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Small Cabin Forum / Off-Grid Living / Creeky does a solar presentation
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creeky
Member
# Posted: 23 Apr 2018 23:25 - Edited by: creeky
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Hi all,

Saturday I was the presenter at the Perth Green Home and Tiny House Festival speaking about solar and the tiny home.

I did a presentation to a packed room. Literally standing room only and apparently quite a few were turned away. To pass on some of that info to those who couldn't get in, I put my presentation up online. For any and all to view.

Of course it comes without the jokes and explanations. Still, you don't have to applaud at the end. Of course, feel free to if you like.

Anyway Tiny House Solar Talk. Its a 30 page crash course in solar tech. Enjoy.

I'm also open to comments. I would like to improve it. Creek.

NorthwoodsGuy
Member
# Posted: 24 Apr 2018 12:57
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This is great information, thanks for sharing!

Bret
Member
# Posted: 24 Apr 2018 14:47
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Way to go Creeky. You da man!

ILFE
Member
# Posted: 24 Apr 2018 16:18
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creeky, very impressive, sir.

I take it, the 33 page PDF was the slideshow during the presentation? I read every page of it. Nice job. Very nice.

I have two questions and one suggestion, if you don't mind:

1. I am under the impression you prefer lithium over lead? Seems like a lot of people stick with FLA or AGM, still? What is your take on this, if you care to share?

2. Any objection to me adding the file to my cloud hosted list of solar resources?

My suggestion is, you should embed a link to your site, in the PDF. Possibly, at the bottom of each page? Or, maybe add a contact page with your information on it, to the PDF?

DaveBell
Member
# Posted: 24 Apr 2018 16:19
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Quoting: creeky
I'm also open to comments. I would like to improve it. Creek.


Build upon that Intro-Level with examples. Wattage needed for appliance list = (80% of what batteries), (solar availability for Lat, Long), (needed usage), etc.

12V, 24V, 48V examples
36, 60, 72 cell examples

Show complete design and parts list for:
Swamp Cooler, Fridge, PC in Arizona
Air Conditioner, Fridge, PC in Florida
Appliance list for Canada

People can adapt from examples.
Good job Creeky!!

creeky
Member
# Posted: 24 Apr 2018 18:48
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Hey ILFE.

Ya. What is missing all my comments and jokes. Its just the pdf of the presentation.

re: 1. Lead is dead. Lithium has many advantages. Primarily to do with cost. Its cheaper. You get 20% more efficiency. Huge lifespan increase. Much smaller. All these things save money. There are many other advantages. Very low self discharge for folks who need to leave the batteries for up to a year. Very little maintenance. I could go on. I can't recommend anyone buy lead anymore. Too expensive.

You can share via cloud. I prefer folks go to the site. I've become a "clicks" addict. I go to site stats everyday and either crow or cry depending on my success with site visits.

I like your idea to embed a link. Doh. Should have thought of that earlier.

Dave.

Thx for your comments. I am doing a seminar so maybe I can get some pics for examples. One of the reasons I try to push folks to the site. There are lots of examples there.

Thx for the kind words all.

CabinBuilder
Admin
# Posted: 25 Apr 2018 17:15
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creeky

I did a quick search, but can't seem to find a source of lithium batteries which are cheap enough to justify the switch from lead.
Which specific li- batteries brands can you recommend? Links to suppliers will be appreciated.

Thanks.

NorthRick
Member
# Posted: 25 Apr 2018 17:54
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Quoting: CabinBuilder
I did a quick search, but can't seem to find a source of lithium batteries which are cheap enough to justify the switch from lead.


I've brought this up before, but some of us aren't sold on lithium just yet. For renewable energy in the US, they just aren't mainstream enough for me. Nearly all the production is for car batteries and that's where creeky gets his.

I'm glad people are pioneering the use of lithium in solar applications. However, for me, for now, lead is just fine and less expensive.

creeky
Member
# Posted: 26 Apr 2018 12:17
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I'm not going to beat a dead horse. But lithium is cheaper. It was proven in 2013 by no less than Princeton University.

Sure, if you build a tiny system and you don't mind the unreliable, poor efficiency and expense of lead. Go ahead.

But if you're building a system for real life and want a reliable system. Lithium looks pricier up front but it will last a decade longer. More efficient. Safer. More reliable etc.

There are a number of systems available. If it takes something more than a quick search. Well, building your small cabin took a lot more than that.

There are many, thousands, tens of thousands of people using lithium for energy storage now. I don't think anyone would call that "new."

I repurpose my batteries from cars. It offers a great price point. But even at 3x the price. New lithium is cheaper, safer, smarter. Used by everyone.

Btw: my lithium solution is cheaper from day one than lead. Proven by quotes and install price as told to me by my customers and folks who found out about lithium too late. And I get a lot of those.

But you know. Some folks still want that 70s Pinto. Others are happier with the 2018 model.

ColdFlame
Member
# Posted: 26 Apr 2018 15:35
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@creeky:

Happened to play with any 18650 cells yet? Lots of guys doing DIY powerwalls using the 18650 cells - look pretty promising. There's a company (https://vruzend.com/) making battery kits that are essentially lego for 18650 cells. Pretty neat idea and looks to make putting them together very simple. Jehu Garcia on YouTube has some good videos as well.

creeky
Member
# Posted: 26 Apr 2018 17:16
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Hey ColdFlame. I've seen those. They look really good. I don't know how they balance the cells tho?

I love the new "easy assemble" kits that are coming out.

I'll be doing some new packs next year or late this fall. They will be pricey but with my 25 year lifespan enabled. Can't wait.

That said. There's a real good chance you'll get 25 years from the LG/Samsung/Panasonic pouch/cylindrical cells too. Esp. in solar energy storage where you just don't have that hard charge/discharge.

Huzzah! Great time to be alive.

ChuckDynasty
Member
# Posted: 28 Apr 2018 14:29 - Edited by: ChuckDynasty
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Permits may be something to consider mentioning.

Work-a-round to permits could be a diy portable solar generator for smaller systems.

Where I am panels that are mounted on a roof for an off-grid system requires an electrical permit only. Inexpensive but an inspection is required.

Mount anything in the ground and it becomes a more complex, multiple permit and more expensive process.

Nice presentation.

creeky
Member
# Posted: 29 Apr 2018 21:29
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Good to mention permits. Every single jurisdiction seems to have wildly varying ideas there. Kind of a bad situation really.

Would be nice to have a single safe code to follow.

KabinKat
Member
# Posted: 16 Jun 2018 19:08
Reply 


Creeky,

Very informative and interesting!

Thanks!

offgridjunkie
Member
# Posted: 19 Jun 2018 18:07
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Creeky, What kind of charge rates can a Lithium battery accept. ie: AGM c/4-c/12 . My batteries are going to need to be replaced this year and I am strongly looking at moving to Lithium - Current set up is with AGM.

redwolfguild
Member
# Posted: 19 Jun 2018 18:50
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Quoting: offgridjunkie
Creeky, What kind of charge rates can a Lithium battery accept.



This is a great question. I only need 100 AMPs at 24 volts, what size solar array would I need. My solar isolation is 4 hrs in the winter.

creeky
Member
# Posted: 20 Jun 2018 10:12
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You can charge your lithium at C/2. Or 1/2 the amperage total. So nobody does that. Way to much power from a solar system. So whatever you have in your system will work. Lithium doesn't have the resistance of lead. So you neither need to beat the electrons into the battery nor worry about heat discharging.

100a at 24 means you have 2400w. How many are you using?
Obviously you're not using all of them. But say you were. 2400/4 = 600.

redwolfguild
Member
# Posted: 25 Jun 2018 12:56
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Creeky, I use 800 watts on a heavy day. 300 watts for my Dometic Fridge when I am at the cabin, 100 watts for charging devices and lights and when I vacuum I use about 200 watts - it is a small space. Currently use AGM batteries and I was just up there this weekend and they running down at night just running the fridge, so I think this winter I will be looking for new batteries.

Wilbour
Member
# Posted: 26 Jun 2018 06:19 - Edited by: Wilbour
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Quoting: redwolfguild
300 watts for my Dometic Fridge when I am at the cabin, 100 watts for charging devices and lights and when I vacuum I use about 200 watts


How close are these numbers to the actual ratings? Not to sound judgemental but 100 watts for lights and charging sounds like a lot. Have you switched to LED bulbs etc.?

Perhaps your inverter is wasting power just by being on. Some of the cheaper ones are quite inefficient.

A lot of problems can be solved by moving over to the Dark Side and powering with Lithium.

1) Efficiency goes up
2) Reliability goes up
3) Maintenance goes down
4) Start to finish costs go down

redwolfguild If your usage is as you have listed, you should look at what Ontario Lakeside has installed or maybe something a little more conservative but similar.

redwolfguild
Member
# Posted: 27 Jun 2018 20:14
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Wilbour, 100 watts is just a thrown out number. It is probably more than half of that.

Wilbour
Member
# Posted: 28 Jun 2018 21:26
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redwolfguild

You got me thinking... (doesn't happen that often)

I ordered the Kill-A-Watt unit from the local library again. I will run it for 24 hours to see what my total draw is. Not too hard since I only have one outlet on my inverter.

I do try to either unplug my wall wart chargers or toggle off the power bar.

Nothing like "Real World" measurements

redwolfguild
Member
# Posted: 29 Jun 2018 13:50
Reply 


Quoting: Wilbour
I do try to either unplug my wall wart chargers or toggle off the power bar.



I am the same way, I never keep my inverter on, only when actively using it. My chargers and Fridge run off 24 volts so no conversion is being done 95% of the time.

troybillett
Member
# Posted: 9 Jul 2018 17:28
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CabinBuilder

yeah we found victron batteries (5 year warranty) for a reasonable price but they are lead, lithium seems to do better in colder temperatures but we can use energy to keep the system at an ideal temperature so I don't see the reason to go lithium...

creeky
Member
# Posted: 9 Jul 2018 17:37
Reply 


not the lack of maintenance
nor the 20% better efficiency
or the ridiculously long lifespan
even the lower cost over time
say the "turn it off and leave it without worry"
not the ... ???

I could go on. Lead is dead.


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