Alternative Power sources - Solar power questions

Author

Solar power questions

dh@.

2005-10-26, 2:21 pm

I'm interested in trying to use Solar power, but so far don't
know anything about it. I want to charge some deep
cycle batteries during the day, and use them to run a
heater for a few hours at night. Even if it takes two days
to charge the batteries I'd be better off just paying for
the heater every other day, than every day. Of course
I'm looking for the cheapest way to do it, since the idea
is to save money. Here

1. What is involved other than the solar panels, wire
and batteries?
2. What would keep the batteries from getting overcharged
and burning out?
3. Would the inverter (Coleman PMP 2000) alone be enough
to regulate when the batteries become dangerously low and
shut down discharge, or would I need to monitor it and do it
myself to avoid damage to the system.
4. How could I monitor the charge level of the batteries?
5. Do the panels only work when there's a certain amount
of light available, or does their performance fluctuate depending
on how much light they're getting at the time?
6. How to calculate what it would take to run a 1.5 KW heater
for a certain period of time, using whatever number of 115
amp hour batteris it would take to get a few hours of use from
the heater, and what type solar panels to use, etc?

I'm sorry to be so completely ignorant, and would appreciate
any help in overcoming it.

Steve Spence

2005-10-26, 3:21 pm

dh@. wrote:
> I'm interested in trying to use Solar power, but so far don't
> know anything about it. I want to charge some deep
> cycle batteries during the day, and use them to run a
> heater for a few hours at night. Even if it takes two days
> to charge the batteries I'd be better off just paying for
> the heater every other day, than every day. Of course
> I'm looking for the cheapest way to do it, since the idea
> is to save money. Here

Well, there are a whole nother bunch of solutions better for heating
than pv, like solar water heating.

>
> 1. What is involved other than the solar panels, wire
> and batteries?

charge controller, disconnects, fuses ....

> 2. What would keep the batteries from getting overcharged
> and burning out?

charge controller.

> 3. Would the inverter (Coleman PMP 2000) alone be enough
> to regulate when the batteries become dangerously low and
> shut down discharge, or would I need to monitor it and do it
> myself to avoid damage to the system.

most inverters have a low voltage shut-off, but they usually will draw
more than 50% from the batteries before doing so. best thing is a kWh
meter showing input and output.

> 4. How could I monitor the charge level of the batteries?

kWh meter.

> 5. Do the panels only work when there's a certain amount
> of light available, or does their performance fluctuate depending
> on how much light they're getting at the time?

fluctuates

> 6. How to calculate what it would take to run a 1.5 KW heater
> for a certain period of time, using whatever number of 115
> amp hour batteris it would take to get a few hours of use from
> the heater, and what type solar panels to use, etc?

1.5 kw x 2 hours = 3kWh's
115ah / 2 = 57ah usable x 12v = 684 wh each. 3 kWh / 684 wh = 5
batteries. Would need 1000 watts of pv and 3 full hrs of sun to recharge
in one day, or 500 watts for 2 days charge, 2 hours discharge. Some
locations get more or less sun.

>
> I'm sorry to be so completely ignorant, and would appreciate
> any help in overcoming it.

Some of us are happy to help. Others will insult you, or the answers we
give.

--
Steve Spence
Dir., Green Trust, http://www.green-trust.org
Contributing Editor, http://www.off-grid.net
http://www.rebelwolf.com/essn.html

LCT Paintball

2005-10-26, 3:21 pm

Dan Bloomquist

2005-10-26, 3:21 pm

Stuart Grey

2005-10-26, 5:21 pm

Derek Broughton

2005-10-26, 6:21 pm

dh@. wrote:

> I'm interested in trying to use Solar power, but so far don't
> know anything about it. I want to charge some deep
> cycle batteries during the day, and use them to run a
> heater for a few hours at night.

It's a rotten way to make heat. Better idea, use a liquid solar collector.
You use a tiny fraction of the sun's power to make electricity, then you
lose power storing it and more power converting it back to AC (which you
don't need for resistive heating, anyway).

> Even if it takes two days
> to charge the batteries I'd be better off just paying for
> the heater every other day, than every day. Of course
> I'm looking for the cheapest way to do it, since the idea
> is to save money.

You won't save money.

> 1. What is involved other than the solar panels, wire
> and batteries?

charge controller

> 2. What would keep the batteries from getting overcharged
> and burning out?

charge controller

> 3. Would the inverter (Coleman PMP 2000) alone be enough
> to regulate when the batteries become dangerously low and
> shut down discharge, or would I need to monitor it and do it
> myself to avoid damage to the system.

It should have a low voltage cutoff - most inverters do.

> 4. How could I monitor the charge level of the batteries?

voltmeter or hydrometer

> 5. Do the panels only work when there's a certain amount
> of light available, or does their performance fluctuate depending
> on how much light they're getting at the time?

fluctuates

> 6. How to calculate what it would take to run a 1.5 KW heater
> for a certain period of time, using whatever number of 115
> amp hour batteris it would take to get a few hours of use from
> the heater, and what type solar panels to use, etc?

There are solar calculators all over the web, but this isn't an appropriate
use of PV power, and I'd be surprised if they actually included
space-heating devices in their tables.
--
derek

Winston Smith

2005-10-26, 11:21 pm

On Wed, 26 Oct 2005 12:58:35 -0400, dh@. wrote:

>I'm interested in trying to use Solar power, but so far don't
>know anything about it. I want to charge some deep
>cycle batteries during the day, and use them to run a
>heater for a few hours at night. Even if it takes two days
>to charge the batteries I'd be better off just paying for
>the heater every other day, than every day. Of course
>I'm looking for the cheapest way to do it, since the idea
>is to save money. Here
>
>1. What is involved other than the solar panels, wire
>and batteries?

At least a charge controller. An inverter if you want 120 VAC. If
you are after efficiency from the panels, some sort of way to track
the sun or at least make seasonal changes.

A hygrometer to measure specific gravity of the battery acid (auto
store). Some way to protect batteries from too hot and freezing.
Some way to vent battery fumes - corrosive and maybe explosive if it
builds up too much.

>2. What would keep the batteries from getting overcharged
>and burning out?

A charge controller adjusts the charge current to a safe level and
tapers it off as the battery gets charged. They usually work
differently but think of it as like the voltage regulator in a car.
There are many flavors from rotten to pretty good.

>3. Would the inverter (Coleman PMP 2000) alone be enough
>to regulate when the batteries become dangerously low and
>shut down discharge, or would I need to monitor it and do it
>myself to avoid damage to the system.

An inverter has nothing to do with charging. It will shut itself down
(most models) if the voltage drops low enough to endanger it.

>4. How could I monitor the charge level of the batteries?

Specific gravity of the acid is best. An approximation can be made by
open circuit voltage after it has sat unconnected for a day.

>5. Do the panels only work when there's a certain amount
>of light available, or does their performance fluctuate depending
>on how much light they're getting at the time?

The panel will produce voltage but not much current in low light. You
only get any practical charging in full day light. Light=Watts.
Watts X time = power. It's common to figure on an effective 5 hour
day, less if you are in an odd place or it's cloudy.

>6. How to calculate what it would take to run a 1.5 KW heater
>for a certain period of time, using whatever number of 115
>amp hour batteris it would take to get a few hours of use from
>the heater, and what type solar panels to use, etc?

For that much power, burning some fuel is probably better.

1,500 W / 120 V = 12.5 Amps. If you are drawing it from a 12.6 Volt
battery, 1500 W / 12.6 V = 119 Amps. If you run it for 1 hour, that's
119 A X 1hr = 119 Amp-Hours. If you run it for 2 hours, that's 119 A
x 2 hr = 238 A hr. If you use an inverter to change the 12.6 VDC to
120 VAC figure on using about 10% more A-hr for inverter losses.

That inverter loss is given off as heat which might be captured. On
the other hand, it's better to locate the inverter at the battery
rather than at the load. The battery to inverter wires carry the
highest current so keep them the shortest.

>I'm sorry to be so completely ignorant, and would appreciate
>any help in overcoming it.

You've asked some very good basic questions, and in the right order
too.

--
WÂ§ mostly in m.s - http://members.1stconnect.com/anozira

Tim May

2005-10-27, 12:21 am

In article <1130373522.c5e28b9ecb12408cbfae3e379eed0b27@secureusenet>,
Winston Smith <bogus@buttterfly.net> wrote:

>
>
> The panel will produce voltage but not much current in low light.

The voltage is constant, above any minor amount of light.

> You
> only get any practical charging in full day light. Light=Watts.
> Watts X time = power.

No, watts x time = energy, not power.

> It's common to figure on an effective 5 hour
> day, less if you are in an odd place or it's cloudy.

There are good tables for different parts of the world. Latitude plays
a major role, not just hours of daylight. (Angle of the sun, etc.)
>
>
> For that much power, burning some fuel is probably better.

For that much energy, you mean. Not power.

>
> You've asked some very good basic questions, and in the right order
> too.

I disagree. Before I started posting to misc.survivalism, I used Deja
News to thoroughly research what had been written on water storage,
power generation, food shelf life, etc. The articles by people like
Patton Turner and Al Hagan, for example.

The OP here seems to have no clue whatsoever about why he wants solar,
what he wants, how much energy storage he needs, or what others have
written.

Helping him is thwarting Darwin. Way too much whiggerization going on
even here.

--Tim May

Jeff Schwartz

2005-10-27, 9:21 am

<dh@.> wrote in message news:s1cvl1p31d400qlc4hhukrpetlqrhcorgt@4ax.com...
> I'm interested in trying to use Solar power, but so far don't
> know anything about it. I want to charge some deep
> cycle batteries during the day, and use them to run a
> heater for a few hours at night. Even if it takes two days
> to charge the batteries I'd be better off just paying for
> the heater every other day, than every day. Of course
> I'm looking for the cheapest way to do it, since the idea
> is to save money. Here

Another poster said it, but I'll say it again: PV for heat is a bad use for
PV. Multiple efficency losses are gonna kill ya. You might be better off
with another way of doing this.

Another question : Where are you located? How far from the equator makes a
big influence on how much sun you get....

>
> 1. What is involved other than the solar panels, wire
> and batteries?

Charge controller is a biggy. It should included fuses inside it, but more
fuses never hurt. And disconnect switches.

> 2. What would keep the batteries from getting overcharged
> and burning out?

Aforementioned charge controller.

> 3. Would the inverter (Coleman PMP 2000) alone be enough
> to regulate when the batteries become dangerously low and
> shut down discharge, or would I need to monitor it and do it
> myself to avoid damage to the system.

If all you're using the thing for is heat, let me make a suggestion: skip
the inverter. There's a loss with each step you go through. Go with a 12V
DC heater : http://www.boatandrvaccessories.com/RPSL-681 or similar.

> 4. How could I monitor the charge level of the batteries?

Some charge controllers have a meter.

> 5. Do the panels only work when there's a certain amount
> of light available, or does their performance fluctuate depending
> on how much light they're getting at the time?

It varies by how much light is hitting them.
Some solar websites have a chart showing "effective hours of sunlight" by
state. Florida, for example, is 5 - even though we get more hours than that,
the "non peak" hours add up to an effective 5 peak hours of output.

> 6. How to calculate what it would take to run a 1.5 KW heater
> for a certain period of time, using whatever number of 115
> amp hour batteris it would take to get a few hours of use from
> the heater, and what type solar panels to use, etc?
>

There's an easy answer and a hard answer. The easy is 1500 W / 12v = 125 amp
draw. Divide total amp-hours by draw and you get how many hours the
batteries last.
That's incredibly optimisitic though, when you add in inverter losses, etc.
Working in all those losses makes it much harder. I'd go "rule of thumb" and
drop it by half or so, and say each 115 amp hour battery gives you 30
minutes.

> I'm sorry to be so completely ignorant, and would appreciate
> any help in overcoming it.

Ok, I'm going to go shopping for you. I'm just ballparking and doing this
quick, so don't take it as set in stone.

http://www.boatandrvaccessories.com/RPSL-681 : $26.88 (15 amp x 12v) plus
shipping

http://store.solar-electric.com/evso115wasop.html : get 2 for $1,030 plus
shipping

http://store.solar-electric.com/ps-30m.html : $186 plus shipping

http://store.solar-electric.com/pvx-12210.html $370 plus shipping (chosen
for 8-hour discharge rate being over 15ampsx8 hours, figure you use the
heater for 8 hours at night)

Misc fuses, cables, etc as needed.

Chose the 2 solar panels based on a 4-hour peak sunlight. Should give you 8
hours of heater per night. A small ceramic heater in a small cabin with good
insulation, you should be OK.

On the other hand, you're looking at like $1700 to set this baby up. I'm not
sure what your costs are for other heating sources to break even.

rebel

2005-10-27, 9:21 am

Hi
Depends on your climate, how much sun daily, but heating is best done with
solar collectors, which are like exterior radiators that collect the heat
from the air and sun rays, feeds the heat to a storage tank until needed.
Photo panels are good for charging batteries, which run small electrical
items, depends on size of system, but heating is out I should say.
////////////////////
"Winston Smith" <bogus@buttterfly.net> wrote in message
news:1130373522.c5e28b9ecb12408cbfae3e379eed0b27@secureusenet...
> On Wed, 26 Oct 2005 12:58:35 -0400, dh@. wrote:
>
>
> At least a charge controller. An inverter if you want 120 VAC. If
> you are after efficiency from the panels, some sort of way to track
> the sun or at least make seasonal changes.
>
> A hygrometer to measure specific gravity of the battery acid (auto
> store). Some way to protect batteries from too hot and freezing.
> Some way to vent battery fumes - corrosive and maybe explosive if it
> builds up too much.
>
>
> A charge controller adjusts the charge current to a safe level and
> tapers it off as the battery gets charged. They usually work
> differently but think of it as like the voltage regulator in a car.
> There are many flavors from rotten to pretty good.
>
>
> An inverter has nothing to do with charging. It will shut itself down
> (most models) if the voltage drops low enough to endanger it.
>
>
> Specific gravity of the acid is best. An approximation can be made by
> open circuit voltage after it has sat unconnected for a day.
>
>
> The panel will produce voltage but not much current in low light. You
> only get any practical charging in full day light. Light=Watts.
> Watts X time = power. It's common to figure on an effective 5 hour
> day, less if you are in an odd place or it's cloudy.
>
>
> For that much power, burning some fuel is probably better.
>
> 1,500 W / 120 V = 12.5 Amps. If you are drawing it from a 12.6 Volt
> battery, 1500 W / 12.6 V = 119 Amps. If you run it for 1 hour, that's
> 119 A X 1hr = 119 Amp-Hours. If you run it for 2 hours, that's 119 A
> x 2 hr = 238 A hr. If you use an inverter to change the 12.6 VDC to
> 120 VAC figure on using about 10% more A-hr for inverter losses.
>
> That inverter loss is given off as heat which might be captured. On
> the other hand, it's better to locate the inverter at the battery
> rather than at the load. The battery to inverter wires carry the
> highest current so keep them the shortest.
>
>
> You've asked some very good basic questions, and in the right order
> too.
>
> --
> WÂ§ mostly in m.s - http://members.1stconnect.com/anozira

BobG

2005-10-27, 10:21 am

d:
I want to charge some deep
cycle batteries during the day, and use them to run a
heater for a few hours at night.
===============================
How about buy a 100ft roll of pex tubing, bury it about 2 ft down, get
a little pump and a little fan, and a little auto heater core. If its
50 deg F in the house, blowing that cold air across the 72 deg F coils
from that nice warm gound water should warm things up a little.

Steve Spence

2005-10-27, 10:21 am

BobG wrote:
> d:
> I want to charge some deep
> cycle batteries during the day, and use them to run a
> heater for a few hours at night.
> ===============================
> How about buy a 100ft roll of pex tubing, bury it about 2 ft down, get
> a little pump and a little fan, and a little auto heater core. If its
> 50 deg F in the house, blowing that cold air across the 72 deg F coils
> from that nice warm gound water should warm things up a little.
>

What kind of climate has 72F ground temperature 2' down and 50F ambient
air temp?

--
Steve Spence
Dir., Green Trust, http://www.green-trust.org
Contributing Editor, http://www.off-grid.net
http://www.rebelwolf.com/essn.html

nicksanspam@ece.villanova.edu

2005-10-27, 11:21 am

rebel <rebel@prosof.net> wrote:

>... heating is best done with solar collectors, which are like exterior
>radiators that collect the heat from the air and sun rays, feeds the heat
>to a storage tank until needed.

IMO, a polycarbonate "solar siding" air heater or deeper low-thermal-mass
sunspace is better, with warm air circulating between the sunspace and the
living space during the day and stopping at night. That can be 20X cheaper
than "collectors" and 100X cheaper than solar electricity per peak watt.
Thermal mass in the living space can store heat.

Nick

LCT Paintball

2005-10-27, 3:21 pm

> Another question : Where are you located? How far from the equator makes a
> big influence on how much sun you get....
>

And how much heat your house needs.

BobG

2005-10-27, 4:21 pm

SS:
What kind of climate has 72F ground temperature 2' down and 50F ambient
air temp?
============
Florida in winter. All the springs emit 72 deg water year round. That
makes me think thats what the temp is down there.

BobG

2005-10-27, 4:21 pm

SS:
What kind of climate has 72F ground temperature 2' down and 50F ambient
air temp?
==========================
Florida in the winter. All the springs around here emit 72 deg water
year round. I assume thats the tenperature down in the ground here.

Steve Spence

2005-10-27, 9:21 pm

BobG wrote:
> SS:
> What kind of climate has 72F ground temperature 2' down and 50F ambient
> air temp?
> ============
> Florida in winter. All the springs emit 72 deg water year round. That
> makes me think thats what the temp is down there.
>
Here in NY, we can find 50F about 8' down year round. That's what makes
ground source heat pumps so effective.

--
Steve Spence
Dir., Green Trust, http://www.green-trust.org
Contributing Editor, http://www.off-grid.net
http://www.rebelwolf.com/essn.html

Solar Flare

2005-10-27, 10:21 pm

50 deg F only if you don't inject frost into the ground by removing all the
heat.

They are not cheaper than NG here at 3:1 COP and the mechanics always sseem to
have too high maintenance costs and a bad MTBF.

Now get one that runs on diesel or NG and we may be getting somewhere.

"Steve Spence" <sspence@green-trust.org> wrote in message
news:m_d8f.19485$ol.2242@fe08.lga...
> ground source heat pumps so effective.
>
> --
> Steve Spence
> Dir., Green Trust, http://www.green-trust.org
> Contributing Editor, http://www.off-grid.net
> http://www.rebelwolf.com/essn.html

r2000swler@hotmail.com

2005-10-28, 2:21 pm

Solar Flare wrote:
> 50 deg F only if you don't inject frost into the ground by removing all the
> heat.
>
> They are not cheaper than NG here at 3:1 COP and the mechanics always sseem to
> have too high maintenance costs and a bad MTBF.
>
> Now get one that runs on diesel or NG and we may be getting somewhere.
>
++++++++++++++++++++
I have 2 frineds that have slightly different approaches to the
ground coupled heat pump.

One guy has the water table fairly close to the surface and pumps
ground water through a heatpump. Pretty effiecent but he has
some issues with calcification that reuqires him to clean the
heat exchanger every few years. Messy, but not all that hard.

The other guy has a large loop installed ~10' down and water is
circulated through the loop to the heat pump.

Both have very similar outputs and operating costs. The ground water
unit was much cheaper to install. The loop unit needs "no" cleaning.
And at the end of the heating or cooling seasons, the units operate
with the same output temps. If ground cooling or warming was an issue
I would expect to see a difference in system effeciency and/or heat
pump output temp.

Terry

Terry

Winston Smith

2005-10-29, 12:21 am

On Wed, 26 Oct 2005 20:09:33 -0700, Tim May
<timcmay@removethis.got.net> wrote:

>In article <1130373522.c5e28b9ecb12408cbfae3e379eed0b27@secureusenet>,
>Winston Smith <bogus@buttterfly.net> wrote:
>
>
>The voltage is constant, above any minor amount of light.
>
>
>No, watts x time = energy, not power.

I stand corrected. I was making the point that current was strongly
dependant on light and I incorrectly looked forward to making some
comments about the energy needed to run a load, which of course is the
final story. You corrections are absolutely correct, I had a brain
fart.

>
>There are good tables for different parts of the world. Latitude plays
>a major role, not just hours of daylight. (Angle of the sun, etc.)
>
>For that much energy, you mean. Not power.

I was seeing the 1.5KW and not the time references; it was late.
Still, you are completely correct. The point I was trying to make is
that using photovoltaic for heating is impractical. Solar thermal and
conventional fuels are much more practical.

>
>
>I disagree. Before I started posting to misc.survivalism, I used Deja
>News to thoroughly research what had been written on water storage,
>power generation, food shelf life, etc. The articles by people like
>Patton Turner and Al Hagan, for example.

Two points. Dejanews was a lot easier to use than the current version
of Google groups. There was not nearly so much material to wade
through back then and most of it was actually worth reading.

>The OP here seems to have no clue whatsoever about why he wants solar,
>what he wants, how much energy storage he needs, or what others have
>written.
>
>Helping him is thwarting Darwin. Way too much whiggerization going on
>even here.

I have faith in Darwin. He will win out even if we help the
occasional barefoot pilgrim.
>
>--Tim May

--
WÂ§ mostly in m.s - http://members.1stconnect.com/anozira

Stuart Grey

2005-10-29, 10:21 am

http://www.backwoodshome.com/article_index.html

Go down to "Energy"

Here's a good overview.
http://www.backwoodshome.com/articles2/yago83.html

Solar power is pretty much a waste of money. You'd be better off with a
generator powered by diesel, gasoline, natural gas or propane. If I had
a lot of land, and it was in a lower lattitude, I might go with a solar
boiler and a steam engine to drive a generator.

There are various reasons for going solar (electrical). One logical
reason is that you're far off the grid and don't find it practical to
haul fuel to where you want the power. That is almost never the case,
however. Another pragmatic but exploitive reason is that you might get
tax credits for it. The people enjoy having their tax money flushed down
the toilet for doing something stupid, and this is an instance of that.

The big reason why people get solar systems is because they think they
are not contributing to the energy problem. What they don't know is that
every kilogram of silicon takes 47 MJ of energy just to get it up to MGS
grade. MGS grade silicon makes a solar cell with lousy efficency.
Recently, solar cells have been made that produce just about as much
energy as it takes to create them over the life of the solar cell, if
they are placed in a good location.

Solar Flare

2005-10-29, 1:21 pm

Ohhh. That's why they always produce them in places where electricity sells for
less than $0.01 per kWh and selll them at a loss???

You need to think those statements out a little more. It disproves itself with
a little logic.

"Stuart Grey" <stuart.grey@nospam.comcast.net> wrote in message
news:oq-dnbzD89ds7v7eRVn-vA@comcast.com...
> Recently, solar cells have been made that produce just about as much
> energy as it takes to create them over the life of the solar cell, if
> they are placed in a good location.

Derek Broughton

2005-10-29, 4:21 pm

Stuart Grey wrote:

> There are various reasons for going solar (electrical). One logical
> reason is that you're far off the grid and don't find it practical to
> haul fuel to where you want the power. That is almost never the case,
> however.

BS. It's rarely practical to haul fuel and you don't have to be very far
off-grid at all to make PV practical. But you _do_ have to be off-grid for
it to be practical unless you've got subsidies.

> Another pragmatic but exploitive reason is that you might get
> tax credits for it. The people enjoy having their tax money flushed down
> the toilet for doing something stupid, and this is an instance of that.

More BS. Your tax dollars are going to be flushed anyway. You might as
well get the use of it as opposed to the usual people who get to take
advantage - those who are already rich.

> Recently, solar cells have been made that produce just about as much
> energy as it takes to create them over the life of the solar cell, if
> they are placed in a good location.

Still more...
--
derek

Anthony Matonak

2005-10-29, 4:21 pm

Stuart Grey wrote:
....
> Solar power is pretty much a waste of money. You'd be better off with a
> generator powered by diesel, gasoline, natural gas or propane. If I had
> a lot of land, and it was in a lower lattitude, I might go with a solar
> boiler and a steam engine to drive a generator.

People value things differently sometimes. Many off-grid folks with
the kind of generator setup you describe put in solar PV just so they
can get some peace and quiet. Those solar steam engines aren't as
simple and reliable as PV panels and steam only really works well at
largish scales.

> Recently, solar cells have been made that produce just about as much
> energy as it takes to create them over the life of the solar cell, if
> they are placed in a good location.

Odd, most of the recent studies seem to say that solar cells made
today produce as much energy as it took to create them in anywhere
from 6 months to 6 years with the more popular panels running in the
4 to 5 year range. Since these things are warrantied for 25 years and
can often be expected to continue producing power for twice that, it
seems the panels would make anywhere from (50/5 to 50/.5) 10 to 100
times this energy.

Anthony

Stuart Grey

2005-10-29, 7:21 pm

Solar Flare wrote:
> Ohhh. That's why they always produce them in places where electricity sells for
> less than $0.01 per kWh and selll them at a loss???

I can only specualate what you're gibbering about. Liberals love to ask
questions to attempt to make a point when they know that any direct
statement they utter would sound stupid.

> You need to think those statements out a little more. It disproves itself with
> a little logic.

Well, if you can, show that it doesn't take 13 KW-h to make 1 kg of MGS
grade silicon.

> "Stuart Grey" <stuart.grey@nospam.comcast.net> wrote in message
> news:oq-dnbzD89ds7v7eRVn-vA@comcast.com...
>
>
>
>

Stuart Grey

2005-10-29, 7:21 pm

Derek Broughton wrote:
> Stuart Grey wrote:
>
>
>
>
> BS.

Thanks for the warning, but I easily spotted your post as being bullshit

> It's rarely practical to haul fuel

I haul fuel all the time. Most people do, if they have a propane gas
camp stove, a gasoline powered lawn mower, or a generator. Fuel is
easily moved from place to place.

Your emotional utternace of a falsehood is noted.

> and you don't have to be very far
> off-grid at all to make PV practical.

A diesel generator is cheaper than a solar set up, and produces
electricity almost as cheap as grid power.

> But you _do_ have to be off-grid for
> it to be practical unless you've got subsidies.

Yes. If it wasn't for subsidies, there would be very little in the way
of solar power installations. Subsidies are as stupid an idea as the HOV
lanes on the freeway; you end up consuming more energy rather than
saving any.

>
>
> More BS.

Yes, Thanks. I see it coming. Why do you bother posting BS if you put a
warning before it?

> Your tax dollars are going to be flushed anyway.

Not if you get a tax cut, and the money isn't in the grubby hands of
politicians who take kickbacks from companies to their campaign funds.

> You might as well get the use of it

See: TAX CUT. Tax cuts are better because the person who earned the
money gets to keep it, rather than having some XXXXXXX playing some
karma game by buying a solar power system and then getting a rebate.

Solar energy, by and large, is a scam.

> as opposed to the usual people who get to take
> advantage - those who are already rich.

Oh yes. You must remember to spit nails in hate of the rich. It's okay
to steal as long as you steal from the rich man.

You're one warped puppy.

>
>
> Still more...

Stuart Grey

2005-10-29, 7:21 pm

Anthony Matonak wrote:
> Stuart Grey wrote:
> ...
>
>
>
> People value things differently sometimes. Many off-grid folks with
> the kind of generator setup you describe put in solar PV just so they
> can get some peace and quiet. Those solar steam engines aren't as
> simple and reliable as PV panels and steam only really works well at
> largish scales.
>
>
>
> Odd, most of the recent studies seem to say that solar cells made
> today produce as much energy as it took to create them in anywhere
> from 6 months to 6 years with the more popular panels running in the
> 4 to 5 year range. Since these things are warrantied for 25 years and
> can often be expected to continue producing power for twice that, it
> seems the panels would make anywhere from (50/5 to 50/.5) 10 to 100
> times this energy.

Cite.

> Anthony

Tim May

2005-10-29, 7:21 pm

In article <MOOdnfIpDPnCdP7eRVn-jQ@comcast.com>, Stuart Grey
<stuart.grey@nospam.comcast.net> wrote:

> Derek Broughton wrote:
>
> Thanks for the warning, but I easily spotted your post as being bullshit
>
>
> I haul fuel all the time. Most people do, if they have a propane gas
> camp stove, a gasoline powered lawn mower, or a generator. Fuel is
> easily moved from place to place.

Or a large propane tank used for heating and cooking. Mine holds 500
gallons, and gets topped off several times a year.

So long as there is any kind of road, gravel or even dirt, going to a
house, propane delivery is usually available. Ditto for fuel oil. And,
as several people here have commented, they own their own
intermediate-sized portable tanks and haul the filled ones to their
remote locations.

(There are many "off-grid" houses or cabins that are nevertheless
served by roads. Some people stay off grid because power companies want
a lot of $$$ to string power lines.)

Has anyone heard recent, solid information on the "propane electrical
generator" (using fuel cells, such as the one touted several years ago
by PlugPower) and when or if it will be available to home consumers?

I would consider a PV setup, but not because it is cheaper than the
local power grid. Rather, because it is quieter, and always available
in emergencies. I wouldn't need much, perhaps as little as 750 watts of
peak power, and the right-sized bank of cells to support this, and a
good inverter, etc., just enough to run a very small number of things.

(I have a 10-watt panel, a couple of 5s, and some AA and AAA solar
chargers. Just enough to play with, not enough to justify getting the
right kind of deep discharge batteries, transfer switches, etc.)

--Tim May

ladasky@my-deja.com

2005-10-29, 7:21 pm

Stuart Grey wrote:
> Anthony Matonak wrote:
[snip][color=darkred]
>
> Cite.

I don't have Anthony's numbers, but I have some from five years ago
which favor his position over Stuart's. Go here:

http://www.ecotopia.com/apollo2/pvepbtoz.htm

This is a reprint of a study from the Centre for Sustainable Energy
Systems, which is located at the Australian National University,
Camberra. The original document was not at an obvious location at the
CSES web site (http://solar.anu.edu.au), but if you emailed them they
could probably supply you with a link or a reprint.

This 2000 study says that the energy payback time for solar PV systems
(those that were in place as of that report) is 8 to 11 years. They
state an expected system lifetime of 30 years.

The term "energy intensity" is used to describe the amount of energy
you make while operating a generator, compared to the amount of energy
you used to manufacture and operate that generator.

Energy intensity can be expressed in a few different ways. You can
describe it in terms of a ratio, energy out / energy in. Obviously,
any generator that has total E(out) / total E(in) < 1 has no place in a
sustainable future.

You can also express the energy intensity as the amount of time it
takes to achieve payback, as the CSES paper does. This is the time at
which the cumulative E(out) equals the cumulative E(in). For PV
systems, the cumulative E(in) and the total E(in) are the same. Once
you install the solar array, you do not expend any more energy to keep
it running. This is not true for a generator that burns fuels. You
need to keep expending energy to generate energy.

PV systems achieved energy intensity ratios above 1.0 over two decades
ago, but there are still a lot of people who haven't heard the news.
The CSES paper assumes a PV system lifetime of 30 years, and therefore
the energy intensity ratio is about 3. This is good enough to get
started! However, I think that the assumption of a 30-year system
lifetime is pessimistic. In California, the Sacramento Municipal
Utility District operates a PV farm which includes some 20 year-old
arrays. These panels still put out 80% of the power that they
generated on the day that they were installed.

http://www.californiasolarcenter.or...20040907-5.html

Why quit ten years from now? Keep the system running.

Research is addressing the issue of how PV systems degrade over the
decades in sunlight. It won't be long now before PV arrays are
operating at 80% capacity after a century of service, rather than after
20 years. Solar PV will achieve energy intensities of 10-15 fairly
soon.

+-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-+
| Ladasky Home Solar, Inc.: blowing sunshine up your |
| power grid since March 24, 2005. Fiat lux! |
+-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-+
| Uptime Downtime kWh generated kWh consumed |
| 213 days none 4837 3829 |
+-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-+

Stuart Grey

2005-10-29, 8:21 pm

Tim May wrote:
> In article <MOOdnfIpDPnCdP7eRVn-jQ@comcast.com>, Stuart Grey
> <stuart.grey@nospam.comcast.net> wrote:
>
>
>
>
> Or a large propane tank used for heating and cooking. Mine holds 500
> gallons, and gets topped off several times a year.

I've seen lots of those big propane tanks out in the hills.

And your propane dealer fills it. Same idea as the old coal truck for
coal fired home heating, or the oil trucks that I still see come by my
way filling people's winter home heating oil tanks.

What's wrong with that?

> So long as there is any kind of road, gravel or even dirt, going to a
> house, propane delivery is usually available. Ditto for fuel oil. And,
> as several people here have commented, they own their own
> intermediate-sized portable tanks and haul the filled ones to their
> remote locations.
>
>
> (There are many "off-grid" houses or cabins that are nevertheless
> served by roads. Some people stay off grid because power companies want
> a lot of $$$ to string power lines.)

Exactly! And some people LIKE living way the hell out there, and would
rather haul the fuel rather than pay to live off the grid or move closer
to civilization.

> Has anyone heard recent, solid information on the "propane electrical
> generator" (using fuel cells, such as the one touted several years ago
> by PlugPower) and when or if it will be available to home consumers?

> I would consider a PV setup, but not because it is cheaper than the
> local power grid. Rather, because it is quieter, and always available
> in emergencies. I wouldn't need much, perhaps as little as 750 watts of
> peak power, and the right-sized bank of cells to support this, and a
> good inverter, etc., just enough to run a very small number of things.
>
> (I have a 10-watt panel, a couple of 5s, and some AA and AAA solar
> chargers. Just enough to play with, not enough to justify getting the
> right kind of deep discharge batteries, transfer switches, etc.)
>
> --Tim May

Stuart Grey

2005-10-29, 8:21 pm

ladasky@my-deja.com wrote:
> Stuart Grey wrote:
>
>
> [snip]
>
>
>
> I don't have Anthony's numbers, but I have some from five years ago
> which favor his position over Stuart's. Go here:
>
> http://www.ecotopia.com/apollo2/pvepbtoz.htm

I like this line:
"However, the predictions for the energy payback time of future PV
systems are all small (a few years). This is because the availability of
PV systems with a sufficiently low cost to be deployed in large
quantities will require the elimination of expensive components, which
also tend to be the energy intensive components (e.g. silicon wafers,
aluminium frames and expensive support structures)."

In other words, it will become better because if it doesn't, it's not
going to be produced in mass quantities. This article fails to address
the alternative: that the expensive components can't be eliminated and
that PV will not become common. It is the basis of this logical error
that it is claimed that energy payback periods will reach 2 years. No
where is the six month payback period claim supported.

This article points out a 8 to 10 year energy payback period, with a
useful life of 30 years. The implicit assumption that the energy output
is constant over the entire 30 year period is not a valid one, however.
If the payback period is 10 years, and the useful life is 30 years, you
are not going to get 3x the amount of energy out that you put into
making it. And given that the 8 to 10 year estimates for pay back are
made with an optimal installation, under constant engineering control,
it becames clear that improvements need to be made before it becomes
practical.

They point to thiner cells, which is a good idea since only the top 10
micro meters or so is actually used. Of course, making it thiner isn't
the slam dunk solution that the article suggests, as you run into
problems of material support, heat disapation, and contaminate migration.

> This is a reprint of a study from the Centre for Sustainable Energy
> Systems, which is located at the Australian National University,
> Camberra. The original document was not at an obvious location at the
> CSES web site (http://solar.anu.edu.au), but if you emailed them they
> could probably supply you with a link or a reprint.
>
> This 2000 study says that the energy payback time for solar PV systems
> (those that were in place as of that report) is 8 to 11 years. They
> state an expected system lifetime of 30 years.

I can see why you say it supports Mr. Matonak position and not mine.
After all, Mr. Matonak's six months is only off by a factor of 16, and I
was way off by a factor of less than 3. LOL!

> The term "energy intensity" is used to describe the amount of energy
> you make while operating a generator, compared to the amount of energy
> you used to manufacture and operate that generator.
>
> Energy intensity can be expressed in a few different ways. You can
> describe it in terms of a ratio, energy out / energy in. Obviously,
> any generator that has total E(out) / total E(in) < 1 has no place in a
> sustainable future.
>
> You can also express the energy intensity as the amount of time it
> takes to achieve payback, as the CSES paper does. This is the time at
> which the cumulative E(out) equals the cumulative E(in). For PV
> systems, the cumulative E(in) and the total E(in) are the same. Once
> you install the solar array, you do not expend any more energy to keep
> it running. This is not true for a generator that burns fuels. You
> need to keep expending energy to generate energy.
>
> PV systems achieved energy intensity ratios above 1.0 over two decades
> ago, but there are still a lot of people who haven't heard the news.
> The CSES paper assumes a PV system lifetime of 30 years, and therefore
> the energy intensity ratio is about 3. This is good enough to get
> started! However, I think that the assumption of a 30-year system
> lifetime is pessimistic. In California, the Sacramento Municipal
> Utility District operates a PV farm which includes some 20 year-old
> arrays. These panels still put out 80% of the power that they
> generated on the day that they were installed.
>
> http://www.californiasolarcenter.or...20040907-5.html

Nice, big fat silicon wafers, too. You're advocating a different
techology, however. There are advantages to fat silicon wafers.

> Why quit ten years from now? Keep the system running.
>
> Research is addressing the issue of how PV systems degrade over the
> decades in sunlight. It won't be long now before PV arrays are
> operating at 80% capacity after a century of service, rather than after
> 20 years. Solar PV will achieve energy intensities of 10-15 fairly
> soon.
>
> +-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-+
> | Ladasky Home Solar, Inc.: blowing sunshine up your |
> | power grid since March 24, 2005. Fiat lux! |
> +-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-+
> | Uptime Downtime kWh generated kWh consumed |
> | 213 days none 4837 3829 |
> +-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-+
>

Anthony Matonak

2005-10-30, 2:21 am

Stuart Grey wrote:
> Anthony Matonak wrote:
>
> Cite.

Since this was brought up in another thread, and seems to be endlessly
repeated by people who don't like solar PV, I just shamelessly clipped
the links someone else provided.

http://www.nrel.gov/docs/fy04osti/35489.pdf
http://www.nrel.gov/ncpv/energy_payback.html
http://www.homepower.com/files/pvpayback.pdf

Anthony

ladasky@my-deja.com

2005-10-30, 5:21 am

Stuart Grey wrote:
> ladasky@my-deja.com wrote:
>
> I like this line:
> "However, the predictions for the energy payback time of future PV
> systems are all small (a few years). This is because the availability of
> PV systems with a sufficiently low cost to be deployed in large
> quantities will require the elimination of expensive components, which
> also tend to be the energy intensive components (e.g. silicon wafers,
> aluminium frames and expensive support structures)."
>
> In other words, it will become better because if it doesn't, it's not
> going to be produced in mass quantities. This article fails to address
> the alternative: that the expensive components can't be eliminated and
> that PV will not become common. It is the basis of this logical error
> that it is claimed that energy payback periods will reach 2 years. No
> where is the six month payback period claim supported.

The paper DOES NOT claim energy payback periods of 2 years, it claims 8
to 11 years. The paper says that "In this study, estimates at the HIGH
END of embodied energy in PV systems have been adopted." They comment
about what improvements they anticipate will be made, but they do
analyze what is actually available now.

> This article points out a 8 to 10 year energy payback period, with a
> useful life of 30 years. The implicit assumption that the energy output
> is constant over the entire 30 year period is not a valid one, however.

Yes, the paper assumes no degradation, which is a bit sloppy. "The
total energy requirement to produce a PV panel is 1,060 kWh/m2. In
Sydney the useable panel output will be 153 kWh/m2/year, giving an
energy payback time (EPBT) for the panel of 6.9 years." Yep, that's
simple division.

But degradation is trivial over these short time scales. It doesn't
change the basic result by much. I pointed you to an article about the
first PV array installed by the Sacramento Municipal Utility District,
back in 1985, which is still generating 80% of its rated output. You
quoted that material in your reply (it's farther down). Assuming that
this 80% represents a constant degradation rate of 1.2% a year,
consistent with figures I've seen quoted elsewhere, what do you think
the chances are that the array will be useless 10 years from now?

> If the payback period is 10 years, and the useful life is 30 years, you
> are not going to get 3x the amount of energy out that you put into
> making it.

Splitting hairs. You will get very close to 3X, given the low
degradation rate.

> And given that the 8 to 10 year estimates for pay back are
> made with an optimal installation, under constant engineering control,
> it becames clear that improvements need to be made before it becomes
> practical.

Where does it say anything about the PV array being under "constant
engineering control"? It's not like you have to babysit a PV module to
get it to produce energy.

And how hard is an "optimal installation"? Here's mine:

http://tinyurl.com/cgdm2

A roof above the second floor, California sunshine, southwest
orientation (optimal, as it turns out, for time-of-use metering, which
I have).

My system consists of 27 BP3160 PV modules, which occupy 40.2 square
meters of space. Taking the paper's value of 1,060 kWh/sq. meter, the
energy embodied in the silicon contained my PV modules is 42,640 kWh.
The silicon, as you point out, accounts for most of the embodied
energy. I was told to expect 6,000 kWh/year from my system, and I'm on
track to produce at least that. Even with a 1.2% annual degradation in
PV output, I expect to reach the energy break-even point on the silicon
after 7.4 years.

BTW, if you assume zero degradation, which this paper does, you would
get an energy payback time of 7.1 years. It doesn't differ by much,
certainly not enough to reject the whole paper.

Add a couple of years for all of the remaining components (cell
fabrication, panel assembly, conduit, wiring, inverters, etc.). You
can recoup your energy investment in under a decade at sites like mine,
which are hardly uncommon.

Let's do the long-term degradation calculation. 30 years from now, my
PV modules are expected to generate only 4,228 kWh / year. But my
cumulative output will be 151.9 MWh, which is 3.56 times the embodied
energy of the silicon.

> They point to thiner cells, which is a good idea since only the top 10
> micro meters or so is actually used. Of course, making it thiner isn't
> the slam dunk solution that the article suggests, as you run into
> problems of material support, heat disapation, and contaminate migration.

You can use cheaper, less energy-intensive materials than the
high-grade silicon to fulfill some of these functions. I am aware that
several research groups, as well as the Evergreen Solar Corporation,
are working on thinner silicon substrates. I am also aware that
degradation is likely to accelerate, if the silicon is thinner.
Controlling contaminate migration is an active area of study.

>
> I can see why you say it supports Mr. Matonak position and not mine.
> After all, Mr. Matonak's six months is only off by a factor of 16, and I
> was way off by a factor of less than 3. LOL!

I left your original quote above at the top of this article. Your
contention was that the energy intensity of PV systems was *barely
reaching a value of 1.0* today. In other words, energy payback time
was nearly infinite.

Anthony Mantonak provided a RANGE of payback times: "6 months to 6
years with the more popular panels running in the 4 to 5 year range."
His values (for the "popular panels") are off by less than a factor of
2 from those quoted in this study. You selected only his most extreme
number, which I agree that the research that I know about cannot
support.

[snip]

>
> Nice, big fat silicon wafers, too. You're advocating a different
> techology, however. There are advantages to fat silicon wafers.

I'm not advocating any technology. The paper analyzed *existing* PV
manufacturing technology: "The wafer thickness is assumed to be 350
microns." That's a pretty standard wafer.

You seem to want to focus exclusively on (and dismiss) the paper's
speculative comments about possible improvements. Those comments are
straw men. If you do not disagree substantially with the paper's
conclusion about the embodied energy of existing PV cells, then you
have no substantial argument with this paper.

+-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-+
| Ladasky Home Solar, Inc.: blowing sunshine up your |
| power grid since March 24, 2005. Fiat lux! |
+-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-+
| Uptime Downtime kWh generated kWh consumed |
| 219 days none 4918 3956 |
+-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-+

Gordon Richmond

2005-10-30, 6:21 am

Interesting thread.

Want to know one industry that DOES frequently make use of solar PV?

The petroleum industry, that's who. It's not at all uncommon to see a
solar PV panel set up at a remote wellsite to run instruments and the
radio transmitter that telemeters the data to a field office for
analysis.

A little 8X10 shack with a solar apnel on its roof is a very common
sight in the oilfields these days.

Gordon Richmond

Jens Kr. Kirkebø

2005-10-30, 6:21 am

On Sat, 29 Oct 2005 14:18:52 -0700, Stuart Grey
<stuart.grey@nospam.comcast.net> wrote:

>
>A diesel generator is cheaper than a solar set up, and produces
>electricity almost as cheap as grid power.

Doesn't matter. I have an off-grid cabin in the mountains in Norway,
served by a road BTW. It's really quiet and peaceful up there. The
absolutely LAST thing I want to hear is a generator running, spoiling
the mood. We have NO subsidies on PVs here, but ALL the cabins around
us have them.

Some have generators, but only for emergency use. I have one too, but
have sized the PVs (now 3x150W 24V panels and a MX60) so that they
should deliver all the needed power in normal circumstances. If we
stay there for a long time in the winter and the weather is really
bad, I might have to fire it up for 3 hours to charge the batteries
(750Ah 12V bank) from 50% to 90% full. I hope to avoid this though. If
I have to do it often, I'll buy more panels as I have space for three
more.

BTW, we use propane (22lbs composite bottles) for the stove and wood
for heating. The fridge is 12V as propane is very inefficient for
refridgeration due to absorption technology instead of compressor
cycle. All lighting is LED, CFL or FL so we do conserve what we can.

That is correct. We do however have more than a hundred thousand
off-grid cabins in this small country of less than 5 million people.
[color=darkred]
>Solar energy, by and large, is a scam.

Completely wrong. It's the best solution to a lot of situations.

Solar Flare

2005-10-30, 9:21 am

What if the PV factories ran totally on PV energy?
Now where is the argument?

<ladasky@my-deja.com> wrote in message
news:1130663200.917831.126250@f14g2000cwb.googlegroups.com...
> Stuart Grey wrote:
> total energy requirement to produce a PV panel is 1,060 kWh/m2. In
> Sydney the useable panel output will be 153 kWh/m2/year, giving an
> energy payback time (EPBT) for the panel of 6.9 years." Yep, that's
> simple division.
>

Stuart Grey

2005-10-30, 12:21 pm

Anthony Matonak wrote:
> Stuart Grey wrote:
>
>
>
> Since this was brought up in another thread, and seems to be endlessly
> repeated by people who don't like solar PV, I just shamelessly clipped
> the links someone else provided.
>
> http://www.nrel.gov/docs/fy04osti/35489.pdf
> http://www.nrel.gov/ncpv/energy_payback.html
> http://www.homepower.com/files/pvpayback.pdf
>
> Anthony

Did you read them? The first two are identical. They admit they take for
granted the energy required to make MGS silicon. The last one I've seen
before, and I would like to know the cites for it. They are unclear as
to what they are including and what they aren't; for example, in their
Figure 2 graphic, they seem to start with polysilicon preperation, which
is probably why they come up with a two year payback period as this
neglects the energy needed to extract and refine the silicon. but they
include other evidence in their Figure 1 graphic. that the period can be
as long as 10 years. Basically, they are making the claim that they have
it nailed down somewhere between 2 and 10. That's a pretty big uncertainty!

Another error is the assumption of a perfect installation in an
"average" area of the United States (which is actually less than half of
the land area).

I note that this is a five year old paper. If it was true, you'd think
there would have been a massive increase in solar power usage; but there
hasn't, even with government subsidies. If you really believe this paper
to be accurate then you would sell your house and invest your last dime
in solar panels, wouldn't you? With energy costs going up, and solar
panels today being made at yesterday's energy rates, you could get a 9X
your return on investment (over 30 years) by selling the power back to
the grid. To me, this last article looks like an advocacy paper written
for one of the popular solar energy advocacy magazines. I wouldn't take
it any more seriously than the flying cars and jet packs in Popular
Science.

Stuart Grey

2005-10-30, 12:21 pm

Solar Flare wrote:
> What if the PV factories ran totally on PV energy?
> Now where is the argument?

Show me the factory and what goes in it, and what comes out of it.

> <ladasky@my-deja.com> wrote in message
> news:1130663200.917831.126250@f14g2000cwb.googlegroups.com...
>
>
>
>

Stuart Grey

2005-10-30, 12:21 pm

Jens Kr. Kirkebø wrote:
> On Sat, 29 Oct 2005 14:18:52 -0700, Stuart Grey
> <stuart.grey@nospam.comcast.net> wrote:
>
>
>
>
> Doesn't matter. I have an off-grid cabin in the mountains in Norway,
> served by a road BTW. It's really quiet and peaceful up there. The
> absolutely LAST thing I want to hear is a generator running, spoiling
> the mood.

In Norway, you don't have mufflers? How odd.

Cliff

2005-10-30, 12:21 pm

On Sun, 30 Oct 2005 08:28:12 -0800, Stuart Grey
<stuart.grey@nospam.comcast.net> wrote:

>I wouldn't take
>it any more seriously than the flying cars and jet packs in Popular
>Science.

How many do you have?
--
Cliff

Solar Flare

2005-10-30, 2:21 pm

What factory?

"Stuart Grey" <stuart.grey@nospam.comcast.net> wrote in message
news:i4WdnRU0NcwZd_neRVn-jg@comcast.com...
> Solar Flare wrote:
>
> Show me the factory and what goes in it, and what comes out of it.
>
>

Solar Flare

2005-10-30, 2:21 pm

Jet packs have been around for decades. Poor example.

"Stuart Grey" <stuart.grey@nospam.comcast.net> wrote in message
news:TpmdnVS-uNItdfneRVn-1Q@comcast.com...
> Anthony Matonak wrote:
>
> Did you read them? The first two are identical. They admit they take for
> granted the energy required to make MGS silicon. The last one I've seen
> before, and I would like to know the cites for it. They are unclear as
> to what they are including and what they aren't; for example, in their
> Figure 2 graphic, they seem to start with polysilicon preperation, which
> is probably why they come up with a two year payback period as this
> neglects the energy needed to extract and refine the silicon. but they
> include other evidence in their Figure 1 graphic. that the period can be
> as long as 10 years. Basically, they are making the claim that they have
> it nailed down somewhere between 2 and 10. That's a pretty big uncertainty!
>
> Another error is the assumption of a perfect installation in an
> "average" area of the United States (which is actually less than half of
> the land area).
>
> I note that this is a five year old paper. If it was true, you'd think
> there would have been a massive increase in solar power usage; but there
> hasn't, even with government subsidies. If you really believe this paper
> to be accurate then you would sell your house and invest your last dime
> in solar panels, wouldn't you? With energy costs going up, and solar
> panels today being made at yesterday's energy rates, you could get a 9X
> your return on investment (over 30 years) by selling the power back to
> the grid. To me, this last article looks like an advocacy paper written
> for one of the popular solar energy advocacy magazines. I wouldn't take
> it any more seriously than the flying cars and jet packs in Popular
> Science.
>
>

TheAlligator

2005-10-30, 2:21 pm

dh@. wrote:

>1. What is involved other than the solar panels, wire
>and batteries?

Solar controller, switching and V/A metering, Fusing (very important),
desulphation device for batteries, regular water check, diode in line
from panels to prevent "backcharging" at night which can put a drain
on the batts (VERY important)..

>2. What would keep the batteries from getting overcharged
>and burning out?

A GOOD controller will prevent this. Since mine is mostly on standby,
I have trickle charging/desulphation on house power, and run the
panels for charging every few days. I started with a cheap
controller, left it on all the time, and boiled out some batts early
on.

>3. Would the inverter (Coleman PMP 2000) alone be enough
>to regulate when the batteries become dangerously low and
>shut down discharge, or would I need to monitor it and do it
>myself to avoid damage to the system.

Don't know. I'm not familiar withe the Coleman, but many units shut
down on low input voltage. If you continually drain your batts to
that point, they won't last very long at all. Try to never discharge
(my opinioin only) not any farther down than 40-50% or so. I try to
keep it above 60%.

>4. How could I monitor the charge level of the batteries?

Charge volts/amps and load volts/amps are usefull. Only accurate way
to determine charge is to test each cell with a hygroscope (sp?).
Anyway, the kind of tester the gas station uses to check the specific
gravity of the fluid in each cell. I wired up my own switching and
control panel (don't skimp on wire guage, switch/connector quality and
don't get cheap meters if you're serious. The meters alone ran, I
believe, a little under a hundred bucks apiece. The hardest-to-find
item was a 40-volt 100-amp DPDT rotary switch to move the ham shack
from house to solar with one click. Never underestimate the hidden
costs - wire in the necessary size can get incredibly expensive, as
can the connectors. For fusing, I used the "mega-car-stereo" 80 amp
jobs, which are fairly easy to find.

>5. Do the panels only work when there's a certain amount
>of light available, or does their performance fluctuate depending
>on how much light they're getting at the time?

Depend entirely on characteristics of the specific panel and how it
interacts with the controller. Even when I'm not getting the full
17.9 VDC down from the panels, I usually still have enough to charge
at 14.1 V and 3 to 6 amps, if it's needed. The controller determines
the charge level to the batteries. Even on a cloudy day, I can get a
trickle charge.

>6. How to calculate what it would take to run a 1.5 KW heater
>for a certain period of time, using whatever number of 115
>amp hour batteris it would take to get a few hours of use from
>the heater, and what type solar panels to use, etc?

Having said all this, just in case you're interested for other
reasons, if electric heat is your only reason, then you've chosen a
VERY expensive, VERY inefficient course. I dare say that even with a
ridiculously above-average system, given the number of sun hours here,
the heat wouldn't run very long or very often. You could bury a
propane tank or get a farm-type diesel tank and buy a truckload of
kero heaters for the money, they'd be much more reliable and efficient
and very cheap to run.
>
>I'm sorry to be so completely ignorant, and would appreciate
>any help in overcoming it.

You're not ignorant. But if you're serious about a solar system,, you
would be wise to hook up with a specialty company and work with them.
It might cost slightly more, but you'll get lots of advice. There's a
lot of BS floating around about the subject.

Stuart Grey

2005-10-30, 3:21 pm

Solar Flare wrote:
> Jet packs have been around for decades. Poor example.

show us your jet pack, and how you use it to get to work.

> "Stuart Grey" <stuart.grey@nospam.comcast.net> wrote in message
> news:TpmdnVS-uNItdfneRVn-1Q@comcast.com...
>
>
>
>

Stuart Grey

2005-10-30, 3:21 pm

Solar Flare wrote:
> What factory?

What do you mean, "what factory"? You asked the question "What if the PV
factories ran totally on PV energy? Now where is the argument?" Well, if
it was truly all solar, from the aluminum ore and sand inputs to the
solar cell outputs, you'd have a very good case. I want to know where
this factory is you're on about, is. I want to know more about it.

> "Stuart Grey" <stuart.grey@nospam.comcast.net> wrote in message
> news:i4WdnRU0NcwZd_neRVn-jg@comcast.com...
>
>
>

Bill Ward

2005-10-30, 3:21 pm

On Sun, 30 Oct 2005 12:54:08 -0500, "Solar Flare"
<sflare@hotmail.com> wrote:

<Reordered for clarity>

>"Stuart Grey" <stuart.grey@nospam.comcast.net> wrote in message
>news:TpmdnVS-uNItdfneRVn-1Q@comcast.com...
<Reordered for clarity>[color=darkred]
>Jet packs have been around for decades. Poor example.

Excellent examples. Both jet packs and flying cars have been
around for decades, but for some reason not many people want
to invest in them.

Perhaps subsidies would help...

Regards,

Bill Ward

R.H. Allen

2005-10-30, 5:21 pm

Stuart Grey wrote:
> Derek Broughton wrote:
>
>
>
> A diesel generator is cheaper than a solar set up, and produces
> electricity almost as cheap as grid power.

It's also noisy, smelly, needs to be refueled, produces toxic gases, and
requires more maintenance than solar. Its cost is also as volatile as
the price of diesel. Clearly, eliminating these things has very little
value to you personally, but some people are willing to pay a premium to
eliminate them. Value is not always about money, even for a product as
fungible as electricity.

>
>
> Yes. If it wasn't for subsidies, there would be very little in the way
> of solar power installations.

Yes. And if it weren't for subsidies, gasoline and grid power would be
substantially more expensive than they are now. Oil companies already
receive large subsidies for exploration and other activities, and you
may remember that a few months ago -- shortly after reporting record
profits -- they were given another $14.5 billion in tax breaks. And just
yesterday, Congress gave them even more to build oil refineries. Natural
gas and coal-mining firms also benefit from large subsidies.

> Subsidies are as stupid an idea as the HOV
> lanes on the freeway; you end up consuming more energy rather than
> saving any.

Absolutely. If gas were more expensive, we'd certainly use less of it.
In fact, the week after Katrina, when gas prices shot up, demand for
gasoline fell by 8%. Of course, people screamed bloody murder -- so much
so that at least one governor suspended his state's gas tax (which is
totally counterproductive in a shortage situation, but that's another
story). People love the subsidies that benefit them directly and hate
all the rest.

I'm all for a level playing field; unfortunately, that means subsidies
for solar, wind, and every other energy technology.

Jens Kr. Kirkebø

2005-10-30, 5:21 pm

On Sun, 30 Oct 2005 08:36:47 -0800, Stuart Grey
<stuart.grey@nospam.comcast.net> wrote:

>
>In Norway, you don't have mufflers? How odd.

Mufflers ? I can hear the friggin' fridge when it runs, how does one
soundproof the generator so it's not possible to hear from 20 feet
away ? Granted, I can probably get it down from 80-90dB to maybe 50dB
or so. I would probably have to get it way under 20dB though for it
not to bother me, and I don't know how to achieve that.

R.H. Allen

2005-10-30, 5:21 pm

Stuart Grey

2005-10-30, 5:21 pm

R.H. Allen wrote:
> Stuart Grey wrote:
>
>
>
> It's also noisy, smelly, needs to be refueled, produces toxic gases, and
> requires more maintenance than solar.

Solar has battery terminals to clean, no panels to wash.

The noise can be reduced with a good mufflers (as frequently found on RV
generators) and while it does need to be refuled, you can't refuel a
solar panel when on a cloudy day. And it's usually cheaper.

> Its cost is also as volatile as the price of diesel.

Yes, as opposed to solar panels which are always going to be more
expensive than any diesel prices in the past 10 years...

When the price of diesel goes way up, I might get solar panels. Right
now, I could take the extra cost of the solar array and invest it, and
use the profits to buy diesel.

> Clearly, eliminating these things has very little
> value to you personally, but some people are willing to pay a premium to
> eliminate them. Value is not always about money, even for a product as
> fungible as electricity.

I have no problem with people buying PV panels because they think their
cool. As a solution to the engineering problem of providing power, they
are still don't measure up to alternatives like fossile fuels.

>
>
> Yes. And if it weren't for subsidies, gasoline and grid power would be
> substantially more expensive than they are now.

< snip >

I'm not going to bother with such silly arguments as that.

Stuart Grey

2005-10-30, 5:21 pm

R.H. Allen wrote:
> Anthony Matonak wrote:
>
>
>
> And if you don't like these,

I didn't.

> I've got some two dozen peer-reviewed
> journal articles I can point you to, though you won't be able to read
> them online.

1) The good to poor journals would appear in a university library. The
real stinkers don't make it.

2) Peer review doesn't count for squat. There was an article that passed
peer review a couple of years ago that was intentionally complete and
utter gibberish. It was published. I've seen LOTS of papers that were
published tha contained fundamental mathematical and conceptual errors
that passed peer reivew. The purpose of peer review is to select the
best papers for publication, it is not intended to be an afformation of
the context of the article. That particular bunch of bullcrap started
with the Pons-Fleishman debacle. The goal of any reputable university is
to enable the degree holder to read the journal articles and do their
own "peer review".

> On the flip side, despite years of searching, I have found
> only one piece of research indicating that solar modules will never pay
> back the energy required to make them -- and that work used a
> controversial method with subjective parameters that has also been used
> to show the opposite conclusion. The only place the negative energy
> payback myth seems to survive is on the internet.

Well, you don't like that article because it came to the wrong
conclusion, so there is no need to bother with that one. :-)

R.H. Allen

2005-10-30, 5:21 pm

Stuart Grey wrote:
> Anthony Matonak wrote:
>
>
>
> Did you read them? The first two are identical. They admit they take for
> granted the energy required to make MGS silicon. The last one I've seen
> before, and I would like to know the cites for it. They are unclear as
> to what they are including and what they aren't; for example, in their
> Figure 2 graphic, they seem to start with polysilicon preperation, which
> is probably why they come up with a two year payback period as this
> neglects the energy needed to extract and refine the silicon.

Did *you* read the paper, or did you just look at the tables and charts?
They explicitly say that they take into account the energy to extract
and refine the silicon. See the second paragraph at the top of the third
page.

> but they
> include other evidence in their Figure 1 graphic. that the period can be
> as long as 10 years. Basically, they are making the claim that they have
> it nailed down somewhere between 2 and 10. That's a pretty big uncertainty!

Of course it's a big uncertainty. For one thing, the chart is a summary
of previous work that uses assumptions and methodologies that are
similar, but not identical to those in this paper. For example, some of
those studies assume the panels are sited in Germany or Japan, and some
assume a range of locations with varying amounts of sunlight. Since
sunlight is not even distributed when it reaches the Earth's surface,
there will always be a large uncertainty.

> Another error is the assumption of a perfect installation in an
> "average" area of the United States (which is actually less than half of
> the land area).

In what way is that an error? I think a little sensitivity analysis is
called for, but I fail to see how it's an error.

> I note that this is a five year old paper. If it was true, you'd think
> there would have been a massive increase in solar power usage;

Why? I know few people who select products on the basis of energy
payback. Besides which, energy payback time for a coal-fired or nuclear
power plant are similar to those for PV that are cited in this paper.
From an energy payback standpoint, PV has no advantage over grid power.

> but there
> hasn't, even with government subsidies.

Well, the industry has averaged nearly 40% annual growth since 1996, and
grew nearly 70% last year alone. It's been growing so fast that neither
the PV industry nor the silicon industry -- 40% of which now goes to PV,
rather than microelectronics -- have not been able to keep up with the
demand.

> If you really believe this paper
> to be accurate then you would sell your house and invest your last dime
> in solar panels, wouldn't you?

Again, why?

> With energy costs going up, and solar
> panels today being made at yesterday's energy rates, you could get a 9X
> your return on investment (over 30 years) by selling the power back to
> the grid.

How do you figure?

Bill Ward

2005-10-30, 6:21 pm

On Sun, 30 Oct 2005 15:20:33 -0500, "R.H. Allen"
<kkarie@hotmail.com> wrote:

>Stuart Grey wrote:
<snip>
[color=darkred]
>
>Yes. And if it weren't for subsidies, gasoline and grid power would be
>substantially more expensive than they are now. Oil companies already
>receive large subsidies for exploration and other activities

I often hear this, but have not yet seen examples of such
subsidies. Are you implying there is a net transfer of
funds from the government to the oil companies, or do you
just mean reduced taxes if the oil companies comply with
certain governmental desires?

I'd appreciate cites showing actual subsidies to oil
companies exceeding their taxes.

>, and you
>may remember that a few months ago -- shortly after reporting record
>profits -- they were given another $14.5 billion in tax breaks.

<snip>

Regards,

Bill Ward

Solar Flare

2005-10-30, 6:21 pm

You need to read a little closer before getting all excited.
Let me requote from below "What if the PV factories ran totally on PV energy?"

Nobody said there was any factories running on PV. I asked "what if". How can I
show you one that was referred to?

Sometimes Newsgroup are fairly counterproductive with all the "know-it-alls"
tryin to best somebody else. We all like to consider ourselves fairly
knowledgable. Consideration of others has to be taken ahead of our need to "jump
down somebdy's throat" because they have a different opinion or make an error
based on their experiences.

"Stuart Grey" <stuart.grey@nospam.comcast.net> wrote in message
news:55udnU96XLGzkvjenZ2dnUVZ_sqdnZ2d@comcast.com...
> Solar Flare wrote:
>
> What do you mean, "what factory"? You asked the question "What if the PV
> factories ran totally on PV energy? Now where is the argument?" Well, if
> it was truly all solar, from the aluminum ore and sand inputs to the
> solar cell outputs, you'd have a very good case. I want to know where
> this factory is you're on about, is. I want to know more about it.
>
>
>
>

R.H. Allen

2005-10-30, 6:21 pm

Stuart Grey wrote:
>
> They point to thiner cells, which is a good idea since only the top 10
> micro meters or so is actually used. Of course, making it thiner isn't
> the slam dunk solution that the article suggests, as you run into
> problems of material support, heat disapation, and contaminate migration.

Just a few points of fact. Solar cells are not microchips. They are
essentially diodes with very large cross-sections and transparent
packaging. They are bulk devices -- meaning that the whole wafer is
used, not just the top 10 µm -- and (concentrator cells aside) they do
not develop the high current densities and electric fields that result
in heat dissipation and contaminant migration issues. If those *were*
issues, you wouldn't see solar cells made from multicrystalline silicon.
(Silicon concentrator cells must support high current densities and are
never made from multicrystalline silicon.) Furthermore, even if they
*were* issues, there is no reason to believe that using thinner wafers
would aggravate them.

Material support for thin cells is a manufacturing problem but not a
service problem, given the mechanical support the cells get from the
module glass, frame, and backing. Until recently, most silicon solar
cells were around 300 µm thick; however, silicon prices have skyrocketed
over the past year and many manufacturers have quickly moved to 250 µm
thicknesses. Slicing of wafers at thicknesses less than 100 µm with good
yield has been demonstrated, but developing the techniques to handle
such thin wafers on the production line without breaking them is ongoing.

The primary design issues for making thin silicon solar cells are light
trapping and passivation of the rear surface of the solar cell. The
former refers to keeping the light that enters the solar cell from
escaping before it is absorbed, while the latter refers to keeping
electrons from being captured by dangling chemical bonds at the cell's
surface. Both problems have been essentially solved in the laboratory
and are now being adapted to the production line.

Long story short (too late, I know), the obstacles to thin silicon solar
cells are well understood and essentially already solved at the
laboratory level. All that remains is to move from the lab to the
production line -- not trivial, but results from pilot production by
multiple manufacturers with wafers in the 100-150 µm range have been
encouraging.

Solar Flare

2005-10-30, 6:21 pm

Reverse taxes at the pumps. They pay you to fill up.

"Bill Ward" <bwardREMOVE@ix.netcom.com> wrote in message
news:436538db.2394172@localhost...
> On Sun, 30 Oct 2005 15:20:33 -0500, "R.H. Allen"
> <kkarie@hotmail.com> wrote:
>
> <snip>
>
>
> I often hear this, but have not yet seen examples of such
> subsidies. Are you implying there is a net transfer of
> funds from the government to the oil companies, or do you
> just mean reduced taxes if the oil companies comply with
> certain governmental desires?
>
> I'd appreciate cites showing actual subsidies to oil
> companies exceeding their taxes.
>
>
> <snip>
>
> Regards,
>
> Bill Ward

R.H. Allen

2005-10-30, 6:21 pm

Stuart Grey wrote:
> R.H. Allen wrote:
>
>
>
> 1) The good to poor journals would appear in a university library. The
> real stinkers don't make it.

Yes and no. You're not likely to find engineering journals at a liberal
arts school, aeronautical journals at a university with no aerospace
engineering program, or energy journals at a university that does no
energy research, no matter how good they are.

> 2) Peer review doesn't count for squat. There was an article that passed
> peer review a couple of years ago that was intentionally complete and
> utter gibberish. It was published. I've seen LOTS of papers that were
> published tha contained fundamental mathematical and conceptual errors
> that passed peer reivew. The purpose of peer review is to select the
> best papers for publication, it is not intended to be an afformation of
> the context of the article.

Having been on both sides of the peer review process, I think it's a bit
more complex than that. At any rate, usenet debates about peer review
frequently descend into flame wars, so I don't really care to discuss
it. The only reason I mentioned peer review was to differentiate these
papers from, say, a Popular Science article or lunatic ravings on
somebody's web site.

>
>
> Well, you don't like that article because it came to the wrong
> conclusion, so there is no need to bother with that one. :-)

The reason I described it as controversial was because the method used
was one that is not widely accepted within *any* discipline, as far as
I'm aware (eMergy). The larger point, of course, is that none of PV's
critics seem to be criticizing it on the basis of energy payback, at
least not in any way that they care to back with their professional
reputations. It would be a powerful criticism, so if it's true, why
aren't they using it?

R.H. Allen

2005-10-30, 7:21 pm

Bill Ward wrote:
> On Sun, 30 Oct 2005 15:20:33 -0500, "R.H. Allen"
> <kkarie@hotmail.com> wrote:
>
>
>
> <snip>
>
>
>
> I often hear this, but have not yet seen examples of such
> subsidies. Are you implying there is a net transfer of
> funds from the government to the oil companies, or do you
> just mean reduced taxes if the oil companies comply with
> certain governmental desires?

Part of the problem with trying to quantify these things is that nobody
seems to agree on what constitutes a subsidy. Some say tax breaks aren't
subsidies, while others think they are clearly subsidies. Still others
think that *some* tax breaks are subsidies, while others are simply
policy tools. Are research grants subsidies and, if so, must they go
directly to the energy company to be counted as such or is it enough
that they go to a university? Then you've got folks who think money
spent protecting strategic oil interests should be counted as a subsidy
while others think that's patently ridiculous.

The research grant question is especially important when it comes to
renewables, since they're typically nascent technologies whose
commercial markets are still small.

> I'd appreciate cites showing actual subsidies to oil
> companies exceeding their taxes.

The bill that passed the House yesterday gives federal land (abandoned
military bases) to oil companies for the purpose of building refineries
and shields them from damages in certain lawsuits. I'm not sure what
it's current status is -- whether it now needs to clear the Senate, etc.

At any rate, I've seen studies by various organizations from time to
time that discuss this. I'm not a big fan of either of the organizations
that put together the two reports that I can quickly locate, but here
they are:

http://www.cato.org/pubs/handbook/hb109/hb_109-45.pdf
http://www.greenpeace.org/raw/conte...bal-warming.pdf

The one from Cato concludes that subsidies represent no more than a
couple percent of energy expenditures, save nuclear (15.6%) and
renewables (25.6%). They give no breakdown of individual renewables.

The one from Greenpeace only addresses fossil fuels, but is more
extensive and acknowledges that the size of the subsidy depends on how
you define a subsidy. It also looks at the impact of foreign subsidies
on U.S. prices. Depending on what you count as a subsidy, their figure
ranges from 2.7% to 17.3%.

Finally, there's a study by the Renewable Energy Policy Project that
analyzes subsidies as a function of time for nuclear, solar, and wind.
It concludes that over the first 15 years of their commercial histories,
nuclear was subsidized at twice the rate of solar (on a per kWh basis).
Over the first 25 years -- which was solar's entire commercial history
in 1999, the end of the report's timeline -- nuclear's total subsidy was
still 30% higher per kWh than solar's.

http://www.crest.org/repp_pubs/pdf/subsidies.pdf

I've seen others that can probably be turned up with a little bit of
googling.