Can we use present perfect and future tenses in one sentence to talk about a project that had started in the past and is predicted to be completed in a particular year?
e.g.
The implementation of one power substation has begun and will be completed in 2019.
On closer observation you may notice that your sentence consists of two clauses, namely
The implementation of one power station has begun.
and
[It] will be completed in 2019.
the "it" being "the implementation of one power station".
This is an entirely valid structure and combining the two clauses to a single sentence is an entirely valid choice.
