Posted by Solar Guppy on December 17, 2003, 10:53 pm
Today's price of $2.50/Watt for "off-spec" is very realistic. I just
yesterday finished installing 18 of the photowatt , 155 watt modules which I
bought from www.sunelec.com. Took about 5 days labor to mount on the roof
the panels, do the wiring , breaker box , disconnect and conduit. Total
cost was about 300 bucks for everything except the panels and inverter.
The "off-spec" modules , being at the lowest performance grade for the panel
size (photowatt 155 , 165 , 175) are all the same modules , they just have a
slightly weak cell and if it's below 165 watt , its sold as a 155 watt. The
2.50 watt ones have differing defects , some the RTV got in front or a cell
, another had bubbles , about a third had one of the cells that had a small
chip/crack but the power was still good , just not in the premium rating.
All the panels came with the actual test data , which made matching the
panel in pairs that further enhanced there delivered power.
In the author of this threads case , the only added cost would be a good
charge controller , figure 500.00 for an MX60 and for a total cost one would
have a 2900 watt array for 8050.00. This is NOT an assumption , that so many
would be solar nay-Sayers banter around the 5-10/watt figure ... this is the
ACTUAL cost and yes , to me my labor is free as it would be to most people
reading these threads for the DIY crowd.
Tomorrow , I start on the second Photowatt array , same as the one I just
completed ... when done , I'll have a 5800 watt STC gridtie system for under
20K , including EVERYTHING
Then there's the 1650 watts of panels I got on the same trip for 1.50 watt
... The plan is to direct drive a DC motor for the pool pump ... Not another
ASSUMPTION as these panels were advertised for close to 6 months and I had
mentioned them to this group before !!!. No inverter , no charge controller
, run the filter when the sunshine's .... but that will have to wait till
spring ...
<William P.N. Smith> wrote in message
> >To establish the costs of the PV generated energy, I'll assume using
> >the discount "off-spec" PV panel deals which run about $2.50 a watt,
> >have a true life of 40 years, Peak Sun Hours of 4.5, and that the
> >panels end up giving me effectively 75% of the rated capacity of the
> >panels, over the life of the panels. Using these assumptions, over
> >the PV life, the cost is $0.038 per kWh. Wow, that's damn cheap!
> Well, it's all in your assumptions, then isn't it? $5-10/watt
> installed costs, 20-year lifetimes, etc, and you'd have more
> traditional costs of around 30 cents per KWHR.
> >guess, we would need to determine/estimate (some how!) the number of
> >times a year that there is multiple extended cloudy days. But how to
> >get this information?
> Put up a pyrometer and a datalogger and do the analysis for your exact
> location (that's what I'm doing!). Or see if you can find the data
> online somewhere.
> Alternately, get the generator and see how much you end up using it.
> You might end up doing something like: When the battery bank drops to
> 25%, use the generator to charge it to 75%.
> >So, lets do some calculations, assuming, once again, an average daily
> >energy demand of 10 kWh a day, and assuming the "base" PV array is
> >rated at 2.5Kw:
> So you are assuming 4 peak solar hours per day, and anything else goes
> to making up your deficit?
> --
> William Smith
> ComputerSmiths Consulting, Inc. www.compusmiths.com
Posted by William P.N. Smith on December 18, 2003, 12:03 pm
>Tomorrow , I start on the second Photowatt array , same as the one I just
>completed ... when done , I'll have a 5800 watt STC gridtie system for under
>20K , including EVERYTHING
Wow, $3.45/watt installed is durn good, even if your time is worth
nothing! What do you figure for a system life time, and what's your
$/KWHR figure?
[I don't mean to be a nay-sayer above, BTW, but my brain says "Wait a
minute!" when I read 3.8 cents per KWHR, and the real costs are
subject to some interpretation...]
--
William Smith
ComputerSmiths Consulting, Inc. www.compusmiths.com
Posted by Ron Rosenfeld on December 18, 2003, 3:10 pm
On Thu, 18 Dec 2003 03:53:51 GMT, "Solar Guppy"
>Today's price of $2.50/Watt for "off-spec" is very realistic. I just
>yesterday finished installing 18 of the photowatt , 155 watt modules which I
>bought from www.sunelec.com. Took about 5 days labor to mount on the roof
>the panels, do the wiring , breaker box , disconnect and conduit. Total
>cost was about 300 bucks for everything except the panels and inverter.
>The "off-spec" modules , being at the lowest performance grade for the panel
>size (photowatt 155 , 165 , 175) are all the same modules , they just have a
>slightly weak cell and if it's below 165 watt , its sold as a 155 watt. The
>2.50 watt ones have differing defects , some the RTV got in front or a cell
>, another had bubbles , about a third had one of the cells that had a small
>chip/crack but the power was still good , just not in the premium rating.
>All the panels came with the actual test data , which made matching the
>panel in pairs that further enhanced there delivered power.
Those are real good prices. And, if you've got lots of room, should be a
good deal. What I discovered, of course, was that the off-spec panels take
up more space for the same generation capabilities.
In my case, my panels are going on my roof, and the good space is somewhat
limited. But I was able to find brand new Sharp 165W panels (*not*
off-spec) at $3.68/watt delivered. Since I'm not doing the work myself, it
will cost me more for labor as well as mounts, cabling, combiners, MX60,
disconnects, etc. I figure the installed cost will be about $6/watt for
2kW.
-- ron (off the grid in Downeast Maine)
Posted by Redmondite on December 20, 2003, 5:58 pm
But the real question is how long will they last? If the offspec ones last
as long as the "spec" PV's then it's really more of a space issue isn't it?
> Today's price of $2.50/Watt for "off-spec" is very realistic. I just
> yesterday finished installing 18 of the photowatt , 155 watt modules which
I
> bought from www.sunelec.com. Took about 5 days labor to mount on the roof
> the panels, do the wiring , breaker box , disconnect and conduit. Total
> cost was about 300 bucks for everything except the panels and inverter.
> The "off-spec" modules , being at the lowest performance grade for the
panel
> size (photowatt 155 , 165 , 175) are all the same modules , they just have
a
> slightly weak cell and if it's below 165 watt , its sold as a 155 watt.
The
> 2.50 watt ones have differing defects , some the RTV got in front or a
cell
> , another had bubbles , about a third had one of the cells that had a
small
> chip/crack but the power was still good , just not in the premium rating.
> All the panels came with the actual test data , which made matching the
> panel in pairs that further enhanced there delivered power.
> In the author of this threads case , the only added cost would be a good
> charge controller , figure 500.00 for an MX60 and for a total cost one
would
> have a 2900 watt array for 8050.00. This is NOT an assumption , that so
many
> would be solar nay-Sayers banter around the 5-10/watt figure ... this is
the
> ACTUAL cost and yes , to me my labor is free as it would be to most people
> reading these threads for the DIY crowd.
> Tomorrow , I start on the second Photowatt array , same as the one I just
> completed ... when done , I'll have a 5800 watt STC gridtie system for
under
> 20K , including EVERYTHING
> Then there's the 1650 watts of panels I got on the same trip for 1.50 watt
> ... The plan is to direct drive a DC motor for the pool pump ... Not
another
> ASSUMPTION as these panels were advertised for close to 6 months and I had
> mentioned them to this group before !!!. No inverter , no charge
controller
> , run the filter when the sunshine's .... but that will have to wait till
> spring ...
> <William P.N. Smith> wrote in message
> > >To establish the costs of the PV generated energy, I'll assume using
> > >the discount "off-spec" PV panel deals which run about $2.50 a watt,
> > >have a true life of 40 years, Peak Sun Hours of 4.5, and that the
> > >panels end up giving me effectively 75% of the rated capacity of the
> > >panels, over the life of the panels. Using these assumptions, over
> > >the PV life, the cost is $0.038 per kWh. Wow, that's damn cheap!
> >
> > Well, it's all in your assumptions, then isn't it? $5-10/watt
> > installed costs, 20-year lifetimes, etc, and you'd have more
> > traditional costs of around 30 cents per KWHR.
> >
> > >guess, we would need to determine/estimate (some how!) the number of
> > >times a year that there is multiple extended cloudy days. But how to
> > >get this information?
> >
> > Put up a pyrometer and a datalogger and do the analysis for your exact
> > location (that's what I'm doing!). Or see if you can find the data
> > online somewhere.
> >
> > Alternately, get the generator and see how much you end up using it.
> > You might end up doing something like: When the battery bank drops to
> > 25%, use the generator to charge it to 75%.
> >
> > >So, lets do some calculations, assuming, once again, an average daily
> > >energy demand of 10 kWh a day, and assuming the "base" PV array is
> > >rated at 2.5Kw:
> >
> > So you are assuming 4 peak solar hours per day, and anything else goes
> > to making up your deficit?
> >
> > --
> > William Smith
> > ComputerSmiths Consulting, Inc. www.compusmiths.com
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> >the discount "off-spec" PV panel deals which run about $2.50 a watt,
> >have a true life of 40 years, Peak Sun Hours of 4.5, and that the
> >panels end up giving me effectively 75% of the rated capacity of the
> >panels, over the life of the panels. Using these assumptions, over
> >the PV life, the cost is $0.038 per kWh. Wow, that's damn cheap!
> Well, it's all in your assumptions, then isn't it? $5-10/watt
> installed costs, 20-year lifetimes, etc, and you'd have more
> traditional costs of around 30 cents per KWHR.
> >guess, we would need to determine/estimate (some how!) the number of
> >times a year that there is multiple extended cloudy days. But how to
> >get this information?
> Put up a pyrometer and a datalogger and do the analysis for your exact
> location (that's what I'm doing!). Or see if you can find the data
> online somewhere.
> Alternately, get the generator and see how much you end up using it.
> You might end up doing something like: When the battery bank drops to
> 25%, use the generator to charge it to 75%.
> >So, lets do some calculations, assuming, once again, an average daily
> >energy demand of 10 kWh a day, and assuming the "base" PV array is
> >rated at 2.5Kw:
> So you are assuming 4 peak solar hours per day, and anything else goes
> to making up your deficit?
> --
> William Smith
> ComputerSmiths Consulting, Inc. www.compusmiths.com