I have List loadRecords where T type defines as follow
public class TransformerLoadRecord
{
public double TotalLoadKva { get; set; }
public double Total
I don't think so you need to group them just for getting record with highest TotalLoadKva,you can just use OrderByDescending to sort them on the TotalLoadKva and then select the top first record using First or FirstOrDefault method:
var maxKVALoad = loadRecords.OrderByDescending(l => l.TotalLoadKva).FirstOrDefault();
// will return the record with highest value of TotalLoadKva
the preferred way will be to use FirstOrDefault() as First() will throw exception saying:
The Sequence contains no elements
If it is guarranted that there will always be rows returned then First() can be safe to use, otherwise use FirstOrDefault which will not throw exception if collection is empty.