[jnsaff2]

The author gets a few things wrong or mixed up (mostly covered in other comments).

None of the other comments also talk about galvanic isolation, you need transformers (therefore AC) for that.

But the article is trying to sell you on DC, like there are lot of marketing around hydrogen and such. I would say the right approach would use the right technology where it is the best option. HVDC to replace HV AC transmission, sure if it makes sense for your use case. DC-ify all homes and appliances just because? Definitely not. DC-ify parts of home lighting? Why not. Tho lighting is usually at 24VDC or 48VDC and then you are going to need either very thick cables (insane waste) or DCDC converters and where is the advantage there?

Besides transmission line level of DC, rest of the article is pretty much noise, generation is where we have big problems at the moment.

Also AC frequency is currently used as signaling mechanism to regulate grid power-balance and stability, spinning reserve and all that jazz. With DC you need some other signaling mechanism, first to mind is Voltage but with all the smart semiconductor devices my guess is that the signal gets lost as these devices tend to compensate. So you'd need a dedicated signaling mechanism like software...

[R0b0t1]

You don't need AC for isolation, you need transformers. Isolated DC to DC is a big area of power supplies. You've also got cabling size backwards: you need thinner conductors for higher V due to lower I.

[jnsaff2]

Transformers only work with AC. Isolated DC-DC has also transformers where there is really high frequency AC. DC->AC||AC->DC. It's all hidden and due to high frequency quite small. But still AC.

Re cabling: currently we have 230V at home, going to 24VDC would mean 100x more losses. So I would say I got it correctly when I said going to 24V or 48V needs thicker cables due to increased I. As for your sentence, you don't NEED thinner conductors when voltage goes up but you would be quite wasteful if you didn't.

[R0b0t1]

Yes, but it's not AC in the sense that most people think of AC, where it's oscillating around 0V. Cable comment was related to you mentioning 12 and 24, it didn't seem compared against 120V in your comment.