Small System Suggestions?

Jerry Allen
3 Posts
Oct 7, 2008 01:38 pm
Small System Suggestions?

I have a system that draws 5 WH per hour 24x7. I have wind power at the site but it has changed drasticly in the last year. New batteries, new generator. The Wind has days where it does not blow enough to charge the batteries some times 4 and 5 days straight. Once the batteries reach a critical level there is no recovery. I want to supplent the site with solar.

I forgot to add I have 2 105 AH deep cyles batteries in series for a 24 volt system. I have visted this site for a couple of days full days, the wind system is not going to work here due to the lack of wind.

I am looking at;
1ea - Morningstar Sunsaver Ss-10L 10A, 24V Pwm

2ea - Global Solar 30W 12V Framed Solar Panel

Is this enough to keep this site alive or is it overkill?
« Last Edit: Oct 7, 2008 04:16 pm by Jerry Allen »
 
 
James Cormican
578 Posts
Oct 8, 2008 10:55 am
Re: Small System Suggestions?

do you mean a load that draws at 5W that is on 24hrs a day (120W-h/day)?

if so, a 60w array may be a little short in winter depending where you are.

60x .8= 48w  --- 48w x 2 sun hours = 96W-h/day {estimated} (deficit operation)

a 60w array certainly wont hurt, but is by no means overkill for a constant load.

james
altE staff
AltE
"Making Renewable Do-able"
http://www.altEstore.com/

Tel: 877.878.4060 x107  or +1.978.562.5858 x107
Fax: 877.242.6718  or +1.978.562.5854
 
 
Michael Riewer
27 Posts
Oct 8, 2008 11:10 am
Re: Small System Suggestions?

^^^Agreed, it is by no means overkill, and possibly not enough for those cloudy days either.  For $130 more over the global solars I would step up to the 85watt Kyocera panel and add a few more batteries for capacity.  100ah @ 24v just isn't enough capacity if you are going to have a constant load draining them with days of no wind or sun.
 
 
Jerry Allen
3 Posts
Oct 8, 2008 11:58 am
Re: Small System Suggestions?

Thanks for the replies.

5 watt hours per hour 24 hours a day is correct, total 120 watt hours per 24 hours.

I was using 4 sun hours, located in Eastern Wyoming. We very seldom have overcast days and no wind. Jumping to 100 watts total of panels is not a huge amount more. That is my intention so;

Adding 2 more 100AH batteries and the solar panels. 100 * .8 = 80 * 2 = 160 even if the sun only shines for 2 hours + counting the deficit and there is no wind. I should be 100% reliable?

Thanks again.

Jerry
 
 
James Cormican
578 Posts
Oct 8, 2008 12:12 pm
Re: Small System Suggestions?

well, with a variable resource, nothing is 100%.  but that takes in the critical design considerations necessary to enable the system to be more likely to succeed.

remember, batteries will have losses, voltage drop losses, inverter losses, etc . . .

but more power should be way closer to getting the job done

the closer you are to a 1:1 ratio between production and storage, the better.  the absolute minimum for array wattage is a 1:1 ratio between production and load (after derations).

james
altE staff

AltE
"Making Renewable Do-able"
http://www.altEstore.com/

Tel: 877.878.4060 x107  or +1.978.562.5858 x107
Fax: 877.242.6718  or +1.978.562.5854
 
 
Michael Riewer
27 Posts
Oct 8, 2008 12:19 pm
Re: Small System Suggestions?

The math works out, but the real world is always different.  Batteries don't store as much when they are cold, panels don't produce as much with bad weather, etc...  I would think adding some panels and 2 more batteries would get you close to 100% up.  Keeping things on a budget is tough and this incremental approach is probably best.  If you are still experiencing downtime after this, you have the extra capacity provided by the batteries onsite and would only need to increase your solar yield during the day with another panel to bridge the up and downtime gap.  

BTW, what is using 5watts of power 24/7?
 
 
Jerry Allen
3 Posts
Oct 8, 2008 02:54 pm
Re: Small System Suggestions?

This is a mountain top (only about 6000 ft) radio repeater. This site will be a hike or snow mobile to it site in about 60 days and I need it to be much more self reliant. I have been there every 21 days for a couple of months for dead batteries, doubled battery capacity and it is obvious that wind alone is not going to keep power to it.

Jerry 
 
 

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
Submit +
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!!