James Cormican's posts

we can figure watt-hours per day and add it to what the calculator comes up with for the other loads.  You can figure out instantaneous watts with a kill-a-watt meter, but fridges are difficult, because they have motors that turn on and off throughout the day.  We will take your yearly number and divide it out to a daily number, which you can add to your total Watt-hours per day.

339 kWh per year x 1000 = 339,000 Watt-hours per year
339,000 / 12 months = 28,250 Watt-hours per month
28,250 / 30 days per month =

942 Watt-hours per day. 

that is the amount of energy your fridge uses on average per day.  that is a pretty energy efficient normal fridge, but that amount of energy costs at least a few thousand to make and store with photovoltaics and batteries.  You would then add the remainder of your loads into the calculator, and figure out total Watt-hours per day.

let me know if you need anymore help

james - Alt-E staff

margaret,

use this link to do a loads calculation.  with this info you can size a system with the off grid calculator on the "how-to" section of the website.

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

that is the loads list above

check out the calculator on how much solar you need based on your loads.  you can also post them and how many hours you use each per day, and i can help you.

good luck

- james Alt-E staff

The servel brand name has been around for some time, and many people trust them.  They only have an 8 cubic foot model, so many people find them to be too small.  We have also had good luck with the Miller brand.  They offer larger sizes and I have not yet heard of any problems or returns on one since I have been around.  Call us up to get a shipping quote on either brand.  hope this helps,

james - Alt-E staff

to my knowledge unisolar does not make a 130w module.  They have a 124w module, but it is nearly 8ft long.  For a boat, I would also suggest either kyocera or unisolar.  the unisolar will be better with shading but will have poorer power density.  feel free to call with any questions.

james - Alt-E staff

I would try giving frank a call at bz products.  He may have a solution for you.  Other brands of charge controllers often advertise low emi emissions that meet or exceed FCC part 15 EMI emissions requirements.  If no solution is found, we can  help you find something that may cause less itnerference if need be.  the number for bz products is 314-644-2490.

james - Alt-E staff

I think we have a slightly dented (bottom rail .75in) unisolar 64 if you are interested.  I believe it was dinged at the warehouse.

- james Alt-E staff

It depends what type of system you have, but check out these products below.  Grid tied systems often have communications packages that are add ons to the inverter.  Off grid systems use monitors with shunts to calculate system performance.  The products below are typically used in off grid or grid tie with battery backup aplications.

http://store.altenergystore.com/Meters-Communications/Meters-Battery-Monitors/Ammeters-Voltmeters-Battery-Monitors/Wes-Power-Technologies-Inc-ARCS-250-Hybrid-Energy-Monitor/p3858/

http://store.altenergystore.com/Meters-Communications/Meters-Battery-Monitors/Ammeters-Voltmeters-Battery-Monitors/PM-5000-U-PentaMetric-Input-Unit/p253/

note for the penta metric you also need the computer interface and display.

Feel free to call us with any further questions.

james - Alt-E staff

I think this would work for what you are trying to do.

check this out - http://store.altenergystore.com/FusesBreakersEtc/Switches/Timers/Aee-FlexCharge-Digital-Timer/p2342/

feel free to give us a call if you have any more questions.

-james Alt-E staff

what happens is that voltage goes up.  40 degres C is not super unusual, and is covered by the national electric code.  a factor of 1.25 times voc is taken for temperatures between -21 and -40 degrees C.  check out NEC section 690.7 for further details.

basically this correction is used to size charge controllers based on estimated pv output, along with extremes.  with this correction factor, you can make sure you dont blow up your charge controller on the coldest, sunniest days.

- james Alt-E staff

If it was my money, I would look for something UL listed, with the best warranty.  Sun Power does interesting stuff, but they only work with positive ground systems, and that requires a lot of extra work.  You are pretty safe with any of the name brand modules.  The sanyo are nice, but the technology is new, and the warranty is structured slightly differently than most other manufacturers.  I am partial to evergreen, shell, isofoton, kyocera, and unisolar, but that is just me.

-james Alt-E staff

Rock!

good work michael.  shoot some photos, we are going to have the gallery up on the community section soon.

cheers

james Alt-E staff

not to be a smart a#%, but it is not very efficient when you are running a load and then clouds go by.  then your load is not running anymore.  or how about this, what if you want to run something at night?!  no lunar modules yet  

that is where the battery and inverter come into play.  if you are worried about efficiency, use dc loads, and eliminate the 10% loss from the inverter.

- james Alt-E staff

the theory is correct, at least, but the charge controller is not that sophisticated.  when it is sunny, it will put into the battery what it gets from the pv.  If you have a load on at the same time, it will draw from the battery to fulfil that load.  If the load takes out more than what the pv puts in on a daily basis, you are operating at a net loss; not good.  welcome to the basics of system design!  If you are using more energy than you are producing, it is not the components' fault, but the system designer's fault.  although more storage (bigger battery) can delay the inevitable, making less energy than you use will ultimately create a system that will work intermittently if at all.

james - Alt-E staff

it is important to note that some charge controllers have what is called a low voltage disconnect (LVD) which will disconnect the load before you wreck the battery by drawing it too low.  with morningstar controllers, the models containing a low voltage disconnect have "L" in the name for the sunsaver series, and the prostar series has an lvd as a standard feature. A low voltage disconnect can protect your batter from an untimely death, but will not fix bad system design.  Incidentally, most inverters (even no frills inexpensive ones) usually have a lvd on them nowadays.

yes, that is a standard system.  that is likely any pwm charge controller sized 6 amps or higher.  Try looking at a morningstar sunsaver 6.

As far as the panel, that voltage at max power seems very low for a 12v nominal module.  17 is a more typical number.  What is the make and model of module?  Or what are the full stats on the back (open circuit voltage, voltage max power, short circuit current, current at max power)?

It is not unreasonable to run things without a battery.  But, those things must be DC loads capable of handling PV direct type voltages!  things like water pumps, and electric fans are run pv direct often.  They usually have electric motors that can handle the higher and slightly variable dc voltage.

you were ablsolutely right, your inverter will not like 17 - 20 vdc!  you can run dc loads without an inverter, but with a battery directly off of a charge controller like the one I mentioned above, but they (the load) must use less than the amount of amps the controller is rated for.

feel free to ask away if any other help is needed.

- james - Alt-E staff

check out the sunlinq by global solar, or the mysoldius solar charger on the website.  they are in the in the foldable solar panels section of the website, in the solar electric panels section of the website.  feel free to call us if you have any questions, but i think those products should fit the bill for what you are looking for.

james - Alt-E staff

my friend, it seems as though you are missing the battery and the charge controller.  correct me if I am wrong.  go in this order.

1. pv module
2. charge controller
3. battery
4. inverter

the inverter is not meant to take the input from the pv modules directly.  Inverters are meant to work off of batteries.  If the inverter is not destroyed, it likely will be if you continue to try to feed it 20+ volts pv direct.

if you want to learn more on your own,
check out the photovoltaics design and installation manual on our website. 

If you want help fixing what you have, please call us, I will help you, because nobody likes blown inverters.

james - Alt-E staff

that is not a good idea.  especially don't do this if they are different types of batteries such as flooded, agm, or gel.  Mixing types is a real no-no, mixing the same type and different sizes and different ages will prematurely wreck your batteries as the weakest/oldest of the bunch will likely drag down they rest of the crew.

more than 3 series strings in parallel is also a no-no.  If you can, it is best to have 1 series string of batteries for their health and longevity.  this also minimizes connections and money spent on the copper to do it.

In a pinch, or if you dont have anything better, you can do it, but I would not.  If they are different types, do not put them together.  If you want a stable battery bank that will last, size it correctly, bite the bullet and buy them all at once. 

check out homepower #114 page 54 for a good article on batteries.

james - Alt-E staff

guys, there is no average home.  the amount of space your house takes up has no bearing on how much electricity you use in it.  a pv system is based on YOUR electric loads.  not your neighbor, not the average american home.  It depends what your goals are.  100% of your electric loads, or maybe 50%.  Or perhaps from this angle:  "I have $10,000 I am willing to spend on renewable energy, what does that get me?"  It is not that most people cant afford solar, it is that they choose to spend their discretionary budget somewhere else like a car or boat or something else.  If you say "solar is too expensive to power my whole house"  then yes, if you are comparing it to the electric company, you are right.  the initial investment for meeting an "average" home's electrical needs completely with solar could easily be $60k.

I would bet that your electrician friends have other toys that they are willing to spend money on, but they don't look at solar the same way.  A Harley will likely not pay itself back.  The solar will.  People can justify a Harley because it is fun, a status symbol, and an activity.  Often those people do not see solar that way, but as an overpriced nice idea, that does not make economic sense in comparison to just buying their energy from the electric company.

what I am getting to is that this topic is near to my heart, and there are a ton of misconceptions about photovoltaics.  Keep your eyes peeled for new articles in the how to section on pv systems for less than $10k, and articles in the community section including interviews with customers about their systems.  If YOU want to do something with solar, do your homework, call us up, and we can get you pointed in the right direction to fit your needs and wants.  Don't worry about the jones's house down the street that probably rolled the pv system into their home loan.

james - Alt-E staff

I just retruned from from sma training, and the web box is pretty impressive.  that is the way to go to get the most data out of your sma.  I dont think the fronius would work with the sma but I can't say I have tried or heard of anyone trying it. 

you can also use the sunny boy control, and that has several features.  you can check out the descriptions on sma's website and order them through us if you want.

james - Alt-E staff

I think you mean xantrex truecharge 40a charger, and if you do , I dont think there is a problem with the both of them running together.  compared to the generator, the air-x output will be minimal.  hopefully you have an appropriate circuit breaker and stop switch, in which case you could shut off the air x while the generator is running, and you would not lose much.  The final word would likely have to come from xantrex and or southwest windpower.  i think it would be okay, but it never hurts to double check.

-james Alt-E staff

here is a link to the spec page of the inverter, and below is a link to the full manual.

http://store.altenergystore.com/Inverters/Off-Grid-No-Utility-Needs-Batteries/1000-to-1999-Watts/Xantrex-1500W-DR1512-12V-Inverter/p2089/

http://store.altenergystore.com/Inverters/Off-Grid-No-Utility-Needs-Batteries/1000-to-1999-Watts/Xantrex-1500W-DR1512-12V-Inverter/p2089/pdfs/xantrex/DR%20Series%20User%20Guide.pdf

the information regarding generators begins on page 30.

-james  Alt-E staff

tom, i should invite you to our meetings!  the people behind the website feel your pain, but . . .  honestly the truth is that what is in OUR stock is not the problem.  The issue comes with keeping track on the fluctuating stock of about a dozen other distributors.  It is a ton of work to do this, and sends us into to a tail chasing frenzy of changing in and out of stock on the website.  because of this, it has been our policy to keep things we carry on the website, because even we don't know if we can or cant find them sometimes. 

It is one of my pet projects to identify the more scarce, or more likely to be scarce modules on the site as something that can be clicked on or off easily.  Let me know if you think this is helpful.  We don't want folks to not order a module because it says scarce because we may have it in stock, but it is not that common or has been discontinued. 

I appreciate the suggestion, and we are working on improving all the time, and we fight about this one a lot, so I hear where you are coming from.  let me know if you think the scarce module idea would help.

and thanks for the continuing participation on the forum with useful, knowledgable answers.

james - Alt-E staff

you can easily add two more sharp 80 to your system.  this would increase the rate with which you charge your batteries, but it would not increase the amount of storage you have.  your charge controller has room for at least two more.  you would just have two more 10a breakers in your pspv.  regarding adding storage, it is suggested not to add new batteries to batteries older than one year, so that you dont wreck the new and the old ones.  If you need more storage, you may have to increase your battery bank, and that may mean a new battery bank.  I can send you a quote if you would like for the equipment you are looking for.  you will likely be on your own for batteries because of international shipping regulations for hazardous materials.

james - Alt-E staff

to me a 48v system would be easier in terms of getting RE equipment for the system.  It would also decrease potential voltage drop issues.  there are other ways to do it and I learned some things from terry's post, but to have a simple system with common off the shelf parts including the air-x turbine, inverter, solar charge controller, i would go to 48vdc if possible.

james - Alt-E staff

don't worry about stupid questions, nobody is born knowing this stuff.  you can learn by asking, doing or both.  Yes you can add more pv modules to your system.  what you add and what you change to allow these additions will depend on what you have in your system now.  if you add more power, you may have to upgrade your wiring and perhaps your charge controller.  let us know what you have already in place and we (the staff and our loyal forum participants) can help you with selecting things to help your system grow.

to answer your question directly, adding more pv would not mean adding more batteries.  to have more energy storage you would need more batteries, to have more energy production to fill a new, larger battery bank, and keep up with your consumption, you may want to add more solar pv modules.

 james - Alt-E staff

I would think long and hard before putting even an air-x on my roof.  One can be loud and cause vibration, two would be worse.  The performance is typically less than a properly pole mounted turbine as well.  Your dealer is right, they are better than they used to be, but even southwest windpower does not actively market the roof kits.  People insist on doing it so they made it as safe and as quiet as possible, but it is certainly not ideal.  Depending on how close your neighbors are, they might not like them on the roof at all.  Those are the negatives, but to be fair, it is much cheaper to mount on a roof, and it allows people to begin in wind who may have never attempted.  roof mounted systems have worked really well for some folks as well.  ultimately, the decision is yours, but I can't say that I am a fan of roof mounted wind turbines.

hey folks,

I was thumbing through an old home power magazine looking for something else when I stumbled upon this gem of an article.  Home Power #93 page 24.  The article is titled PV Orientation and is written by Zeke Yewdall.  It has some good info including charts and graphs that may help you.  enjoy.

james - Alt-E staff

Hi tom,

Home power magazine issue 112 has an article about used solar hot water collectors.  That may help you repair them or perhaps decide that the time for new ones has come.

james - Alt-E staff

I will try to get a quote out to you today or tomorrow. 

- james

first things first.  to reduce your electric bill, use less electricity.  period.  every dollar you spend on conservation and efficiency is worth about 5 or more in renewable energy products.  read every article you can find on phantom loads, and then eliminate them.  If you have money burning in your discretionary/re fund, use $35 to get a kill-a-watt and see where you are wasting electricity.  Then attack your lighting and appliances with the most energy efficient varieties you can find, unless you have already done so.  Once your loads do the limbo and are as low as they can go, THEN go for the PV system if your purpose is to reduce bills.

Yes, you can install a basic system with a general understanding of electricity.  I would start by reading homepower magazine, but especially issue #93 page 86, and issue #111 page 60 for examples of do-it-yourself small systems.

please feel free to contact us with any other questions.

james- Alt-E staff