Old IPP's constructed in the 90's during peoples party era runs on furnace oil, now expensive and not readily available. Also the decline in production capacity is there, barely running on 30% capacity like HUBCO and many more.
The new power plants are a mix of RLNG, Coal, imported coal and local Thar coal, Hydel power, Wind energy projects, Pakistan now reaching 2000 MW's in wind energy production. Solar, Bahawalpur solar plant will have 1000 MW capacity, but the actual production never gets to optimum level in solar energy.
Then there is the newly inaugurated CHASHMA IV, 350 MW'ts, two 1100x2 MW's nuclear power plants near old KANUPP, so it is always better to have a mix of energy production resources than to rely on one source.
If interested check these power production updates...with new pictures.
http://www.skyscrapercity.com/showthread.php?t=1730245&page=16
http://www.skyscrapercity.com/showthread.php?t=1932434&page=4
http://www.skyscrapercity.com/showthread.php?t=1905967&page=3
Wind power projects...
http://www.skyscrapercity.com/showthread.php?t=1957491&page=5
Bahawalpur solar park, 1000 MW's
http://www.skyscrapercity.com/showthread.php?t=1685017&page=20
Chashma nuclear complex with 5x350 MW's plants.
http://www.skyscrapercity.com/showthread.php?t=1947531&page=5
Bhikki power plants.
http://www.skyscrapercity.com/showthread.php?t=1932100&page=8
Karachi 1100x2 MW's hasn't got updated. Also there are many Hydel projects under construction...