• Post Reply Bookmark Topic Watch Topic
  • New Topic
permaculture forums growies critters building homesteading energy monies kitchen purity ungarbage community wilderness fiber arts art permaculture artisans regional education skip experiences global resources cider press projects digital market permies.com pie forums private forums all forums
this forum made possible by our volunteer staff, including ...
master stewards:
  • Anne Miller
  • jordan barton
  • Pearl Sutton
  • Leigh Tate
  • paul wheaton
stewards:
  • r ranson
  • Nicole Alderman
  • Greg Martin
master gardeners:
  • Carla Burke
  • John F Dean
  • Jay Angler
gardeners:
  • Nancy Reading
  • Mike Barkley
  • Christopher Shepherd

PV start voltage

 
Kevin York
Posts: 2
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Hi all you solar experts. I was looking at a 5 kw solar power center that requires 90 volts from the panels to "start".  I have never heard of this anywhere except for this one product.
Has anyone else heard of this?  Here is the product in question

http://www.electriccarpartscompany.com/5000W-Residential-Boat-Light-Commercial-Battery-Storage-Systems

Thanks

Kevin
 
Rob Rock
Posts: 2
1
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Kevin,

Not at all uncommon.   The furnished MPPT controllers (two ?) require that you maintain a PV input voltage much greater than the nominal system voltage (evidently 48 vdc). As an example, to develop 5kW output from a solar array using 250 watt 24v panels, you might be asked to configure your panels in two separate circuits (two MPPT controllers @ 2.5 kW ea.)  .   Maybe each circuit will contain about 12 panels in a series/parallel arrangement which does not exceed the 150vdc maximum input voltage limitation but does (must) operate at greater than 90vdc.

Until you have sufficient panel illumination to furnish 90vdc to the MPPT controller(s), you will not have power delivered to your storage. The beauty of the MPPT controller is that the higher voltage input from your panels is converted to very useful levels of current and voltage in order to maintain the batteries.

RobRock
 
Mike Barkley
gardener & hugelmaster
Posts: 2841
Location: Gulf of Mexico cajun zone 8
1228
cattle hugelkultur cat dog trees hunting chicken bee woodworking homestead ungarbage
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
The basic idea is it's a waste to drive a Ferrari to the corner store. Looks like a nice system.
 
Kevin York
Posts: 2
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Thanks Rob.  That clears things up.  Data sheets I have read on other mppt systems never list this requirement, so that is why I said I never heard of it before.
 
I agree. Here's the link: http://richsoil.com/cards
reply
    Bookmark Topic Watch Topic
  • New Topic