James Cormican's posts

I agree with steve.  The battery may not be of a type that is a deep discharge renewable energy battery.  because of this, it may not like to be discharged very deeply over long periods of time.  also, batteries do not like severe heat or cold. 

it is important to know how many hours the pump runs so we can then figure the watt hours.  although it is likely that a 100w panel will provide suffiecient energy to your load, it would be nice to make sure. 

please feel free to caontact me with any other questions, and thanks for the post, hope this helps.

james - alt-e staff

Hey guys,

I checked on availability and they are back-ordered for a month. 

Regarding the junkyard fan idea:
that should work fine if you are using 12v battery.  If you intend on going pv direct, however, the motor will not likely appreciate the 16-18 vdc that a solar panel would supply.  It may tolerate it, but I suspect it may have a narrower voltage window since it was designed to be powered by a battery.

just an fyi, this item is not like a solar attic fan.  It is just a dc fan.  we also sell a kit with the dc fan and the pv panel.  the solar attic fan is different and you can get that from us as well as other retailers.  There are several brands, but we carry natural light, who were just featured in home power magazine #112.

feel free to contact me with any questions.

- james -Alt-E staff
877-878-4060 x107
james @ altenergystore.com

hi greg,

give me a call and I can help you sort out your system.  Once we figure out what you have and what should be done, I will write it in a post later.  the fundamentals are that overcurrent devices go on the positive, the fuses are sized based on what the panel says the max series fuse rating is (or 1.56 x ISC) and the charge controller disconnect for 25a charge controller will be either 20 or 30a depending on what kind it is.

james- Alt-E staff

okay, for the solar.

parallel is + to + and - to -.  Putting things in parallel is current additive.  that is current increases, voltage remains constant, power increases.

Series is + to -.  Putting things in series is volttage additive.  Voltage increases, current reamains the same, power increases.

The way you orient the panels in series/parallel configuration depends on your system voltage and the type of charge controller you select.

 The way you go about sizing the system you need is based on the watt-hours you require. the only way you know what size array is sufficient for you is to do the calculations of what you need and then size the pv for about 125% of that to take into account inefficeincies.  You will be different since you will have wind contributing as well.  lastly the panels you have selected are known to be scarce and may not be available.  Isofoton makes good modules but you would be more likely to get your hands on the 150 24v variety here in the states.

the post berfore me is right, get your hands on home power magazine.  the solar cds are very helpful.  Also check out the books on the website, especially "photovoltaics design and install manual" it is very good and I keep a copy handy here at work.  please feel free to contact me with any questions.

-james -- Alt-E staff

Hi debra,

I used to live in new mexico, so I have some sources for you to go to.  Contact the nmsea (new mexico solar energy assoc) and see what info they have for you.  Every year in late summer/early fall they host the solar fiesta in ABQ and there are many booths filled with retailers, installers, manufacturerers, my alma mater San Juan College, and a few banks and credit unions that can help you with your financing question.  Try asking the folks at homepower or mother earth news magazines if they have heard of any new financing options as well.  Realize that the better you can have things documented, the better your chances are.  Get a reputable installer involved along with local electrical inspector (before trying to get financing) and your chances may get better.

take care and good luck,

james - Alt-E staff

Regarding the land and the wind:

You need to find your average annual windspeed.  This can be done a few ways.  Consult charts we have on our website or other simiar resources such as southwest windpower, national renewable energy laboratories (nrel) etc.  You said you had wind between 9 and 24 miles per hour.  that is like saying I drive between 5 and 300 mph on the freeway!  the gap of available energy in that span is gigantic.  You can also try to get in touch with local weather stations, airports, or universities, to find wind data. 

The voltage of your system may also determine your turbine choice.  that being said, the height of your tower needs to be 30 ft above the tallest object within 100 yards in most cases.  If this pushes your turbine farther from the house, this may require you to reconsider system voltage to avoid a  long low voltage wire run, which would be very costly.  Turbine selection will also depend on good load data or estimates.  The whisper 200 you mentioned will provide roughly 200kwh at 12mph average windspeeds.  Other turbines do not use such nomenclature, so finding average monthly production requires further digging, but you can usually find it on spec pages or pdf documents on our site.

- james -- Alt-E staff

Okay, you wrote a lot, so I will try to answer in stages with input for you.  First, that is good that you have past bills to work on to anticipate your loads, but always estimate high.  The average caller we find is usuall between 800kwh and 1500 kwh per month!  If you have not had a geothermal system before, you must consider the effects of the usually large pump on your electrical usage.  this surprises many people.  in some cases, it may be beneficial to live in the place for a year to get good data before investing in RE.  In other cases if the whole place is going to be under construction, it makes sense to do all of the installs at once.  Just things to consider. 

- james

yes, you can connect it to the load partition of your charge controller.  If your charge controller has a low voltage disconnect (like a morningstar sunsaver 6L) then you want to use the charge controller so that your load (in this case the lights) do not discharge your batteries to the point of doing harm to them (the batteries).  If your charge controller has no low voltage disconnect feature (morningstar sunsaver 6) then it really does not matter whether you use the charge controller or battery posts.  In a code compliant system, by hooking the loads up to the charge controller, you should have a disconnecting means via the circuit breakers between the charge controller and the batteries and PV panel.  This ensures that you have a way to shut off the current to the lights if you should need to service them, without having to touch live dc wiring.

- Alt-E staff  -- james