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Small Cabin Forum / Off-Grid Living / Basic entry level solar?
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turkeyboyslim
Member
# Posted: 3 Jul 2019 21:05
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So I'm trying to make the transition for paying rent at my apartment to moving on my land full time.
I have a good camper on the property where I sleep, I've built an outdoor shower and plumbed it into a spring, with a pump powered by a marine battery. I have a 2000w Honda generator so all is good.
However I know I will add solar once my cabin is built but I still don't know all the ins and outs, just the basic overview of what components go in a system.


So what I want to do now is add a small solar system, just enough to power a laptop, a small electric grill and maybe charge a phone battery or 2. I don't think I need more then 300w.
I presume I would need batterys/panels/charge controller and an inverter, right?
So is it possible to get all that for my currently uses and later once i have a cabin just add more panels and batterys?

I guess my question is, If I buy a good inverter and charge controller now, but don't have a lot of batterys or Panels, will a big inverter draw too much idle?

Any advice would be greatly appreciated, I don't even know where to begin in terms of sourcing panels and parts.

Wilbour
Member
# Posted: 3 Jul 2019 22:48
Reply 


The electric grill may be your Achilles Heel. Anything that uses resistance to heat can be your enemy.

Could you migrate to a propane cooktop?

Check out my simple setup:

http://www.small-cabin.com/forum/3_8226_0.html

I run a small fridge with freezer built in. Charge my cordless tools, cell phone, laptop. Run 3 indoor led lights and 3 outdoor LEDs.

Yes you can buy quality stuff and take it with you as you upgrade (to a point).

Yes you should size your inverter wisely. Too small and it will fail, too large and it will use up a lot of power on idle.

Brettny
Member
# Posted: 4 Jul 2019 07:45
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Any thing with an electric heating element will be expensive to run on solar.

We dont know what your system is now so csnt really tell you what you need.

Any solar system should have a generator and a way to charge the batterys from that generator. Your honda eu2000k is a very good generator for a small solar system.


We use to run a 12v water pump off a car battery i would bring back and forth. It would pump 200gal of water before i would recharge it. We didnt run the generator until we needed to shop vac to clean up...we have dogs. The place had a propane fridge (from and old camper) propane stove, propane lights and a propane on demand water heater. No cell service so keeping them charged wasnt really needed.

razmichael
Member
# Posted: 4 Jul 2019 08:42
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We started 9 yrs ago with a 3rd hand pop-up trailer - I bought 2 T-105 batteries (& a battery box), wired with a few ft of heavy gauge cables and connector. Modified the trailer by bypassing most of the converter, adding in a HF1800 inverter (that includes a smart charger & transfer switch) and a heavy gauge connector to the outside. This provided 12v plus 120 available when we turned on the inverter. Initially I would take the batteries home to charge, then I used a honda 2000 and finally, in prep for the cabin build, added two 165w panels and Morningstar Prostar charge controller.

All of this moved to the cabin 5 yrs ago and is now running all the lights, water pump ceiling fan, charging phones, a cell booster etc. The inverter is turned on only when needed (hairdryer, vacuum, tools). Granted this is still a "small" system - no fridge, heating elements (although the odd blender use for margaritas). Are we careful with use? A bit during cloudy times but not generally an issue (plus I still have the Honda if needed). And we really only stay a week or so at a time.

All this to say that if you set you expectations carefully (such as not using a electric cook stove as noted by Wibour and Brettny), you can put together a small system now that can evolve to your cabin eventually. If on the other hand you think your want to eventually upgrade your cabin to be more like a full time off grid house, then this will change your options a lot. For us, the small system has met our requirements and more. I'm sure the almost 10 yr old Trojan batteries (that are left hooked up for 6 or so months each winter running the security lights/camera without any maintenance) are no longer holding a full charge but so far nothing that has impacted our use.

turkeyboyslim
Member
# Posted: 4 Jul 2019 08:50
Reply 


So forget about the small cook stove, I can just run it off the generator its not something I use constantly. It say's it only draws 100w so I'm confused why everyone says it's off limits for a small system, aren't there other common things that draw well over 100w?

Either way charging my battery bank with my generator is something I want to know about. Lets say I want to start without panels but I want to make use of my generator's extra power while I run it. How do I charge batteries through the generator? Do I need a charge controller for that?

FishHog
Member
# Posted: 4 Jul 2019 09:02
Reply 


Technically you could cook with a 100 w. My easy bake oven when I was a kid cooked with a light bulb but I have a hard time believing a 100 w claim on a cook top. It must be very small

Resistance heat is just an energy sucker. Most items are closer to 1000 w or more which is why people are warning you about them

turkeyboyslim
Member
# Posted: 4 Jul 2019 09:11
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It is very small, it's the size just large enough to put my kettle on to make my pour-over coffee haha. I actually bought it because In the morning I couldn't get a fire going because all my firewood was wet and I didn't want to spend an hour getting a camp fire when I first wakeup for coffee.

What are good brands for Inverters and charge controllers? I'm going to try to get a basic solar system set up before the end of the month. I know amazon sells kits and stuff but people usually end up swapping out the charge controller and inverter as there system becomes more advanced. This is what I'm trying to avoid, I want to buy once, and add on as I need, if possible.

Steve_S
Member
# Posted: 4 Jul 2019 09:44
Reply 


OK... that little single element jobby is likely 1000W and not 100W as 100W would never make enough heat to cook anything (EZbake oven excluded).

If you intend on an electric "plate" the most efficient are the Induction Types (do not work with aluminium pots / pans) and they still use a minimum of 750W to 2000W. A nuke-a-lator is still winner on electric cooking.

Completely understand the buy once and not have to buy again to upgrade... That IS expensive, I know and so does my wallet ! In that regard, when looking at solar gear, look for things like

"Stackable" charge controllers:
which allow you to link more than one Charge Controller to expand the field of panels, and common controls for them collectively. Several Companies do have this ability / capability.

"Stackable" Inverter / Charger:
again, these allow you to stack on an extra inverter & interconnect it to work as one bigger unit and allowing centralised configuration & management. Several are available.

Some "Kits" on the web offer such while others don't. Some can be mad to interoperate and work cooperatively and others do not. You can be assured that this affects Cost.

The real question is, pay more today for a better & more capability / ability to expand later OR save now and pay later if / when you want to grow your system. It's the Penny Wise / Dollar Foolish question which can be inverted to Dollar Wise & Penny Foolish, pending on point of view. Your budget, how much value you want per $ and what do you really expect to do within the next 5 years is something only you know.

One thing I will certainly raise here as it happens more often than people admit. Say you decide a 2Kw Panel system with 2Kw Inverter / Charger will do what you want / need today. Appreciate that things chance and you'll likely need an upgrade in < 5 yrs because your using more or adding new stuff. It then makes more sense to step up to the next level in advance... Ohh but it will cost more ! Yes it will but much less than having to buy stuff in 5 years, prices ted to go up, not down right... (exception battery tech is changing and prices are falling, so are panels (but falling much slower now) ).

Batteries: Lithium is Best ! Creeky apparently has great deals for EV Batteries converted to RE Storage batteries. Worth looking into, may be best for you if the price is right (remember, batteries are the most expensive part).
Have a look here: https://bobolinksolar.com/product-category/lithium-battery-packs/ and ask him what kind of package would suit you. Too bad he doesn't have pre-packaged prices like
5Kw @ 24vdc = $#### 10Kw @ 24vdc = $####
5Kw @ 48vdc = $#### 10Kw @ 48vdc = $####
which include battery, BMS & Harnesses etc.

IF you decide that Lithium is too much and wanna go cheaper, then do that but think forward as FLA & others are fading out and will likely be hard to get in 5 years. Also remember that if you have an established FLA bank and then 2 years later want to add more, the new batteries will be "drawn down" to the lowest level of the existing bank. This is not the case with Lithium.

Nobadays
Member
# Posted: 4 Jul 2019 09:44
Reply 


Your eu2000 I think can be used directly to charge a battery but the output will be very low taking hours to charge. There are good battery charges out there that using your 120v output will charge your battery/s quickly.... this one is very good: URL

What you may want to consider though is an inverter/charger so you can then put it into use in your future solar system. The size you need.... you will have to determine based on your expected FUTURE usage. Take care to not buy too low of output equipment now and have to buy again a year or so down th he road.

As far as charge controllers and inverters.... there are many "good" brands like, Victron, Outback, Schneider to name a few. A word of caution is to choose good name brand equipment and try to stick to the same gear for both inverter and charge controller as they will work well together. You seem to be planning to live full time so you will be depending on the equipment you buy daily. It is tempting to buy cheap equipment but far better to buy the more expensive, "buy once, cry once" gear and have a dependable system.

Wilbour
Member
# Posted: 4 Jul 2019 12:37
Reply 


If you follow my thread the end product was below $2000. I believe you may even be able to get it below that now.


Final specs were 2kw Lithium + 1 285w panel + 500w inverter + 100/15 charge controller. Plus all the fixin's.

That's up and running

Quoting: Brettny
Any solar system should have a generator and a way to charge the batterys from that generator.


Hmm. Brettny has a point but it's a little too broad of an assumption.

I encourage you to read as much as you can on this forum. There are a good number of people who have real-time experiences with off the grid solar.

ICC
Member
# Posted: 4 Jul 2019 15:49 - Edited by: ICC
Reply 


Quoting: Wilbour
Quoting: Brettny
Any solar system should have a generator and a way to charge the batterys from that generator.


Hmm. Brettny has a point but it's a little too broad of an assumption.


Yes. A well designed off grid system can be built to be generator free. I have not had to use a generaator for a few years and I know others who do not own generators. These are full time places too.
Quoting: Nobadays
There are good battery charges out there that using your 120v output will charge your battery/s quickly.... this one is very good: URL



I like Iota. I have one of the 12VDC 55 amp models that is something like 15 years old now. Note they have many more of the plug-in modules than they used to. They have one that is designed to be used with LiFePO4 batteries as well as a host of others. I added the IQ-LIFEPO module to the old charger in the worktrailer when I swapped the lead acid batteries out for LiFePO4.

cluttonfred
Member
# Posted: 6 Jul 2019 07:08
Reply 


I am no expert but the all-in-one solar generators like those from Goal Zero and other companies can be interesting for a small system, especially the ones with lead acid batteries that are often on sale as folks that want them for camping want the lighter lithium models. Some of then can support additional external lead acid batteries as well using the same charge controller. The Goal Zero 1250 is available "open box" for $999 and you can add 240W of solar panels for about $500.

Wilbour
Member
# Posted: 6 Jul 2019 08:54 - Edited by: Wilbour
Reply 


Cluttonfred has a point. The goal zero units, and others similar, are excellent choices for camping. Everything is in one tidy box including usb charging ect.

Now I'm not an expert about amp hours or why in the lithium world we us watts instead, but my system is almost as portable and has 2kw of 24v power.

It cost me about the same as a Goal Zero and panel but I paid in Canadian $. The best part is if one part fails, i can replace (or upgrade) that part.
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Steve_S
Member
# Posted: 6 Jul 2019 09:05
Reply 


Goal Zero stuff is quite cool and for a Plug & Play system it's an ideal solution for many but it also has limitations too... Compromises = limitations right. Although I found that Goal Zero is marketing it's product on the high side considering what it really all is, when you look at the componentry used. As Wilbour points out, this is something that could be DIY'ed for much less.

On that same vein though... have a look here !
Fuel Zero is a Chinese Company with a really good idea similar to Goal Zero but with a few extras. With the specs and features listed, it's a better bag for buck and with free shipping to US... well... it's worth a look. NB: These have batteries & prices reflect that.

https://www.fuelzero.com/category-s/140.htm

turkeyboyslim
Member
# Posted: 7 Jul 2019 20:30
Reply 


So I'm back on the land, the electric cook top was 1000 watts not 100, my mistake. It does work great though, for $20 I'm glad I got it. it gives the 2000w honda something to do heh.

The Fuel Zero units look interesting. It seems like you get a lot of bang for your buck. I wonder how had it would be to add additional panels to it. Also could you leave the unit indoors while it's running or do lithium batteries need to be vented?

the FuelZero Solar Generator 1460WH looks kind of enticing for $2,200. My concern would be customer support/warrenty complains and tech support since they seem to be an uncommon brand.
It says they only have 2 units in stock and they have 0 reviews.

Wilbour
Member
# Posted: 7 Jul 2019 21:47 - Edited by: Wilbour
Reply 


They claim you can add more panels.

"supporting up to 520 watts of PV input"

So you start with 200w and can add 320w more.

Lithium batteries can stay inside your living space since they don't need venting. Actually it's better for them because you heat them up in the winter before charging them.

But.....

They want $2200 US and mine was $1200 US

Theirs is 1500w hours and mine is 2000w hours

They have 2 x 100w panels and I have 1 x 285w

They have a 1500w inverter and i have a 500w

They have 4 110v outlets and I have 1

They have multiple usb ports and I have 1

They have 12v socket and I have none.

They have an LCD readout and I have an app for my phone

Theirs is portable and so is mine

Just a few things to compare.

ICC
Member
# Posted: 7 Jul 2019 21:52 - Edited by: ICC
Reply 


Quoting: Wilbour
Now I'm not an expert about amp hours or why in the lithium world we use watts instead, but my system is almost as portable and has 2kw of 24v power.


The battery type does not matter. When discussing the energy content of a system watt-hours is the measure.

Amp-hours is only half the information when it comes to the capacity rating. The other half is the nominal voltage. The Amp-hours or the voltage are pretty much meaningless without the other.

Amp-hours X the system voltage = watt-hours.

EG: 100 amp-hours at 12 volts = 1200 watt-hours or 1.2 KwH. 100 amp-hours at 24 volts = 2400 watt-hours (2.4 KwH). So your 2 KwH system, at 24 volts must have an amp-hour rating of, 2000/24 = 83.33 AH. If calculated on only using about 80% of the total capacity the actual total would be about 100 AH.

ChuckDynasty
Member
# Posted: 8 Jul 2019 15:16 - Edited by: ChuckDynasty
Reply 


What I might do if I were you since you have the Honda that'll run your hot plate and will also run a microwave and induction cook top and many tools is go very small right now until you know exactly what your needs for the cabin are later.
It doesn't take much to charge a laptop and phones and have a couple of LED lights. See if there is a 12v cig charge adapter available for your laptop, if there is you won't even need an inverter.
You could always continue to use the small system in a shed or the rv when you get a larger system for the cabin.
100w panel, 10a sunsaver charge controller, 100 ah battery, Magnadyne Multi-Use Vehicle Charger with Dual USB Ports and Dual 12 Volt Sockets, Samlex PST series 120w 0r 300w inverter depending on your laptop requirements.
Check out Will Prowse on youtube his last two videos are interesting for something cheap all in one.

Wilbour
Member
# Posted: 8 Jul 2019 20:49
Reply 


Interesting article. You will have to calculate the final cost.

https://www.mobile-solarpower.com/all-in-one-solar-power-packages.html

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