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How I Gave Up Alternating Current

robrhinehart.com

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Re: How I Gave Up Alternating Current

#71

Post by maxerickson »

david-given wrote: post #63
justinph wrote: post #4

Interesting, but it seems like a lot of the lifestyle choices are just pushing the carbon/climate impact to someone else where the author doesn't have to think about it. Getting custom clothes made in china and shipped frequently is certainly far less environmentally friendly than simply re-using the clothes you already have. Taking an uber still burns gasoline. A bike would be better.

Hmm. A washing machine consumes about 100Wh == 360kJ for a load (ref: http://www.rpc.com.au/information/faq/power-consumption/wash... ). The Emma Mearsk, one of the largest container ships around, uses 13 tonnes of fuel an hour to transport 18000 containers, over a distance of (say) 20000 kilometres, which is 1kg of fuel to transport one container 45km (according to Wikipedia: https://en.wikipedia.org/wiki/Energy_eff…

360 KJ is 0.1 KW-h. So it would be 1.5 cents, not 15.

Re: How I Gave Up Alternating Current

#72

Post by davis_m »

> Even in less temperate locales I wonder if we really need to define our environment to within single degree Fahrenheit. I am not so controlling, but I do want to take back the rooftops from those horrible HVAC units.

I understand that the temperature is usually pretty nice in LA, but here in Iowa temperature control isn't an issue of defining our environment to within a single degree Fahrenheit, it is an issue of defining out environment into a livable temperature. Heck, most people I know have up to a ten degree delta between what they keep their home at in summer vs. winter.

However, without temperature control at all in Iowa, people would die. Sub-zero temperatures in the winter and above 100 degree heat in the summer are not mild inconveniences.

Re: How I Gave Up Alternating Current

#73

Post by rtkwe »

david-given wrote: post #63
justinph wrote: post #4

Interesting, but it seems like a lot of the lifestyle choices are just pushing the carbon/climate impact to someone else where the author doesn't have to think about it. Getting custom clothes made in china and shipped frequently is certainly far less environmentally friendly than simply re-using the clothes you already have. Taking an uber still burns gasoline. A bike would be better.

Hmm. A washing machine consumes about 100Wh == 360kJ for a load (ref: http://www.rpc.com.au/information/faq/power-consumption/wash... ). The Emma Mearsk, one of the largest container ships around, uses 13 tonnes of fuel an hour to transport 18000 containers, over a distance of (say) 20000 kilometres, which is 1kg of fuel to transport one container 45km (according to Wikipedia: https://en.wikipedia.org/wiki/Energy_eff…

This does assume that the custom made clothes are being slow shipped from China on a cargo boat instead of being shipped via air. Running clothes single use with a 2-3 week lead time for ocean freight sounds a bit tricky.

Re: How I Gave Up Alternating Current

#74

Post by abandonliberty »

shawabawa3 wrote: post #61
ovulator wrote: post #43

Earlier quoted context omitted.

When I got to the washing part (I skipped over the Soylent part because I assumed it was just a paid advertisement), I expected him to talk about using a washing board or something. No, I just buy new clothes. So instead of using a little energy for a spin cycle, I have factories in China spew coal, then have shipping freights (some of the worst environmental offenders) bring it half way across the world for me so I…

> then presumably add it to the land fill. He said he donates it, so presumably some charity ends up footing the bill for his laundry

Most charity donations these days get freighted out to poorer countries.

It's possible that it gets shipped back to China, washed, and resold to him.

Re: How I Gave Up Alternating Current

#75

Post by ars »

teamonkey wrote: post #46
wklauss wrote: post #30

I have long wanted to fully switch to DC in my life and would love to see common appliances designed for a DC world. It's a shame that the opportunity to discuss this is lost in this post because of the pedantic tone of the author. Phrases like "I think it was a bit presumptuous for the architect to assume I wanted a kitchen with my apartment and make me pay for it" or "I don’t want to live with red hot heating eleme…

Just what practical options are currently available? With roof-mounted solar panels becoming commonplace (at least where I live) it seems like 12V DC is a practical target, but it irks me that it gets converted to AC before being reconverted back to DC by a wall wart a few meters away.

80V DC might work, but 12V DC means the wires would be far too thick to be practical.

In the past you needed AC for the ability to have transformers. These days you can do that in other ways. But you still need a high voltage, meaning you still need that wall wart.

Re: How I Gave Up Alternating Current

#76

Post by shawabawa3 »

54mf wrote: post #56

"For storage a $65 lead acid automobile battery does the trick. It’s 12V so can be charged directly from the solar panel, and holds 420Wh, way more than I use in a day. That’s $0.15 / Wh so I don’t see why everyone is so excited about Tesla charging $0.43 / Wh for the Powerwall, sans inverter and installation." I'm not smart enough to take this apart, but my gut tells me the best-in-class engineers and (tens/hundreds…

It's summed up nicely here:

> http://www.powertechsystems.eu/en/technics/lithium-ion-vs-le...

Basically, lead acid have much lower lifespans, and also degrade very quickly if discharged below 50%. So straight off you have to double the size of your battery to not massively shorten the lifespan, so his costs are already closer to $0.30/Wh.

Also, lead acid batteries are larger/heavier per Wh, and even if you never discharge below 50% last less than half the time of Lithium batteries

Re: How I Gave Up Alternating Current

#77

Post by wklauss »

teamonkey wrote: post #46
wklauss wrote: post #30

I have long wanted to fully switch to DC in my life and would love to see common appliances designed for a DC world. It's a shame that the opportunity to discuss this is lost in this post because of the pedantic tone of the author. Phrases like "I think it was a bit presumptuous for the architect to assume I wanted a kitchen with my apartment and make me pay for it" or "I don’t want to live with red hot heating eleme…

Just what practical options are currently available? With roof-mounted solar panels becoming commonplace (at least where I live) it seems like 12V DC is a practical target, but it irks me that it gets converted to AC before being reconverted back to DC by a wall wart a few meters away.

That's the problem, there are not many (some fridges designed to be operated from car plugs, camping gear, things like that) and often is just an appliance that has a converter inside, so it is as inefficient as you'd expect. Not sure if there's a way to design stoves, fridges, ovens and washing machines powerful enough just using DC, though.

Re: How I Gave Up Alternating Current

#78

Post by soneil »

54mf wrote: post #56

"For storage a $65 lead acid automobile battery does the trick. It’s 12V so can be charged directly from the solar panel, and holds 420Wh, way more than I use in a day. That’s $0.15 / Wh so I don’t see why everyone is so excited about Tesla charging $0.43 / Wh for the Powerwall, sans inverter and installation." I'm not smart enough to take this apart, but my gut tells me the best-in-class engineers and (tens/hundreds…

Car batteries simply aren't designed for deep-discharge. It actually damages (sulphates) them. They're designed to provide thousands of cycles at 2-5% discharge. Using them for deep discharge, you're likely to see them increasingly unusable (or at least, holding nowhere near the designed charge) after 30-150 cycles.

So that 420Wh battery is most likely designed to actually provide about 21Wh. Past that it's a good assumption it's lifespan is being degraded faster than design.

To match a 7kW powerwall with these figures, he'd need roughly 350 such batteries (nearly $23k) to stay within a 2-5% discharge cycle.

So his setup may be capable of delivering 420Wh cheap. Or it may be capable of lasting 1-2000 cycles. But not both.

(Deep-discharge SLA are available. They're usually marketed as marine batteries rather than car batteries. They'll survive such usage better - a couple of years, rather than a couple of months in this scenario. But still not tesla's claimed 5000 cycles.)

Re: How I Gave Up Alternating Current

#79

Post by ars »

alextgordon wrote: post #20

Reminds me of Shabbat lamps. Since observant Jews are forbidden from using electricity ("starting fires") on Saturdays, what they do is turn on the lamp on Friday and just keep it on the entire time. That way they're not using any electricity.

> Since observant Jews are forbidden from using electricity

That is not true. They are forbidden from changing electricity. i.e. turning something on or off.

The Sadducees believed like you, that it was forbidden for the fire to be on, but the oral Torah is very clear that only starting (or extinguishing) a fire is prohibited.

http://www.chabad.org/library/article_cdo/aid/484251/jewish/...

And only Jewish humans are prohibited from turning on the fire, machines (timers, etc) are allowed to. So are non-Jews.

Re: How I Gave Up Alternating Current

#80

Post by jbondeson »

tedks wrote: post #49
jhildings wrote: post #16

>First, I never cook. I am all for self reliance but repeating the same labor over and over for the sake of existence is the realm of robots. Well then he does cooking wrong, he could also try to improve himself but in the craft in itself but also add more creativity to it

Who the fuck wants to do that? Here are 10 things I could be doing besides slaving over a stove (the seventh might surprise you): 1. Reading hacker news 2. Reading reddit 3. Engaging with people engaging with my brand on Twitter 4. Reviewing my productized consultancy analytics 5. Reviewing my startup numbers and analytics 6. Emailing brand leaders to gauge interest in new startup ideas 7. Posting on hacker news 8. W…

It's sad that I had to get to bullet point 9 before I could tell if this was satire...
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