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Small Cabin Forum / Off-Grid Living / So getting started on solar - opinions welcome
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Borrego
Member
# Posted: 22 Nov 2012 18:28
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I'm going to start small due to $$ and add on on as I go. So in order to power up primarily lighting and a few outlets at the house (600 sq ft), I figure 2 panels like this: http://www.costco.com/.product.11760095.html?cm_sp=RichRelevance-_-ensemblepageVertic alRight-_-PopularProductsInCategory&cm_vc=ensemblepageVerticalRight|PopularProductsIn Category would be a good start, right? anyone had experience with them?
Then a decent charge controller: http://www.donrowe.com/solar_charger/pr_solar_charger.html
An inverter: http://www.donrowe.com/inverters/xr750.html
And 2 batteries: http://www.wholesalesolar.com/products.folder/battery-folder/USBattery.html#BatteryBa nk
I know the purists will say wait and do it right, but I need some lighting NOW and seems this is the way to go (to me). And can I buy a larger capacity charge controller and Inverter now and grow into them, or do they always have to match the panel output?
This is only $910 (not incl. accessories) and I could have it up next month instead of waiting.
Comments?

GomerPile
Member
# Posted: 22 Nov 2012 18:54 - Edited by: GomerPile
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You can save some dough by getting a panel here:

http://www.solarblvd.com/Solar-Panels-&-Systems-12-Volt-Solar-Panels/c1_269/p2666/Sol ar-Cynergy-100-Watt-12-Volt-Solar-Panel/product_info.html

I have used them to buy several panels in the past. For a charge controller consider a Morningstar Sun Saver: http://www.morningstarcorp.com/en/sun-saver

It's a cool black box that is a charger and low battery disconnect. You can connect several together for higher current. They are $85 on amazon. FTR I have not used this product but have one sitting in a box waiting to install...I did a bit of research in the past. I also plan to get one of their true sine wave inverters.

For batteries a cheap option are the 100ah wal mart deep cycle marine. If you plan large loads that will drain them a lot then maybe these are not the best choice. I use 5-10 amp hours each day from mine and they have been going strong for 4 years. It's a pretty good deal for $120 IMO.

BTW your inverter connects to the battery on its own circuit not thru the sun saver. The sun saver only runs your low power stuff but charges the batteries for everything.

Just
Member
# Posted: 22 Nov 2012 20:34
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its nice to be able to run a few small power tools and with that system you can , i think you will be very happy with everything you have picked it,s just a little larger than mine [soon to be 6 years] ..let there be light.

clearwater
Member
# Posted: 22 Nov 2012 21:44
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Let there be light indeed, when it comes to the relentless oversell by alternative energy companies. I've run my home comfortably for the past 25 years on four panels and two deep-cycle batteries, and started out with just two as you are doing. A little lateral thinking and a reasonable number of sunny days solves most solar problems.
Go for it, Borrego.

spencerin
Member
# Posted: 23 Nov 2012 00:44
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Borrego,

Depends on how much power you are going to draw from the batteries and for how long. So, what are you going to be running? Also, where is your place geographically? I installed a solar system myself for ~$650, so if you are looking at a small DIY system, I can help with the basics. And, yes, you can buy a larger capacity charge controller and inverter for expanding your system.

groingo
Member
# Posted: 23 Nov 2012 11:50
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I had looked at the Grape panels at Home Depot, then I spoke to the manufacturer and found the pricing is directly related to their efficiency ranging from 17 to 23% efficient, same goes for the power inverter's which can range from as low as 70% to as high as 93% (Outback).
Not knowing where you are I used a local brand called Budget Battery which are actually made for them by Empire Forklift Co. in the US, $119.00 each, deep cell, wide deep plate spacing warranted 3 years 115 AH each (6 volt) good for 800 cycles, more if you desulfate occasionally.

Unfortunately I lacked enough light in winter to make the system viable and have gone a different route that works better for me and is now costing less than grid power so I am seeing a payback rather than an outlay of money for power....so far.

Borrego
Member
# Posted: 25 Nov 2012 12:35
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Quoting: spencerin
Also, where is your place geographically?

Thanks for the replies, guys! I just got back from our place, which is located in the SoCal desert, so no worries sun - wise
I am glad to hear that most think i can get started this way and build into it as the need arises.
I only need (for now) 2-3 lights (overhead) 1 circuit of receptacles (more lights, coffepot, battery chargers etc....) 2 ceiling fans. This will make a huge difference as I'm sure you all can relate to?
The cabin is 600 sq ft and well insulated and placed in relation to the sun/weather/wind.
I'll look into the alternative products you guys mentioned, thanks again...
Oh, when I buy panels, are they all able to be expanded upon? What do i need to look out for? Also is it better to buy the largest inverter and c controller with future expansion a probability?

Borrego
Member
# Posted: 25 Nov 2012 12:40 - Edited by: Borrego
Reply 


Quoting: spencerin
I installed a solar system myself for ~$650, so if you are looking at a small DIY system, I can help with the basics.


I would appreciate that. email is bawoodruff@gmail.com.

CabinBuilder
Admin
# Posted: 25 Nov 2012 17:03
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...Or post it here for all to see.

MJW
Member
# Posted: 25 Nov 2012 17:57
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Quoting: spencerin
I installed a solar system myself for ~$650, so if you are looking at a small DIY system, I can help with the basics.


Quoting: CabinBuilder
...Or post it here for all to see.


Absolutely!

Borrego
Member
# Posted: 25 Nov 2012 18:30
Reply 


Yes! If you don't mind getting into details too much, I'd sure appreciate it. And there must be more than just me needing a little help. I'm pretty handy and good at electrical, just new to solar and totally overwhelmed by the abundance of information, and overkill as clearwater said...... I just want to get some power in the house as cheaply as possible for starters, y'know?
Thanks to all!

spencerin
Member
# Posted: 25 Nov 2012 20:55
Reply 


Borrego,

My system has a 90W Grape Solar solar panel, 2 50' strands of solar cable to connect the panel to the 10A SunForce charge controller, 3 110Ah marine batteries, and a 1500W inverter with connector cable set. Altogether they cost me ~$650. If you want to know where I got them from and what brands / models they are, let me know. I got the lowest cost items I could get, and they serve my needs okay. I run a 1.2 cu. ft. refrigerator, a floor lamp with a CFL bulb,, a small TV, a DVD player, and I use a 700W microwave and a 1140W vacuum cleaner on occasion.

This is not continuous usage, nor do I use them all at once. I use the items about once every week or 2 for only a couple of days max. My place is in central IN, and so far everytime I've arrived at my cabin, the batteries have been 100% charged from the prior stay's usage. My system was sized based on my planned usage.

For starters, you need to know what wattage each of your planned appliances are going to draw and for how long. Most of sizing your system is basic math, but you have to do some research to get there, and this is where you should begin. For example, a coffee make draws a lot of wattage. The smallest ones draw at least 800W, which is a lot for a small appliance. The appliances all should have tags on the back displaying what their wattages are. Also, question whether you need that particular appliance, versus a smaller version (i.e. a 1.2 cu. ft. fridge versus something larger, a 36" tv versus something smaller, etc.). These all draw different levels of power.

So, I'd reply with a list of each individual appliance you think you want to run, and list the wattage that each appliance draws next to each appliance.

d h
# Posted: 26 Nov 2012 00:45
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A first solar system can be a bit tricky in that you don't want to spend a lot of money because you're learning and if you make a mistake, you won't be out a bunch of money. At the same time, you don't want to go too cheap and end-up with useless junk laying around when you do upgrade.

I have a true sine wave Xantrex Pro Watt SW 2000 (12V). It has a good/reliable reputation and because it's true sine wave, it won't fry your electronics over time like the modified sine wave inverters. I've seen it as cheap as $325 shipped. I use it to give my Outback inverter a rest at night.

Be aware that when you do upgrade or add more panels, if you only have a 10A or 20A controller you'll have to buy a higher amp controller. If say, your panels put out 7 amps each, wired in parallel, three panels would equal 21 amps or more depending on conditions. With good quality panels under ideal conditions, you could get as much as 12 amps/panel. Morningstar controllers have a good reputation.

Then there is the 'how many panels, batteries' question. There is a formula for this but you definitely don't want a zillion battery amp hours and very little solar panel amps.. unless you like to replace batteries often. And you need to figure-out your loads and if your loads turn-out to be too expensive, then cut back on things like vacuum cleaners and electric coffee pots. Get a broom and a gas or wood-fired pot instead. Try not to run your batteries below 12.5 volts, they'll last longer. Generally, deep cycle batteries are a little better than marine. I've had good luck with Costco golf cart batteries on my 12 volt system. $95 each; 6 volts.

12V, 24V, 36V or 48V? Basically, you get more bang for your buck with higher voltages but can be more expensive too and more complicated for a newb. And don't put cheap #4 or #6 wire on your batteries, especially with a 12 volt system! (I have 4/0 between my Xantrex 12V inverter and the batteries. Overkill? Maybe, but when the house refrigerator starts, it doesn't trip the inverter because the wire can't handle the load). For correct battery wiring see http://www.smartgauge.co.uk/batt_con.html

As far as which panels? I'd go with a name brand like Kyocera. Get the highest wattage you can get in a size that can be shipped UPS instead of freight - usually, 145 watt panels. I picked up a couple of DM Solar solar panels from overseas on Amazon. One word - flimsy! Can't beat the price of $120/panel though.

You'll discover a whole lot more details along the way but once you get there, it feels pretty good knowing your stuff is running off of sun-power!

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