&gt; It&#x27;s not as if sunlight is a sparse resource (on a global scale)<p>But land is, particularly arable land, and particularly in a country like Japan. You can see for yourself in the picture that they have ~15 tiers of gardens, compared to a maximum of two or three when using sunlight. And sure, you could probably devise some method of piping and reflecting sunlight through to the lower tiers just to avoid consuming electricity, but then it wouldn&#x27;t work at night, wouldn&#x27;t work as well in winter, and so on.