most efficient way to light, given a 48vdc pv system? - Page 3

 

He doesn't have anything 48v now. Only a new energy storage system that
isn't compatible. I assume you read his post.

He has 12v wiring now and 12v circuits in his walls and ceilings. This can
be a whole different code class of wiring. How do you propose to get all
these bulbs in series without stringing wires across his living room?

 



He also said "I'm deep in Baja "  I doubt that code standards are even
enforced, and IIRC anything under 50 vts is treated the same anyway.


The easest way is to cluster four lamps in a group - IE: chandelier.
Modifying a dedicated circuit is probably the next choice.

You are correct that the current draw should be similar.

 

Geeezzzz I thought that was like "Deep in Dooo-doo"

 

I really want to thank all you folks for your assistance. I've been
travelling and haven't been able to get to a machine for a bit.

Eric- I was just throwing out a number when I said 50% of the load was
lighting. The fridge will be an occasion load unless I put a timer on
it to prohibit night operations, maybe a coffee maker, blender etc.
might make up the rest of the load.  I still haven't heard anything
about the efficiency of a 48-12vdc converter.

Anthony - I had thought of a seperate 12v system but assumed a
converter would be simpler/less expensive than a new pv panel, charge
controller, and battery.

George - I'm also interested in efficiencies at the low end of inverter
loading.

Harry - Great idea about series lighting, but as has been noted: the
construction is concrete with embedded wiring, It might be too
difficult to configure every circuit. The house is approx 2000 sq. ft.

So far it doesn't sound like there is a consensus about whether to
convert voltage, convert from 12v lighting, run 48vdc lighting, or
install a seperate 12v system.

Thanks again,
Per

 


I've just bought a couple of
http://golfcarcatalog.com/catalog/index.cfm?fuseaction=product&id '88
for my golf carts, pretty pricey at nearly $200 each, but less than
the "buck a watt" rule of thumb for low-volume power converters I
usually use.

The data sheet for it claims 20-60V input and {80% minimum, 85%
average, 92% maximum) efficiency from 1-25A output.  My primary
criteria was weatherproof, and this one seems to do that.  It claims
100-200mA quiescent current drain, which seems like a lot, but I'll
have to measure it to be sure it's really that high.

I haven't installed them yet (one cart's 48->12V converter has a
fault, and draws significant 48V current all the time, the other one
has a 16->12V converter, which offends my sensibilities), but am
planning on it in the next couple of weeks.