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Re: solar car porch

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  • streamline.rm
    Kevin, Thanks for the response, I didn t mean that your company stands behind only 80%, I realize my wording was not clear. I guess a better example of what
    Message 1 of 39 , Mar 31, 2008
      Kevin,
      Thanks for the response, I didn't mean that your company stands
      behind only 80%, I realize my wording was not clear. I guess a
      better example of what I meant is as most companies with their
      products, they stand 100% behind a certain point, and warantee that.
      If the user wants to go past that, they can, but void warranties.
      Like computer guys do with Chips. They will work faster than "RATED
      BY INTEL", but, Intel won't warranty it if they find evidence of
      tampering, or, a Chevy truck, when someone alters the suspension
      drastically, GM will not warranty it.

      Anyways, now I understand what you mean. And yes, it makes sense,
      that a whole system is different than one cell. I checked out your
      website, I'd love to see one of your installations, and make a report
      on it on our website. The hybrid system is very cool, as well as the
      mini Wi-Fi.

      Best Regards,

      George J. Strnad
      800-391-2291
      www.alternateenergycentral.com



      --- In hreg@yahoogroups.com, "Kevin Conlin" <kconlin@...> wrote:
      >
      > George, No to both questions. You cannot cook a PV module to provide
      > excess power, and we don't stand behind anything 80%, we stand behind
      > everything we do 100%. It's not just a simple matter of derating the PV
      > panel 20%, we assume a system efficiency of 80%, which is much different
      > than derating the panel 20%, then after looking at the worst month in 30
      > years, we make sure there is 20% "head room" as a safety margin.
      You may
      > consider it a matter of semantics, but if fact we are talking about two
      > entirely different things. Stand alone system sizing is a whole lot
      more
      > than simply derating the PV module, however, if a panel is rated -5% and
      > +10%, then it is prudent to derate it 5% at the onset of the system
      design.
      >
      >
      >
      > Hope I'm not confusing the issue even more.....
      >
      >
      >
      > Kevin
      >
      >
      >
      > _____
      >
      > From: hreg@yahoogroups.com [mailto:hreg@yahoogroups.com] On Behalf Of
      > streamline.rm
      > Sent: Saturday, March 29, 2008 9:30 AM
      > To: hreg@yahoogroups.com
      > Subject: [hreg] Re: solar car porch
      >
      >
      >
      > Hey Kevin,
      >
      > So, that brings me to a question, if You are derateing these panels,
      > can someone go into them and boost their performance? Like
      > "overclocking" guys do to their Intel chips? Or, are your panels
      > just capable of producing 20% better out of the box, but your company
      > just stands behind 80%.
      >
      > George J. Strnad
      > 800-391-2291
      > www.alternateenergycentral.com
      >
      > --- In hreg@yahoogroups. <mailto:hreg%40yahoogroups.com> com, "Kevin
      Conlin"
      > <kconlin@> wrote:
      > >
      > > Hi Jim, A minor correction, perhaps I didn't explain myself
      adequately.
      > > For weather data, we look at the NREL 30 year data, pick the worst
      > month in
      > > 30 years, and that is our design month. We derate the PV output 20%
      > to allow
      > > for system losses, battery charging efficiency, dusty modules,
      etc..THEN
      > > make sure we have at least a 20% safety factor (head room) on top of
      > that.
      > > This strategy generally results in our systems being larger than our
      > > competitors, and if the purchase is simply price driven, we lose
      > every time.
      > > BUT, if the customer needs high reliability, and has hundreds of
      > systems, we
      > > cannot afford to have massive failures during a bad winter. In the
      > oil and
      > > gas industry, where a dead battery on an offshore platform might
      > cost $2000
      > > to replace, our customers have come to understand the importance of
      > > conservative design. I always tell my customers to "consider the
      > > consequences of failure"
      > >
      > >
      > >
      > > More than once a lost account has come back after experiencing the
      > joys of
      > > buying the lowest cost system.
      > >
      > >
      > >
      > > Sorry for any confusion.
      > >
      > >
      > >
      > > Best, Kevin
      > >
      > >
      > >
      > > _____
      > >
      > > From: hreg@yahoogroups. <mailto:hreg%40yahoogroups.com> com
      > [mailto:hreg@yahoogroups. <mailto:hreg%40yahoogroups.com> com] On Behalf
      > Of Jim &
      > > Janet
      > > Sent: Friday, March 28, 2008 2:47 PM
      > > To: hreg@yahoogroups. <mailto:hreg%40yahoogroups.com> com
      > > Subject: Re: [hreg] Re: solar car porch
      > >
      > >
      > >
      > > The 20% Kevin speaks of is known as the derate factor for a PV
      > system. In
      > > the real world, a 3 kW PV array won't put out 3 kW of AC power due to
      > > derating. You can see what the percentages of the losses are
      > attributed to
      > > at the PVWATTS site.
      > >
      > > http://rredc. <http://rredc.
      > <http://rredc.nrel.gov/solar/codes_algs/PVWATTS/version1/>
      > nrel.gov/solar/codes_algs/PVWATTS/version1/>
      > > nrel.gov/solar/codes_algs/PVWATTS/version1/
      > >
      > > * Pick Texas & a city.
      > > * Click on "Derate Factor Help". Note the default percent given to
      > > soiling.
      > > * Click on "Help" for details about derating including soiling.
      > >
      > > While 5% does not sound like a lot, over the 30 year life of a PV
      > system it
      > > can add up to a lot of lost power. And it's not that much work to
      > squirt the
      > > array with a hose to get off the worst of the dust. Just don't ever
      > wet the
      > > modules during mid-day full sun, while they are hot.
      > >
      > > Jim Duncan
      > >
      > > North Texas Renewable Energy Inc
      > > 817.917.057
      > > ntrei@earthlink. <mailto:ntrei@> net
      > >
      > > www.ntrei.com
      > >
      > >
      > >
      > >
      > >
      > > ----- Original Message -----
      > >
      > > From: Chris <mailto:boyer.chris@> Boyer
      > >
      > > To: hreg@yahoogroups. <mailto:hreg@yahoogroups.
      > <mailto:hreg%40yahoogroups.com> com> com
      > >
      > > Sent: Friday, March 28, 2008 12:17 PM
      > >
      > > Subject: [hreg] Re: solar car porch
      > >
      > >
      > >
      > > Mr. Han,
      > >
      > >
      > >
      > > I have a solar system. It is covered with pollen right now because
      > we have
      > > pine trees all around us and we have not had rain in a while. I
      can not
      > > tell that I am loosing any performance - I'm probably loosing a
      > little, but
      > > not enough that I can tell. I expect the pollen will be washed off
      > in the
      > > first rain (I'll let you know after the rain we're supposed to get
      this
      > > weekend). You said that solar PV needs maintenance because it needs
      > to be
      > > washed - is this statement based on hearsay, or experience from
      your own
      > > system.
      > >
      > >
      > >
      > > The glass on solar panels are pretty much self-cleaning if they are
      > > installed at a tilt. I understand that there are systems installed
      > > horizontally on flat roofs in California (and I have seen some) that
      > have to
      > > be cleaned because they don't get much rain and without a tilt,
      the dirt
      > > just pools on the panels.
      > >
      > >
      > >
      > > For others that have systems out there, do you have to clean your
      > panels?
      > >
      > >
      > >
      > > -Chris
      > >
      >
    • streamline.rm
      Kevin, Thanks for the response, I didn t mean that your company stands behind only 80%, I realize my wording was not clear. I guess a better example of what
      Message 39 of 39 , Mar 31, 2008
        Kevin,
        Thanks for the response, I didn't mean that your company stands
        behind only 80%, I realize my wording was not clear. I guess a
        better example of what I meant is as most companies with their
        products, they stand 100% behind a certain point, and warantee that.
        If the user wants to go past that, they can, but void warranties.
        Like computer guys do with Chips. They will work faster than "RATED
        BY INTEL", but, Intel won't warranty it if they find evidence of
        tampering, or, a Chevy truck, when someone alters the suspension
        drastically, GM will not warranty it.

        Anyways, now I understand what you mean. And yes, it makes sense,
        that a whole system is different than one cell. I checked out your
        website, I'd love to see one of your installations, and make a report
        on it on our website. The hybrid system is very cool, as well as the
        mini Wi-Fi.

        Best Regards,

        George J. Strnad
        800-391-2291
        www.alternateenergycentral.com



        --- In hreg@yahoogroups.com, "Kevin Conlin" <kconlin@...> wrote:
        >
        > George, No to both questions. You cannot cook a PV module to provide
        > excess power, and we don't stand behind anything 80%, we stand behind
        > everything we do 100%. It's not just a simple matter of derating the PV
        > panel 20%, we assume a system efficiency of 80%, which is much different
        > than derating the panel 20%, then after looking at the worst month in 30
        > years, we make sure there is 20% "head room" as a safety margin.
        You may
        > consider it a matter of semantics, but if fact we are talking about two
        > entirely different things. Stand alone system sizing is a whole lot
        more
        > than simply derating the PV module, however, if a panel is rated -5% and
        > +10%, then it is prudent to derate it 5% at the onset of the system
        design.
        >
        >
        >
        > Hope I'm not confusing the issue even more.....
        >
        >
        >
        > Kevin
        >
        >
        >
        > _____
        >
        > From: hreg@yahoogroups.com [mailto:hreg@yahoogroups.com] On Behalf Of
        > streamline.rm
        > Sent: Saturday, March 29, 2008 9:30 AM
        > To: hreg@yahoogroups.com
        > Subject: [hreg] Re: solar car porch
        >
        >
        >
        > Hey Kevin,
        >
        > So, that brings me to a question, if You are derateing these panels,
        > can someone go into them and boost their performance? Like
        > "overclocking" guys do to their Intel chips? Or, are your panels
        > just capable of producing 20% better out of the box, but your company
        > just stands behind 80%.
        >
        > George J. Strnad
        > 800-391-2291
        > www.alternateenergycentral.com
        >
        > --- In hreg@yahoogroups. <mailto:hreg%40yahoogroups.com> com, "Kevin
        Conlin"
        > <kconlin@> wrote:
        > >
        > > Hi Jim, A minor correction, perhaps I didn't explain myself
        adequately.
        > > For weather data, we look at the NREL 30 year data, pick the worst
        > month in
        > > 30 years, and that is our design month. We derate the PV output 20%
        > to allow
        > > for system losses, battery charging efficiency, dusty modules,
        etc..THEN
        > > make sure we have at least a 20% safety factor (head room) on top of
        > that.
        > > This strategy generally results in our systems being larger than our
        > > competitors, and if the purchase is simply price driven, we lose
        > every time.
        > > BUT, if the customer needs high reliability, and has hundreds of
        > systems, we
        > > cannot afford to have massive failures during a bad winter. In the
        > oil and
        > > gas industry, where a dead battery on an offshore platform might
        > cost $2000
        > > to replace, our customers have come to understand the importance of
        > > conservative design. I always tell my customers to "consider the
        > > consequences of failure"
        > >
        > >
        > >
        > > More than once a lost account has come back after experiencing the
        > joys of
        > > buying the lowest cost system.
        > >
        > >
        > >
        > > Sorry for any confusion.
        > >
        > >
        > >
        > > Best, Kevin
        > >
        > >
        > >
        > > _____
        > >
        > > From: hreg@yahoogroups. <mailto:hreg%40yahoogroups.com> com
        > [mailto:hreg@yahoogroups. <mailto:hreg%40yahoogroups.com> com] On Behalf
        > Of Jim &
        > > Janet
        > > Sent: Friday, March 28, 2008 2:47 PM
        > > To: hreg@yahoogroups. <mailto:hreg%40yahoogroups.com> com
        > > Subject: Re: [hreg] Re: solar car porch
        > >
        > >
        > >
        > > The 20% Kevin speaks of is known as the derate factor for a PV
        > system. In
        > > the real world, a 3 kW PV array won't put out 3 kW of AC power due to
        > > derating. You can see what the percentages of the losses are
        > attributed to
        > > at the PVWATTS site.
        > >
        > > http://rredc. <http://rredc.
        > <http://rredc.nrel.gov/solar/codes_algs/PVWATTS/version1/>
        > nrel.gov/solar/codes_algs/PVWATTS/version1/>
        > > nrel.gov/solar/codes_algs/PVWATTS/version1/
        > >
        > > * Pick Texas & a city.
        > > * Click on "Derate Factor Help". Note the default percent given to
        > > soiling.
        > > * Click on "Help" for details about derating including soiling.
        > >
        > > While 5% does not sound like a lot, over the 30 year life of a PV
        > system it
        > > can add up to a lot of lost power. And it's not that much work to
        > squirt the
        > > array with a hose to get off the worst of the dust. Just don't ever
        > wet the
        > > modules during mid-day full sun, while they are hot.
        > >
        > > Jim Duncan
        > >
        > > North Texas Renewable Energy Inc
        > > 817.917.057
        > > ntrei@earthlink. <mailto:ntrei@> net
        > >
        > > www.ntrei.com
        > >
        > >
        > >
        > >
        > >
        > > ----- Original Message -----
        > >
        > > From: Chris <mailto:boyer.chris@> Boyer
        > >
        > > To: hreg@yahoogroups. <mailto:hreg@yahoogroups.
        > <mailto:hreg%40yahoogroups.com> com> com
        > >
        > > Sent: Friday, March 28, 2008 12:17 PM
        > >
        > > Subject: [hreg] Re: solar car porch
        > >
        > >
        > >
        > > Mr. Han,
        > >
        > >
        > >
        > > I have a solar system. It is covered with pollen right now because
        > we have
        > > pine trees all around us and we have not had rain in a while. I
        can not
        > > tell that I am loosing any performance - I'm probably loosing a
        > little, but
        > > not enough that I can tell. I expect the pollen will be washed off
        > in the
        > > first rain (I'll let you know after the rain we're supposed to get
        this
        > > weekend). You said that solar PV needs maintenance because it needs
        > to be
        > > washed - is this statement based on hearsay, or experience from
        your own
        > > system.
        > >
        > >
        > >
        > > The glass on solar panels are pretty much self-cleaning if they are
        > > installed at a tilt. I understand that there are systems installed
        > > horizontally on flat roofs in California (and I have seen some) that
        > have to
        > > be cleaned because they don't get much rain and without a tilt,
        the dirt
        > > just pools on the panels.
        > >
        > >
        > >
        > > For others that have systems out there, do you have to clean your
        > panels?
        > >
        > >
        > >
        > > -Chris
        > >
        >
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