I am reposting a short, nice fb post by Engr. Gabriel Pamintuan, Jr. Then my short discussion after.
Why underground coal mining is challenging
We take for granted our electricity, 30% of which comes from coal; do you know how hard it is to mine coal underground?
No matter what you say about its being “dirty” and clamor for non-fossil and renewable energy, coal is here to stay.
The underground is not always this clear; and the seams can even be thinner, I had to crawl “spiderman-style” to get to the lower level, where we hoped to get out through a ventilation outby, only to find out that it was not passable. We had to go back up from where we came, maybe some 50 m of 20+ degrees incline.
The coal bed is not very thick, so workers and supervisors at the coal face have no standing room, bending or squatting most of the of time. The panel and haulage drifts are bigger to enable one to stand.
The coalbed is won by using pneumatic picks and the broken coal either falls directly to a chain face conveyor or is shoveled to the face conveyor; then it is transferred to the panel conveyor to be brought to the surface. (If the seam is steeper, a half-pipe slide is used to convey the coal from the face to the panel conveyor.) The run-of-mine is brought to the surface using cable-drawn mine cars.
The “fun” thing when you walk upwind and coal dust is in the air. It gets to land on your sweaty face and other exposed skin . . . Walking downwind, the back of your neck gets the dust; too bad if even the back of your neck is sweaty . . .
That’s why that look on coal miners’ faces; the face mask and respirator are there, but you can go short on air when wearing one, especially in less-than-optimal ventilation conditions . . . Nothing beats a well-ventilated heading, either in a hard-rock or a coal mine . . .
But you should, for comparison, also visit a small-scale mine, where conditions are perhaps doubly harder . . .
Wow, hard work in the exploration and development of a coal mine, thanks for that piece. Actually coal produces not just 30% of the PH’s electricity supply, it is about 50%. In terms of installed capacity nationwide, coal share in 2016 was 36.5%, followed by natural gas (from Malampaya field which feeds 4 natgas power plants in Batangas) at 17.2%. But in terms of actual electricity production, the various coal power plants produce about 50% of the total electricity needs of the country from Luzon to Mindanao.
The variable REs like wind-solar-biomass, their share in installed capacity is almost 6% of the total but their actual electricity production is only about 1-2% of total because these are intermittent, unstable sources and produce zero electricity when the Sun does not shine (at night, or thick clouds, or raining hard) or if the wind does not blow.
Semirara is the biggest coal mine in the country but I think not all of its output is used by the coal power plants here mainly because of its coal quality. Not all coal are of the same quality, some have higher energy density than others.
People who demonize coal mining and coal power are confused if not outright dishonest. They want cheap and stable, 24/7 electricity, they hate brownouts even for 1 minute, and coal power can give that, along with natgas, nuke and oil power plants.