Building a new home in Ariel, WA - need spec recommendations

1 Posts
May 11, 2004 03:48 pm
Building a new home in Ariel, WA - need spec recommendations

I am building a home in Ariel WA where we have sun January through October. I need help designing the system. The home is 3600 square feet and I will be purchasing a 20k generator for periods when the sun is unavailable and to power wood working shop tools. I will power everything I can on propane.

We will be purchasing Sunfrost 16cf DC refrigerator and freezer. I will run the washer/dryer off generator as needed.

The recommendation we received is:
                                                2 @ Outback VFX 3648 Inverters in a Power panel prebuilt with MX 60 controller                

16 @ L-16 style Batteries, Cables, Class T fuses& holders power vent

PV Modules Monocrystalline Style 24vdc

The power estimated for average wattage per day is 4200.

Can someone recommend a supplier and evaluate if this system will supply the necessary wattage? We are unsure of the number of modules needed to supply the wattage required.

Any help would be appreciated.

Thx, Don

May 20, 2004 04:58 am
Hours of equivalent full rated charge.

I see from the inverter designation that we have a 48 volt nominal system. The L-16's have, I assume, 350 amp hrs. @ the 20 hr. rate. Sixteen such batteries wired for 48 volts would give a total of 700 amp hrs. of capacity. Speaking for myself, I like to size a battery bank so that no more than the top 20% of a fully charge battery is use in a 24 hour period, then size the PV array so that it can replace that 20% the very next day provided of course; its a pretty day, the PV modules are in full sunlight from 8:00am to 4:00pm, and perpendicular to the sun at noon time. But thats just me. So, 20% of 700 = 140 divided by 3 hours of equivalent full rated charge (winter time) brings us to 47 amps of PV array at 48 volts nominal. That 3 hours of equivalent full rated charge may vary for your neck of the woods. The Sharp 185W NT-S5E1U has the higher "working voltage" that I like, but it also has the higher price tag. 18 of these would run $14,778 at Alt-E store, where as 20 - Matrix M-PW1650's would run for $12,690. The thing to look at here is the MX60 charge controller and its capabilities. I could be wrong but it seems like I read that the maximum short circuit amperage from the array to the MX60 is 48. I'll have to check on this and back too you.
May 23, 2004 06:34 am
Outback's MX60 cc

 If you go to Outback's web site and pull up the manual for their MX60 with serial numbers 2,000 and up, then scroll down to page 5, at the top of the page you will read (in terms of NEC compliance) that the maximum short circuit amperage from a PV array is (* not more than) 48 amps. The output amperage can be as high as 70 amps. Another one of the great things about the MX60 is the fact that one can vary input voltage from the output voltage and maintain high efficiencies in the transition. There is no longer the need to wire a PV array for same nominal voltage as the battery.

400 watt MH or HPS lights have a similar device. In these lights is a multi tap ballast or transformer. One can feed the light with any one of 120, 208, 240, 277, and recently 480 vac. effectively reducing the amperage with higher voltages, which means more lights on a single circuit, while maintaining 400 watt lamps. But of course direct current would not work through a alternating current transformer. In a manner of speaking, this is basically what the MX 60 can do. Only in the case of the MX 60 the input voltage is higher than the output voltage, raising the output amperages while maintaining the wattage of the PV array to within certain efficiencies. Ohm's law.
I bet Edison would have loved to of had this technology to rub in Tesla's face.

* - "not more than" - a term of NEC compliance.

May 23, 2004 07:21 am
Re: Building a new home in Ariel, WA - need spec recommendations

>The power estimated for average wattage per
>day is 4200.  
>if this system will supply the
>necessary wattage?  

Hours of equivalent full rated charge.
You will need to know this for your area.
Go to and look accross the top of their home page you see "Education" scroll down to "Solar" then choose the "The Atlas for The Solar Radiation Data Manual for Flat-plate and Concentrating Collectors" fill out the appropriate answers. All you need to know are the number of hours. Work mostly with the winter months since this is typically when more power is used and less is made from a PV array. If the data shows 2 to 3 hours, go with the lesser number. If 2 then simply divide 4200 by 2 for 2100 then divide by 48 volts nominal for 43.75 amps of PV array. Or you can use wattage. 2100 watts divided by a PV modules rated out put. 2100/100=21. This could work with the MX60 controller. 3 wired in series and then 7 sets of 3 in parrallel or any variation of this. Keep in mind though the maximum short circuit amperage and maximum open circuit voltage of the MX60.
It's all in the math using Ohm's law.


Disclaimer and Disclosure

The Alternative Energy Store, Inc reserves the right, within its sole discretion, to refuse or delete any posting or portion thereof, or terminate or block the access to this forum.

The opinions and statements posted on this forum are the opinions and statements of the person posting same, and do not constitute the opinion or act of the Alternative Energy Store, Inc (AltE). The Alternative Energy Store, Inc does not endorse or subscribe to any particular posting. No posting shall be construed as the act or opinion of the Alternative Energy Store, Inc.

Click here for BBB Business Review

McAfee SECURE sites help keep you safe from identity theft, credit card fraud, spyware, spam, viruses and online scams
Desktop Website | Mobile Website


Click on an icon to share! If you don't see the method you want, hover over the orange "+".


What can we do to help you?

Please enter a summary
Sorry, the copyright must be in the template.
Please notify this forum's administrator that this site is using an ILLEGAL copy of SMF!
Copyright removed!!