Is the grammar of this sentence correct?

[albertage]

I can not understand the last sentence in this text . "This article is a review of the current understanding of tidal energy resources in the context of the emerging technology of tidal stream power generation. The geographical focus is on the north-west European continental shelf, the scope of a number of published reports on exploitable tidal stream energy resources. These estimates are reviewed as are some analytical models of energy extraction by tidal stream generators." Why use the second "are" ?Is the grammar of it correct? Please help me.

[Teia]

Originally Posted by albertage

I can not understand the last sentence in this text . "This article is a review of the current understanding of tidal energy resources in the context of the emerging technology of tidal stream power generation. The geographical focus is on the north-west European continental shelf, the scope of a number of published reports on exploitable tidal stream energy resources. These estimates are reviewed as are some analytical models of energy extraction by tidal stream generators." Why use the second "are" ?Is the grammar of it correct? Please help me.

These estimates are reviewed as are some analytical models of energy extraction by tidal stream generators.

It`s an inversion of the verb[ in front of the subject] used to emphasize the idea of the sentence:

These estimates are reviewed as some analytical models.....are.

[Horsa]

There is not enough of the context in your extract to allow me to decide whether the sentence contains an error or not. However, the sentence as it stands has meaning and so I presume it to be correct. The second 'are' works with 'as' and together they give us the understanding that the 'analytical models' referred to although not included in 'These estimates' are also reviewed.

Without the insertion of 'are' here the meaning would be unclear because 'as' would tend to take on its other meaning of 'similar to'/'like' and in this sentence could then mean 'as if they were'. That said, the use of 'some' would make that interpretation clumsy and therefore I am of the opinion that the original sentence conveys the intended meaning and is correct.

[albertage]

Thanks a lot! It is very helpful to me!