Comments by "seneca983" (@seneca983) on "China’s Electricity Problem" video.

  1. "being an HVAC tech is a great job" By "HVAC" do you mean "Heating, Ventilation, and Air Conditioning" or "High Voltage Alternating Current"? Both would fit to the theme of this video.
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  2.  @robertlomax543  "Having said that I would love to see the actual design for the step down converter. That's a hell of a shift in DC voltage. I wonder if they are using vacuum tubes or solid state and what switching frequency is used?" I'm not an expert but here's what I've seen on the subject. HVDC lines have converter stations at both ends. The DC voltage itself isn't stepped up or down but the converter stations that convert AC to DC and DC to AC also have transformers that step up the voltage before conversion to DC and down before conversion to AC. Nowadays the conversion is done with thyristor banks. In the AC to DC conversion they work similarly to diodes and then any ripple is filtered out with big capacitors and inductors. In the DC to AC conversion the thyristors are switched based on signal from the receiving grid making sure the phases are in sync. This kind of switching produces square waves. Then harmonics are filtered out using capacitors and inductors turning it into sine wave.
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  3.  @SpencerHHO  "The input takes the standard high voltage 3 phase, runs it through a transformer that phase shifts it to make it 6 phases" This is slightly off. You can already get 6 phases from 3 phase power by using both phases (opposite) phases from each line. However, you can further increase this to 12 phases by using two transformers. One transformer should use a delta configuration on one side and wye on the other. This causes the phases to be rotated by 30° relative to ones from a transformer with the same configuration on both sides. In the case of 12 phases the phases next to each other are 30° apart so this way you can get 12 phases.
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  4. No, I think those happened over a longer period of time than in China.
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  5. Air conditioners are heat pumps.
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  6. Solar output is greatest when there is greatest need for air conditioning. Thus, those two should go well together.
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  7.  @creamofbotulismsoup9900  "Not really, pretty much any building with A/C will be insulated to prevent the heat from immediately transferring in." A delay of 3 h or something doesn't ruin it. Houses also have thermal inertia so you have some leeway to run AC when electricity is the cheapest. Doing it during the day if solar PV is very plentiful is still easier than doing it during the night (which is also still feasible if the house has enough mass not heat up too much in one day).
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  8.  @micaledayurst7462  That does not comport with figures I find with short googling. Based on what I found AC would use about 3 kW on average whereas a fridge would be closer to 250 W on average meaning AC uses more than 10x more. Also, AC usage tends to be higher in regions where solar power is more viable.
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  9. Because it's the one being highlighted.
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  10. Part of that gas was used for direct heating of homes (as well as cooking with gas stoves). That's definitely something we should get rid of.
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