Use below query to copy one column to another column.

Syntax: UPDATE Table_Name SET[COLUMN1]=(COLUMN2) WHERE '%CONNDITON%';

UPDATE [ELNetDB_ratan].[dbo].[PPS_Customer] SET[MeterVer]=(Area) WHERE MeterVer='0';

If above query is showing any error regard datatype then use below query to change datatype of column

Syntax: ALTER TABLE Table_Name ALTER  COLUMN Column_Name Datatype;

where data type is INT, Varchar, nvarchar, Real etc. 

  ALTER TABLE [ELNetDB_ratan].[dbo].[PPS_Customer] ALTER  COLUMN MeterVer REAL;