Car Park System Design

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Permalink Reply by Martin Herzfeld on March 14, 2011 at 7:04pm

If you are specifically looking for off-grid you may consider http://www.solarone.net/ or another product.

 

By the way, if you are looking for ground-mounted, on-grid open structures, suggest you consider a new solar application for agricultural greenhouse and shade structures - Solyndra:

 

http://www.solyndra.com/2011/02/solyndra-cylindrical-modules-offer-...

 

 

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Permalink Reply by John Fensie on April 3, 2011 at 12:08am

I would imagine you would start with the demand of the bulb multiplied the hours of operation per night.  Making sure your batteries can handle the demand without draining the batteries past 30% was it?  I though of doing a little unite that would do the 12v lighting.  20 lights is usually enough to light a driveway and to create landing strip feel at night.  Just enough so that your house is only properly lit in case of black out. check out vista sometime you can make lighting more dramatic with alternative placements.  Good Luck

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Permalink Reply by Martin Herzfeld on April 3, 2011 at 1:41pm

"Making sure your batteries can handle the demand without draining the batteries past 30% was it?"

 

Correct or ~less.  The depth of discharge (DOD) also impacts the longevity of the battery.  Simply, since the DOD in is different in the summer months and should factor worse case in the winter months. Temperature is also a factor, since some types of batteries are more resistance to cold temperatures. 

 

"Just enough so that your house is only properly lit in case of black out" !  John, a wonderful application to propose to customers for low voltage landscape lighting.  

 

"The lighting in question is 100W."   There are various ways to size a battery system.  One simple way is determine you daily energy requirement, number of sun hours,   ... 

 

1. 100W for 10 hours would be 1000 watt hours - ~1kWh

2. If insolation at ~5 hours at let's say 65% "system efficiency" - 1kWh/65% = ~1.5kWh

3. 1500 Wh/5 hours = ~300 watt array.

 

But what about DOD?  This is at ~100% and the insolation in the winter is different that the insulation of the summer and consider worse case.  Including days of autonomy, ...  and other things based on the requirement.  But what about the 30%? 

 

4.  1kWh x ~if 3 days / 30% DOD = 10 kWh requirement from batteries. 

5.  1kWh x ~if 3 days / 20% DOD = 15 kWh requirement from batteries.

 

6.  If 10kWh / 12V = ~833 Ah

7.  If 10kWh / 24V = ~416 Ah

8.  if 10kWh / 48V = ~208 Ah

 

I left out many factors with assumptions for simplicity such as inverter efficiency, ... and other things and for discussion only.  The array size calculation changes based on scaling for the charge controller.  Remember, batteries charge at a higher voltage with a charging current based on battery type,  

 

In addition to performance requirements for your 'design,' there are also practical safeguarding requirements of an accessible or readily accessible public structure.  As a result, I suggest a "packaged system" for off grid.

 

What do you think? 

 

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Permalink Reply by Peter Walsh on May 6, 2011 at 7:56am

Hi Huhg,

 

 

     My name is Pete Walsh and I work with a few people in the LED lighting and we have solar panel powered lighting systems. If you are interested in hearing more leave a message here or send an email to : pete@ecoappsolar.com

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Permalink Reply by Peter Walsh on May 12, 2011 at 9:28am

Hi Hugh,

 

 

     I actually work with a company that does large scale LED solar lighting if interested contact me at 508-360-5351

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