.mit.edu/news/transparent-solar-cells http://mitei.mit.edu/news/transparent-solar-cells