Short term it depends on the weather.
I mean that literally so. Energy consumption in any society is substantially tied to weather in the short term - even in the cave dwelling days they'd have burned more wood when it was cold.
In modern times that applies to both production and consumption.
Production side:
Wind and solar production is directly tied to weather at the time.
Run of river hydro is tied to short term runoff which is itself primarily a function of current and recent past rainfall.
In extreme cases weather may disrupt the operation of fossil fuel, biomass or nuclear power production or transmission, it may disrupt the movement of coal by rail or road. etc.
Consumption side:
Weather directly drives heating and cooling load most obviously.
With a time lag average temperatures affect water heating load.
In more extreme cases, eg snowed in, weather may drive significant changes in consumer behaviour and use of energy.
So that's an attempt to answer it but not really doing so. In any situation where there's an energy supply system on the edge, what happens with weather will determine whether it goes over the edge and falls in a heap or whether it takes a step back and the lights stay on. That goes anywhere from Australia to China to the US.
Ideal situation = mild temperatures, sunny days wherever there's a solar panel, windy wherever there's a wind farm, heavy rain into hydro catchments. But not to the point of being so wet or windy to disrupt anything eg coal mining or railways.
Worst case = winter starts early and bites hard combined with poor wind and solar yields, low runoff into hydro catchments and some level of disruption to power generation, fuel production or transport.
Looking at the longer term it's actually somewhat easier.
China's ultimately recoverable coal reserves are estimated as being in the order of 225 billion tonnes. China being China it's hard to obtain independently audited figures consistent with the approach used in the West but, broadly speaking, most figures (including Chinese government official ones) do put it broadly around that either directly or when the data is reverse engineered. They're all of that order of magnitude.
Coal produced to date = about 90 billion tonnes by most estimates noting there seems to be little disagreement there, most sources give very similar figures noting that most of it has been in the relatively recent past.
Remaining reserves = About 135 billion tonnes. That one's simple maths, 225 - 90 = 135.
Annual extraction at the present rate = about 3.5 billion tonnes give or take a few % in any given year. Chinese government official statistics and various external estimates all put it around that figure +/- 15% so there's no real disagreement on that one.
Putting all that together it's pretty clear that China's rate of coal extraction can't continue too much longer before geological limits, that is the coal resource base itself, becomes a key constraint.
That does not mean China runs out of coal. Rather, it means that the highest quality and most easily accessed coal is gradually used up and what remains is lower quality and/or physically harder to mine. It means that fewer mines operate as one by one individual mines are exhausted and close and, with fewer opportunities to develop new ones, the pace of opening new mines slows to a trickle.
The historic coal production profile of the UK, which is now almost complete (that is, it's almost over) illustrates that pretty clearly:
The harsh truth there is UK coal extraction peaked in 1913, that's decades before anyone had heard of Margaret Thatcher who in the minds of many is heavily associated with the decline of the industry. She may have slightly accelerated the final plunge but it was well and truly past peak by the time she became PM, indeed the peak was 12 years before she was born.
Why?
Because as the technically and economically recoverable resource diminishes, slowly but surely you end up with fewer mines and lower production. It doesn't die overnight, just slowly declines much like the once ubiquitous video rental shops all closed one by one.
Is the same happening now in China? Impossible to answer with certainty but from the figures above it's fair to assume that it's not too far away. Sometime in the next decade or so China's coal production will peak due to resource limits if the figures are anywhere close to accurate. China's mining half the world's coal but with nowhere even remotely close to half the world's reserves it's inherently unsustainable.
By about 2027 China will have mined 50% of its viable coal reserves, and by 2043 at present rates that would be 75%. It would be pretty much impossible to not see production start to decline in the face of such a shrinking resource base.
Now before someone says "but exploration will find more coal" it's important to note that the 225 billion tonnes isn't current proven reserves, it's an estimate of the total recoverable reserves including that not yet properly defined. So future exploration changes it only if substantially more is discovered than has been assumed - that's possible but requires that China's an exception versus international precedent.
Some light reading on the subject here:
https://web.cup.edu.cn/peakoil/docs/20130324090311797020.pdf
That being so, if China's to continue to rely heavily on coal beyond the very short term then large scale imports will be required.
For the EU well the issue isn't coal but gas and it's a similar story. Gas production in the UK peaked 20 years ago and has since declined sharply whilst that within the EU peaked last decade and is slowly but surely trending down. Combined with more gas being used for power generation the end result is heavy reliance on imports, especially by pipeline from Russia and in LNG form from elsewhere.
Beyond that it gets into the murky world of politics rather than logistics, economics or engineering.
In short China could import more coal if they really wanted to and they could get at least some increase in domestic production as well by re-opening the mines they've closed which still have coal left in them and there's rather a lot of such mines.
As for the EU and UK well it's a real minefield of politics covering all manner of issues. It's a somewhat bizarre mix of all sorts of ideologies and conflicting objectives from one extreme to the other.
I'll avoid trying to forecast politics.....
I will say however that before anyone gets too excited about China restricting the playing of video games and so on, well I guess that would save a little bit of energy yes. One thing though - an Australian state government briefly did that about 21 years ago. From memory it was in force for about 5 or 6 hours but it did happen. Victoria for the record.
Looking more broadly well here in Australia natural gas is presently trading in the east coast market (which includes SA and Tasmania) at between $7.70 and $8.62 / GJ depending on location. That's current (live) AEMO data as of 1 October 2021.
Where it becomes more alarming is with the Australian Competition and Consumer Commission (ACCC) forecasting of the LNG netback price. In simple terms that's how much gas in the domestic market is worth to an LNG exporter having regard to the cost of processing and international value of it.
The ACCC's forecast LNG netback price for February 2022? Well it's $29.83 / GJ.
Suffice to say there wouldn't be too many people, and I'm referring to financial and senior management sort of people, financial traders and so on, in the Australian energy industry who aren't aware of that. It's a high enough price that most certainly has such people paying very firm attention. Anything much over $10 tends to prompt use of the word "crisis" and here's the ACCC forecasting almost $30.
How that plays out domestically remains to be seen. To some extent the limited capacity of LNG facilities does offer protection, it's not physically possible to send the entire volume of gas production into them, but it does mean they can afford to outbid pretty much anyone on the spot market to obtain supply. As such, the gun is loaded - it just needs any disruption to domestic gas production, even a fairly minor one, and off we go with a price surge.
US is much the same by the way. Price is low but the LNG exporters could pay far more if they needed to for feedstock gas so long as international prices remain sky high. So even if US domestic prices double from here, or even triple, they'll keep exporting flat out. As such, the gun is loaded much like in Australia - just needs something to set it off (eg an abnormally cold winter could do it).
Now what about oil?
There's two main points of relevance to the oil market in all this:
1. Ability to substitute oil in lieu of coal (China) or gas (elsewhere) for industrial fuel, power generation and so on is significant. Either fuel switching in the same facility or by means of changing the priority order of use (eg the oil-fired plant becomes priority and the gas one is the backup whereas normally the reverse would be true).
2. In the specific case of propane and butane, which whilst partly supplied by extraction from natural gas are also produced at oil refineries, it's technically workable to inject either of those gases plus a measured quantity of air to produce a direct substitute for natural gas for supply to consumers.
Both of the above are established practice with numerous facilities to do it sitting there around the world ready to go. It's no coincidence that the ACCC's forecast peak in the LNG netback price just happens to match, on an energy content basis, the price of diesel delivered to what would normally be gas-fired power stations.
In most cases the change of fuel can be done whilst the unit remains in operation and for those where it can't, it's just a case of running gas today and diesel tomorrow if that makes sense financially.
That's already happening in some places:
https://www.thehindubusinessline.co...r-fuel-as-lng-prices-bite/article36269208.ece
“LNG (imported) into Pakistan is now about $250 per tonne more expensive than 180-cst (centistoke) HSFO,” a senior Singapore-based fuel oil trader said.
He added that on a forward price basis, spot LNG cargoes are trading above fuel oil prices through the first-quarter of 2022.
“We will see unprecedented switching into first quarter of next year at current prices,” the trader said, noting that fuel switching is already occurring across Asia and the Middle East.
All that said - what happens next literally does depend heavily on the weather in major producing and consuming parts of the world.