The article doesn't quote much on algae; it just dismisses them. In fact, there is no comparison of the actual economies involved; its just a sunlight-efficiency argument which is interesting but far from conclusive.
Solar cells cost something to build - ignored in the article. Using all sorts of minerals and industrial processes, very hard to trace thru our entire economy to get an 'energy budget' and thus a payback. So its easy to call them more efficient, if you don't actually calculate their cost.
Plants 'build' themselves - essentially nanotechnology for free. They can be built over and over again, or the land can be repurposed for food or grazing or parks or whatever. Solar cell farms are heavy infrastructure investments that have to be manufactured, hauled into place, installed, maintained, replaced.
