Recent Posts

Posted by Robert Sorensen on Nov 10, 2015 10:10 pm

#11 -  Renewable Energy > Technical Discussion: Solar Electric System - Photovoltaic > Mounting panels to the roof
I have purchased an IronRidge solar panel mounting system to mount 33 280 watt panels to a metal roof. The plan is to use Iron Ridge slotted L foot to go between the rails and the roof and use  lag screws to fasten the L foot to the roof. With all of this in mind I have three questions:

1. What is the optimal spacing between the panel and the roof. Currently with the height of the L-Foot and the height of the rail the bottom of the panel frame will be approximately 4 inches off of the surface.

2. How long and what size should the Lag screws be? They will be driven into 2" X 6" purlins.

3. Should I use stainless steel lag screws?

Thanks in advance for any feedback you can give.

Bob
 

Posted by Amy Beaudet on Nov 6, 2015 04:04 pm

#12 -  Renewable Energy > Technical Discussion: Solar Electric System - Photovoltaic > Re: catamaran pv array
What an interesting question. While there is not one "right" answer, my instinct is to have 2 parallel strings of 24V, with a breaker for each string. When you have to fold up one string, open the breaker to take it completely out of the system, preventing any potential unwanted interaction between the 2 strings.

However, I know space is always at a premium, so I'm thinking the idea of wiring them all in series may actually work. Even with 2 blocked out, you'd still be at nominal 24V and enough to charge the battery.

I'm interested to see if anyone else has thoughts on this.
Amy
altE Store
 

Posted by Stephen Broos on Nov 6, 2015 12:24 am

#13 -  Renewable Energy > Technical Discussion: Solar Electric System - Photovoltaic > catamaran pv array
I am installing a pv array on a 21 ft Wharram catamaran. Its function is to charge batteries to power an electric outboard motor.
System consists of:
    4 pv panels of 90 watts @ 12vdc (total 360 watts)
    4 golf cart batteries (6volts) wired in series for 24vdc
    Midnight solar "Kid" mppt charge controller
     2000 watt electric outboard motor @ 24vdc
 The panels are mounted so that at times I will fold one on top of another so that only 2 panels are charging. This will only be occasionally, most of the time all 4 panels will be in full sun.
  My question is which would be better, to wire the panels in series for nominal 48vdc or series/parallel with 2 strings @ 24vdc? If the array is in series and 2 panels are covered, does that stop the charging or does it carry on at 24vdc?
 

Posted by Andy Rose on Nov 5, 2015 12:06 pm

#14 -  Renewable Energy > RE General Discussion > Re: hebco wind generator newbie quetion
I also have a Hebco, mostly complete. Dennis...would like to communicate directly? andy59rose @ gmail.com.

 

Posted by Josh Roberts on Nov 2, 2015 08:09 am

#15 -  Renewable Energy > For Sale > Re: for sale used Reynolds solar hot water system
Oh forgot to mention. I'm near Richmond VA. Where are you located ?
 

Posted by Josh Roberts on Nov 2, 2015 08:08 am

#16 -  Renewable Energy > For Sale > Re: for sale used Reynolds solar hot water system
I am interested in the system. I have this system already but would like to have spare parts. Still new here don't know how send private message yet.
 

Posted by Brent Stewart on Oct 27, 2015 08:39 am

#17 -  Renewable Energy > For Sale > Re: Jacobs 1.8kW 32Vdc Wind Generator and Tower For Sale
Is this unit still available and do you know the year and model ?
Or have pictures ?
 

Posted by Timothy Dennis on Oct 23, 2015 11:43 pm

#18 -  Renewable Energy > RE General Discussion > Re: Sun tracking solar hot water system by Solar Resource International
Hello I just bought a sol-R-Beam system. Do you still have parts left from the unit you parted out in 2012? Thanks
 

Posted by Amy Beaudet on Oct 20, 2015 09:31 am

#19 -  Renewable Energy > Technical Discussion: Solar Electric System - Photovoltaic > Re: Extremely Long Run Solar Calculation
The cool thing about MPPT charge controllers is that the input is low current, high voltage, but the output is high current, low voltage.
Watts = volts x amps.

So, if you have two nominal 24V 100W panels in series, that's 36Vmp x 2 = 72Vmp. One string is 2.78A Imp. 72V x 2.78A = 200 watts.

The MPPT charge controller takes that and reduces the voltage to about 14V to charge the 12V battery bank.  200W / 14V = 14.2A output into the battery bank.

You have two 12V 130Ah batteries in parallel (is that true, or are they 6V batteries?).  That's 260Ah at 12V. 260Ah / 14.2A = C/18 charge rate. That's a little slow, those batteries would be happier with under a C/10 charge rate, so if possible, 400W would be better.  However, you are currently charging the batteries with 130W, and you say it's working great. So while it is not ideal, it seems you have low enough loads that you are not using that much power. So jumping up to 200W is better than what you are currently doing.
 

Posted by Jeff King on Oct 19, 2015 06:50 pm

#20 -  Renewable Energy > Technical Discussion: Solar Electric System - Photovoltaic > Re: Extremely Long Run Solar Calculation
Thanks SO much!

3A will be enough to charge both those batteries?

I assume to get more amps (closer to 5) I just add more panels to keep upping the volts (too a point the wire can support, of course).
 

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

Share

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

Feedback

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!!