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

Post by nikodunk » Sat, Jul 22, 2017, 1:04 AM UTC

cr0sh wrote: post #13

galdosdi wrote: post #8

Cool! The one thing I notice the author gets wrong is (out of modesty perhaps) claiming the system isn't very financially successful. But it actually is! > 200W system payback period: $300 / $48 = 6.5 years until payback > Either way you cut it, this is not a money saving machine. Energy prices are just too low. That represents like a 16% rate of return with little risk, which any investor would take in a second. How…

You can also get cheaper batteries and larger panels off Craigslist for much less. You can easily find much larger panels for around $100.00 - same kind you see on roofs. Batteries are more difficult to find cheap, but 6 volt golf cart batteries are readily available and low cost. Sometimes you can also find the 12V 35 AH wheelchair batteries (same as what the author used) cheaply too. Point being, if you look around…

Post by nikodunk » Sat, Jul 22, 2017, 1:06 AM UTC

diafygi wrote: post #75

I work in solar, and your panel really, really, REALLY needs to be secured from wind. Luckily, they make ballast mounts that don't require screwing into the roof[1][2]. [1]: http://www.orionsolarracking.com/commercial-roof-mount/balla... [2]: https://www.civicsolar.com/products/racking-mounting/applica...

Post by dragonwriter » Sat, Jul 22, 2017, 1:08 AM UTC

nikodunk wrote: post #89

adrianmonk wrote: post #84

> Renters don’t need permission from their landlords to place things on their windowsill and rooftops if it’s not altering the building This has never been the case in any apartment community I've lived in, ever. Every time I've looked into anything like this, the lease says I have to follow community rules, and those rules include stuff like pool hours and parking but also say I can't put foil in my windows, have a…

Good point. I'll clean up the language there. I've never lived in a non-ac unit and non-satellite dish place, but I probably have friends who do. How to work around that then? You could only use an ESCO (energy service company) on the east coast or cleanpowerSF for those scenarios.

Post by enraged_camel » Sat, Jul 22, 2017, 1:18 AM UTC

Retric wrote: post #63

sitkack wrote: post #54

Please bolt the panel down, if wind picks it up and blows it off the roof it could easily kill someone.

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.

Post by jws » Sat, Jul 22, 2017, 1:20 AM UTC

throwanem wrote: post #85

radiorental wrote: post #78

Earlier quoted context omitted.

I think you might mean solenoid?? It's controlled by the ignition. When the key is on / car running both batteries are in parallel. When the ignition is cut, the solenoid isolates a few circuits that are wired on the backup battery side of the solenoid. This is what I have in my vanagon. I run the radio, fridge, interior lights and some 12v / USB outlets. http://www.gowesty.com/product-details.php?id=2418

Both no doubt exist. A diode would let the secondary battery charge, but never let the engine draw on it; a solenoid-driven contactor would let the engine both charge and draw on the secondary battery, but only when the engine is running. Combining both might not be the world's worst idea, depending on the design purpose. The diode alone would allow the secondary system to draw from the primary battery, potentially d…