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Repost please: $1/watt solar panals.

V

vaughn

Jan 1, 1970
0
For a laptop, printer and a couple of 15 watt compact florescent lights?
Hardly a huge expense, with 1000watt inverters $100.00 on ebay, a couple
of Sams' club deep cycle batteries ?

Actually for system you don't really need inverters at all. I use
12-volt compact florescent lamps, and 12 volt adapters are available for
laptops. I use the lamps out in my yard, and my in-home 12-volt wiring
system is slowly growing.

Vaughn
 
P

Paul Keinanen

Jan 1, 1970
0
Actually for system you don't really need inverters at all. I use
12-volt compact florescent lamps,

Which definitely contains an inverter, thus, adding cost.
and 12 volt adapters are available for
laptops.

Which possibly also contains an inverter to convert 12 V to 17 V.
I use the lamps out in my yard, and my in-home 12-volt wiring
system is slowly growing.

This is a good strategy if the 12 V system total cost is less than the
cost of more common 120 V (US) or 230 V (Europe) systems added with
the inverter cost.

Paul
 
V

vaughn

Jan 1, 1970
0
Paul Keinanen said:
Which definitely contains an inverter, thus, adding cost.

Actually, the 120 or 240 versions also contain electronics, which also
adds cost. That said, the 12-volt bulbs do cost more, mainly because they
are a specialty item.
Which possibly also contains an inverter to convert 12 V to 17 V.

Perhaps, but it would be an inverter sized for the specific job and would
only be on and taking power when plugged in, (which in the case of a laptop
could be rarely)
This is a good strategy if the 12 V system total cost is less than the
cost of more common 120 V (US) or 230 V (Europe) systems added with
the inverter cost.

I do it mostly to avoid the 24/7 drain of a central inverter. (Yes, I know
that some inverters have power sensing, but they have their own issues.)
With or without the inverter, I would still want a separate, protected power
system, so that cost falls out of the equation. The outdoor lighting part
of my wiring system is inexpensive because it uses common low-voltage Malibu
lighting cable that is made just for that purpose. Inside my home I wire to
code, so the expense is comparable either way. That leaves me with the
option of converting any circuit to mains power in the future..

Vaughn

Vaughn
 
M

Martin Brown

Jan 1, 1970
0
Paul said:
Which definitely contains an inverter, thus, adding cost.

Although they are cheaply mass produced as emergency standby lights.
And pure solid state LED based units are still more expensive.
This is a good strategy if the 12 V system total cost is less than the
cost of more common 120 V (US) or 230 V (Europe) systems added with
the inverter cost.

Although you really need to pay attention to the current flowing in a
low voltage DC wiring system. It takes a lot more of a percentage when
you drop half a volt off 12v than the same drop on 120 or 240v.

And to deliver the same power into the load takes 10x or 20x the current
on a 12v service. Useful if you are off grid but not so good in winter
at my latitude. Not enough winter sun to keep things topped up.

Wind power is a bit better in that respect if you have the space.

Regards,
Martin Brown
 
Ten years from batteries? Not if you actually used them and didn't just
keep them on float.

I have heard this story over and over from manufacturers but I have not
heard of anybody, actually using their batteries and discharging them each
night to a resonable level, that gets more than a few years of dependable
usage out of them.

My batteries are 14 years old and still going strong. There's a pretty
good chance they'll make 20, which is their nominal lifetime rating.
They're the bare minimum size in the context of my consumption -
generally between 12 and 15kWh per day. Only a fraction of that makes
a trip through the batteries, which is as it should be for any
well-managed setup.

Wayne
 
D

Dirk Bruere at NeoPax

Jan 1, 1970
0
vaughn said:
Actually for system you don't really need inverters at all. I use
12-volt compact florescent lamps, and 12 volt adapters are available for
laptops. I use the lamps out in my yard, and my in-home 12-volt wiring
system is slowly growing.

Does a low voltage DC house supply make sense?
It's looking like it for lighting.

--
Dirk

http://www.transcendence.me.uk/ - Transcendence UK
http://www.theconsensus.org/ - A UK political party
http://www.blogtalkradio.com/onetribe - Occult Talk Show
 
V

vaughn

Jan 1, 1970
0
Dirk Bruere at NeoPax said:
Does a low voltage DC house supply make sense?
It's looking like it for lighting.

My system is mostly for lighting, with possibly a laptop and a portable
TV thrown in during power failures. The "40-watt-equiv" 12 volt CFL's that
I use draw 1 amp each. So far, the most I have on one circuit is 2 of them.
For minimum voltage drop, I wire my interior circuits with #10 THHN wire.

Vaughn
 
D

Dirk Bruere at NeoPax

Jan 1, 1970
0
vaughn said:
My system is mostly for lighting, with possibly a laptop and a portable
TV thrown in during power failures. The "40-watt-equiv" 12 volt CFL's that
I use draw 1 amp each. So far, the most I have on one circuit is 2 of them.
For minimum voltage drop, I wire my interior circuits with #10 THHN wire.

How would one go about powering a laptop from a 12VDC supply? DC-DC
converter? The only things I would likely power from PV would be lights,
computers (laptops) and a fridge.

--
Dirk

http://www.transcendence.me.uk/ - Transcendence UK
http://www.theconsensus.org/ - A UK political party
http://www.blogtalkradio.com/onetribe - Occult Talk Show
 
V

vaughn

Jan 1, 1970
0
Dirk Bruere at NeoPax said:
How would one go about powering a laptop from a 12VDC supply? DC-DC
converter?

Google the term "laptop auto adapter" for zillions of returns like this:
http://www.powerstream.com/ADC.htm
The only things I would likely power from PV would be lights, computers
(laptops) and a fridge.

My 'fridge does not like my square wave inverter (some do, some don't).
Also remember that your defrost heaters can take well over 1,000 watts. My
present disaster plan is to run my refrigerator only when my generator is
running.

Vaughn
 
S

stu

Jan 1, 1970
0
DU in a *bomb* would be pretty pointless, if you stop to think about it.
From Wikipedia: "Depleted uranium is used as a tamper in fission bombs
and as a nuclear explosive in hydrogen bombs. It is a potential
containment material for a Nuclear shaped charge due to its opacity to X-
Rays." (http://en.wikipedia.org/wiki/Depleted_uranium)

Depleted Uranium _is_ used in some ordnance rounds (most famously tank
rounds), and if the person in question is "relaxed" with her usage of
military terminology, that may be what she was referring to.

--
Encrypted email encouraged and PREFERRED
Thursday, October 29, 2009 @ 1454
** Friends help you move. Real friends help you move bodies. **
----------------------------------------------------------------

I just checked her book. [In my edition, it is pages 51-52.] No
mention of DU use in a bomb. Just the fact that it is used in ordnance
and stockpiles are leaking. I invite the original poster to cite a
reference or retract the statement.

maybe I could cite a reference of a private email as Helen does, would that
make it a fact?
"Facts from unnamed dead people" page 4 note 2 Nuclear power is not the
answer.
"DU in bombs" page 156 (about) note 25. The new nuclear danger.
"Contrary to accepted norms of etc." page 146 The new nulcear danger
 
D

daestrom

Jan 1, 1970
0
Josepi said:
Ten years from batteries? Not if you actually used them and didn't just
keep them on float.

I have heard this story over and over from manufacturers but I have not
heard of anybody, actually using their batteries and discharging them each
night to a resonable level, that gets more than a few years of dependable
usage out of them.

The solar savings would never pay for the batteries, compared to bulk
manufactured energy

Well, these aren't exactly 'cheap', but are guaranteed for 3300 cycles.

If you discharge/charge about 1/2 a cycle per day and immediately
recharged it, that 'should' last 6600 days that would be 18 years.

Problem is, solar applications are more like discharge 30%, wait 8
hours, charge 20%, discharge another 30%, wait 8 hours charge 25%, etc...

That kind of 'cycle' is pretty hard on any battery.

http://www.affordable-solar.com/surrette.battery.2v.1700.ah.2-ks-33ps.htm

daestrom
 
Well, these aren't exactly 'cheap', but are guaranteed for 3300 cycles.
http://www.affordable-solar.com/surrette.battery.2v.1700.ah.2-ks-33ps.htm

If you discharge/charge about 1/2 a cycle per day and immediately
recharged it, that 'should' last 6600 days that would be 18 years.

Problem is, solar applications are more like discharge 30%, wait 8
hours, charge 20%, discharge another 30%, wait 8 hours charge 25%, etc...

That scenario should only be happening during multiple-day dark
periods. For typical installations, the rest of the time the routine
discharge should be less. To make the math easy, figure 4 days supply
and 20% reserve. Which makes a sunny day's dark-period discharge
perhaps half of a day's consumption - 10%, then back to full by early
afternoon. It depends on the owner's habits though. If they tend to
leave early for work and arrive home late, and had no daytime loads,
then most or perhaps all the consumption might make a trip through the
batteries. Then I could see how it could come close to your scenario,
in winter at least.
That kind of 'cycle' is pretty hard on any battery.

I think that's what's worse are setups where the batteries get
deep-discharged, and then on the first sunny day it's charge back to
50%, discharge back to 30, charge to 60, back to 40 etc. I've seen
that scenario a lot, and when you combine it with (most) owners who
don't have a convenient way to gauge battery charge level, it's easy
to see how some installations have short-lived batteries. I really
lean on people to get and use battery meters. Then they can see right
away if their full-charges are too infrequent.

Wayne
 
V

vaughn

Jan 1, 1970
0
Josepi said:
Read the manufacturers warranties. 3-5 years on most batteries if you
never discharge them below 50% and treat them perfectly.

Your point? My car was warrantied for 40,000 miles or 3 years. It has
already lasted longer than that. Given proper care, I expect it to soldier
on for several more years and may more tens of thousands of miles.

Vaughn
 
Your point? My car was warrantied for 40,000 miles or 3 years. It has
already lasted longer than that. Given proper care, I expect it to soldier
on for several more years and may more tens of thousands of miles.

Vaughn

You're wasting your time. "josepi" is gymmy-bob the top-posting
crackpot's latest nym. Remember solar flare, john p benji, etc? Same
nitwit.

Wayne
 
K

krw

Jan 1, 1970
0
Your point? My car was warrantied for 40,000 miles or 3 years. It has
already lasted longer than that. Given proper care, I expect it to soldier
on for several more years and may more tens of thousands of miles.

To put a finer point on it, my truck battery lasted eight years even
though the warranty on it (new vehicle battery warranty) was only one
year. "Josepi" is talking through his ass; both sides of it.
 
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