The shade provided has value, too. Imagine reducing the amount of heat reaching your building with the same system that provides energy for it? Leveraging one's investment in such fashion is always a good idea, making your expenditures yield two benefits is just smart.

Concentrated solar is almost by design a utility scale installation with significant control and power conditioning considerations. CSP installations, by necessity, start big and stay big. They need a lot of land with nothing else on it Rooftop PV, on the other hand, starts small and can scale up as time and money allow. Its design and building considerations conform to the individual project very conveniently.

Are CSP installations more efficient? The very best ones are maybe 25% efficient at converting solar power into electricity. Even the very best PV panels aren't as good as that but unlike CSP, PV has many promising developments under research that could as much as double its efficiency into the mid-40s, whereas CSP is, at its core, steam power. That is very mature technology and energy harvesting improvements in that field in the last 50 years have been, by comparison, marginal. Algeria's high temperature doesn't really improve things, it makes generating steam in the CSP slightly easier while also reducing the capacity of condensers. If there's a good use for the waste heat of the condensers then there are energy reclamation opportunities there, of course.