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Slow Electricity: The Return of DC Power? (2016)

lowtechmagazine.com

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Re: Slow Electricity: The Return of DC Power? (2016)

#191

Post by bluGill »

ClumsyPilot wrote: post #183
emacsen wrote: post #88

Earlier quoted context omitted.

> Though I do think that Americans uses clothes dryers _much_ more than they should. There are many reasons for this. Some of them are cultural, and other are legal. Many Americans simply don't remember drying clothes on a clothes hanger outside, and aren't used to hanging them indoors as many Europeans do. And to be fair, indoor clothing hanging is time consuming in comparison to "transfer clothes from one machine t…

"it's often banned in many home owners' associations, and banned in many apartment leases" That seems extremely inappropariate. Are there no restrictions on what they can ban, like can they ban children or cooking curries?

There are a few restrictions, but not very many. You agree to them before you move in, so you are expected to not move there in the first place if you don't like the rules.

I just refuse to live in one which solves it for me.

Re: Slow Electricity: The Return of DC Power? (2016)

#192

Post by AnIdiotOnTheNet »

ashtonkem wrote: post #178
AnIdiotOnTheNet wrote: post #146

Earlier quoted context omitted.

> Meanwhile the thing that has actually gotten people out of their cars is the ebike. This is not my experience. People just put their ebike on a rack and drive it somewhere to ride it for fun.

And this is why it's useful to check the literature, individual results might provide misleading anecdotes. > This paper reports on a review of the European literature about the impacts of having an electrically-assisted bike available to use, together with results from a trial in the UK city of Brighton, where 80 employees were loaned an electrically-assisted bike for a 6–8 week period. In the Brighton trial, three-…

Another big factor might be that I live in the US. Generally speaking, everything you want to go to is a lot farther away here.

Re: Slow Electricity: The Return of DC Power? (2016)

#193

Post by bluGill »

Karrot_Kream wrote: post #72
ashtonkem wrote: post #55

Earlier quoted context omitted.

You do have to wonder if they’re confused on why this isn’t persuasive to normal people. Go cook outside on a rocket stove[0] and washing clothes by hand every day? Come on. Meanwhile the thing that has actually gotten people out of their cars is the ebike. It turns out it’s much more effective to produce a more convenient and comfortable solution for people rather than just demand that they go back a century or two…

> 0 - It’s also telling that such advocates never seem to actually say who should be stuck doing all the labor that machines like washing machines now do for us. Washing clothes and dishes by hand is hard labor, and someone is going to have to give up their career or free time to do it if we’re going to ban these machines. No extra credit if you figure out who will get stuck with the task… Yeah lol I always find this…

> since a restaurant will be more energy efficient at preparing food than an individual

Really? Most restaurants have a grill and deep fry vats hot 100% of the time even when nobody is there.

Re: Slow Electricity: The Return of DC Power? (2016)

#194

Post by tootie »

ClumsyPilot wrote: post #169
pleb_nz wrote: post #97

Earlier quoted context omitted.

I read somewhere modern people spend the same amount of time doing chores as someone before electricity. It wouldn't surprise me if it were that far off the truth. We own so much more and are told we need things when in reality maybe we don't?

Have your ever seen what it's like to wash clothes by hand? It's like a 3 hour hour process. Its arduous, tedious, and keeoing the house in order used to be a full-time job Washing machine has done more to liberate women than all political efforts combined.

I think the distinction is we have 50X more clothing to wash. And it's partly because washing is so easy. I have a family of four and spend a lot of time folding clean clothes.

Re: Slow Electricity: The Return of DC Power? (2016)

#195

Post by flavius29663 »

jusssi wrote: post #96
Karrot_Kream wrote: post #86

Earlier quoted context omitted.

I've usually hung my laundry indoors or on the stairs if I lived in a place with stairs. I realize this requires some space, but usually keeping the clothes in front of the window is enough to have them dry. I've had one of [1] these for years and it hasn't let me down yet. [1]: https://www.ikea.com/us/en/p/frost-drying-rack-indoor-outdoo...

Effectiveness of indoor hang drying depends on air humidity and circulation. In our previous place, at end of August indoor RH would be around 70% (edit: outdoor would be around the same so opening a window wouldn't make a difference). In practice that meant that some of the clothes hadn't completely dried the next day, and were starting to smell.

I'm hanging my clothes next to the dehumidifier. We need the dehumidifier anyway for the basement. It dries the clothes in no time, they're already on hangers, without wrinkles, and without wearing them out like the drier does.

Re: Slow Electricity: The Return of DC Power? (2016)

#196

Post by mindslight »

Robotbeat wrote: post #28

So, I used to be "team DC" as well, but after learning up a bit, I realized there are still a lot of advantages to AC in the 21st Century. One reason DC power is more viable nowadays is (as others here have mentioned) the use of DC-DC converters. They internally actually use AC to do the conversion (usually at much higher frequency to save weight and cost on inductive elements). But they're not super cheap (not cheap…

DC-DC converters can be much simpler than PFC [0] AC-DC converters.

There are actually scant few things in modern houses that inherently want to run on 60Hz single phase AC - basically just fixed-speed induction motors [1]. And the amount of those are shrinking as more and more appliances get "inverter" technology for the energy savings.

The transformers on the poles are bona fide 60 Hz devices (and I'll take the electricity I can get). Industrial customers with large 3 phase induction motors want 60Hz AC. But for household use, DC would be straightforward.

I agree about the self-extinguishing arcs, although it seems like moving to solid state switches would solve much of that.

[0] power factor correction

[1] And actually, "single phase" induction motors don't even want to run off of a single phase. They all contain capacitors to create a second phase so the motor rotates.

Re: Slow Electricity: The Return of DC Power? (2016)

#197

Post by bluGill »

skybrian wrote: post #62

I'm not sure I care whether it's AC or DC, but it might be nice to have some parallel off-the-grid wiring that comes from a solar-charged battery and will run during a power outage. What would work best for this?

Why parallel as opposed to the same wires? There are good answers for this, but for most people what is best second circuit box that runs just the fridge and a few important lights (in my case the well for water). This way you use the same appliances for everything. A parallel circuit implies when the power is out you have to use something different.

As I type this my house is running from a backup generator. The power company has their repair crew in route to whatever the issue is. I'm looking into how/if I can add solar to the system as well.

Re: Slow Electricity: The Return of DC Power? (2016)

#198

Post by bluGill »

lbriner wrote: post #160
zurn wrote: post #68

Many of the loads discussed, eg washing machines, are also reasonable matches a local solar power source, as it's much cheaper to buffer hot water than have large batteries. (Water heating dominates the energy used in those, the mechanical sloshing around takes trivial power compared to it).

And what do you do for the 6 months of the year when there is not enough solar to heat water to a suitable temperature?

Depends on where you live, but generally this is enough solar, you just need enough well insulated storage to last a few weeks.

Re: Slow Electricity: The Return of DC Power? (2016)

#199

Post by ip26 »

ashtonkem wrote: post #171
ip26 wrote: post #64

Earlier quoted context omitted.

never seem to actually say who should be stuck doing all the labor They are probably not actually closet misogynists or anything like that, they probably just haven’t thought that far ahead.

> They are probably not actually closet misogynists or anything like that, they probably just haven’t thought that far ahead. I agree, this is more probable than the closet misogyny theory. But it's still not exactly a ringing endorsement to say "whoops, we didn't think about who would have to do all that labor once we took away all those labor saving devices!" It's not like this is some hard to predict third order e…

Yup, I'm with you, lowtechmag has a lot of articles that seem unmoored from reality. There's always a few good ones though. There's one arguing if the grid was designed for 98-99.9% uptime instead of 99.999999% uptime, we'd a) survive just fine b) have cheaper power and c) be more resilient against power failure when it inevitably happens, which I found pretty thought provoking.

Re: Slow Electricity: The Return of DC Power? (2016)

#200

Post by bluGill »

gwbas1c wrote: post #20

If you read to the end... This kind of system only makes sense where there aren't major appliances. (Think RVs, off-grid cottages, and developing countries.) I wonder what would happen if we redesigned the grid today? Would it be AC or DC? If AC, would it be a higher frequency? (Smaller transformers) Is modern DC-DC voltage conversation easier than AC-DC? What voltages would we use?

It would be both AC and DC. Different applications do best for different things. DC for long distance, AC for medium distances, and DC very short distances - exactly what we do today. Probably we would use a higher frequency, but that is the only change worth considering. Transformers are efficient and easy, and the things that need high power tend to want AC anyway (though they are moving to VFD which can use DC).

The biggest factor is AC is a lot safer. Switches and branch protection devices (fuses) work best on AC. For low voltage DC we can make them work, but for high voltages we don't - instead we put in the protection on an AC side, then convert that to DC.

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