Interesting topic. Pakistan relies mostly on Hydro and Natural Gas, which are far cleaner than Coal or Oil for producing energy. Pakistan also uses nuclear (two plants). This makes Pakistan's energy production quite clean, but it is not by choice, but by chance. For all practical purposes, these are the only real solutions to the clean energy problem, because as any engineer will tell you, people who talk about using wind and solar to replace Coal and Oil don't know what they are talking about.
Wind energy is naturally limited to ~70% efficiency, that is, if the wind turbine itself functions at 100% efficiency (impossible), the most you will get out of it is just over two thirds the energy it takes to turn the blades. Wind energy is also very unreliable, and depends highly on the location and wind conditions. Wind power plants cannot be situated near densely populated areas because there isn't much wind there. Ideally, you would want your wind plants to be situated on high ground or out in the sea. However, this will add to the transmission costs, not to mention that wind power plants require a lot more infrastructure and provide irregular energy.
Solar has even more problems. It is the most expensive type of energy producing method today, and it is damn near impossible to produce enough energy to power a small town using solar alone. It also has the irregularity problems of wind power.
Nuclear and Natural Gas still have polluting issues. The extraction of nuclear material to be used in plants, and then the disposal of nuclear waste, are some of the dirtiest businesses around. Environmentalists do not like the idea of nuke power at all, but for me and many other engineers, it is the only short-term solution to the problem of increasing pollution due to energy production.
Considering this, at least in the short term, Pakistan should pursue an energy program based primarily on Hydro, Nuclear, Natural Gas, Geothermal and Coal (all of which we have in abundance, by the Grace of Allah). Yes, we should increase the use of Coal because it makes no sense to not use the great Coal resources of Sindh. Using Coal plants to generate, say, less than a quarter of the energy required, and exporting the rest, will be extremely beneficial to our economy and society. Even if Coal were to power 50% of homes in Pakistan, we still would not be contributing to the pollution to the region significantly, mainly because India and China, out neighbors, are the leading polluters in the world today. China has shown willingness to control its accelerated pollution (which is being hailed by environmentalists all over the world), but India is yet to show such an initiative.
Here is my rough guess of the direction our energy program should be heading focusing on:
Hydro: This is already being used quite a bit. Punjab has been gifted with 5 rivers, we can make the most use of these resources by settling our issues with India and using their power producing potential to the max. Hydro plants are probably the cleanest practical way of producing energy, if you can design them well enough, that is.
Geothermal: We have a pretty long coastline. Geothermal is still an experimental way of producing energy, but I personally see huge gains to be made. It utilizes the heat stored deep within the Earth to boil water, which in turn rotates turbines, which in turn produce AC current. It required quite a bit of investment, but once you have dug deep enough, it's pretty much running-cost only. The heat is provided by the Earth, all you have to do is ensure your plants are functioning properly. This would be a viable option for producing energy for lower Sindh and Karachi, and even Gawadar. I think it's an idea worth exploring.
Coal and Natural Gas: Like I said, we have an abundance of these resources. For all internal areas of Pakistan, including Sarhad, Northern Balochistan, Northern Sindh, Gilgit-Baltistan and Azad Kashmir. this will be a viable option.
Nuclear: This is very important for more than one reasons. Increased use of nuclear technology for peaceful purposes is not only great for our image and trade, but will make us a responsible nuclear power. We should be able to produce nuclear plants on our own, without external help, if we want to maximize this potential. These plants can be used to power relatively less dense areas (for security reasons) all over Pakistan, including Western Punjab, Western Sindh, Eastern Sarhad and Eastern Balochistan. We shouldn't build any of these close to the border regions, for obvious reasons.
Edit
Some people here are delusional. India will never rely on wind or solar to produce most of its energy, stop trying to use that to claim that you are "green". Like I've said above, nobody in their right minds would recommend large-scale production of energy using wind and solar. Also, nuclear energy is not clean. If you consider the life-cycle of nuclear fuel you will realize that, everything considered, nuclear is pretty damn dirty itself. But like I said, it's our only reasonable short-term (next 50 years) solution. Natural Gas is also a viable option for the short term.