There is potentially a very large effect. Order some i-buttons, very low-cost, wire-free temperature data-loggers, and set them out around the site so you have some data.

Then look at the plant performance record before and after the installation on similar weather days - look for condenser pressure if you have it, or for number of pump trip-outs which can indicate condenser temperature getting too high.  

Dear Susan krumdieck,

how can we eliminate the affect of near TG building  ?

what is the number of option ? 

Thank you

@Sudhir, if it has already been erected and cannot be moved, then you cannot eliminate the effect. You will have to live with the effects of derating of the condenser due to maldistribution of airflow.

Dear friend, LJ Yang and X.Du work more in this field. If turbine building and boiler are considered then due to the obstruction in the path of air flow flow will be changed and also boiler has some heat flux which also rise the temp of air around the buildings 

In their analysis they didnt consider the other direction of winds so these are the areas on which you can work on