Building my first solar system

You didn't read it wrong.....but you have to understand Ohm's law:

Take the wattage of the inverter.

Divide by the voltage.

That gives you the amperage.

4000 / 120 = 33

The most you will get is 33 amps on the 120v legs...BUT not at the SAME TIME.
You pull 120 off both legs, at the same time.....and you'll get about 17amps

That would require about an 8,000 watt inverter.....or 24,000 watts of inverter power to get to that 100 amp service you're wanting.

Starting to see the problem/cost ?

See WHY grid power is a bargain ?

I have a 3.2kw PV system, on trackers ( about 25% increase over fixed mounting ) and my average generation ( year round ) is about 250kw/hrs/month....about 1/4 to 1/3 of my total Kw/hr use per month.

That's about a $20,000 system with the battery backup....all self installed, including building my own tracking system........to eliminate 60-70 bucks a month in power bill.....figure the payback on that, and it's out somewhere past NEVER.....THAT'S what a BARGAIN grid power is !

Go look at your average monthly electric bill and figure it from there, IF you plan to keep your power consumption at the same level.

Most off grid folks use WAY lots less than the national average ( which is around 900kw/hrs/month) .....way lot less.

THAT is the reason I'll never go off grid unless forced too.....and the primary reason I set up and run my system....to have the ability to produce enough electric power to keep some refrigeration and lights going SHOULD the grid go down. ( the secondary reason is my power company pays a dandy premium for solar back fed power OVER the retail rate, and by grid connecting, it eliminates most of our power bill......the last 6 months average being 16 bucks/month )

I'm not trying to discourage you from going with alternative.....but when I see you state you want a 100 or so amp service, what I see is someone thinking in conventional house terms...where the power is dirt cheap......throw in a 100 amp panel and go to wiring, forget the cost of production. ( I'm a State licensed electrician, by the way......done a 'few' houses too )

BUT when you start down the off grid road ( or in my case, what might BE off grid someday not by choice ), you have to start watching every watt, and making decisions on use and production.

THAT is where you are trying to get right now.

Once you arrive at WATT (ahahaa) you need, then you can design ( and price ) a system to meet your needs.

Now, quit screwing around looking at equipment, and go make a list of:

1. what you want to power

2. how much power each takes

3. and the length of time you want to power those items

THEN you start looking at the equipment it takes to do that.

Otherwise, you're gonna flounder around trying to back into alternative energy from the wrong end, and likely to spend money you don't need to spend and get a disappointing result.

 

Sobering for sure. So I am better off first lowering our usage to a point where a smaller system would power it. This house was and is still an energy hog. I have much cutting to do do get it under control. I think our first purchase is going to be a Honda powered 6000 watt propane powered generator built by Winco. This unit will pump our well in the event we lose grid power. Next will be to get the most energy efficient freezer and refrigerator I can find. I also need a better way to make hot water. My wife wants to go back to a propane gas range as well. One step at a time gets you where youre going. Kingfish

 

All of this is very good an ignorant guy like me .
I have been pondering this for awhile now and would like to get off grid .I'm building panels with 208 1.6 watt cells and am thinking about using this inverter ,but don't know anything about them except for 1500 watt one with 2 105AH batts that the tractor keeps charged that I now use when the power goes out. I'd like to know if any of you know about this inverter.

<b>5000/10000 Watt Power Inverter, 12V DC to 220/240V AC in 60Hz with Free Wireless Remote Control</b>

And if it really has 220 capabilities ,just running the pump ,2freezers ,1 fridge, and the fan on the heater .
Thanks guys for for all of this info so far !!

 

I think you are beginning to understand a little more. That is why I suggested that little game a couple of posts ago. It is to teach you and your family what it is really going to be like.

On generators there is a unit you may want to look at that is designed just for what you are talking about. It is called Kohler, is about 12kw, propane powered, and made to run all of the above with little or no problems. I know of several people around here that have them and I can tell you from what I have see, they are great. They are air cooled and cost roughly $4,200.00 Elec start as well and easy to wire up to your trace / xantrax/ or outback inverter. By the way , all three of these brands are all designed by the same people. If you really want to step up to the plate you can get a Kohler 10kw. water cooled gen. Small ford motor inline and of course radiator. Now your talking money. By keeping your household units and the generator all on propane, you can put in a tank say 500 or 1000 gal, and run them all on the same tank, the gas man fills them up as nec or monthly etc. Not to mention that a generator running on propane will run very clean and much longer then a gas or desiel unit

 

Kingfish - I'm here for the same reason, also sent by our mutual new mentor nadja Hope we can learn and help each other.

 

I was told the same thing by several inverter stores. There are a ton of big 12 volt inverters out there claiming to put out 5000 watts with only 12 volts in. Though they may work for a short time that is a lot of step up. I am also aware that there are many cheap Chinese made inverters that are junk. Kingfish

 

Kingfish
I work for a local well drilling outfit here in Nc we have just started getting into geothermal i have done 2 systems so far. let me tell you they aint cheap just for the hole in the ground is 11-12$ per foot then the grout and sand. then you get into the system to run the house with the last one we put in cost the homeowner close to 10,000$ i hope this helps

 

Kingfish -

I've said it before, but it's worth repeating here: Every dollar you spend on energy-efficiency will save you a dollar or two on your off-grid PV system. You're on the right track looking at highly efficient appliances like the Sun Frost fridge.

When you're transitioning from a lifetime of essentially infinite grid power, one of the things that's hard to get your mind wrapped around is that you only size your PV system for your largest load. Then you stagger the running of all your other loads. So, if you size your system to run your well pump, you won't have any other significant load running at the same time as the well.

It's just not economically feasible to live on off-grid PV the same way you do now with grid power. However, you can easily live a very pleasant life off-grid - the biggest change will be that you don't turn everything on at once without a thought. The second biggest change will be, as someone already pointed out, that you will have to do largely without resistive heating elements - you may still use your coffeemaker, but you won't leave it on for hours anymore! (I bought one with a thermal carafe. It has no heating element for the carafe at all.)

Another thing you might consider is putting in a large water storage tank and running your deep well pump just once or twice a month with your backup generator. Then, you'd get by fine with a much smaller motor to keep the pressure tank full. That's worth thinking about, because the well pump is probably the only 220 volt load you really need to power. You'd save thousands by building a 110 volt off-grid system instead of a 220 volt setup. The thousands you save should more than set up the water storage, and could also go toward a diesel backup generator instead of a gasoline unit. (Diesel fuel stores far longer, and diesel generators are much more durable and far more fuel efficient.)

I would echo what others have said about inverters as well. Stay with Xantrex or Outback. The inverter is the most critical component of the system, and only the best will keep you happy the long run. And, I would only use pure sine wave power. The modified sine wave inverters are a lot less expensive, but as Nadja has observed, motors don't last as long on modified sine wave power. They also run louder on modified sine wave power. I'm sure the increased noise and the reduced service life are related, and you don't want the noise anyway, which can become pretty annoying over time.

FYI, Xantrex was originally named Trace. They were the pioneers of high-quality off-grid inverter technology. Trace/Xantrex inverters have been in the field a long time, with uniformly good performance and durability. Outback was started by a handful of former Xantrex engineers. Outside of those two companies, the off-grid knowledge pool gets shallow quickly.

I also concur with the recommendation of building the DC side (modules, batteries and inverter) to be at least 24 volts if not 48. (With DC, as voltage rises resistance drops, meaning with higher voltages you'll save a bunch on cabling alone.) Also, I suspect the 48 volt PV module market is the most price competitive, since that's what's used in most grid-tied systems.

Also, whichever brand of inverter you settle on, make sure all the ancillary bits and pieces are the same brand, as far as is possible. (Otherwise, you'll probably some of the inverters on board diagnostic features, and you'll get little if any help from the factory when it comes time to program or troubleshoot the system. Those tech support folks are only responsible for knowing their own companies products - it's not their job to help you figure out your mix and match system!)

 

Let me add a plug for Outback.....these guys are GREAT on the phone ! It's not tollfree, but if you have an issue with their equipment, I haven't run into an issue they can't talk you thru.

One of my inverters took a lightning hit ( my fault, lack of grounding and such ), and fried. The guy on the phone covered it under warranty, they sent me the parts ($1200 worth) to completely rebuild the inverter inside, along with a really GOOD step-by-step manual for dummies, and I had it up and running again in no time.

I simply can't say enough good stuff about Outback...except BUY THEIR STUFF !

 

Outback has been around for quite awhile. However there are better deals out there as well. For instance, I talked to Kingfish, about some panels that are much cheaper then most, yet have one of the best warrentees on the marked. Sorry about the spelling. The brand is "Shucko" and they are from Germany. 24 volt, 255 watt, and here at my local store, they can be had for about 260.00 give or take each. One heck of a deal, especially if your already on 24 volt.

 

Demand Factor

King,

Don't forget when calculating your demand factor, you must multiply it by 125% to get the actual number as per the national electrical code book.

 

Shuco is the brand.

I can't find a listing for 255w panels, nor anything close to that price.

California Approved List of Panels

What's the name/address/phone# of the local store ?

If I can buy a first quality panel for a buck/watt, I want to know about it.

 

Sorry Tn, That was a mistype on my part. Those panels are around $565.00 each but still a pretty darn good deal. The local store that has them is " The Solar Exchange" Matt Hamiliton and the phone number is: 928-536-4026.

 

Yeah, that's a LOT more inline with what I just paid for Solarworld 240w.....628 bucks/each.....and considering the shipping from California on a small order was probably 50 bucks each, that puts them pretty close to that price.

 

Andy, Kingfish found them close to him up in Mich. so , if you check out on the web, you may find them closer to you. Not shipping is a good thing !

 

I know Kingfisher and Nadja from another forum about the world of survival and off grid lifestyles and we have had a few talks about the socalled solar and wind power system for the homestead

The thing i did learned was not to put the water system for fresh water and black water on any type of system that need power to have pump water into or out of the place along with most of the items i have are design to run off the 110.volt power with a inverter and 12.volt d,c power items that runs saight off the battie bank system .

So all my basic flesh water needs are met by a simple hand pumped into the three 55.gallon water tanks and filtered as it comes into the tanks before it gets used inside the cabin with a basic 12.volt rv pressure pump to do the basic pressure with a 110.volt tankless heater system plumbed into the line that runs into the shower and sink units and the rv combo washer and dryer unit is used with cold water inside of hot water to wash the cloths ...

The black water waste from the marine style toliet that is hand pumped into a a 28.gallon sized boat holding tank then handed pumped through a macerator grinder pump system that works with the hand pumping of the waste going into the line up to the septic system to be farther broken down as it ..

so learning how magaging the power draw from our battie bank and what you do run off a battie bank

 

Welcome aboard Hank, glad you could make it. I am sure you will find alot of what your looking for here at the monkey forum. Nadja

 

thanks Nadja i have been looking around alot here last night when i joined