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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

#101

Earlier quoted context omitted.

It's called a battery isolator, and it's basically a monster diode from the alternator to the battery. Very common setup for RV's, etc. I had one set up in my Jeep so that it would charge the deep cycle marine battery for my fishing pontoon's electric motor... way, way faster than anything you plug into the wall.

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

I've always known it as a battery isolator, and have purchased/installed 3 of them, and that's what I bought them as.

https://en.wikipedia.org/wiki/Battery_isolator

https://www.amazon.com/NOCO-IGD140HP-140-Battery-Isolator/dp...

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

#102
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...

Funny that we live in a world where one renewable energy source is powerful enough to (literally) blow away another.

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

#103
post #55

A couple nice things about SF on this topic: 1. Davis Stirling (Housing related laws) mandates that building associations cannot prohibit owners from installing solar panels. Basically, they have to work with you to find a way and can't just say no. 2. As of this year, SF is the first city to require that all new buildings (10 stories or less) have solar installed.

Another excuse to raise rent...

It's been clearly shown that they don't need excuses to raise rent.

Solar on an apartment building wouldn't impact the cost too much. The real issue is whether construction/zoning is allergic to density.

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

#104
post #102
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...

Funny that we live in a world where one renewable energy source is powerful enough to (literally) blow away another.

Right which is why I believe that after the coming consumer solar revolution there will be something similar with wind energy. Especially with newer VAWT designs and areas that have a lot of wind.

They compliment each other so wind can continue producing at night.

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

#105

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-…

During Iraq/Afg conflict, US army started investing in solar systems because they realized every fuel (alot used for generators) convoy that doesn't have to make runs to outposts means less exposure to attacks by enemy. Solar systems can help lower fuel consumption for generators.

I heard fairly high percentage of US veterans back at home are more interested in solar systems because they saw the high cost of moving fuel around.

Ironic. We supposedly went there to secure our energy source and we learned solar system is a viable solution...

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

#106

> 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…

That's the downside to living in complexes!

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

#107
post #55

A couple nice things about SF on this topic: 1. Davis Stirling (Housing related laws) mandates that building associations cannot prohibit owners from installing solar panels. Basically, they have to work with you to find a way and can't just say no. 2. As of this year, SF is the first city to require that all new buildings (10 stories or less) have solar installed.

How many buildings are being built in SF that are 10 stories or less ?

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

#108

> 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.

The fact is, making any sort of broad statement about what you can or can't do, landlord be damned, is a tough thing. You get into a morass of local and state laws that may very well vary from jurisdiction to jurisdiction. This is assuming, of course, it's not just easier to extend the courtesy of talking to the landlord in advance.

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

#109

Earlier quoted context omitted.

Those calculations also assume he'll use all of the energy it produces, every day, with no loss; it's a back-of-envelope best-case calculation, at best.

If we're getting into the nitty-gritty, then let's also include energy cost inflation into the equation. These numbers are for PG&E which is roughly equivalent for SF: 2001: 0.10c kw/h 2017: 0.28c kw/h (as per my recent bill) That's an average of 10% increase in energy cost per year ! https://www.pge.com/tariffs/electric.shtml

2.8x increase over 16 years is a CAGR of 6.6%, not 10%.

(1.066 ^ 16 = 2.8)

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

#110
post #64

Obvious Problems: 1: You're not using a pure sine wave inverter so right off the back you are losing significant efficiency (Most the things you're charging use DC power anyways so it would be better to just get a nice DC charger). 2: If you are discharging your battery past 50%, you're going to significant reduce it's life span.

Ditto re: battery capacity. Using all 35 Amp-Hours repeatedly will destroy the battery. Anode terminals dissolve during discharging. They are electrolytically plated (thickened) during charging. So repeated full-discharging can reduce their solid volume to such an extent that they cannot be fully restored during charging.

In general, "deep-cycle" lead-acid batteries shouldn't be discharged to less than 50% of their rated capacity to ensure a healthy, long life in an off-grid solar setup like this one.

So more like 17 yrs to repayment - as long as he hasn't already bricked his battery.

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