Suggestions wanted

bgarrett · August 2008

I am located in north Arkansas with a travel trailer out in the woods.
I have been camping out without power for almost a year and
I am learning how little electricity I need to get by
but I want to upgrade.

The bulldozer cleared a place so the sun can shine in.
I got the Horrible Freight 45W panels and have been reading all I can find about solar.
I plan to put up a pole barn with a concrete floor and insulated walls (maybe real thick spray foam.)

The information says to add up your usage to figure out how many panels to buy
but I really dont have any usage to start from.

Will someone please suggest a set of components to build a system for whats usually described as a 'small cabin'?

I am willing to pay for good quality components but not extravagant.
I will live there full time, no TV, no air conditioning, I want to use LED lighting,no incandescents, no CFLs, no telephone landline
I will have to connect with the internet, maybe by satellite and a 12Volt laptop
I dont know about the refrigerator yet (propane or an Energy Star ?)
I'm thinking of propane for heat, water heating, and cooking.
I plan a very large tank for water pumped out of the creek with a gasoline powered pump, maybe a ram in the future.
I think I can fill a 3000 gallon or larger tank a few times a year to keep the use of gasoline to a minimum.
Using ferro cement, its cheap and easy to make an even larger tank.
I think a small DC pump to pump out of the large tank to a 55 gallon (or so) tank elevated the 22 feet necessary for the propane tankless water heater to function.

The pole barn is planned as 40X40 with living space in a corner, possibly20X20.
The rest of the space will be used to restore my own antique automobiles.
I have been driving a 1939 Ford pickup for 16 years and do not own any modern cars.

Power for the shop will have to be another phase of upgrade later.
A lot of my tools are 220 volt and I may just crank the gasoline generator when I use them.

What do you think?

westbranch · August 2008

Re: Suggestions wanted

as a starter estimate the placement of needed lights in the structure, say 60w per, and this will get you started.
yes use the gen for tools.
use the rated usage fro the various amenities, pump, sat receiver, tv, radio etc.
look into batt powered versions or radio etc, may be less power than AC versions
good idea to use 2 tanks for water and gravity feed

total up projected usage and then size batt's to about 1.5 to 2 x what you project as the usage has a habit of 'growing'. then suss out batt brand and typre, CC , batt monitor, Inverter etc .

Bring your Q'a to the boaard as you work your way through the puzzle and we will help as we can...

HTH;)

Eric

bgarrett · August 2008

Re: Suggestions wanted

Thank you West
I guess I should have been more clear---
there won't be any 60W lights---at all
I plan to use LEDS, so that load is too small to measure...
there will be no TV, the radio has its own batteries
the only load I see (in the beginning) is the once a day use of the pump to small tank, the satellite receiver and possibly a Energy Star refrigerator
Some Refrigerators are rated at 400 to 450KW a year,
is that more than 1 kw a day?
propane may be better
http://www.thegreenguide.com/reports/product.mhtml?id=21&sec=2

The MPPT controller sounds good but the smallest one is larger than I need now.
I wonder if it will be a wise purchase for when the system grows?

It seems that a meter will be essential
Right now I have no idea how much charge the Horrible Freight panels are giving my batteries
I dont want to just start buying stuff at random..........

niel · August 2008

Re: Suggestions wanted

spray on urethane foam is great, but you need to protect it from light as it degrades in light. painting it is often done, but if you get a company to do the insulation they may recommend what is best to use. this also applies to nicks, chips, or peels that may occur in the paint as it must be patched with more paint or whatever product is used.
in seeing you had posted before i finished, do know that rather than buy the minimum required stuff you may want to buy the bigger controller as you can grow into it without having to buy another for you can add pvs as you go along. as to the batteries you may wish to use cheap deep cycle batteries for now as they don't last more than about 4-5 years give or take and depending on care given to them and by then you may have need of more battery power and can get the better batteries to fill the bill. adding batteries as you go along for years is not recommended as the newest will be reduced to the oldest and i tell you this so you know what to expect from the new batteries if you add them to the old ones.
we can guess at what you need, but ultimately the detective work will be needed by you to do as it depends on the products powered and the time involved for them to be on. it does sound like you are trying to minimize your needs, but you may need to learn to refine them. read as much as you can, anywhere you can, (here too) so you know the direction you will go and with what wants, needs, and goals. costs involved are also part of the equation that influences those wants, needs, and goals.
no matter what we recommend, ultimately the decision is yours, but i hope your indecision is short lived through this forum.

bgarrett · August 2008

Re: Suggestions wanted

backwoodssolar.com has 6 examples with number 1 being near 1KW.
http://www.backwoodssolar.com/
Its vague.
how do I translate their advice into identified components?

I have been reading this forum for about a year and some of the things you guys talk about are WAAY beyond me

bgarrett · August 2008

Re: Suggestions wanted

niel wrote: »

spray on urethane foam is great, but you need to protect it from light as it degrades in light. painting it is often done, but if you get a company to do the insulation they may recommend what is best to use. this also applies to nicks, chips, or peels that may occur in the paint as it must be patched with more paint or whatever product is used.

thank you niel
I sprayfoamed and painted the underside of the roof in my existing shop.
Great stuff!

niel · August 2008

Re: Suggestions wanted

if you are refering to prepackaged deals i think you need to figure out what you need in a system before opting to buy a system. also most systems don't save you money unless it is exactly what you were looking for. it may even be cheaper for you to buy individual components and assemble it yourself. i am of course assuming you are totally off grid too.

BB. · August 2008

Re: Suggestions wanted

Bgarrett,

You have two ways to proceed... One is to take the solar panels you have and get a good charge controller + batteries + inverter and see how much power you use...

So, the questions for this would be:

How many 45 watt panels did you get and what is their Vmp/Imp rating.
Do you have any existing inverters?
Do you have an existing Solar Charge Controller?

So, say you got 4x 45 watt panels and the are rated for Vmp=17 volts and Imp=2.6 Amps.

So, your 4x45=180 watts of solar panels can output 4x2.6=10.4 amps to your battery bank.

You would need a 12-15 amp charge controller. You do not need a "fancy" MPPT controller--but getting the MorningStar MPPT controller (with battery temperature sensor) would not be a bad one to get. Full featured, very efficient, and allows you flexibility later (add more panels and change to 24 VDC battery bank).

If you want a 12 VDC battery bank (use for loads/inverters <1,000 watts), a 4x45watt panels at 10% of battery Amp*Hour rating would suggest a starting battery bank of:

10.4 amp solar panels / 10% = 100 amp*hour battery bank (at 12 volts).

The amount of power you can get from your solar panels (this website is down at the moment)--But, basically, the amount of power you can get/store/use from your solar panels will be around 2-5+ hours of full sun per day (location, weather, season)--and use a 50% derating (for over-spec. panels and system losses):

4x45watt panels * 5 hours (summer sun) * 50% (derate)=450 Watt*Hours...

During winter, you may get 1/2 as much power.

So--if you have 450 Watt*Hours available (4x 45 Watt panels)--0that would power:

100 watt light bulb for 4.5 hours per sunny day
10 watt light bulb for 45 hours
1kW Energy Star Fridge (1,000 Watt Hours) for about 1/2 a day

Build this system out with a couple "golf cart" batteries and decent charge controller and (true sine wave) inverter(s)--and see how much power you need/use--then size your "next system" based on what you have now.

Basically, this smallish system will power the loads in your home (lighting, light water pumping, radio, battery chargers) pretty nicely--you might need a generator in winter/bad weather to top off your system. Will give you a nice quite home life--except when you are running your shop.

But, it will not power large loads. Don't even bother to try it... Use your generators to supply those needs for now.

I would also suggest you put an old utility kWHour meter (electric) on your generator--You can measure your actual loads (just like you were paying the utility) (write down the numbers once per week or per month)--and you will quickly see how much "additional" power you would need to supply the rest of your loads.

In the end, getting a energy star fridge plus solar panels+charge controller+batteries+inverter will save you money in the long term vs a "solar powered fridge" (very expensive) or a propane powered fridge (sort of expensive, fuel costs, maintenance--and less life vs a regular AC powered fridge).

-Bill

System2 · August 2008

Re: Suggestions wanted

hung it there, i am in the same situation try to figure out how to power my camp in Maine. more i read more i am confuse. when talk to some one about have it install ,price for 3kw system come to about 30,000 to 45,000 $ too much for me and is that enough for refrigerator rate 450 kw year, a small tv, computer and 2-3 lights at night time.

i am try to come up with a small set up and do it my self hopefully we will get an answer that we can understand.

bgarrett wrote: »

Thank you West
I guess I should have been more clear---
there won't be any 60W lights---at all
I plan to use LEDS, so that load is too small to measure...
there will be no TV, the radio has its own batteries
the only load I see (in the beginning) is the once a day use of the pump to small tank, the satellite receiver and possibly a Energy Star refrigerator
Some Refrigerators are rated at 400 to 450KW a year,
is that more than 1 kw a day?
propane may be better
http://www.thegreenguide.com/reports/product.mhtml?id=21&sec=2

The MPPT controller sounds good but the smallest one is larger than I need now.
I wonder if it will be a wise purchase for when the system grows?

It seems that a meter will be essential
Right now I have no idea how much charge the Horrible Freight panels are giving my batteries
I dont want to just start buying stuff at random..........

bgarrett · August 2008

Re: Suggestions wanted

niel wrote: »

if you are refering to prepackaged deals i think you need to figure out what you need in a system before opting to buy a system. also most systems don't save you money unless it is exactly what you were looking for. it may even be cheaper for you to buy individual components and assemble it yourself. i am of course assuming you are totally off grid too.

I am not aware of any 'prepackaged' deals.
That leaves a bewildering array of choices.
Thats the problem, too many choices for a novice and none of the components seem to be standardized.

totally off grid? YES thats what I mean when I say no power in the first post

bgarrett · August 2008

Re: Suggestions wanted

BB. wrote: »

Bgarrett,

You have two ways to proceed... One is to take the solar panels you have and get a good charge controller + batteries + inverter and see how much power you use...

So, the questions for this would be:

How many 45 watt panels did you get and what is their Vmp/Imp rating.

Do you have any existing inverters?

Do you have an existing Solar Charge Controller?

So, say you got 4x 45 watt panels and the are rated for Vmp=17 volts and Imp=2.6 Amps.

So, your 4x45=180 watts of solar panels can output 4x2.6=10.4 amps to your battery bank.

You would need a 12-15 amp charge controller. You do not need a "fancy" MPPT controller--but getting the MorningStar MPPT controller (with battery temperature sensor) would not be a bad one to get. Full featured, very efficient, and allows you flexibility later (add more panels and change to 24 VDC battery bank).

If you want a 12 VDC battery bank (use for loads/inverters <1,000 watts), a 4x45watt panels at 10% of battery Amp*Hour rating would suggest a starting battery bank of:

10.4 amp solar panels / 10% = 100 amp*hour battery bank (at 12 volts).

The amount of power you can get from your solar panels (this website is down at the moment)--But, basically, the amount of power you can get/store/use from your solar panels will be around 2-5+ hours of full sun per day (location, weather, season)--and use a 50% derating (for over-spec. panels and system losses):

4x45watt panels * 5 hours (summer sun) * 50% (derate)=450 Watt*Hours...

During winter, you may get 1/2 as much power.

So--if you have 450 Watt*Hours available (4x 45 Watt panels)--0that would power:
100 watt light bulb for 4.5 hours per sunny day

10 watt light bulb for 45 hours

1kW Energy Star Fridge (1,000 Watt Hours) for about 1/2 a day

Build this system out with a couple "golf cart" batteries and decent charge controller and (true sine wave) inverter(s)--and see how much power you need/use--then size your "next system" based on what you have now.

Basically, this smallish system will power the loads in your home (lighting, light water pumping, radio, battery chargers) pretty nicely--you might need a generator in winter/bad weather to top off your system. Will give you a nice quite home life--except when you are running your shop.

But, it will not power large loads. Don't even bother to try it... Use your generators to supply those needs for now.

I would also suggest you put an old utility kWHour meter (electric) on your generator--You can measure your actual loads (just like you were paying the utility) (write down the numbers once per week or per month)--and you will quickly see how much "additional" power you would need to supply the rest of your loads.

In the end, getting a energy star fridge plus solar panels+charge controller+batteries+inverter will save you money in the long term vs a "solar powered fridge" (very expensive) or a propane powered fridge (sort of expensive, fuel costs, maintenance--and less life vs a regular AC powered fridge).

-Bill

THANK YOU BB!!
Now we're cooking!

I appreciate this kind of guide.

I got one set of 3 panels from Harbor Freight.
I have no idea about VMP and IMP
They say 45 watts
they came with a cheap controller
no inverters yet

I am positive I need more panels and a decent controller and 24 volts seems better than 12v.

You mention 'true sine wave'

Why do I need that?---I'm not being rude--I really wonder

***solar panels+charge controller+batteries+inverter ***

Very Good Bill! I can pick out panels on my own, and batteries and you say the MorningStar MPPT controller (with battery temperature sensor) is good, so whats your suggestion for inverter?

Thank you very very much!

bgarrett · August 2008

Re: Suggestions wanted

BB also said,
"You have two ways to proceed... One is to take the solar panels you have and get a good charge controller + batteries + inverter and see how much power you use..."

Ok and what is the other way to proceed?
Was it included in your post?
Thanks

BB. · August 2008

Re: Suggestions wanted

Hmm, Don't know that it needs to be that expensive... Since the website I use to estimate people's solar production is down right now... Just make some SWAGS...

Guess that fixed mounted array tilted to Latitude, standard panels, 3 hours per day minimum average sun, flooded cell batteries, true sine wave inverter, 50% overall derating factor, and assume that this is for 9 months out of the year, and that a generator will probably be needed every few days 3 months out of the year...

1,233 Watt*Hours per day = 450 kWhr per year fridge. (450kWhr * 1,000 watt/kW * 1/365 days year)
384 WH / day=8 hours x 4 lights x 12 watt CFL's
240 WH/ day=40 Watt DVD/TV/Laptop computer x 6 hours
=============================================
1,857 Watt*Hours per day...

Solar panel requirement (assuming 3 hours per day minimum sun, 50% derating--includes panel, inverter, battery efficiencies):

1,857 WH * 1/3 hours of sun per day * 50% derating = 310 Watts of solar panels ($5 per watt = $1,550)

Storage battery--assume battery is 6x daily load (3 days without sun, 50% max discharge for good life):

1,857 WH load * 1/80% inverter efficiency * 6 = 13,930 Watt*Hours

If this is a 12 volt battery bank, then:

Battery AH rating = 13,930 W*H / 12 volts = 1,161 Amp*Hours (at 12 volts)

Or, Crown 395 Amp-Hour Deep Cycle Battery, 6 Volt:

1,161 AH * 2 (6 volt battery) * 1/395 AH = 6 batteries (~$1,800 worth of batteries)

Get a nice true sine wave inverter--but, if we choose a "larger" inverter, say around 600 watt--lets make the battery system a 24 VDC version (same number of batteries and solar panels--just wired for 24 VDC operation):

Exeltech XP600 24-volt 600 watt sine wave inverter ($535)

And a good charge controller...

310 watt of solar panels / 24 VDC battery bank = 13 amp.

The Morning Star MPPT (15 amps at 12 or 24 volts) controller would be nice for this setup at $234....

Personally, with $1,800 worth of batteries, I would through in a battery monitor. I like the Xantrex LinkLite/LinkPro because of the programmable output--but Nigel and WindSun think the Timetric at $140 is hard to beat (1/2 the price of the Xantrex units).

Add $1,000 for wiring, mounts, trips to the hardware store, shipping, etc... And we get:

$1,550 for solar panels (just a SWAG)
$1,800 for very good quality flooded cell batteries
$535 for a 600 watt true sine wave inverter
$234 for a solar charge controller
$1,000 for misc wiring+stuff
$~900 for a Honda eu2000i 1,600 watt inverter/generator
$300 or less for a good quality 20 amp AC battery charger
============================================
$6,319 total system cost for 9 month of off-grid fridge+lights+computer+gen backup...

I think this is a reasonable system for what you asked about.

-Bill

PS: I think that this address how the "other way" to proceed would work.

BB. · August 2008

Re: Suggestions wanted

To save bandwidth... Here is WindSun's FAQ regarding the choice between True Sine Wave inverter and Modified Square (some say Sine) wave inverters...

Basically, MSQW's are cheap, work with 90% of the stuff out there, and can ruin some electronic devices and electric motors (like fridge).

True Sine Wave inverters cost much more. Will run 100% of the stuff out there (if the ratings are correct). And, when running loads like motors are much more efficient (the MSQW wave form just ends up as wasted heat in electric motors--typically an additional 25% efficiency loss in induction motors).

-Bill

System2 · August 2008

Re: Suggestions wanted

bill thanks, i like the number you come up better.

is it ok to get a larger inverter say 2500-3000 watt for this set up, for the future when adding panels and battery .

BB. wrote: »

Hmm, Don't know that it needs to be that expensive... Since the website I use to estimate people's solar production is down right now... Just make some SWAGS...

Guess that fixed mounted array tilted to Latitude, standard panels, 3 hours per day minimum average sun, flooded cell batteries, true sine wave inverter, 50% overall derating factor, and assume that this is for 9 months out of the year, and that a generator will probably be needed every few days 3 months out of the year...

1,233 Watt*Hours per day = 450 kWhr per year fridge. (450kWhr * 1,000 watt/kW * 1/365 days year)
384 WH / day=8 hours x 4 lights x 12 watt CFL's
240 WH/ day=40 Watt DVD/TV/Laptop computer x 6 hours
=============================================
1,857 Watt*Hours per day...

Solar panel requirement (assuming 3 hours per day minimum sun, 50% derating--includes panel, inverter, battery efficiencies):

1,857 WH * 1/3 hours of sun per day * 50% derating = 310 Watts of solar panels ($5 per watt = $1,550)

Storage battery--assume battery is 6x daily load (3 days without sun, 50% max discharge for good life):

1,857 WH load * 1/80% inverter efficiency * 6 = 13,930 Watt*Hours

If this is a 12 volt battery bank, then:

Battery AH rating = 13,930 W*H / 12 volts = 1,161 Amp*Hours (at 12 volts)

Or, Crown 395 Amp-Hour Deep Cycle Battery, 6 Volt:

1,161 AH * 2 (6 volt battery) * 1/395 AH = 6 batteries (~$1,800 worth of batteries)

Get a nice true sine wave inverter--but, if we choose a "larger" inverter, say around 600 watt--lets make the battery system a 24 VDC version (same number of batteries and solar panels--just wired for 24 VDC operation):

Exeltech XP600 24-volt 600 watt sine wave inverter ($535)

And a good charge controller...

310 watt of solar panels / 24 VDC battery bank = 13 amp.

The Morning Star MPPT controller would be nice for this setup at $234....

Personally, with $1,800 worth of batteries, I would through in a battery monitor. I like the Xantrex LinkLite/LinkPro because of the programmable output--but Nigel and WindSun think the Timetric at $140 is hard to beat (1/2 the price of the Xantrex units).

Add $1,000 for wiring, mounts, trips to the hardware store, shipping, etc... And we get:

$1,550 for solar panels (just a SWAG)
$1,800 for very good quality flooded cell batteries
$535 for a 600 watt true sine wave inverter
$234 for a solar charge controller
$1,000 for misc wiring+stuff
$~900 for a Honda eu2000i 1,600 watt inverter/generator
$300 or less for a good quality 20 amp AC battery charger
============================================
$6,319 total system cost for 9 month of off-grid fridge+lights+computer+gen backup...

I think this is a reasonable system for what you asked about.

-Bill

PS: I think that this address how the "other way" to proceed would work.

BB. · August 2008

Re: Suggestions wanted

Since I am clogging up this thread anyway--I might as well add information on how to pick a solar panel too...

First, there are three major types of solar panels...

Thin Film
Mono-Crystalline Silicon
Poly-Crystalline Silicon

Thin Film are the new "Holy Grail" in solar panels... Perhaps someday you can buy $1.00 per watt Thin Film panels--but that is not today... The thin film panels cost almost the same as Crystalline Silicon panels--but are less efficient (therefore need to be larger) and many are not very well built (tend not to last very long--and the flexible Thin Film panels don't hold up well either). The panels tend to look uniformly dark, no round or soldered together disks under the glass/plastic. Harbor Frieght panels typically are Thin Film Panels.

Mono and Poly Crystalline panels are typically the long, efficient, glass covered panels we have today. Mono Crystalline are slightly more efficient and cost slightly more--for most people, buy these panels on $/watt basis (from major vendors).

Now, I have just suggested 310 watts of solar panels. If this was a "12 volt" battery system--then any combination of "12 volt" solar panels with Vmp~17 volts will work just fine. A few large panels, or many small panels connected in parallel at "12 volts"--either will work.

For a "24 volt" system, we are looking at Vmp=34 VDC or so... So, typically with PWM controllers (not MPPT)--we would look at pairs of "12 volt" panels connected in series.... So, we would need:

310watt/2=155 watt panels (2x)
310watt/4=77.5 watt panels (4x)
310watt/6=52 watt panels (6x)

Etc...

Now, looking through commonly available solar panels, we see that typically, panels over 100 watts are no longer "12 volt" panels (Vmp=~17 volts). But these larger panels are usually higher voltages for use with Grid Tied Inverters (typically 200-600 VDC solar bus required)--but they can also be used with "MPPT" (Maximum Power Point Tracking) Solar Charge Controllers (like the Outback, Xantrex, and some MorningStar, BlueSky controllers)...

So, we probably won't find a 155 watt "12 volt panel", but 80 watts or less, there are a bunch to pick from. Typically, you don't want 31x 10 watt panels--the fewer panels, the less wiring/mounting you will require (and larger panels tend to cost less money per watt).

But, if we choose a MPPT type charge controller, we can also look at the larger (over 100 watt) panels...

For example if we choose an Outback or Xantrex MPPT controller, the panels should work between max. Battery Charging Voltage + 2 volts (as a minimum) and about 130 volts DC maximum.

So, for example, a Mitsubishi 170 watt panel has a Vmp=24.6 volts and Imp=6.93 amps... Now, a 12 volt flooded cell battery needs about 15 volts to equalize and the solar panel would need to be rated at 15+2volts=17 volts or greater.

With an MPPT controller, these panels will work at 12 volts. But, a 24 volt battery would need 30+2=>32 VDC--the 170 watt panels in parallel, their Vmp=24.6 volts is too low--but you can put them in series and get Vmp=49.2 volts out of them--plenty for a MPPT controller charging a 24 VDC battery bank...

But, you have to look at the controller's maximum voltage rating... I suggested a MorningStar MPPT controller--so what is it's Vmax solar panel voltage... It has a 75 VDC maximum rating for its solar panel input--so the Voc=70.2 volt of 2 solar panels in series should be just fine (read next two paragraphs about where 70.2 volts came from).

It does get a bit more complex because batteries change their voltage with temperature--and so do solar panels... You need to make sure your Vmp of the solar panel needs to be able to charge a cold battery bank (higher voltage) on a hot day (when the solar panel voltages drop).

Also, you need to check Voc (voltage open circuit) on your solar panels with respect to your solar charge controller... The Morning Star Rating of 75 volts vs the 170 watt Mitsubishi panel Voc of 30.6 volts (at 77F--but as the temperature drops, the Voc rises even further)--for example, at 0F, Voc=35.1 volts--put two of those in series, and your get Voc at the solar charger of 70.2 volts--still OK, but close.

I won't get into how this is calculated right now (Voc when cold, and Vmp when hot)--but I use the Xantrex String calculator to look up panel ratings and to get an idea of how heat and cold affects the panels.

I will stop here--more than enough confusing information here--Please feel free to ask specific questions--it is easier to answer those vs trying to write a solar engineering course here.

-Bill

BB. · August 2008

Re: Suggestions wanted

boonwsun wrote: »

bill thanks, i like the number you come up better.

is it ok to get a larger inverter say 2500-3000 watt for this set up, for the future when adding panels and battery .

Larger inverters typically are less efficient when driving smaller loads--plus if you are getting true sine wave inverter, you are going to be spending $2,000 or more--vs the price for a 600 watt inverter...

Sometimes, what folks do is get a small TSW inverter for powering the home fridge/electronics and get one of the big/cheap MSQW inverter to power a saw or well pump....

A quick rule of thumb... If you are powering 1,000 watts or less, can be done with a 12 volt battery bank.

If you are powering 2,000 watts or less, look at 24 volt battery bank.

If you are powering over 2,000 watts, look at a 48 volt bank.

Basically, at 120 volts, a 10 amp load (1,200 watts) becomes a 120+ amp load at 12 volts from the battery bank--big wiring, big fuses, required to power these loads.

No hard and fast rules, but big loads require heavy wiring (upping battery bank voltage helps reduce current) and large battery banks--or else it becomes the equivalent of trying to start your car with a car battery (you will get a few minutes of work--but will quickly kill the battery).

Typically, if you have a smaller system--just get a good generator for the larger loads... Unless you want to expand your solar system to run your shop--can be done--but requires planning and $$$...

Look for posts from "adas" here... He has converted his fabrication shop in Hawaii to run primarily from solar PV power (and recycled forklift batteries and inverters--I think I got that correct). He would be a good one to talk with about the details and what he has learned in the process (many good posts too).

-Bill

bgarrett · August 2008

Re: Suggestions wanted

Wow Bill, all that hurts my brain

Great info and I really appreciate it.
I will keep this info and use it to guide me.
Thank you very much
B Garrett

BB. · August 2008

Re: Suggestions wanted

I will also add, from WindSun's (our host's) Catalog page... They have a link to the Kyocera Product Catalog...

I recommend down loading the Kyocera and possibly printing a few of the sections. It does a pretty good job of taking you from a blank sheet a paper, through sizing/design the system, and into the parts (including rails/wiring) in one place... Very nicely laid out document and will help many people with their "what if" and "how do you do that" questions...

Also on Wind-Sun's Catalog page, are links to many of their major vendors... For example, I have learned a lot going through several of the "water pump" vendors--picking pumps, sizing flows, solar panels, battery or no battery questions, and such.

-Bill

quid_non · August 2008

Re: Suggestions wanted

Wow! BB -you da' man!
Excellent review of small solar options - I read all with great concentration. You have the gift of excellent understanding couples with magnificent translation. Thanks for taking the time to go theough the options!

FWIW...
I have a small cabin system, initally powered by 4 HF 15W amorphous panels and an inexpensive "shunt" type 7A controller. This fed a single 110ah deepcycle marine batt. Monitored status with a trimetric 2020 meter. Did "OK" for the SW Virginia cabin: (2 40W 12V fluorescents (est ~2hrs/day), sat radio (~1A, 6hrs/day), composting toilet fans (~0.5A, 24 hrs/day, occasional 12V blender (adult drinks), charging cell phone and laptop (DVD player) and 2-3 small 12V fans (~0.5A total) to circulate air/cool as needed. Needed to use my Honda 1000EU genset (output ~8A DC) maybe 1-2 hrs early in am, let panels top off remaining of day. Total use per day was about 15A. The HF panels were inexpensive and got me hooked!

In time, added two additional monocrystalline panels (Solarex 20W, Powerup 30W (e-bay and craiglist purchases) - this increased power to 110W (stated, not actual). Got a much better controller (Morningstar SS20 L). Now my batt is 100% full by noon (~2-3 hrs full sun) and "float" @ 14.4V the remainder of the day. Use genset only when rain sets in for 2 days . Life is good! Now trying to figure out how to add enough power to run a AC fridge. Will do this by getting an inverter and more panels/batt. Likely will go to higher voltage and an MPPT controller (my panels are located ~150ft from the cabin) and downconvert ~75V to feed a 12V bank.

I'm still a newbie - but appreciating all is possible (and cost effective)- I've learned this from your forum and getting the advice/input from excellent people like yourself!

Thanks for the help!
Best
Wayne

bgarrett · August 2008

Re: Suggestions wanted

Ok Bill,
I have put together a shopping list from the Wind and Sun catalog with one question.

2 mitsubishi 170W PANELS $829 each

morningstar mppt CONTROLLER w/bat temp sensor 15 amps $234

true sine wave INVERTER exceltech XP6000 24v 600W $532

trimetric METER $140

BATTERY CHARGER xantrex tc20 $300 4 stage

OR
Iota DLS2725 $240 (w/IQ4 $28 more) 3 stage

Which battery charger do you recommend?

quid_non · August 2008

Re: Suggestions wanted

bgarrett wrote: »

Ok Bill,
I have put together a shopping list from the Wind and Sun catalog with one question.

2 mitsubishi 170W PANELS $829 each

morningstar mppt CONTROLLER w/bat temp sensor 15 amps $234

true sine wave INVERTER exceltech XP6000 24v 600W $532

trimetric METER $140

BATTERY CHARGER xantrex tc20 $300 4 stage

OR
Iota DLS2725 $240 (w/IQ4 $28 more) 3 stage

Which battery charger do you recommend?

Did you consider the non UL listed Sun 190W panels??
(~$660)

http://sunelec.com/

System2 · August 2008

Re: Suggestions wanted

bill, thank you very much for take time to explain things in term that i can understand.
boon.

BB. wrote: »

Larger inverters typically are less efficient when driving smaller loads--plus if you are getting true sine wave inverter, you are going to be spending $2,000 or more--vs the price for a 600 watt inverter...

Sometimes, what folks do is get a small TSW inverter for powering the home fridge/electronics and get one of the big/cheap MSQW inverter to power a saw or well pump....

A quick rule of thumb... If you are powering 1,000 watts or less, can be done with a 12 volt battery bank.

If you are powering 2,000 watts or less, look at 24 volt battery bank.

If you are powering over 2,000 watts, look at a 48 volt bank.

Basically, at 120 volts, a 10 amp load (1,200 watts) becomes a 120+ amp load at 12 volts from the battery bank--big wiring, big fuses, required to power these loads.

No hard and fast rules, but big loads require heavy wiring (upping battery bank voltage helps reduce current) and large battery banks--or else it becomes the equivalent of trying to start your car with a car battery (you will get a few minutes of work--but will quickly kill the battery).

Typically, if you have a smaller system--just get a good generator for the larger loads... Unless you want to expand your solar system to run your shop--can be done--but requires planning and $$$...

Look for posts from "adas" here... He has converted his fabrication shop in Hawaii to run primarily from solar PV power (and recycled forklift batteries and inverters--I think I got that correct). He would be a good one to talk with about the details and what he has learned in the process (many good posts too).

-Bill

BB. · August 2008

Re: Suggestions wanted

I believe the mitsubishi 170W PANELS are out of stock at NAWS store right now (call to confirm--I was just using them as an example because the specs where handy and it was close to the size of my example system--sorry I did not pick an available panel).

Be aware, that shipping costs of large solar panels can be a real killer--especially when only purchasing a couple panels instead of a full factory pallet.

I do not work at/for NAWS/WindSun--so any prices I quote are just from various websites (including NAWS) and don't include shipping, taxes, insurance, etc...

If there are any questions, always contact NAWS directly (phone or email--they do not monitor these forums for business related questions/issues).

Also, regarding the MorningStar controller, don't forget to order the Remote Battery Temperature Sensor (round $30 from NAWS).

Regarding which charger--I have heard good things about both on this forum--I have not used either, so perhaps some recommendations from other people here can help you (the small 20 amp Xantrex will run nicely on a Honda eu1000 900 watt inverter/generator, again, from other users here like "Icarus"--the small Iotas should too).

Don't normally use the Honda's small 8 amp at 12 volt (96 watt) output to charge your battery bank--it is unregulated and not very large--you will be much better off using a good quality charger on your battery bank (faster, more fuel efficient, better battery charging).

For inverter choices--again, I don't work at NAWS--so do your own due diligence and download the manuals for all of your items before you purchase them--make sure they will do what you need--and you have all of the needed parts (including correct wire, fusing, etc.) before you start your project.

The items I suggested are starting points--you may find different models/vendors will better meet your specific needs.

I also tend to point at our host's webstore--They offer good products, reasonable prices, and excellent support (including free to us support of this forum). They also try to stock products that have worked well over the years (few returns/problems) [wind power products--they have them because people demand small wind turbines--not anyone's favorite product at this time].

Anybody else--please feel free to jump in--I have been known to make mistakes

and I am still learning :roll: .

-Bill

Suggestions wanted

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