Alternative Power sources - Using Solar to supplement and Off grid Generator

Author

Using Solar to supplement and Off grid Generator

philkryder

2007-05-25, 8:25 pm

Colleagues -
We currently run off grid with an 8kw generator with 13500 surge.

We estimate our average usage at about 4kw.
For f hours
on 3 days per week - Wednesday, Saturday, Sunday.

We operate from about 9am to 4 pm.

We spend around $3000 per year on fuel.

I was wondering if SOLAR makes sense as a fuel cost mitigator.

Can we use our generator to handle surge load and dark days and have
the SOLAR act as a load reducer.

Will the SOLAR inverter match the generator as it would match the
grid?

Thanks
Phil

Eeyore

2007-05-26, 3:25 am

philkryder wrote:

> I was wondering if SOLAR makes sense as a fuel cost mitigator.

PV solar makes no sense for anything at present costs and efficiencies.

Graham

Anthony Matonak

2007-05-26, 3:25 am

philkryder wrote:
> Colleagues -
> We currently run off grid with an 8kw generator with 13500 surge.
> We estimate our average usage at about 4kw.
> For f hours
> on 3 days per week - Wednesday, Saturday, Sunday.
> We operate from about 9am to 4 pm.
> We spend around $3000 per year on fuel.
> I was wondering if SOLAR makes sense as a fuel cost mitigator.
> Can we use our generator to handle surge load and dark days and have
> the SOLAR act as a load reducer.
> Will the SOLAR inverter match the generator as it would match the
> grid?

I'm no expert in these things but I think I can answer some of your
questions.

If fuel costs alone are your concern then perhaps you could explore
using a diesel generator and waste vegetable oil. With a little
looking around, it's likely that you could get all the used fry
oil you need either free or for very little cost.

I don't think a grid-tie inverter will work with a generator.
The grid-tie regulations require that the inverter only connect
when the grid waveform is stable and I don't think most generators
are stable enough.

You could go with an inverter plus battery bank combination as
an alternative. You put your ordinary (less than 4kW) loads on
the inverter and charge the batteries off the generator at the
same time you need to power your big loads. This would give you
power 24/7 without having to run that monster all the time. This
would also allow you to add PV to extend the run time on batteries.

Anthony

philkryder

2007-05-26, 3:25 am

On May 25, 8:52 pm, Anthony Matonak
<anthony...@nothing.like.socal.rr.com> wrote:
> philkryder wrote:
>
> I'm no expert in these things but I think I can answer some of your
> questions.
>
> If fuel costs alone are your concern then perhaps you could explore
> using a diesel generator and waste vegetable oil. With a little
> looking around, it's likely that you could get all the used fry
> oil you need either free or for very little cost.
>
> I don't think a grid-tie inverter will work with a generator.
> The grid-tie regulations require that the inverter only connect
> when the grid waveform is stable and I don't think most generators
> are stable enough.
>
> You could go with an inverter plus battery bank combination as
> an alternative. You put your ordinary (less than 4kW) loads on
> the inverter and charge the batteries off the generator at the
> same time you need to power your big loads. This would give you
> power 24/7 without having to run that monster all the time. This
> would also allow you to add PV to extend the run time on batteries.
>
> Anthony

Anthony, thanks for your consideration.

We don't need 24/7.

We considered diesel, but feel the fuel spill potential untenable in
our location.
And, the fuel gathering and prep are not practical given our labor
costs.

We would consider batteries - and would love to go there eventually,
but they add a lot to the initial costs. Moreover, batteries have a
finite life, which adds to operating costs. If they prove cost
effective, we'd sure want to use them.

Thanks again for your comments.
Phil

philkryder

2007-05-26, 3:25 am

On May 25, 8:34 pm, Eeyore <rabbitsfriendsandrelati...@hotmail.com>
wrote:
> philkryder wrote:
>
> PV solar makes no sense for anything at present costs and efficiencies.
>
> Graham

Graham -
Thanks for weighing in with your opinion.

Do you feel that is true even for off grid locations at current and
future projected fuel costs with say 10% annual compounded increases?
What level of projected fuel costs would you see as a break even
point?

If you have some easy to follow data and analysis, it would be very
helpful and save us from wasting time.

I felt originally that have 7 days to gather power, but only 3 days
consumption might help us - If we had batteries. But, batteries have
their own downsides....

Again, thanks for joining in.
I'd really appreciate and data and analysis you could provide to help
show your conclusion.

Phil

Vaughn Simon

2007-05-26, 9:25 am

"philkryder" <alt.google@Kryder.com> wrote in message
news:1180139756.590967.323680@j4g2000prf.googlegroups.com...

You will have to talk to the inverter folks to see if their products will stay
synced up with a generator. I assume that your generator would need to have a
waveform and frequency stabilility that mimics the grid.

Given your desire to not have batteries, you are giving up much of the (already
marginal) economics of PV. First, you are giving up their potential output for
4 days out of every 7, and second, you would still need to run your generator
full time for those three working days. Even if the PV took all of the load off
of the generator, it would still be using considerable fuel and the difference
in wear on your machinery would be insignificant.

I understand your reluctance to go with a battery bank. As I recall, the
depreciation alone on a battery bank comes in at somewhere between $.10 and
$.25 per Kwh. In your situation the economics might be even worse, because the
battery is only available for use 3/7 of the time. That said, without a battery
bank to allow you to gather energy all week and to allow you to shut off your
generator, the economics of PV for your situation are a non-starter.

Vaughn

Ron Rosenfeld

2007-05-26, 9:25 am

On 25 May 2007 17:35:56 -0700, philkryder <alt.google@Kryder.com> wrote:

>Colleagues -
>We currently run off grid with an 8kw generator with 13500 surge.
>
>We estimate our average usage at about 4kw.
>For f hours
>on 3 days per week - Wednesday, Saturday, Sunday.
>
>We operate from about 9am to 4 pm.
>
>We spend around $3000 per year on fuel.
>
>I was wondering if SOLAR makes sense as a fuel cost mitigator.
>
>Can we use our generator to handle surge load and dark days and have
>the SOLAR act as a load reducer.
>
>Will the SOLAR inverter match the generator as it would match the
>grid?
>
>Thanks
>Phil

Phil,

There's a free program called HOMER (www.nrel.gov/homer)that will allow you
evaluate this question from a dollars and cents perspective, so long as you
have the relevant data.

In a word, it depends.

An off-grid capable inverter, such as the Trace/Xantrex SW5548, will be
able to handle the combining (and control) of your generator and PV panels
and batteries.

The HOMER program will allow you to fairly accurately model your power
requirements (9-4, 4kW continuous draw, three days/week) and optimize your
panel array size and battery bank requirements. You will then be able to
compare it with fuel costs and decide on an optimal system. Economic
assumptions are also modelled into the program.

At my location in Downeast Maine, it would cost approximately $40,000 to
set up a system to generate 100% of your power requirements from PV.
Depending on the cost of money to me, and my predictions as to fuel costs,
that might be worthwhile.

--ron

somebody@somewhere.com

2007-05-26, 9:25 am

Charles Foot

2007-05-26, 5:25 pm

Eeyore wrote:
>
> philkryder wrote:
>
>
> PV solar makes no sense for anything at present costs and efficiencies.
>
> Graham
>
Hmmmm.... horses for courses really. Here on Great Barrier Island, where
there is no power grid, and diesel is so costly, PV makes a lot of
sense. I've just boosted our solar array by 1200 watts worth. Compared
to the cost of generating our power with diesel, I see a financial
payback within about 4 years (including framing, wiring, bigger charge
controller, etc.) And, the saving on the environment: priceless.

George Ghio

2007-05-26, 8:25 pm

philkryder wrote:
> Colleagues -
> We currently run off grid with an 8kw generator with 13500 surge.
>
> We estimate our average usage at about 4kw.
> For f hours
> on 3 days per week - Wednesday, Saturday, Sunday.
>
> We operate from about 9am to 4 pm.
>
> We spend around $3000 per year on fuel.
>
> I was wondering if SOLAR makes sense as a fuel cost mitigator.
>
> Can we use our generator to handle surge load and dark days and have
> the SOLAR act as a load reducer.
>
> Will the SOLAR inverter match the generator as it would match the
> grid?
>
> Thanks
> Phil
>
As is usual, nonsense abounds.

Suppose;

You are using 4kW hours a day. So you invest in say 900Ah of batteries for a cost of $3000(a years
fuel bill) and use the batteries to supply one days worth of energy.

Then the batteries will have paid for themselves in 3 years of use. Given that with proper maint.
and care a good quality set of batteries can last at least fifteen years, you would save $12000 over
the life of the batteries.

Also given that fuel prices are not likely to fall and that you do not have a grid connection your
real savings over the life of the batteries is likely to be far greater.

Now this is a very simplistic accounting for just adding a battery bank to your system.

My question is "What are you in fact running?" 4kW is not that much of an ask for solar to be cost
effective. Used to knock off the lot or just a days worth of fuel. It's just not that hard.

There is a printing business in NSW that uses solar for their computers and mains for the presses.
It is at the end of the grid run and suffers from a rather variable power supply.

The reason is that the owner does not mind if the presses run a bit slower, but really gets pissed
off if the computers crash.

--
Posted via a free Usenet account from http://www.teranews.com

Vaughn Simon

2007-05-26, 9:25 pm

"George Ghio" <ghio@nobodyhome.com.au> wrote in message
news:4658bc52$0$16341$88260bb3@free.teranews.com...
> As is usual, nonsense abounds.
>
> Suppose;
>
> You are using 4kW hours a day.

But he is not using 4 kWh per day.

7 Hours of operation at an average load of 4 kW = 28 kWh

Further, that 900 AH (@ an assumed 48 volts) would only give you 4 kWh at nearly
100% DOD. It might do that, but I doubt that it would last 15 years doing that.

Correct me if I am wrong here:

If $3,000 worth of batteries gives you 900 amp/hours @ 100% DOD, (48 V. X
900 A. = 4.32 kWh) then you need $6,000 worth of batteries for each hour of
operation if you design to 50% DOD. 7 X $6,000 = $42,000 for a battery bank
sized to supply one day's autonomy @ 50% DOD. If that is correct, it is no
wonder that Phil wants nothing to do with a battery bank.

What did I do wrong?

Vaughn

Vaughn

David Williams

2007-05-27, 3:25 am

-> If $3,000 worth of batteries gives you 900 amp/hours @ 100% DOD, (48 V.
-> 900 A. = 4.32 kWh) then you need $6,000 worth of batteries for each hour of
-> operation if you design to 50% DOD. 7 X $6,000 = $42,000 for a battery bank
-> sized to supply one day's autonomy @ 50% DOD. If that is correct, it is no
-> wonder that Phil wants nothing to do with a battery bank.

-> What did I do wrong?

-> Vaughn

1000 ah at 48 volts would be 48 kWh. 900 ah at 48 volts is 43.2 kWh.
You're wrong by a factor of ten. So the cost of the battery bank would
be $4,200.

dow

Vaughn Simon

2007-05-27, 9:25 am

"David XXXXXXXX" <david.XXXXXXXX@bayman.org> wrote in message
news:1180241402.912.1180235156@bayman.org...
>-> If $3,000 worth of batteries gives you 900 amp/hours @ 100% DOD, (48 V.
> -> 900 A. = 4.32 kWh) then you need $6,000 worth of batteries for each hour of
> -> operation if you design to 50% DOD. 7 X $6,000 = $42,000 for a battery
> bank
> -> sized to supply one day's autonomy @ 50% DOD. If that is correct, it is no
> -> wonder that Phil wants nothing to do with a battery bank.
>
> -> What did I do wrong?
>
> -> Vaughn
>
> 1000 ah at 48 volts would be 48 kWh. 900 ah at 48 volts is 43.2 kWh.
> You're wrong by a factor of ten. So the cost of the battery bank would
> be $4,200.

Excuse me while I go beat my head on a large rock... OK, that feels better
now. I thought $42 Grand sounded like a bunch of money.

Vaughn

>
> dow

wmbjk

2007-05-27, 1:25 pm

On Sun, 27 May 2007 01:40:30 GMT, "Vaughn Simon"
<vaughnsimonHATESSPAM@att.FAKE.net> wrote:

>
>"George Ghio" <ghio@nobodyhome.com.au> wrote in message
>news:4658bc52$0$16341$88260bb3@free.teranews.com...
>
>But he is not using 4 kWh per day.
>7 Hours of operation at an average load of 4 kW = 28 kWh

Right. I made it 3 generator runs per week, 7 hours each at 4kW
average - 84kWh per week, somewhat less than we use. Our setup might
have cost $35k if we'd hired out the job.

>Further, that 900 AH (@ an assumed 48 volts) would only give you 4 kWh at nearly
>100% DOD. It might do that, but I doubt that it would last 15 years doing that.

> What did I do wrong?

He lives in a 12V world so he probably meant to suggest 10.8kWh of
batteries. Good ones could last 20 years, or some that cost half as
much might last half as long.
http://www.thesolarbiz.com/Cost_Table_batteries.htm. Regardless,
unless a new *source* is added, the energy would still have to come
from burning fuel. Phil might use HOMER as Ron suggested to compare
the savings of somewhat reduced fuel and substantially less generator
hours against the additional cost of batteries and inverter(s). Throw
in solar to reduce the fuel even further. After that one would have to
put a value on preferences - battery maintainance versus generator
maintainance etc. At $3k per year (and rising) for fuel, I expect
there's a generator-battery-inverter-solar scheme that would pay, plus
be more convenient and less work overall.

Wayne

Todd

2007-05-27, 8:25 pm

On May 25, 10:34 pm, Eeyore <rabbitsfriendsandrelati...@hotmail.com>
wrote:
> philkryder wrote:
>
> PV solar makes no sense for anything at present costs and efficiencies.
>
> Graham

For once I agree with Graham. First, I've found there to be a big
difference between rated PV output and actual (in my case actual is
about 50% of rated under the best of circumstances). Next, you only
get 5 hours of useful power so you need lots of storage. Finally,
there are lots of days you get little useful power.

My preferred solution is a very small diesel engine (2KW) burning WVO
driving a car alternator through my PV charge controller to the
battery bank. Originally I had huge coking problems but that has been
largely mitigated by better filtering of the WVO and starting and
shutting down on diesel. On small engines this amounts to very little
time on diesel.

I am able to deploy 3 small diesels to this solution (I have at least
one backup ready at all times) for the cost of just a single 160W
(rated ... 90W actual) PV panel. I don't use expensive deep discharge
batteries. Rather I use 10 70AH 6 year car batteries. I don't use
expensive deep discharge inverter/chargers. Rather, I use off the
shelf 12V 1500W inverters.

My batteries never fall below 11.5V.

My experience so far has been gratifying.

somebody@somewhere.com

2007-05-27, 8:25 pm

On 27 May 2007 16:16:28 -0700, Todd <Todd@WithGLEE.com> wrote:

>Rather, I use off the
>shelf 12V 1500W inverters.
>
>My batteries never fall below 11.5V.

What brand inverters? Some shut down or complain at 12vts.

(PeteCresswell)

2007-05-27, 9:25 pm

Per Todd:
>WVO

Waste Vegetable Oil?
--
PeteCresswell

Todd

2007-05-28, 9:25 am

On May 27, 7:58 pm, someb...@somewhere.com wrote:
> On 27 May 2007 16:16:28 -0700, Todd <T...@WithGLEE.com> wrote:
>
>
>
> What brand inverters? Some shut down or complain at 12vts.

I've used a Cobra 2500W and a MAXXsst 1500W. I think both are rated at
15V max. I did have to lower the equalize voltage to 15V on the Cobra
but the MAXX is able to take the controller's default 15.2V without
shutting down. I also have a small Instant Power 750W (AutoZone) which
can also take the 15.2V without shutdown. All shutdown at about 11.5V
on the low side. With my charging and loading regimen that almost
never happens.

Todd

2007-05-28, 9:25 am

On May 27, 8:34 pm, "(PeteCresswell)" <x...@y.Invalid> wrote:
> Per Todd:
>
>
> Waste Vegetable Oil?
> --
> PeteCresswell

Yes. Filtered Waste Vegetable Oil.

sylvan butler

2007-05-28, 1:25 pm

On Fri, 25 May 2007 20:52:33 -0700, Anthony Matonak <anthonym40@nothing.like.socal.rr.com> wrote:
> I don't think a grid-tie inverter will work with a generator.
> The grid-tie regulations require that the inverter only connect
> when the grid waveform is stable and I don't think most generators
> are stable enough.

That's most likely correct.

If you use a battery+inverter solution then another very similar option
might work for you.

The Trace SW line has (or had) a "generator support" feature whereby it
would reduce charging and even start inverting to assist the A.C. output
from a generator (or the grid if on a small grid circuit) up to about
60amps total output. Mine has no problem syncing to a generac 4000XL if
the generac has a few watts of load already on it. (I use a 100watt
"trouble light".) I don't know if this feature is still provided by
current production Xantrex SW inverters.

sdb

--
What's seen on your screen? http://pcscreenwatch.com
sdbuse1 on mailhost bigfoot.com

sylvan butler

2007-05-28, 1:25 pm

On Sun, 27 May 2007 14:56:26 GMT, wmbjk <wmbjkREMOVE@citlink.net> wrote:
> the savings of somewhat reduced fuel and substantially less generator
> hours against the additional cost of batteries and inverter(s). Throw
> in solar to reduce the fuel even further. After that one would have to
> put a value on preferences - battery maintainance versus generator
> maintainance etc. At $3k per year (and rising) for fuel, I expect
> there's a generator-battery-inverter-solar scheme that would pay, plus
> be more convenient and less work overall.

I suspect even the batteries and inverter added to the generator
solution would pay off. Unless his loads are very well matched to
generator output during the entire gen run, the generator will spend the
mis-matched time as a very ineffecient source of electricity.

Matching a proper inverter, batteries and charger into the solution
could allow most efficient generator operation for heavy loads and
battery charging, and then provide battery->inverter power all the rest
of the time.

As you mentioned, this can result in "reduced fuel and ... generator
hours" and I've found it can be cost effective. And do it right up
front so the possiblity to add solar is left open, and run the numbers
later to make that decision.

sdb

--
What's seen on your screen? http://pcscreenwatch.com
sdbuse1 on mailhost bigfoot.com

philkryder

2007-05-29, 3:25 am

On May 28, 9:32 am, sylvan butler
<ZsdbUse1+noZs_0...@Zbigfoot.Zcom.invalid> wrote:
> On Sun, 27 May 2007 14:56:26 GMT, wmbjk <wmbjkREM...@citlink.net> wrote:
>
> I suspect even the batteries and inverter added to the generator
> solution would pay off. Unless his loads are very well matched to
> generator output during the entire gen run, the generator will spend the
> mis-matched time as a very ineffecient source of electricity.
>
> Matching a proper inverter, batteries and charger into the solution
> could allow most efficient generator operation for heavy loads and
> battery charging, and then provide battery->inverter power all the rest
> of the time.
>
> As you mentioned, this can result in "reduced fuel and ... generator
> hours" and I've found it can be cost effective. And do it right up
> front so the possiblity to add solar is left open, and run the numbers
> later to make that decision.
>
> sdb
>
> --
> What's seen on your screen? http://pcscreenwatch.com
> sdbuse1 on mailhost bigfoot.com

Well this is interesting.

PV seems to not have any payback.

But, the battery bank CAN pay based on running the generator harder
for reduced hours...

What would the fuel price have to reach for the PV to pay?

George Ghio

2007-05-29, 3:25 am

philkryder wrote:
> On May 28, 9:32 am, sylvan butler
> <ZsdbUse1+noZs_0...@Zbigfoot.Zcom.invalid> wrote:
>
> Well this is interesting.
>
> PV seems to not have any payback.
>
> But, the battery bank CAN pay based on running the generator harder
> for reduced hours...
>
> What would the fuel price have to reach for the PV to pay?
>
>
What about the rest of it? Not one of my solar panels has ever;

Broken a con rod

Burnt a valve

Run a bearing

Or seized

Common warranty for panels - 25 years

Fuel for 25 years (at current cost of $3000/year) $75,000. Add to that 5 - 6 gen-sets
and solar looks pretty good.

Or you can look at it as many here do. i.e. Invest the money.

So sell every thing you own and put the cash into stocks.

By your own admission you do not have a grid connection. Given the state of oil reserves in the
world, do you think you will be able to afford fuel by the end of 2010.

Get your batteries and add solar along the way.

Oh yeah, never take advice from people who can't provide the numbers for their own systems.If they
don't know what their own system does then how the hell do you think they can help you with your system.

--
Posted via a free Usenet account from http://www.teranews.com

Todd

2007-05-29, 1:25 pm

On May 29, 1:01 am, George Ghio <g...@nobodyhome.com.au> wrote:
> philkryder wrote:
>
>
>
>
>
>
>
>
>
> What about the rest of it? Not one of my solar panels has ever;
>
> Broken a con rod
>
> Burnt a valve
>
> Run a bearing
>
> Or seized
>
> Common warranty for panels - 25 years

Is it common knowledge that panels only give out about 1/2 of their
rated capacity under the best of conditions? Is it common knowledge
that panels under the best of conditions only deliver output for 5
hours per day ... and virtually nothing on a cloudy day? Is it common
knowledge that you to have the best of conditions the panels must
track the sun? Is it common knowledge that you can buy two (or more)
small diesel engines for the cost of just a single panel?

>
> Fuel for 25 years (at current cost of $3000/year) $75,000. Add to that 5 - 6 gen-sets
> and solar looks pretty good.

I don't agree. First, I have been having good success burning WVO
which has a very low cost (virtually the opportunity cost of a small
amount of my time).

>
> Or you can look at it as many here do. i.e. Invest the money.

Actually it's "waste the money". If you want to invest money in stand
alone power, put it in storage (i.e. batteries).

>
> So sell every thing you own and put the cash into stocks.
>
> By your own admission you do not have a grid connection. Given the state of oil reserves in the
> world, do you think you will be able to afford fuel by the end of 2010.

My fuel costs have very little to do with the state of oil reserves.

>
> Get your batteries and add solar along the way.

With any system, batteries are the key. Whether you are using PV or IC
driven generation, it's the batteries that make the system work by
meeting peak loads and filling in the valleys in the demand vs. time
trace.

>
> Oh yeah, never take advice from people who can't provide the numbers for their own systems.If they
> don't know what their own system does then how the hell do you think they can help you with your system.

Any particular numbers you'd like to know from me?

wmbjk

2007-05-29, 1:25 pm

On 28 May 2007 21:19:35 -0700, philkryder <alt.google@Kryder.com>
wrote:

>Well this is interesting.
>
>PV seems to not have any payback.

That part of your conclusion is faulty. For example, PV has paid me
back several times over. A proper analysis is required to see if it's
worthwhile for you.

>But, the battery bank CAN pay based on running the generator harder
>for reduced hours...

Most likely. But that will require inverter(s) as well and they may
cost more than the batteries, or not. Depends on your goals and
strategy. For example, if your plan is to skip one generator run per
week, that would require about 40kWh, perhaps $3500 for L-16s, plus
8kW of inverters which might cost another $4500. That strategy could
cut generator time by 1/3 and generator wear and fuel by perhaps 20%.
Or you could stick with the 3 runs per week, using the generator for
the largest loads and the inverter-battery for the smaller ones (if
that fits). Which might achieve the same savings on generator time and
fuel on 1/3 of the battery and 1/2 the inverter cost.

>What would the fuel price have to reach for the PV to pay?

From what you've written so far it's impossible for anyone to say
whether or not solar would pay in your application. I see from your
other post that you're in the Santa Barbara area. If your location is
anything like where I used to live (near Ronny Ray Gun's ranch), then
morning fog will frequently kill 4 hours of production per day.

Wayne

wmbjk

2007-05-29, 1:25 pm

On 29 May 2007 07:56:00 -0700, Todd <Todd@WithGLEE.com> wrote:

>Is it common knowledge that panels only give out about 1/2 of their
>rated capacity under the best of conditions?

No. Some posters report more than 100% in the right conditions. One
might get down to 50% in the worst circumstances - perhaps a very hot
location, or by tying a 24V module without MPPT to a 12V battery.

> Is it common knowledge
>that panels under the best of conditions only deliver output for 5
>hours per day ...

No. Output for fixed installations is usually calculated using average
equivalent full-sun hours which takes into account local conditions. 5
might be a common number for that. My hours are cut a little by
mountains, nevertheless the (tracking) arrays will get some 11 hours
of sun today.

> and virtually nothing on a cloudy day?

Yes, most people know that, although on some "cloudy" days production
can still be worthwhile.

>knowledge that you to have the best of conditions the panels must
>track the sun?

Tracking pays on some installations, but most folks do without it.

> Is it common knowledge that you can buy two (or more)
>small diesel engines for the cost of just a single panel?

Doesn't really matter since that strategy is only practical for a
small percentage of off-gridders.

Wayne

George Ghio

2007-05-29, 8:25 pm

Todd wrote:
> On May 29, 1:01 am, George Ghio <g...@nobodyhome.com.au> wrote:
>
> Is it common knowledge that panels only give out about 1/2 of their
> rated capacity under the best of conditions?

No

> Is it common knowledge
> that panels under the best of conditions only deliver output for 5
> hours per day ... and virtually nothing on a cloudy day?

No

> Is it common
> knowledge that you to have the best of conditions the panels must
> track the sun?

No

> Is it common knowledge that you can buy two (or more)
> small diesel engines for the cost of just a single panel?

No

>
> I don't agree. First, I have been having good success burning WVO
> which has a very low cost (virtually the opportunity cost of a small
> amount of my time).

How long do you think that's going to last?
>
>
> Actually it's "waste the money". If you want to invest money in stand
> alone power, put it in storage (i.e. batteries).

And fuel. A properly sized and designed PV system is a good investment if the cost is below a grid
connection. In my case, $26,000 cheaper.
>
>
> My fuel costs have very little to do with the state of oil reserves.

How long do you think that's going to last?
>
>
> With any system, batteries are the key. Whether you are using PV or IC
> driven generation, it's the batteries that make the system work by
> meeting peak loads and filling in the valleys in the demand vs. time
> trace.

Ah, A correct statement. Batteries are the heart of standalone systems.
>
>
> Any particular numbers you'd like to know from me?

Your entire energy use from all fuel sources would do for a start.

--
Posted via a free Usenet account from http://www.teranews.com

sylvan butler

2007-05-29, 8:25 pm

On 28 May 2007 21:19:35 -0700, philkryder <alt.google@Kryder.com> wrote:
> Well this is interesting.
> PV seems to not have any payback.

I don't think I'd go that far. That's why I said:

> On May 28, 9:32 am, sylvan butler
><ZsdbUse1+noZs_0...@Zbigfoot.Zcom.invalid> wrote:
[color=darkred]
> But, the battery bank CAN pay based on running the generator harder
> for reduced hours...

Given the current widely available system components, it seems
battery+inverter is a logical first step on the road to PV. Until you
have the data from that first step, it is grasping in the dark to
further quantify the PV.

> What would the fuel price have to reach for the PV to pay?

How much fuel do you burn to produce how much power, AFTER you have a
battery+inverter system?

Without the battery+inverter, you have no storage. Grid-tie systems are
essentially using the grid for storage. You need the battery+inverter
and then the PV will be a direct replacement for generator run-time.

Currently PV is about $4/watt, plus infrastructure and install costs
(but of course everything comes in chunks*, so you cannot say "I need
some N watts, please" and get exactly that N for any N). If you are the
hypothetical "average" that $4 will get you 20wattHours per day. How
much will it cost you to produce 20wattHours per day for the next 20
years?

Once you get the battery+inverter than we can ballpark the PV...

*Chunks:

Adding PV to an existing battery and inverter system has the cost of
some infrastructure costs that can be shared among several panels
(charge controller and wire from panels to charge controller to battery
and possibly such things as a pole mount and/or tracker) plus installing
(purchase and mount and wire) the panels (ca $4/watt). If you buy a LOT
of panels, you might need a second chunk of infrastructure (either
bigger or a duplicate set of charge controller and assoc. wiring, etc).

For example, I put in infrastructure to support about 2.5kw of panels (I
found that to be a reasonable minimum, planning for less did not save
significant money but planning for more cost significantly more). I
installed only 1.2kw of PV. My incremental cost to install 100% more
panels is simply the cost of each panel to mount and wire it to the
combiner. If after that I want to install another kw of panels I need
another charge controller, etc. in addition to the panels.

sdb
--
What's seen on your screen? http://pcscreenwatch.com
sdbuse1 on mailhost bigfoot.com

philkryder

2007-05-29, 9:25 pm

On May 29, 4:57 pm, sylvan butler
<ZsdbUse1+noZs_0...@Zbigfoot.Zcom.invalid> wrote:
> On 28 May 2007 21:19:35 -0700,philkryder<alt.goo...@Kryder.com> wrote:
>
>
> I don't think I'd go that far. That's why I said:
>
>
> Given the current widely available system components, it seems
> battery+inverter is a logical first step on the road to PV. Until you
> have the data from that first step, it is grasping in the dark to
> further quantify the PV.
>
>
> How much fuel do you burn to produce how much power, AFTER you have a
> battery+inverter system?
>
> Without the battery+inverter, you have no storage. Grid-tie systems are
> essentially using the grid for storage. You need the battery+inverter
> and then the PV will be a direct replacement for generator run-time.
>
> Currently PV is about $4/watt, plus infrastructure and install costs
> (but of course everything comes in chunks*, so you cannot say "I need
> some N watts, please" and get exactly that N for any N). If you are the
> hypothetical "average" that $4 will get you 20wattHours per day. How
> much will it cost you to produce 20wattHours per day for the next 20
> years?
>
> Once you get the battery+inverter than we can ballpark the PV...
>
> *Chunks:
>
> Adding PV to an existing battery and inverter system has the cost of
> some infrastructure costs that can be shared among several panels
> (charge controller and wire from panels to charge controller to battery
> and possibly such things as a pole mount and/or tracker) plus installing
> (purchase and mount and wire) the panels (ca $4/watt). If you buy a LOT
> of panels, you might need a second chunk of infrastructure (either
> bigger or a duplicate set of charge controller and assoc. wiring, etc).
>
> For example, I put in infrastructure to support about 2.5kw of panels (I
> found that to be a reasonable minimum, planning for less did not save
> significant money but planning for more cost significantly more). I
> installed only 1.2kw of PV. My incremental cost to install 100% more
> panels is simply the cost of each panel to mount and wire it to the
> combiner. If after that I want to install another kw of panels I need
> another charge controller, etc. in addition to the panels.
>
> sdb
> --
> What's seen on your screen? http://pcscreenwatch.com
> sdbuse1 on mailhost bigfoot.com

So, it seems the recommendation is to start with storage and inverter
rather than production.

Let's assume that an 8kw inverter will meet our surge needs. And that
a battery bank needs to run 2 full days (a weekend with fog and no
PV).

And an 8 kw inverter.

Then it seems we need:
5kw*7hrs/day*2days = 70kwh of storage.
But, since we wouldn't want to fully discharge them, what what
additional capacity would we need?

And, what would that cost approximately?

On PV side then $4 per watt.
Would 10000 watts capacity suffice to keep the batteries charged?
I assume that the actual produced electricity is less than the amount
installed except at peak hours of optimum angled days.

philkryder

2007-05-29, 9:25 pm

On May 26, 4:43 am, Ron Rosenfeld <ronrosenf...@nospam.org> wrote:
> On 25 May 2007 17:35:56 -0700,philkryder<alt.goo...@Kryder.com> wrote:
>
>
>
>
>
>
>
>
>
>
>
> Phil,
>
> There's a free program called HOMER (www.nrel.gov/homer)thatwill allow you
> evaluate this question from a dollars and cents perspective, so long as you
> have the relevant data.
>
> In a word, it depends.
>
> An off-grid capable inverter, such as the Trace/Xantrex SW5548, will be
> able to handle the combining (and control) of your generator and PV panels
> and batteries.
>
> The HOMER program will allow you to fairly accurately model your power
> requirements (9-4, 4kW continuous draw, three days/week) and optimize your
> panel array size and battery bank requirements. You will then be able to
> compare it with fuel costs and decide on an optimal system. Economic
> assumptions are also modelled into the program.
>
> At my location in Downeast Maine, it would cost approximately $40,000 to
> set up a system to generate 100% of your power requirements from PV.
> Depending on the cost of money to me, and my predictions as to fuel costs,
> that might be worthwhile.
>
> --ron

The HOMER looks interesting, but I can't seem to get the batteries to
become part of the setup...

George Ghio

2007-05-30, 3:25 am

philkryder wrote:
> On May 29, 4:57 pm, sylvan butler
> <ZsdbUse1+noZs_0...@Zbigfoot.Zcom.invalid> wrote:
>
> So, it seems the recommendation is to start with storage and inverter
> rather than production.
>
>
> Let's assume that an 8kw inverter will meet our surge needs. And that
> a battery bank needs to run 2 full days (a weekend with fog and no
> PV).
>
>
> And an 8 kw inverter.
>
>
> Then it seems we need:
> 5kw*7hrs/day*2days = 70kwh of storage.
> But, since we wouldn't want to fully discharge them, what what
> additional capacity would we need?
>
> And, what would that cost approximately?
>
> On PV side then $4 per watt.
> Would 10000 watts capacity suffice to keep the batteries charged?
> I assume that the actual produced electricity is less than the amount
> installed except at peak hours of optimum angled days.

48 Volt system
3500wh/day
250Ah batteries
Total Ah demand 81.02
Days Autonomy 2
Daily depth of discharge 33%
20 - 80W panels (1.6kW)

--
Posted via a free Usenet account from http://www.teranews.com

Ron Rosenfeld

2007-05-30, 9:25 am

On 29 May 2007 19:07:34 -0700, philkryder <alt.google@Kryder.com> wrote:

>The HOMER looks interesting, but I can't seem to get the batteries to
>become part of the setup...

In the upper right panel, just under the menu icons, there is a line that
says "Equipment to consider". Select the Add/Remove button and you will
see all of the components available for selection.
--ron

Todd

2007-05-31, 9:25 am

On May 29, 11:03 am, wmbjk <wmbjkREM...@citlink.net> wrote:
> On 29 May 2007 07:56:00 -0700, Todd <T...@WithGLEE.com> wrote:
>
>
> No. Some posters report more than 100% in the right conditions.

I have never seen a post reporting more than 100% in "any" conditions.
All postings are available to us. Point me to one.

> One
> might get down to 50% in the worst circumstances - perhaps a very hot
> location, or by tying a 24V module without MPPT to a 12V battery.

My panel starts at 50% in the "best" of circumstances. I have had it
for more than 2 years. I have used it in the winter when it should be
most efficient. I have used it in the summer when it gets the most
direct sun. I have pointed it at the sun with precision. I have
manually tracked the sun. Never better than 50%. And I've reported
this numerous times in this and other groups. I use a 36V panel with
MPPT so I get everything I can possibly get out of my panel. You're
the first one whose ever challenged my contention. Do you have panels?
What is the brand? What is the performance? How do you measure it?

>
>
> No. Output for fixed installations is usually calculated using average
> equivalent full-sun hours which takes into account local conditions. 5
> might be a common number for that. My hours are cut a little by
> mountains, nevertheless the (tracking) arrays will get some 11 hours
> of sun today.

Sure? My grass gets sun more than 11 hours per day. But when I look at
the output of the panel, even when I manually point it, 5 hours of
useful output (e.g. more than 5% of rating) is about all I can ever
expect. This 5 hours figure has also never been challenged in a group.

>
>
> Yes, most people know that, although on some "cloudy" days production
> can still be worthwhile.

Sure. It's going to be worth the while because the "while" takes no
effort. But as far as being of worth in relation to real power needs
(we're not driving a transistor radio with these), it's worthless on a
cloudy day. The fact that you would attempt to debate this point is
suspect.

>
>
> Tracking pays on some installations, but most folks do without it.

Name one. It would "pay" it "all" installations but that pay would
never exceed the "cost".

>
>
> Doesn't really matter since that strategy is only practical for a
> small percentage of off-gridders.

Oh really? Just what is it that makes this strategy impractical for
the large percentage of off-gridders?

>
> Wayne

Todd

2007-05-31, 9:25 am

On May 29, 6:48 pm, George Ghio <g...@nobodyhome.com.au> wrote:
> Todd wrote:
>
>
>
>
>
>
>
> No
>
>
> No
>
>
> No
>
>
> No
>
>
>
> How long do you think that's going to last?

As long as I choose it to last. The engines will wear out and need
refurbishing. But I can buy 2 for the cost of a single panel. I can
repair them for less than that. And an engine puts out 20 times as
much output as a panel and using WVO for fuel, the cost is minimal.

>
>
>
>
>
> And fuel. A properly sized and designed PV system is a good investment if the cost is below a grid
> connection. In my case, $26,000 cheaper.

The grid is unbelievably efficient. Using a diesel I can beat any PV
system in cost or performance, but I still can't beat the grid. I beat
people on the grid by my usage and conservation (e.g. insulation)
practices.

>
>
>
>
>
>
> How long do you think that's going to last?

Well, right now I have about a 5 year reserve and it's growing at 3
times my usage rate.

>
>
>
>
>
> Ah, A correct statement. Batteries are the heart of standalone systems.

Always a warm feeling when honest agreement is achieved.

>
>
>
>
>
> Your entire energy use from all fuel sources would do for a start.

I burn about 3 quarts of WVO daily. I collect it weekly when doing
other things I would normally have to do (like buying groceries, gas
for the car, going to work, and errands). Thus, collection cost is
time which amounts to less than 10 minutes. Then there is the
filtering cost. This amounts to pouring it into and elevated bucket
which feeds a 5 micron water filter (cartridge cost less than $3 and
lasts at least a month) and collecting it in a lower bucket. Cost ...
very low. I buy about 4 20# propane refills annually, mostly for
cooking and rarely for heat during cold spells.

Now, how about yours.

>
> --
> Posted via a free Usenet account fromhttp://www.teranews.com

R.H. Allen

2007-05-31, 9:25 am

Todd wrote:
> On May 29, 11:03 am, wmbjk <wmbjkREM...@citlink.net> wrote:
> My panel starts at 50% in the "best" of circumstances. I have had it
> for more than 2 years. I have used it in the winter when it should be
> most efficient. I have used it in the summer when it gets the most
> direct sun. I have pointed it at the sun with precision. I have
> manually tracked the sun. Never better than 50%.

I suggest you check your warranty then. Most PV companies nowadays
guarantee your output for at least 20 years, allowing for about 1%
degradation per year. While most PV modules come nowhere near that rate
of degradation, if you've never seen 50% of the rated output even when
pointing the module directly at the sun it suggests there's something
wrong with it. Mind you, you will only see the rated output when the
amount of sunlight received is about 1000 W/m^2 and the module's
temperature is about 25C (information that almost certainly appears on
your module's spec sheet) -- lower light levels will reduce output
proportionally, and higher temperatures will cause a slight reduction in
power output.

That said, you should be able to get close to 1000 W/m^2, if not more
(depending on your location), on a cloudless midsummer's day within a
couple hours of noon. Obviously it would be best, in terms of supporting
a warranty claim, if you could measure the incoming sunlight with a
pyranometer or somesuch, but under those conditions you will definitely
be in the right neighborhood. The spec sheet for the module should give
you some idea how much to derate for temperature -- a crystalline
silicon module will lose about 10% of its efficiency under those
conditions (relatively speaking, so a 100 W module would be expected to
produce about 90W at temperature), while an amorphous silicon or cadmium
telluride module will lose more like 6%.

> And I've reported
> this numerous times in this and other groups. I use a 36V panel with
> MPPT so I get everything I can possibly get out of my panel. You're
> the first one whose ever challenged my contention. Do you have panels?
> What is the brand? What is the performance? How do you measure it?

Do you use an inverter? If so, are you measuring the DC or AC output
when you see less than 50% of the module's rated output? If AC, what is
your reading on a cloudless day near noon, and how much power is your
inverter rated to handle? It's possible that you're operating in a
regime where your inverter is not very efficient.

>
> Sure? My grass gets sun more than 11 hours per day.

Your grass doesn't get 11 hours of *full* sun per day, though, and when
people talk about their PV systems getting 5 hours of sun they're
usually talking about a full sun equivalent. In other words, the energy
content of the sunlight received is about 5000 kWh/m^2 (the amount that
would be received if the sun shone at 1000 W/m^2 for 5 hours then turned
off like a lightbulb) even though the sun might actually be in the sky
for 11+ hours over the course of the day.

> But when I look at
> the output of the panel, even when I manually point it, 5 hours of
> useful output (e.g. more than 5% of rating) is about all I can ever
> expect. This 5 hours figure has also never been challenged in a group.

Perhaps it wasn't challenged because people thought you meant 5 full
hours of sun equivalent.

>
> Sure. It's going to be worth the while because the "while" takes no
> effort. But as far as being of worth in relation to real power needs
> (we're not driving a transistor radio with these), it's worthless on a
> cloudy day. The fact that you would attempt to debate this point is
> suspect.

Many, if not most, off-gridders who rely on PV have batteries for energy
storage (it's not clear to me whether you do). They size the PV system
so that on a bright, sunny day it produces more power than they need,
with the excess going into storage. On a cloudy day, they take what they
can get from the PV system and draw the rest from the batteries. Under
those circumstances, even a trickle from the PV system on a cloudy day
makes an *enormous* difference in the number of (very expensive)
batteries that are needed to ensure power is always available. If you're
running a diesel generator in situations where others rely upon
batteries, though, I can see how you would be unimpressed with PV in
cloudy conditions.

>
> Name one. It would "pay" it "all" installations but that pay would
> never exceed the "cost".

Using trackers increases energy output per module. That reduces the
number of modules you need to produce a given amount of energy. Suppose
five modules costing $400 each can be eliminated from the system by
using trackers. Then if the cost of buying and installing trackers is
less than 5 x $400 = $2000, the system is cheaper with trackers and the
trackers pay for themselves (neglecting maintenance and replacement
costs, which may or may not be negligible).

Mike

2007-05-31, 8:25 pm

On 31 May 2007 05:06:25 -0700, Todd <Todd@WithGLEE.com> wrote:

>My panel starts at 50% in the "best" of circumstances. I have had it
>for more than 2 years. I have used it in the winter when it should be
>most efficient. I have used it in the summer when it gets the most
>direct sun. I have pointed it at the sun with precision. I have
>manually tracked the sun. Never better than 50%. And I've reported
>this numerous times in this and other groups. I use a 36V panel with
>MPPT so I get everything I can possibly get out of my panel.

Winter = possibly clear skies, low cell temperature which are good but
this may be combined with a low sun angle and thus a large loss
through the atmosphere.

Summer = sometimes higher levels of obscuration due to cloud cover or
atmospheric pollutants, a high sun angle, which is good but it also
gives high cell temperatures

Cool the cell in summer and output will increase.

--

Todd

2007-05-31, 8:25 pm

On May 31, 9:20 am, "R.H. Allen" <kka...@hotmail.com> wrote:
> Todd wrote:
>
>
> I suggest you check your warranty then. Most PV companies nowadays
> guarantee your output for at least 20 years, allowing for about 1%
> degradation per year.

I'll check the warranty. My panel performs today exactly as it did on
the day I first began experimenting with it over 2 years ago.

> While most PV modules come nowhere near that rate
> of degradation, if you've never seen 50% of the rated output even when
> pointing the module directly at the sun it suggests there's something
> wrong with it.

So what amount of degradation do most PV modules come near?

> Mind you, you will only see the rated output when the
> amount of sunlight received is about 1000 W/m^2 and the module's
> temperature is about 25C (information that almost certainly appears on
> your module's spec sheet) -- lower light levels will reduce output
> proportionally, and higher temperatures will cause a slight reduction in
> power output.
>
> That said, you should be able to get close to 1000 W/m^2, if not more
> (depending on your location), on a cloudless midsummer's day within a
> couple hours of noon. Obviously it would be best, in terms of supporting
> a warranty claim, if you could measure the incoming sunlight with a
> pyranometer or somesuch, but under those conditions you will definitely
> be in the right neighborhood. The spec sheet for the module should give
> you some idea how much to derate for temperature -- a crystalline
> silicon module will lose about 10% of its efficiency under those
> conditions (relatively speaking, so a 100 W module would be expected to
> produce about 90W at temperature), while an amorphous silicon or cadmium
> telluride module will lose more like 6%.

My panel is a RWE Schott Solar, Inc. SAPC-165

http://www.us.schott.com/photovolta...lish/index.html

The data they give me is:
Max Power (Pmax) 165.0W
Open-Circuit Voltage (Voc) 43.1V
Short-Circuit Current (Isc) 5.31A
Operating Voltage (Vpmax) 34.6V
Current at Vpmax (Ipmax) 4.77A

They give me no degradation data.

Degrading by 6% would be 155W.

As it is evident that PV needs to be an order of magnitude more cost
effective than they are now by my experience, I still have a factor of
5 to make up. However, you have rattled my cage and I'll contact the
manufacturer to see if they think I have a defective panel.

>
>
> Do you use an inverter?

Of course I do. What else would I use?

> If so, are you measuring the DC or AC output
> when you see less than 50% of the module's rated output?

DC of course. I get the readings right off my Blue Sky Energy IPN-
ProRemote monitor. I see input (to the buck charge controller) voltage
and current and output current and battery voltage. It's very easy for
me to know the power I'm getting.

> If AC, what is
> your reading on a cloudless day near noon, and how much power is your
> inverter rated to handle? It's possible that you're operating in a
> regime where your inverter is not very efficient.

Silly question. Of course it's not AC. What panel puts out AC?

>
>
>
> Your grass doesn't get 11 hours of *full* sun per day, though, and when
> people talk about their PV systems getting 5 hours of sun they're
> usually talking about a full sun equivalent. In other words, the energy
> content of the sunlight received is about 5000 kWh/m^2 (the amount that
> would be received if the sun shone at 1000 W/m^2 for 5 hours then turned
> off like a lightbulb) even though the sun might actually be in the sky
> for 11+ hours over the course of the day.
>
>
> Perhaps it wasn't challenged because people thought you meant 5 full
> hours of sun equivalent.

So what is your challenge? I get output on cloudy days. I get output
as soon as the sun comes up until the sun goes down. But I only get
meaningful output for about 5 hours a day. And anyone who has
experience with PVs would know exactly what I was saying and what I
was meaning.
>
>
>
> Many, if not most, off-gridders who rely on PV have batteries for energy
> storage (it's not clear to me whether you do).

Then let me make that clear. I have 10 70AH batteries in parallel. My
system is 12V.

> They size the PV system
> so that on a bright, sunny day it produces more power than they need,
> with the excess going into storage.

Well duh.

> On a cloudy day, they take what they
> can get from the PV system and draw the rest from the batteries. Under
> those circumstances, even a trickle from the PV system on a cloudy day
> makes an *enormous* difference in the number of (very expensive)
> batteries that are needed to ensure power is always available.

One of us has a confused notion of "trickle" and "enormous". You're
not going to be getting very far when you're sinking an average of say
40W and sourcing with an average of say 6W (It's now 6:30PM on a sunny
day in Texas. My PV is doing 13.2V at .2A or 2.64W. Just for you I'll
point it directly at the sun rotating 90 degrees to the west ... I get
11.9V at .2A or 2.34W). This is the same as reducing the load from 40W
to 34W which I wouldn't call enormous (or 40W to 38W as my actual data
shows which for sure isn't enormous).

> If you're
> running a diesel generator in situations where others rely upon
> batteries, though, I can see how you would be unimpressed with PV in
> cloudy conditions.

I am not. I am using the diesel in place of the PV. It's as simple as
that. The main problem with a diesel is that as the batteries get
charged they present a smaller and smaller load. I now have what I
believe to be a novel solution for that.

>
>
>
> Using trackers increases energy output per module. That reduces the
> number of modules you need to produce a given amount of energy. Suppose
> five modules costing $400 each

You must be talking about modules 1/2 the size of mine. As I recall I
paid about $5 per watt over two years ago.

> can be eliminated from the system by
> using trackers. Then if the cost of buying and installing trackers is
> less than 5 x $400 = $2000, the system is cheaper with trackers and the
> trackers pay for themselves (neglecting maintenance and replacement
> costs, which may or may not be negligible).

I would be really surprised to find trackers cheaper than my module. I
considered building a tracker myself and preliminary to that I tracked
manually for several days. My findings were that the additional
performance would not be worth the cost of a tracker and this was
aggravated by my finding that under perfect tracking a PV system was
not sensible. Interesting that we can consider zero maintenance on
modules and tracking maintenance and replacement but not so on the
diesel.

Please give me the numbers you have on the cost of trackers and data
points on the power delivery curve for the day (before and after). And
by the way, considering practicality, how many PV systems do you see
tracking vs those you see stationary. I have never seen a tracking
system in the flesh though I have seen many stationary systems.

Steve Spence

2007-05-31, 8:25 pm

pointing solar south at solar noon at the same angle as your latitude should
indeed produce 165 watts (what battery voltage are you running?).

--
Steve Spence
Director, Green-Trust
http://www.green-trust.org
"Todd" <Todd@WithGLEE.com> wrote in message
news:1180654561.543456.31810@o5g2000hsb.googlegroups.com...
> On May 31, 9:20 am, "R.H. Allen" <kka...@hotmail.com> wrote:
>
> I'll check the warranty. My panel performs today exactly as it did on
> the day I first began experimenting with it over 2 years ago.
>
>
> So what amount of degradation do most PV modules come near?
>
>
> My panel is a RWE Schott Solar, Inc. SAPC-165
>
> http://www.us.schott.com/photovolta...lish/index.html
>
> The data they give me is:
> Max Power (Pmax) 165.0W
> Open-Circuit Voltage (Voc) 43.1V
> Short-Circuit Current (Isc) 5.31A
> Operating Voltage (Vpmax) 34.6V
> Current at Vpmax (Ipmax) 4.77A
>
> They give me no degradation data.
>
> Degrading by 6% would be 155W.
>
> As it is evident that PV needs to be an order of magnitude more cost
> effective than they are now by my experience, I still have a factor of
> 5 to make up. However, you have rattled my cage and I'll contact the
> manufacturer to see if they think I have a defective panel.
>
>
> Of course I do. What else would I use?
>
>
> DC of course. I get the readings right off my Blue Sky Energy IPN-
> ProRemote monitor. I see input (to the buck charge controller) voltage
> and current and output current and battery voltage. It's very easy for
> me to know the power I'm getting.
>
>
> Silly question. Of course it's not AC. What panel puts out AC?
>
>
> So what is your challenge? I get output on cloudy days. I get output
> as soon as the sun comes up until the sun goes down. But I only get
> meaningful output for about 5 hours a day. And anyone who has
> experience with PVs would know exactly what I was saying and what I
> was meaning.
>
> Then let me make that clear. I have 10 70AH batteries in parallel. My
> system is 12V.
>
>
> Well duh.
>
>
> One of us has a confused notion of "trickle" and "enormous". You're
> not going to be getting very far when you're sinking an average of say
> 40W and sourcing with an average of say 6W (It's now 6:30PM on a sunny
> day in Texas. My PV is doing 13.2V at .2A or 2.64W. Just for you I'll
> point it directly at the sun rotating 90 degrees to the west ... I get
> 11.9V at .2A or 2.34W). This is the same as reducing the load from 40W
> to 34W which I wouldn't call enormous (or 40W to 38W as my actual data
> shows which for sure isn't enormous).
>
>
> I am not. I am using the diesel in place of the PV. It's as simple as
> that. The main problem with a diesel is that as the batteries get
> charged they present a smaller and smaller load. I now have what I
> believe to be a novel solution for that.
>
>
> You must be talking about modules 1/2 the size of mine. As I recall I
> paid about $5 per watt over two years ago.
>
>
> I would be really surprised to find trackers cheaper than my module. I
> considered building a tracker myself and preliminary to that I tracked
> manually for several days. My findings were that the additional
> performance would not be worth the cost of a tracker and this was
> aggravated by my finding that under perfect tracking a PV system was
> not sensible. Interesting that we can consider zero maintenance on
> modules and tracking maintenance and replacement but not so on the
> diesel.
>
> Please give me the numbers you have on the cost of trackers and data
> points on the power delivery curve for the day (before and after). And
> by the way, considering practicality, how many PV systems do you see
> tracking vs those you see stationary. I have never seen a tracking
> system in the flesh though I have seen many stationary systems.
>
>

George Ghio

2007-06-01, 3:25 am

Todd wrote:
> On May 29, 6:48 pm, George Ghio <g...@nobodyhome.com.au> wrote:
> As long as I choose it to last. The engines will wear out and need
> refurbishing. But I can buy 2 for the cost of a single panel. I can
> repair them for less than that. And an engine puts out 20 times as
> much output as a panel and using WVO for fuel, the cost is minimal.
>

Ah, wishful thinking. What a wonderful thing. There will be a point at which "Waste Veg Oil" will
become owned by the state and reserved for strategic applications. i.e. returned to the farmers
where it will be used to keep you fed, emergency transport and military. Quite simply you will be
priced out of the market.
>
>
> The grid is unbelievably efficient. Using a diesel I can beat any PV
> system in cost or performance, but I still can't beat the grid. I beat
> people on the grid by my usage and conservation (e.g. insulation)
> practices.

Wow! Imagine that. The grid is unbelievably vulnerable to everything from nature to terrorism.
>
>
> Well, right now I have about a 5 year reserve and it's growing at 3
> times my usage rate.

See above. If you have a reserve and use it, what makes you think you will be allowed to keep it.
>
>
> Always a warm feeling when honest agreement is achieved.
>
>
> I burn about 3 quarts of WVO daily. I collect it weekly when doing
> other things I would normally have to do (like buying groceries, gas
> for the car, going to work, and errands). Thus, collection cost is
> time which amounts to less than 10 minutes. Then there is the
> filtering cost. This amounts to pouring it into and elevated bucket
> which feeds a 5 micron water filter (cartridge cost less than $3 and
> lasts at least a month) and collecting it in a lower bucket. Cost ...
> very low. I buy about 4 20# propane refills annually, mostly for
> cooking and rarely for heat during cold spells.
>
> Now, how about yours.

Well you see, you have not supplied yours yet.

I said, "Your entire energy use from all fuel sources would do for a start".

Do you, in fact, have any idea how much energy you use in a day?

--
Posted via a free Usenet account from http://www.teranews.com

R.H. Allen

2007-06-01, 3:25 am

Todd wrote:
> On May 31, 9:20 am, "R.H. Allen" <kka...@hotmail.com> wrote:
>
> I'll check the warranty. My panel performs today exactly as it did on
> the day I first began experimenting with it over 2 years ago.
>
>
> So what amount of degradation do most PV modules come near?

It's difficult to say -- those that degrade badly enough to need
replacement are easy for manufacturers to count, but those that are
never returned to the manufacturer tend not to be monitored. It's not
uncommon to see figures like 5% over 10 years and 10% over 20 years in
long-term field studies, though. The warranties, for obvious reasons,
are designed to avoid having to replace modules, so when manufacturers
warranty 1% per year you can bet they feel quite confident that very few
of their modules will fare that badly.

>
> My panel is a RWE Schott Solar, Inc. SAPC-165
>
> http://www.us.schott.com/photovolta...lish/index.html
>
> The data they give me is:
> Max Power (Pmax) 165.0W
> Open-Circuit Voltage (Voc) 43.1V
> Short-Circuit Current (Isc) 5.31A
> Operating Voltage (Vpmax) 34.6V
> Current at Vpmax (Ipmax) 4.77A
>
> They give me no degradation data.
>
> Degrading by 6% would be 155W.

You're using "degrade" in the sense that I was using "derate". When I
mentioned degradation above, I was talking about permanent loss of
output of no more than 1% per year. When I talk about derating I'm
referring to the fact that as PV modules heat up their efficiencies go
down. This loss of efficiency is completely reversible, though -- simply
cool the module down.

That said, your module uses multicrystalline silicon solar cells for
their modules. I don't see a spec sheet for your module at their web
site, but I see one for the SAPC-170, which is almost certainly your
model with a slightly higher efficiency. It lists a temperature
coefficient of -0.8446 W/degree C, or about -0.5%/C. They don't list a
normal operating cell temperature (which is usually specified for
insolation of 800 W/m^2), but a typical value for this type of module is
47C. At that temperature, you would expect to lose about 11% of your
power output. However, in full sun it isn't unusual for modules to run
hotter -- though rare, I've seen reliable documentation of them hitting
80C. At that temperature, you would lose 27.5% of your power output.

>
> Of course I do. What else would I use?

Some people use DC lights and appliances, hence need no inverter. If you
described your setup earlier in the thread I missed it -- sorry -- so I
wasn't entirely sure how you had things arranged.

>
> DC of course. I get the readings right off my Blue Sky Energy IPN-
> ProRemote monitor. I see input (to the buck charge controller) voltage
> and current and output current and battery voltage. It's very easy for
> me to know the power I'm getting.

I'm not familiar with that particular product. The information on the
web site seems to suggest that you can only monitor battery voltage and
current, in which case you'd only know what's flowing out of the panels
if absolutely nothing were flowing anywhere else. You indicate that it
can monitor much more, though, so I can't really argue....

>
> Silly question. Of course it's not AC. What panel puts out AC?

I was asking whether you were basing your observations on the DC output
of the panel or the AC output of the inverter. Sheesh....

>
> So what is your challenge? I get output on cloudy days. I get output
> as soon as the sun comes up until the sun goes down. But I only get
> meaningful output for about 5 hours a day. And anyone who has
> experience with PVs would know exactly what I was saying and what I
> was meaning.

I'm not sure I saw your original statement in this thread and I don't
think I've seen any other posts from you before, so it's hard for me to
know what people might think based on whatever it was you originally
said. However, I have nearly 20 years of experience with PVs (mostly in
solar cell design) and when someone makes a statement like "my system
gets five hours of sun a day," I and pretty much everybody else I know
in the industry and in these newsgroups interprets that as "my system
gets the equivalent of five hours of full sun a day." That's what Wayne
was getting at a few posts back. I do, however, interpret a statement
like "my system gets five hours of *usable* output a day" quite
differently (it's rather ambiguous, for one thing).

>
> Then let me make that clear. I have 10 70AH batteries in parallel. My
> system is 12V.

Duly noted.

>
> One of us has a confused notion of "trickle" and "enormous". You're
> not going to be getting very far when you're sinking an average of say
> 40W and sourcing with an average of say 6W (It's now 6:30PM on a sunny
> day in Texas.

You don't say where in Texas, but 30 years worth of measured data at San
Antonio suggests that on a sunny day in late May/early June around
6:30pm you can expect to see something like 200 W/m^2 of insolation.

> My PV is doing 13.2V at .2A or 2.64W. Just for you I'll
> point it directly at the sun rotating 90 degrees to the west ... I get
> 11.9V at .2A or 2.34W).

Based purely on your module efficiency and 200 W/m^2 of insolation you'd
expect about 33W from the module. Temperature will drop that a bit,
though I don't expect the module is all that hot at that hour. However,
at 200 W/m^2 you're hitting the insolation regime where the efficiency
of crystalline silicon solar cells (like yours) drops like a rock. Your
2.64W might be a *little* low, but it isn't as far off the mark as you
seem to expect. Other types of cells do much better in low-light
conditions (you find those cells in solar calculators and other consumer
electronics designed to work indoors).

> This is the same as reducing the load from 40W
> to 34W which I wouldn't call enormous (or 40W to 38W as my actual data
> shows which for sure isn't enormous).

With a 700Ah battery bank that you can safely drain to 80% depth of
discharge, the difference between 40W and 34W is about 30 hours of
operation. Put another way, if you pull 40W from a 700Ah battery bank it
will last the same amount of time as if you pull 34W from a 600Ah
battery bank. Therefore, that tiny amount of PV production during a week
of lousy weather can either extend your battery bank by more than a day
or reduce your battery expenses by nearly 15%. It might not seem
enormous to you, since your system is rather small, but when you're
spending $12,000 on batteries that trickle can be worth a lot of money.

>
> You must be talking about modules 1/2 the size of mine. As I recall I
> paid about $5 per watt over two years ago.

Fine. Modules costing $400 exist and I needed a number to create an
illustrative example. It works exactly the same way if I double the
price and half the number of modules....

>
> I would be really surprised to find trackers cheaper than my module.

They don't need to be cheaper than your module, they simply need to be
cheap enough to justify the incremental increase in power output that
you'll get by using them. They may or may not work for your situation
and I wasn't trying to insinuate that they are always cheap, good, or
even practical. I was simply answering your challenge to name a
situation in which trackers would be cost-effective. If your situation
matches the sort of situation I described -- and some situations do --
they're cost-effective for you. Not all situations are a match, though.

> Interesting that we can consider zero maintenance on
> modules and tracking maintenance and replacement but not so on the
> diesel.

I never said we could -- in fact, I acknowledged that those costs may or
may not be negligible. However, field data suggest that annual O&M costs
on non-tracking PV systems are a few tenths of a percent of the
installed system cost. In other words, if a complete, installed PV
system costs $40,000 (typical for a grid-connected 4.5-5.0 kW system),
annual O&M costs will be in the neighborhood of $100-200/year. Diesel
generators, of course, have one big operating cost that can never be
ignored even if you ignore everything else: fuel.

> Please give me the numbers you have on the cost of trackers and data
> points on the power delivery curve for the day (before and after).

It varies from site to site -- there's no universal set of numbers for
such a thing. Personally, I'm not a big fan of trackers for residential
PV systems (for a number of reasons, including moving parts that are
more likely to require maintenance) and haven't paid much attention to
how much they actually cost, but they are used by some folks and those
folks generally claim a cost savings.

> And
> by the way, considering practicality, how many PV systems do you see
> tracking vs those you see stationary. I have never seen a tracking
> system in the flesh though I have seen many stationary systems.

Most tracking systems I see are in utility or commercial PV systems.

wmbjk

2007-06-01, 5:25 pm

On 31 May 2007 05:06:25 -0700, Todd <Todd@WithGLEE.com> wrote:

>On May 29, 11:03 am, wmbjk <wmbjkREM...@citlink.net> wrote:
>
>I have never seen a post reporting more than 100% in "any" conditions.
>All postings are available to us. Point me to one.

Here are two from memory. The first is a post from a current thread.

http://tinyurl.com/ys337o

http://tinyurl.com/2ezs3y

>
>My panel starts at 50% in the "best" of circumstances.

Then your installation and/or measurements are faulty.

> I have had it
>for more than 2 years. I have used it in the winter when it should be
>most efficient. I have used it in the summer when it gets the most
>direct sun. I have pointed it at the sun with precision. I have
>manually tracked the sun. Never better than 50%. And I've reported
>this numerous times in this and other groups. I use a 36V panel with
>MPPT so I get everything I can possibly get out of my panel. You're
>the first one whose ever challenged my contention. Do you have panels?
>What is the brand? What is the performance? How do you measure it?

I have 2kw of tracked modules connected to batteries, and routinely
see about 75% of rated in a warm climate. 12 year old setup. Charge
controller records peak watts each day. My results are typical, yours
are not.

> But when I look at
>the output of the panel, even when I manually point it, 5 hours of
>useful output (e.g. more than 5% of rating) is about all I can ever
>expect. This 5 hours figure has also never been challenged in a group.

There are thousands of posts per day containing baloney that goes
unchallenged.

>
>Sure. It's going to be worth the while because the "while" takes no
>effort. But as far as being of worth in relation to real power needs
>(we're not driving a transistor radio with these), it's worthless on a
>cloudy day. The fact that you would attempt to debate this point is
>suspect.

That's exactly the kind of statement that will prevent most folks from
trying to correct your misconceptions. Which is your loss.

>
>Name one. It would "pay" it "all" installations but that pay would
>never exceed the "cost".

Tracking pays whenever the value of the extra hours of production
exceed the cost of the tracker. Besides the obvious increase in total
energy, those extra hours can improve system efficiency and save a lot
of wear and tear on batteries. For example - Joe has a fixed array, so
the energy to cook his morning coffee has to make a trip through his
batteries, while Fred has a tracking array and the energy to make his
morning coffee comes direct from the array. Joe has a less efficient
strategy, and will be replacing his batteries sooner than Fred.

>
>Oh really? Just what is it that makes this strategy impractical for
>the large percentage of off-gridders?

Most people don't want the extra cost, noise, and headache of running
a generator. Likewise most won't try to harvest "free" fuel, and if
they did, there wouldn't be any left for you. I'm happy that you like
using generators and fryer oil, more power to you. But there's no
sense pretending that your strategy will ever fit more than a relative
handful of home power folks.

Wayne

wmbjk

2007-06-01, 5:25 pm

On 31 May 2007 16:36:01 -0700, Todd <Todd@WithGLEE.com> wrote:

>However, you have rattled my cage and I'll contact the
>manufacturer to see if they think I have a defective panel.

You can easily test it yourself.
http://www.otherpower.com/otherpower_solar_used.html

Wayne

Steve Spence

2007-06-01, 5:25 pm

Some folks have unrealistic expectations, and don't have a good handle on
the terms used in the industry.

--
Steve Spence
Director, Green-Trust
http://www.green-trust.org
"wmbjk" <wmbjkREMOVE@citlink.net> wrote in message
news:rsr063tu138vmh2s0268rtia1shfh1sskg@4ax.com...
> On 31 May 2007 16:36:01 -0700, Todd <Todd@WithGLEE.com> wrote:
>
>
> You can easily test it yourself.
> http://www.otherpower.com/otherpower_solar_used.html
>
> Wayne

sylvan butler

2007-06-01, 8:25 pm

On 31 May 2007 16:36:01 -0700, Todd <Todd@WithGLEE.com> wrote:
> So what amount of degradation do most PV modules come near?

Mine are warranteed for 25 years to produce at least 80% of spec.

> My panel is a RWE Schott Solar, Inc. SAPC-165
>
> http://www.us.schott.com/photovolta...lish/index.html

Hmm. Don't see your model listed there.

> They give me no degradation data.

Any warranty?

> I would be really surprised to find trackers cheaper than my module. I
> considered building a tracker myself and preliminary to that I tracked
> manually for several days. My findings were that the additional
> performance would not be worth the cost of a tracker and this was

That has been my conclusion as well. The additional performance (best
estimates I've read have peaked at about 30% added power) really only
make sense when space is limited (so adding more panels is not an
option) or when the mounting mechanism is such that adding tracking is a
very small added expense (eg, already "top of pole" mounting).

> system in the flesh though I have seen many stationary systems.

Consider ... If diesel were as good as you believe, or solar as bad as
you believe, why would all those solar systems exist?

sdb
--
What's seen on your screen? http://pcscreenwatch.com
sdbuse1 on mailhost bigfoot.com

sylvan butler

2007-06-01, 8:25 pm

> philkryder wrote:

That would be my recommendation, yes.
[color=darkred]

OK.
[color=darkred]

Since you have a generator, that is a very conservative assumption.
[color=darkred]

You really _use_ 35kwh per day or is that just generator run time?
(That's above the norm even for grid connected homes in my area...)

Do not forget that your most economical solution may be to reduce
generator runtime, not eliminate it. In other words, you may still need
to run the generator for some time every day to supply your largest
loads, but the rest of the day could be provided by the batts.
[color=darkred]

50% to 20% additional. (Using less than 50% of capacity means you
probably over bought battery capacity, while using more than 80% really
hurts your battery lifetime.)
[color=darkred]

I haven't kept up on battery prices at all, nor inverter prices. If you
really need 70kwh+ of storage, it isn't going to be cheap. OTOH, it may
compare favorably to buying gas or diesel.
[color=darkred]

10kw of panels, for an "average" of 5 hrs of production a day, would
produce 50kwh on an "average" day. That means you have produced enough
for your normal use, plus 40%. That is a conservative assumption. More
than I would probably spec if you were planning to run a genny every
day.

Note I do not size panels "to keep the batteries charged." I size
panels based on daily usage, plus how quickly you want to charge the
batteries.
[color=darkred]

Mostly correct.

On Wed, 30 May 2007 13:22:35 +1000, George Ghio <ghio@nobodyhome.com.au> wrote:[color=darkred]
> 48 Volt system
> 3500wh/day
> 250Ah batteries
> Total Ah demand 81.02
> Days Autonomy 2
> Daily depth of discharge 33%
> 20 - 80W panels (1.6kW)

George slipped a decimal... George's "3500wh/day" does not match up to
Phil's 35kwh/day.

sdb
--
What's seen on your screen? http://pcscreenwatch.com
sdbuse1 on mailhost bigfoot.com

sylvan butler

2007-06-01, 8:25 pm

On 31 May 2007 05:06:25 -0700, Todd <Todd@WithGLEE.com> wrote:
>
> I have never seen a post reporting more than 100% in "any" conditions.

Over what period of time? My panels have produced over 100% over an
hour or so.

> My panel starts at 50% in the "best" of circumstances. I have had it

Let me guess... Your panel is amorphous silicon.

> the first one whose ever challenged my contention. Do you have panels?
> What is the brand? What is the performance? How do you measure it?

Photowatt PW-1000's. trace c40 voltage and current measurements.

> Oh really? Just what is it that makes this strategy impractical for
> the large percentage of off-gridders?

The fuel costs for acquistion and transport. Not everyone has ready
access to a sufficient supply of WVO for a cost of only 10 minutes per
week.

sdb
--
What's seen on your screen? http://pcscreenwatch.com
sdbuse1 on mailhost bigfoot.com

George Ghio

2007-06-02, 3:25 am

sylvan butler wrote:
Snip
>
> Mostly correct.
>
> On Wed, 30 May 2007 13:22:35 +1000, George Ghio <ghio@nobodyhome.com.au> wrote:
>
> George slipped a decimal... George's "3500wh/day" does not match up to
> Phil's 35kwh/day.
>
> sdb

Bugger. I did to. That pushes the battery capacity to a bit over 2100 Ah and 128 - 80W panels.

But then with 5 days to recover the energy spent 10kW would be overkill. Could probably get by with
5kW. 2.5kW of there was guaranteed sun for five days

Mind you it would be interesting to see phil's actual energy audit.

--
Posted via a free Usenet account from http://www.teranews.com

Vaughn Simon

2007-06-02, 9:25 am

"sylvan butler" <ZsdbUse1+noZs_0706@Zbigfoot.Zcom.invalid> wrote in message
news:slrnf61e8r.doa.ZsdbUse1+noZs_0706@sdba64.internal...

> Not everyone has ready
> access to a sufficient supply of WVO for a cost of only 10 minutes per
> week.

And unfortunately, even fewer will in the future. Free WVO is a very
temporary phenomenon. As the price of oil goes up, most WVO will eventually be
professionally collected, and paid for. Enjoy it while it lasts.

Vaughn

Todd

2007-06-02, 1:25 pm

On Jun 1, 2:14 pm, wmbjk <wmbjkREM...@citlink.net> wrote:
> On 31 May 2007 16:36:01 -0700, Todd <T...@WithGLEE.com> wrote:
>
>
> You can easily test it yourself.http://www.otherpower.com/otherpower_solar_used.html
>
> Wayne

That link is not helpful. I know exactly what my panel is capable of
putting out. What I don't know is why it's putting out so much below
its rating. The link doesn't help me with that question.

Todd

2007-06-02, 1:25 pm

On Jun 1, 4:18 pm, "Steve Spence" <sspe...@green-trust.org> wrote:[color=darkred]
> Some folks have unrealistic expectations, and don't have a good handle on
> the terms used in the industry.
>
> --
> Steve Spence
> Director, Green-Trusthttp://www.green-trust.org"wmbjk" <wmbjkREM...@citlink.net> wrote in message
>
> news:rsr063tu138vmh2s0268rtia1shfh1sskg@4ax.com...
>
>
>
>

And just what is that supposed to mean?

Todd

2007-06-02, 1:25 pm

On Jun 1, 7:34 pm, sylvan butler
<ZsdbUse1+noZs_0...@Zbigfoot.Zcom.invalid> wrote:
> On 31 May 2007 16:36:01 -0700, Todd <T...@WithGLEE.com> wrote:
>
>
> Mine are warranteed for 25 years to produce at least 80% of spec.
>
>
>
> Hmm. Don't see your model listed there.
>
>
> Any warranty?
>
>
> That has been my conclusion as well. The additional performance (best
> estimates I've read have peaked at about 30% added power) really only
> make sense when space is limited (so adding more panels is not an
> option) or when the mounting mechanism is such that adding tracking is a
> very small added expense (eg, already "top of pole" mounting).
>
>
> Consider ... If diesel were as good as you believe, or solar as bad as
> you believe, why would all those solar systems exist?

First, my sense of the issues is not belief ... it's experience. Just
getting such arguments as yours (e.g. why so many PVs if they're no
good) tells me a lot of people just aren't paying attention.

>
> sdb
> --
> What's seen on your screen? http://pcscreenwatch.com
> sdbuse1 on mailhost bigfoot.com

Todd

2007-06-02, 1:25 pm

On Jun 1, 2:11 pm, wmbjk <wmbjkREM...@citlink.net> wrote:
> On 31 May 2007 05:06:25 -0700, Todd <T...@WithGLEE.com> wrote:
>
>
>
>
>
> Here are two from memory. The first is a post from a current thread.
>
> http://tinyurl.com/ys337o
>
> http://tinyurl.com/2ezs3y
>
>
>
> Then your installation and/or measurements are faulty.

Oh really? Well, my instrument is a Blue Sky 3024i with an IPN-
ProRemote monitor. It's operating perfectly. How do I know? I can
measure current and voltage directly on the shunt and across the panel
output. It matches the monitor readings. In all your wisdom which
allows you to make the intuitive leap you just made, can you think of
something about my installation that is faulty? Right now the panel is
in a wood frame that allows me to adjust it perfectly perpendicular to
the rays of the sun and a severely clear day. Help me improve on that
"Test" installation!!!

>
>
> I have 2kw of tracked modules connected to batteries, and routinely
> see about 75% of rated in a warm climate. 12 year old setup. Charge
> controller records peak watts each day. My results are typical, yours
> are not.
>
>
> There are thousands of posts per day containing baloney that goes
> unchallenged.
>
>
>
> That's exactly the kind of statement that will prevent most folks from
> trying to correct your misconceptions. Which is your loss.

Scolding duly noted. I just get disgusted by the arrogant
disinformation I see sometimes. When challenged the debate ends with
just such punts.

>
>
>
> Tracking pays whenever the value of the extra hours of production
> exceed the cost of the tracker. Besides the obvious increase in total
> energy, those extra hours can improve system efficiency and save a lot
> of wear and tear on batteries. For example - Joe has a fixed array, so
> the energy to cook his morning coffee has to make a trip through his
> batteries, while Fred has a tracking array and the energy to make his
> morning coffee comes direct from the array. Joe has a less efficient
> strategy, and will be replacing his batteries sooner than Fred.

You avoid the question ... unless you want me to greatly inflate the
value of a hot cup of coffee. PVs by themselves are not cost
effective. Adding cost to pick up the even less cost effective wings
of their operation with tracking only makes them less cost effective.

>
>
>
>
> Most people don't want the extra cost, noise, and headache of running
> a generator. Likewise most won't try to harvest "free" fuel, and if
> they did, there wouldn't be any left for you. I'm happy that you like
> using generators and fryer oil, more power to you. But there's no
> sense pretending that your strategy will ever fit more than a relative
> handful of home power folks.

And of course I didn't state that it would. What I did state is that
its more effective, cost efficient, and robust than the PV
alternative ... by at least an order of magnitude (an expansion of my
earlier statements). With people have money to burn on PVs and the
willingness to burn it, rational arguments can't be very effective. I
can only view these people as stupid because the grid is more
efficient and effective and robust than either PV or personal diesel.
And if you can't be on the grid (which I can't), trusting in PV only
is a non-starter so you have to have an IC backup anyway. I don't
expect exhaustion of my fuel supply any time soon because most people
are ignoring this "green" nonsense and getting their power off of the
unbelievably efficient grid.

>
> Wayne

Todd

2007-06-02, 1:25 pm

On Jun 1, 7:26 pm, sylvan butler
<ZsdbUse1+noZs_0...@Zbigfoot.Zcom.invalid> wrote:
> On 31 May 2007 05:06:25 -0700, Todd <T...@WithGLEE.com> wrote:
>
>
>
> Over what period of time? My panels have produced over 100% over an
> hour or so.

I have an inquiry into the manufacturer. I hope my panel is indeed
defective. However, even if it's not, PV effectiveness needs to
improve by an order of magnitude to play in Peoria.

>
>
> Let me guess... Your panel is amorphous silicon.

Ok ... go ahead and guess that. Now what?

>
>
> Photowatt PW-1000's. trace c40 voltage and current measurements.

Easy to do and I do it.

>
>
> The fuel costs for acquistion and transport. Not everyone has ready
> access to a sufficient supply of WVO for a cost of only 10 minutes per
> week.

More do than don't. Show me an "off gridder" that doesn't make trips
to the grocery store. On the way they'll likely pass at least one
establishment that has a deep fryer.

>
> sdb
> --
> What's seen on your screen? http://pcscreenwatch.com
> sdbuse1 on mailhost bigfoot.com

Todd

2007-06-02, 1:25 pm

On Jun 2, 6:55 am, "Vaughn Simon" <vaughnsimonHATESS...@att.FAKE.net>
wrote:
> "sylvan butler" <ZsdbUse1+noZs_0...@Zbigfoot.Zcom.invalid> wrote in message
>
> news:slrnf61e8r.doa.ZsdbUse1+noZs_0706@sdba64.internal...
>
>
> And unfortunately, even fewer will in the future. Fre