James Cormican's posts

john,

thanks for the posts on this one, I learned a lot. 

the community section and the forum have been successful because of folks like yourself sharing your knowledge with the RE / Alt-E community.  we appreciate it.

don - good luck with the system.

james - Alt-E staff

wow guys,  i go home for the night and 4 responses.  I agree with ken, as usual, the fridge is likely a monster, and I would say to ditch it for a small solar starter system.

If you don't mind the expense $32 + shipping (prob 10) then get a kill-a-watt and measure the heck out of what you would like to run.

I fear that your budget will be insufficient to run the loads that you listed if you include the fridge.  If you have access to back issues of home power magazine, (library or online) I would suggest issue 93 page 86.  This is a great article on a starter system.

In response to John, also a great forum contributor, there are MANY competitors that can post lower prices.  Whether they have things in stock, and or answer the phone are usually a different story.  As far as New Mexico and Arizona companies knowing more, well, perhaps, but I think our staff here is fairly knowledgeable, and more importantly, we will tell you when we don't know.  Heck, I would rather be in New Mexico, the weather here in Mass is AWFUL, but it is the people that keep me here.  I/We remember our customer's names and have visited a few in person.  It's about RE and the RE community here, not just internet sales.  If it was not that way, you would not see - Alt-E staff after my name. 

anyway, good luck with the research, and call or email me if you want some more help.

james - Alt-E staff

I am pretty sure that is a no, but for curiosity, what charge controllers?

If I know what you are using, I will dig into it further.

I think it wont work because each charge controller will be looking for a battery voltage to base how it regalates incoming voltage/current.  It will be expecting a 12v system and would not be able to work in tandem with another controller or do the switching necessary if the voltage was over the expected parameters.

If it were me, I would get a proper 24v controller and not risk breaking two 12v controllers, and potentially some batteries too.  I am pretty boring though.

james- Alt-E staff

one of our customers just finished a cool 6.2kw grid tie system install.  see pics here http://gallery.altenergystore.com/Damon-Glastetter-gallery/v/4463346131/?g2_GALLERYSID=a4fb07d48099977cb895b85d2e28770d

anyway, his sunny boy 6000 was misbehaving and he called me
with some questions.  I knew it was not right, so we both got on the horn with paul at sma tech support.  the problem was trouble-shot and a new inverter was sent out within the week.

although it is not that cool to have problems with a new product, I was impressed with how sma handled the situation and I wanted to get on my soap box and share it.  way to go paul and sma .

james - Alt-E staff

I have heard of folks using fork lift batteries before and charging them from solar without a problem.  The key is don't assume.  Find out as much info as possible about the battery included make, model, voltage, amp-hours, battery chemistry, and how hard it was "used".  If you have 3-4 weeks to charge it, the amount of current is not as important as the voltage.  The voltage must be at an appropriate level to charge the battery.  If that condition is met, then it is back to the old watt-hours in vs. watt-hours of storage equation to see how much solar/generator you need for adequate charging.

- james Alt-E staff

First off, props to Ken for holding down the forum while I was visiting home for the holiday.  Ken is right on the money on this one. 

Like he said, it is easiest to turn everything into watt-hours.  That way your equation uses the same units all the way through.  If you know how much you use per day, you can then figure how much you need to produce and store. 

1. To figure out loads, use a kill-a-watt meter to measure power and energy, and input data into a load calculator sheet.
http://store.altenergystore.com/Meters-Communications/Meters-Battery-Monitors/Power-Meters/P3-International-P4400-Kill-A-Watt-Power-Meter/p932/
http://shop.altenergystore.com/Calculators/OffGridCalculator.html#

End up with watt-hours per day figure

2.  To figure out average daily solar production, take rated watts by the sun hours in your area.  For example a 100w module in a place with 4 sun-hours per day would make 400 watt-hours per average day, wink-wink.  we usually take off 25% for inefficiencies, so I would count on 300 watt-hours.

Daily solar production MUST meet or exceed daily energy usage if you are only using solar, and you want your system to work.

3.  To size battery bank, turn batteries into watt-hour values.  For your case, 2 batteries in series makes for double the voltage (12v) and the same current.  So, at 216ah, times 12v = 2592 watt-hours of storage.  But you can only use half without hurting them. 1300 watt-hours.  This number must meet or exceed your usage total.  you then increase the battery bank based on how many days of storage you want without sunshine.

I've reached my typing patience limit, but check this out if you want to learn more in depth.

http://store.altenergystore.com/Books-Seminars-Videos/Solar/Photovoltaics-Design-Install-Manual/p481/

hope that helps

- james Alt-E staff

size your inverter based on the maximum instantaneous wattage load you could have. 

If you have motors, compressors, or other surge loads, you need to take the surge of these things into account when sizing the inverter.  some inverters can surge to almost 3x their continuous capacity, others not so much.

as far as over-demanding your inverter, the easy answer is don't do it.  larger inverters sometimes beep and shut themself off, but inexpensive inverters may just kick the bucket.  The circuit breaker between the battery and the inverter is meant to protect the conductor, not the inverter.  It can be sized to do both, however.  The problem with that is that surges are fractions of a second and the damage may be done before the breaker trips if ever in many cases.

as far as product, outback and xantrex have inverter configurations up to 14kw and 11kw respectively. 

-james   Alt-E staff

if the manual is of no help, try contacting morningstar. 

realistically, if you run that car battery down, you could easily kill it, as they are not meant for deep cycle jobs.

- james  Alt-E staff

hmm?  how many amps does your load draw?  if it is more than the imp of your module, it is likely too small a power supply for too large a load. 

Is pv the only charging source for this system?

why are you using a car battery?

you can find the manual and troubleshooting info here.

http://store.altenergystore.com/Charge-Controllers/Solar-Charge-Controllers/Pwm-Type-Solar-Charge-Contollers/Morningstar-Charge-Controllers-Pwm/Morningstar-Corp-Sunsaver-Ss-6L-6A-12V-Pwm-Chg-Cntrl-Lvd/p804/pdfs/morningstar/Morningstar-SS-Manual.pdf

james - Alt-E staff

okay, now we are getting somewhere! 

I like most of the stuff you are doing.  I take it you are not going to run the pump direct off of pv then?  The circuit breakers in the pspv are the wrong size, they can be up to 7a by code (see max series fuse size) in the kaneka.

that is good that you found a single axis tracker, and zomeworks makes good stuff.

But the case for the tracker is a tough one.  the unit you speak of, that you sized correctly, is $1100.  Trackers gain between 20% and 40% for single axis models.  for $1100, you could buy another 4 kanekas, and leave them still.  That is a 100% increase in power, and no moving parts. 

Other factors play into it, including space, aesthetics, shading and more. 

as for john's reponse, high-voltage modules can be great for pv direct pumping (like grundfos) or they can be run through an mppt controller to a battery bank.  kanekas have great price per watt, and, as thin film, they also do well in heat and lower light/shade conditions.

that's all for now,

james - Alt-E staff

now for the actual mounting.  normally, when folks buy dual axis trackers for a pole mount, they are designed specifically to the make, model, and quantity of modules they have.

If this dual axis tracker was not designed for your kanekas, what was it designed for? 

do the modules fit on the racking system of the dual axis tracker?  If you have to modify the tracker to hold your modules (which you may because kanekas have a strange size) you may have performance problems with the tracker.  It may be a good idea to contact the tracker manufacturer.

feel free to call or respond for more help because I am still a little confused on what you have and what you are trying to end up with.

james - Alt-E staff

first, for clarification.

a solar cell is one part of a photovoltaic module.  usually they are squares and there can be 36 or more cells in a module.

A pv module is a collection of cells operating as a unit.  pv modules are commonly in aluminum frames with glass on the front and with junction boxes on the back.

A photovoltaic panel is what the national electric code defines as group of modules wired together, typically in series.  nearly nobody uses this term.  people in the industry refer to modules connected in series as "strings".  for example the phrase 3 strings of 4, would mean that modules are grouped into series strings of 4 modules, and that 3 groups of 4 modules are then connected in parallel for 4x the voltage of 1 module and 3x the current.

a pv array is the term that applies to the whole group of modules/strings of photovoltaics that belong to a particular system.  if you had two groups of modules of different brands going to different charge controllers, you could refer to them as separate arrays.  most people only have 1 array at their site.


forum-ites please feel to correct or add to these definitions as needed to provide clarity.

- james Alt-E staff

I don't understand your question.  Can you explain a little furter?  What do you mean by mounting them to an array?

as far as mounting kaneka modules in general . . .

Mounting of kaneka modules is usually an adventure.  they are an odd shape and I believe only unirac has published sizing data for racking systems with kaneka modules.  Even those are for ground or roof, not top of pole.  If you give more data such as what configuration (2x2 i assume) and what size pole, maybe we can help.

james - Alt-E staff

miller or servel (domenic) have natural gas conversion options.  I think the miller option is $70 while the servel is like $200.  hope that helps.

- james Alt-E staff

do you need it to run on either, or do you just want a natural gas fridge?

james- Alt-E staff

better yet, put the modules at latitude and leave them there.  you are likely to see between 2 and 8% total losses from seasonal adjustment if that.  Don't make it harder than necessary.  Plenty of people have non-adjustable arrays.  set the array to the angle = to the degrees in latitude of the place you live.

- james Alt-E staff

I am so used to living in my renewable energy bubble, that I assumed you were asking about flooded lead acid, agm, or gel batteries. 

I have no idea what alkaline batteries will do in freezing weather. 

A. do nothing and find out

or

B. call battery manufacturer and ask

either way, I would like to know out of curiousity.

-james Alt-E staff

hi karen,

if you have a 48v air-x, you are correct, you need a 48v battery bank.  In order to add pv to your setup, you need at least 48v nominal to charge the batteries.  this is either 4x12v nominal modules in series, 2x24v nominal modules in series, or 1x a 48v or higher module (kaneka) going into a mppt controller.

as far as battery bank, they are sized based on loads, not on charging input.  you need to figure out your watt-hours per day and go from there.

this book is good for starters:

http://store.altenergystore.com/Books-Videos/Solar/Photovoltaics-Design-Install-Manual/p481/

also, use the off grid system calculator located here:

http://shop.altenergystore.com/Calculators/OffGridCalculator.html

lastly, call if you need more help.  I can help you design your system over the phone, but I can't do it over a forum response (especially without knowing your loads).  I am not that cool . . . yet.

james - Alt-E staff

hit up renewableenergyaccess.com

Several co-workers and friends have used it to land the RE
jobs they have.  I found work here on RE access.  They have cool articles too.  Their jobs section is separated by type of work so you can skip straight to the manufacturing section.

good luck,

james - Alt-E staff

the short answer is yes.

It may be a good idea to take this things in for the winter if they are only for decoration.  If they are for useful lighting there may be steps that can be taken to keep things working.

the long answer is that it depends what kind of batteries, what kind of enclosures, how bad the temperatures get, if the enclosures are insulated, etc.

reply with more info, and I am sure that myself and the forum crew will have more to say on this one.

- james Alt-E staff

I think we have talked before, but here are my two cents.

I vote for separate systems.  Economies of scale and interchangeable parts.  Like tom says, keep loads low, maybe even dc.   if you want "normal" appliances and "normal" wiring with servicing done by "normal" electricians, perhaps a small inverter per cabana is possible, say 600 watts or so.  obviously, no blenders or toasters, but in the case that someone does something silly, it does not knock out several rooms at once. 

the physical distances, the battery charging means, and the loads list are crucial for what you end up deciding.

- james Alt-E staff

dc switches are getting very hard to find.  I think we still carry one that I went out of my way to source for a cabin guy.  That one was only a two way switch.  let me know if you need one, or if you think we should have it on the website.

oh yeah, T rated switches will also work to the best of my knowledge.  the one we carry is  a surface mounted T switch, and it is ugly and brown, but safe for 12v dc situations. 

If I could avoid it, I would not use an ac switch for dc loads. 

Also, good ole square d "QO" circuit breakers are dual rated for dc usage up to 48 volts total.  for battery apps 12 or 24vdc is okay, for solar, we stick to 12vdc nominal only because of the possibility of going over the 48v rating.

- james Alt-E staff

there are not enough nabcep certified pv and solar thermal installers.  As more rebates come through from government, there is and will be a need for QUALIFIED installers on the ground.  You can look in the yellow pages and find a mechanic, electrician, or plumber.  You cant find a solar installer, and with more rebates, more people will be looking for one.  If I were not working here, I would be installing, maybe with my own business.  whatever you do, do it with passion, and know what you are doing and you will succeed.

- james Alt-E staff

okay, once you use the obscure ferris beuller reference, I have to respond.  ben stein rocks, and it is too bad he doesn't have that cool game show anymore.

my answer is that we used to do that in the midwest.  It is called putting things in the garage when relatives are over for the holidays.  The fridge gets full, it happens to be cold outside, ba-da-bing!

I suppose that you could rig something to do what you are trying, but the energy to run the fan(s) and the trouble to do it would not be worth it to me.

maybe an old fridge (not plugged in) that is outside with an externally mounted gauge for an internal thermometer with a system for pumping cold outside air through the unit and valves?? perhaps to shut off when no more cold air is needed.

I dont think that effort would be worth it, but if you are a tinkering kind of person- with a non-functioning fridge- I am sure you could have fun trying.

- james Alt-E staff

Hey forum friends!  check this out!

We have been working hard to provide system packages on the website and this is the first one.

http://store.altenergystore.com/Kits-and-Package-Deals/Off-Grid-Residential-Systems/1kW-Off-Grid-Residential-Packaged-System/p4272/

this took a good number of man-hours to get looking clean on the website.  Give us some feedback; we want to know your thoughts.  More are on the way.

yours in solar ;]

james - Alt-E staff

the kit is up, you can check the diagram!

http://store.altenergystore.com/Kits-and-Package-Deals/Off-Grid-Residential-Systems/1kW-Off-Grid-Residential-Packaged-System/p4272/

basically, you are connecting them in series + to - to make 24 volts, and then connecting the pairs in parallel + to + and - to - to add current.

let me know what you think of the kit and if you need any more help.

- james

well joseph,

yes, I did go to sma training.  I did learn about the communications systems.  Unfortunately, I am not a computer or network guy.  The questions you asked are well over my head.  sorry .

On the bright side, I have found that sma does great tech support work.  I think it is very unusual that you have not received good help.  if you are up for another try, call and ask for antonio or paul.  they are the folks I am familiar with.

If not, send me an email with your contact info and I can try to get some help for you but putting in a request for help as a dealer.  my email is my name @altenergystore.com.

james - Alt-E staff

we have a package deal that is very similar to your system that will be going online in a matter of hours.  I will try to get the diagram posted on here so you can check it out.  until then, feel free to call me and I can try to walk you through it. 

you can also get the installation manuals to the products you are working with on our website.

for the kyocera: http://store.altenergystore.com/mmsolar/others/KC40T-130TM_Install_Manual.pdf

for the C40:  http://store.altenergystore.com/mmsolar/others/C_Series_User_Guide.pdf

james - Alt-E staff

Wayne is right.  for the set it and forget it model, put them at latitude with a minimum of an inch or two under the modules for airflow.  the right angle and no airflow will hurt modules much more than the wrong angle and more airflow.

If you are going to bother to adjust, usually folks go with latitude +15 degrees in the winter, and -15 degrees in the summer.

- james Alt-E staff

I can tell you it won't be me

nick is taking a well deserved break from computer madness.
I think he returns next week, and we will find out.  thanks for the reminder.  I am curious to find out as well.

on an unrelated note, I think the photo gallery is going to go up soon (prob when nick returns from vacation) so you guys can post shots of your systems for others to drool over.

thanks for all the cool posts you guys have been doing.

- james  Alt-E staff