Yeah no, Hydel WAS the biggest contributer, but that was long long ago.
The situation has changed a lot. Currently thermal power plants, whether they are Independent power plants (IPPs) or PEPCO's or any other owned, contribute the most. Hydel is second. No Major DAM has been built in the past several several years.
Problem with thermal is that most of them run on furnace/fuel oil and some on gas, which costs a lot. And since we are always in debt etc, the Govt can't meet the payment requirement, which results in less production, increasing shortfall. This could be averted if they use coal instead of oil, especially our own coal.
In Winter's Hydel barely produce any electricity because of very low water inflow. Most of the electricity depends on thermal and in theory, if they pay the oil bills and provide full gas, there should be no load shedding in winters due to reduced consumption. And even in summers, with full hydel capacity also included, there should be very little load shedding because our installed capacity actually is more than the demand, if everything works at optimal scenarios. BUT here, with corruption, theft and debt etc issues, situation is anything but optimal.
Nuclear production is very little compared to the above mentioned ones. And solar/wind etc are almost nonexistent.