Construction costs are currently skyrocketing

and why are they building new coal power plants instead of using renewables?

It has already been mentioned that China is building more renewable energy plants than fossil fuel power plants. I can recommend the book "Weltuntergang fällt aus" by Jan Hegenberg. It debunks or informs about myths such as "Germany cannot save the world alone !!!111" and "China builds ONLY coal power plants etc." with exact sources. China and the Scandinavian countries have already surpassed Germany in terms of renewable energy expansion, and countries like India (largest solar park in the world + more planned/under construction), USA are on the rise.

It has already been mentioned that China is building more renewable energy plants than fossil fuel power plants. I can recommend the book "Weltuntergang fällt aus" by Jan Hegenberg. It "debunks" or informs with exact sources myths such as "Germany cannot save the world alone !!!111" "China only builds coal power plants etc." China and the Scandinavian countries have already overtaken Germany in terms of renewable energy expansion anyway, and countries like India (largest solar park in the world + more in planning/construction), USA are on the rise.

How do we secure the power supply in autumn and winter? Solar and wind will by far not be sufficient and are not reliable. If there are no renewable energies available for one day, how do we then reliably fill the huge gap? Storage technologies are not in sight, at least not in the next 10 years. So?

Düsseldorf (dts News Agency) - Rising energy prices are increasingly driving up the costs of building materials such as roof tiles, insulation materials, or bitumen. "Many home financings could now be at risk due to the sudden price jumps," said H.R., deputy chief executive of the construction associations NRW, to the "Westdeutsche Allgemeine Zeitung."

Due to the more expensive building materials alone, costs for building a home are expected to rise by ten to twenty percent compared to the previous year. Although most building materials are still available, "the effort to obtain them is much greater than before." Last year, a phone call to a nearby dealer might have sufficed; this year, one might have to drive to a neighboring country.

According to the construction associations, metal building materials are on average almost 25 percent more expensive than the previous year, petroleum products like Styrofoam are between ten and thirty percent, and bitumen is thirty to forty percent more expensive than the year before. In addition to these problems, there are others that have existed for a longer time in construction, such as the poor availability of gravel and sand as well as missing landfills for construction waste.

How do we secure power supply in autumn and winter? Solar and wind will by far not be sufficient and are not reliable. If there are no renewable energies available for one day, how do we reliably fill the huge gap then? Storage technologies are not in sight, at least not in the next 10 years. So?

I consider it rather unlikely that all renewable energies in all of Germany/Europe will fail simultaneously. They consist not only of solar and wind, but also, among others, of hydro and biomass. Besides, there are still conventional power plants currently for the base load. Why are no storage technologies in sight? Germany currently consumes about 83 gigawatts of electricity per day. Alone the currently 600,000 registered pure electric cars have a combined storage capacity of 41 gigawatts, so not quite half. Bidirectional charging could solve the problem here. Alone last year, over 300,000 pure e-cars were registered. Theoretically, we will have reached the storage capacity quite unspectacularly in about 2 years... Additionally, using the already existing production peaks for producing hydrogen or synthetic fuels solves the problem.

I consider it rather unlikely that all renewable energies throughout Germany/Europe would fail simultaneously. These do not only consist of solar and wind, but also include hydro and biomass, among others. Furthermore, there are still conventional power plants for the base load at the moment.

Why are no storage technologies in sight? Germany currently consumes about 83 gigawatts of electricity per day. The 600,000 currently registered pure electric cars alone have a combined storage capacity of 41 gigawatts, so not quite half. Bidirectional charging could solve this problem. Last year alone, more than 300,000 pure e-cars were registered. Theoretically, we will have reached the storage capacity in about 2 years quite unspectacularly...

Additionally, using the already existing production peaks to produce hydrogen or synthetic fuels would solve the problem.

And at the same time, from November to February there is relatively little solar energy across Europe, especially only at certain times. If calm weather is added, it will certainly get tight in the evenings. It will still take many years before cars can be used as storage. Neither inverters nor cars of the current generation are capable of doing so. So we are talking about at least 10 to 15 years until market maturity.

Don’t get me wrong, it’s all doable and must be tackled. But it is dangerous to believe that this change would be possible within 3 years.

By 2040, it is planned that nuclear power plants should have a total nominal capacity of 150 gigawatts. So 1/7 of what renewable energies in China already produce today.

So, now nuclear power plants have an efficiency of over 90%, i.e. more than 8000 full load hours per year. They are very plannable and predictable and controllable up to nominal capacity.

Wind power in China maybe has 3000 or in the best locations 4000 full load hours, difficult to plan and predict and how much of the nominal capacity is currently available is more or less random.

With OPV it looks even worse, in China you might have about 1500 full load hours.

So 5 kWp photovoltaic capacity then produces 7500 kWh per year.
But 1 kW nuclear power capacity produces 8000 kWh per year.

In other words: newly installed nominal capacity without stating the achievable full load hours is rubbish, big time!
Or: you only need to build about 1 kW conventional capacity for 4 kW from a wind/photovoltaic mix for the same annual output. Whereas the photovoltaic/wind mix is so erratic that it either requires a shadow power plant park of conventional power plants or gigantic electricity storage.

That means for 1 kW secured capacity you need nearly 1 kW conventional power plant running on standby plus 4 kW renewable energy generators. Alternatively 4 kW renewable energy generators plus storage (for photovoltaics at least a 2-month winter demand, for wind about 1 week demand).

It really looks different with coal, there China actually is the "world champion". But even there I assume that for China this is a bridging technology that will eventually be phased out and replaced by clean energy.

Coal is at least a substitute for missing storage. Somehow you have to have something for power generation at night when the wind is weak or you risk a blackout. In Germany the latter is increasingly preferred, in China I strongly suspect the former.

Why are no storage technologies in sight? Germany currently consumes about 83 gigawatts of electricity per day. The currently 600,000 registered pure electric cars alone have a total storage capacity of 41 gigawatts, so not quite half.

Why not 83 GW per hour right away? Per second would also be correct! GW is a power. Power is not consumed, it is provided. Like a gasoline engine that delivers 100 kW. The 20 liters of gasoline or 200 km range that one may achieve with it in an hour is the work done. So work = power times time.

Now electric cars have batteries to store work. So you probably mean 41 GWh storage capacity. That is what 83 GW of power plants can deliver in about 30 minutes. But if of the 83 GW only 41 GW were available because it is night and the wind is not blowing much, then of course you could take the car batteries and feed their power into the grid. Provided they are all fully charged, no one has to drive soon and they may therefore be discharged to a SOC of 0, you could compensate the underperformance of the power plants exactly for 1 hour, 41 GW*1h = 41 GWh. After that it’s over. Blackout for days.

For comparison: in the year 2020 about 500 billion kilowatt hours of electricity were generated in Germany. That is 500,000 GWh and you come here with 41 GWh... factor 12,000. Even if the existing 600,000 BEVs once became 60 million, the factor is still 120. And then nothing would be left for the actual purpose of a BEV (providing driving performance).