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Show HN: $200 Solar Self-Sufficiency Without Your Landlord Noticing

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Re: Show HN: $200 Solar Self-Sufficiency  Without Your Landlord Noticing

#121

Post by 1_2__4 »

Retric wrote: post #114
accountyaccount wrote: post #83

Earlier quoted context omitted.

20lbs is nothing for a strong gust of wind on a roof.

Flat roof, low profile, is very different from even an 1/8th inch gap on a slanted roof.

You really need to stop replying to every reasonable comment pointing out a very real risk with all this ignorant nonsense. You know not a thing about air flow on that roof (or anyone else's), and you seem to be utterly clueless as to how powerful even mild gusts of wind can be. Trying to convince people they DONT need to take reasonable safety steps, even when presented with knowledgeable arguments that are clearly better informed than yours, is incredibly irresponsible. Please reconsider.

Re: Show HN: $200 Solar Self-Sufficiency  Without Your Landlord Noticing

#122

Post by liyanage »

ChuckMcM wrote: post #26

Fun stuff. I've built several systems just like this one for camping, they let you keep things like iPads or laptops charged and they aren't noisy like running a generator. Something that my wife discovered was that an igloo "lunchmate" cooler was perfect to hold the battery and charge controller. Makes it easy to carry. I recommend using Anderson Powerpole connectors ( https://powerwerx.com/anderson-power-powerpole-…

+1 on the Powerpole connectors, I used them on a small solar system very similar to what's described in the article and they work great.

Re: Show HN: $200 Solar Self-Sufficiency  Without Your Landlord Noticing

#124

Post by JumpCrisscross »

galdosdi wrote: post #42
pilom wrote: post #28

Earlier quoted context omitted.

Unfortunately it isn't a 16% return because he can't sell that system for what he paid. If you buy a stock at $300 and sell it for $348, that's a 16% return. But for him, he probably would have trouble selling all of that for $100 (the battery will be worthless in about 2 years given how far it is being discharged and very few people buy these things on craigslist for anywhere near what they cost). If he can sell it…

Being able to sell the system is irrelevant as long as the system will last indefinitely (or say, 30 years, which approximates the same value anyway). Everything but the battery is solid state and should last indefinitely -- or certainly more than 8 years. I already excluded the battery as a consumable to calculate the 13% rate of return. But one thing you are right about is the other parts will fail eventually, drag…

> as long as we believe we are right and the market is wrong about the likely future earnings

In a liquid market like the stock market, the odds of this being true is small. Recognizing a 10% return against a stock that's crashed 50% borders on, depending on if you're investing your money or others', delusion and fraud, respectively. There is no liquid secondary market for home-solar components, however, so approximating cash flows and amortization schedules works.

(If you've heard the terms "mark to market" and "mark to model", this is what they're talking about.)

Re: Show HN: $200 Solar Self-Sufficiency  Without Your Landlord Noticing

#125

Post by Retric »

trhway wrote: post #120
Retric wrote: post #63

Earlier quoted context omitted.

I really doubt the wind is going to pick up a 2'x4' ~20lb panel like that when it's flat on a roof. Now if he had lifted an edge to try and get a better angle with the sun that would IMO be a much larger issue.

>I really doubt the wind is going to pick up a 2'x4' ~20lb panel like that when it's flat on a roof. thus the difference between the air speeds over the panel and under the panel in this case equals to the wind speed. To compare - Cessna wing loading is 15lb per square foot and it is generated at the minimum no-stall speed required by the FAA for general aviation of something around 70 miles/hour, and in that situati…

That's not how wings work. https://www.grc.nasa.gov/www/k-12/airplane/wrong1.html

Most obvious problem aircraft can fly upside down.

Re: Show HN: $200 Solar Self-Sufficiency  Without Your Landlord Noticing

#126

Post by Retric »

1_2__4 wrote: post #121
Retric wrote: post #114

Earlier quoted context omitted.

Flat roof, low profile, is very different from even an 1/8th inch gap on a slanted roof.

You really need to stop replying to every reasonable comment pointing out a very real risk with all this ignorant nonsense. You know not a thing about air flow on that roof (or anyone else's), and you seem to be utterly clueless as to how powerful even mild gusts of wind can be. Trying to convince people they DONT need to take reasonable safety steps, even when presented with knowledgeable arguments that are clearly…

Run some actual math > fear.

Yes, in a slightly different situation this would be an issue. But, wind is not magic fairy dust that can lift arbitrary loads.

Re: Show HN: $200 Solar Self-Sufficiency  Without Your Landlord Noticing

#127

Post by Retric »

serf wrote: post #77
Retric wrote: post #63

Earlier quoted context omitted.

I really doubt the wind is going to pick up a 2'x4' ~20lb panel like that when it's flat on a roof. Now if he had lifted an edge to try and get a better angle with the sun that would IMO be a much larger issue.

"Really doubt" is probably a poor level of confidence with regards to a decision that may or may not kill someone.

Tell that to the average car driver.

But sure, bolt it down. Minimal effort vs minimal risk is something people do all the time. My point is the actual risk is very close to zero.

Re: Show HN: $200 Solar Self-Sufficiency  Without Your Landlord Noticing

#128

Post by nikodunk »

bonniemuffin wrote: post #98
reaperducer wrote: post #45

Will the landlord notice? Maybe not. Will the wife notice all the wires all over the place? You bet!

Because men love electronics projects and women love keeping a tidy house and ruining their dreams, am I right?

Hahaha both of those comments were some of the most entertaining on here!

Re: Show HN: $200 Solar Self-Sufficiency  Without Your Landlord Noticing

#129

Post by snowwindwaves »

nikodunk wrote: post #18
snowwindwaves wrote: post #16

I find the title kind of click baity, "$200 solar self sufficiency for my bedroom" would be more accurate

Hey. You're completely right :) My original title was was "Solar Self-Sufficiency for Renters", but my mates in marketing told me to clickbait it the f up. Would you have clicked on the former, though?

it adds to the misinformation regarding solar energy and going off-grid

Re: Show HN: $200 Solar Self-Sufficiency  Without Your Landlord Noticing

#130

Post by nikodunk »

bvanderveen wrote: post #119

Can't imagine why OP has an inverter in the stack when everything connected to it is DC.

Because it's easier and I don't want to fry my $1500 laptop with some hair-brained project's DC-power spike. But I admit that's not really well thought through and an earlier version of this project was DC only. Also, the main inspiration for this project was DC only, as I mentioned in the article (but reposted here: https://arstechnica.com/gadgets/2015/08/op-ed-how-i-gave-up-...)
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