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Re: [hreg] Workshops and threads

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  • Kim & Garth Travis
    This has been a detailed reply and you sound very knowledgeable. I have a few further questions. ... But; many people run a generator hooked into their power
    Message 1 of 9 , May 11, 2000
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      This has been a detailed reply and you sound very knowledgeable. I have a few
      further questions.

      > There are two types of PV solar electric systems, stand-alone and
      > utility-intertie.
      >

      Why can we not have a hybrid of the two systems? I know you say:


      > If the utility power goes down, you don't have any power. This is
      > done as a safety measure, because if the grid is down, you don't want to
      > backfeed power into it and maybe fry a lineman who expects no voltage to be
      > present.

      But; many people run a generator hooked into their power system with a relay that
      controls a main breaker switch and prevents power from going out on the line when
      the grid is down. If one could use the grid as their batteries so to speak and
      only keep a minimum of batteries for power outs, then the cost of a back up system
      comes out of the budget and can be applied to the cost of PV. Here in the rural
      part of Texas, when the power goes out we loose our water and septic system.
      Having some sort of backup system is a necessity. The size of the system depends
      on how rich you are and what you have to have. The problem with generators is
      that if you run out of fuel, and there is a power outage, you can not buy fuel.
      Gasoline does not store well, so you must use a diesel generator.

      > It's expensive to produce power with PV panels. Refrigeration uses about 20%
      > of the power in a typical home. We have a large side-by-side refrigerator that
      >
      > uses 913 kwh/year. If you plug this into my solar sizer tool, it comes up with
      >
      > these figures on a system to run the refrigerator.
      >
      > Location -Houston TX, 24V system / 5 day backup
      > Refrigerator 250whr * 7hr/day = 2.5 kwh/day @ .08 per kwh (HL&P) = $73/yr.
      >
      > Needed: 8 - 6V, 350 ahr lead-acid batteries @ $169 ea., 8 - 100W PC panels @
      > $479 ea., 1 1500W inverter @ $739 ea,
      > 1 60A charge controller @ $269 ea.
      >
      > System production: 2.66 kwh/day System load: 2.48 kwh/day
      > Total system cost $6700
      > Total paypack time @ .08 per kwh = 94.63 years
      >

      The obvious response to this is that you need the fridge that NASA has developed
      that does not need battery back up to make it through the night. I am designing
      my place to use far less electricity than a "normal" home. One of the tactics
      that we are looking at is using pumps that run on DC current for the hydronics and
      other parts and hooking them to small PV installs. This avoids the cost, both
      environmental and financial of a large set of batteries that must all be replaced
      at once.

      > Here's a quote from an article in Home Power magazine
      > #64 written by James Udall and one from William Lord's website that sums up my
      >
      > feelings pretty well on the payback issue:
      >
      > "If PV systems get to $2 watt, everyone will do it and won't ask why. Today,
      > though, we've got to wrestle with the economics. "What's the payback?"
      > probably got its start after the first oil crunch, when some builder was
      > trying to figure out whether it made sense to add fiberglass insulation to his
      >
      > next 2 by 4 shell. Duh. Twenty years later, "what's the payback?" has become a
      >
      > mindless chant. In no other realm does this mentality prevail. Your wife's
      > pregnant!? Jeez, I'm sorry, kids aren't cost effective. Honey, let's buy a new
      >
      > sofa. Have you done a cost-benefit analysis? We've been brainwashed, infected
      > with bean counter disease."
      >

      While this is an interesting comment on financial planning, when there is a finite
      amount of money available, the decision of what to buy has to be based on
      something....

      >
      > Solar Capital of the World!: Yes, Maine has been the cat's meow during the
      > month of June, 1999 as the American Solar Energy Society held its annual
      > convention in Portland...and I got to speak about "Living Well with Solar in
      > Maine." It was an impressive gathering. Most notable was Steven Strong's
      > answer (my architect) to the question about pv payback? "Engineers in
      > Switzerland have meticulously attempted to measure the electrical output of
      > asphalt shingles and other conventional roofing material, " he noted. "Because
      >
      > there is no current flowing, there appears to be no payback on most roofs
      > throughout the world...unlike a solar roof," he concluded with a sly grin.
      >

      The pay back on the roof is lack of damage. Ask me I know. I have been living
      with a leaky roof since a tornado hit my place last June. The real pay back is
      being able to sleep through the night, not listening for a storm. There is
      nothing wrong with trying to save money and the environment at the same time. By
      going to an alternative building method, our finished home will have cost about
      1/4 of a normal stick frame shell.

      >
      > > I am still interested in solar cooking but find that the wind is a major
      > > problem. I would like to correspond with anyone who is doing solar
      > > cooking, but at present I cannot join another group in Houston.
      >
      > I have the same problem. My cooker can't handle moisture or wind. I decided
      > that I wasn't going to solar-cook on a regular basis until I could build a
      > unit that could stay outside all the time because that's the only way it would
      >
      > be useful.
      >

      > James Ferrill
      >

      Does anyone have any design ideas to make a solar cooker convenient? I do most
      of my cooking outside in the summer months, [May through Oct.] and have placed my
      auxiliary kitchen on the NE side of my building for comforts sake. The real,
      indoor kitchen is therefore on the same side of the building to make life
      convenient. A solar cooker needs the south or SW exposure. This leads us to the
      problem of carrying food either through the building or around the building.
      Carrying hot food through doorways, [auxiliary kitchen is screened] leads to
      accidents.

      I have heard of, but not seen heat wells designed for heating water. Does anyone
      know if such a concept would work for cooking? This could possibly solve the wind
      problem as well.


      > Kim Travis
      > ------------------------------------------------------------------------
      > Now the best and coolest websites come right to you based on your
      > unique interests. eTour.com is surfing without searching.
      > And, it's FREE!
      > http://click.egroups.com/1/3013/0/_/58590/_/957797214/
      > ------------------------------------------------------------------------
    • James Ferrill
      ... The only inverter I know of that can do this is the popular Trace SW series. The manual says that you can set a battery voltage set point , which means if
      Message 2 of 9 , May 11, 2000
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        Kim & Garth Travis wrote:

        > > There are two types of PV solar electric systems, stand-alone and
        > > utility-intertie.
        >
        > Why can we not have a hybrid of the two systems?

        The only inverter I know of that can do this is the popular Trace SW series. The
        manual says that you can set a "battery voltage set point", which means if your
        batteries are fully charged and you're not using the power, the inverter will feed
        that extra power back to the utility grid. You can also use the grid as backup. If you
        are running off of batteries and they are going dead, the unit can either switch to a
        grid source to power the load and recharge the batteries, or it can start a generator
        and use that. The transfer switch and battery charger are built into the SW series.
        The only restriction on this is that you are running off of the inverter, therefore
        your load is limited to the inverter output. In a pure utility-intertie inverter, you
        can feed back the inverter output back to the grid, even if you're using 50KW from the
        grid at the time. You're just offsetting XX number of KW with the inverter.

        > > If the utility power goes down, you don't have any power. This is
        > > done as a safety measure, because if the grid is down, you don't want to
        > > backfeed power into it and maybe fry a lineman who expects no voltage to be
        > > present.
        >
        > But; many people run a generator hooked into their power system with a relay that
        > controls a main breaker switch and prevents power from going out on the line when
        > the grid is down. If one could use the grid as their batteries so to speak and
        > only keep a minimum of batteries for power outs, then the cost of a back up system
        > comes out of the budget and can be applied to the cost of PV. Here in the rural
        > part of Texas, when the power goes out we loose our water and septic system.
        > Having some sort of backup system is a necessity. The size of the system depends
        > on how rich you are and what you have to have. The problem with generators is
        > that if you run out of fuel, and there is a power outage, you can not buy fuel.
        > Gasoline does not store well, so you must use a diesel generator.
        >

        Pros of utility-intertie are: Grid is the battery, simpler installation, no charge
        controller, battery charger, generator, batteries, big cables, big disconnects, or
        battery enclosure are needed, excess energy is typically produced and fed back midday
        when needed most. Cons: When grid is down, you have no power, location must be near a
        grid source.

        Pros of stand-alone are: You can have power all the time at any location. Cons:
        Requires more equipment (charge controller, big cables, big disconnects, big fuses,
        batteries, battery charger and enclosure), backup requires wind, microhydro, or
        generator.

        It just depends on what you need. The most typical stand-alone systems run on inverter
        power until batteries are too low, then the inverter will start a generator and switch
        the load to it while charging the batteries at the same time. In systems like this,
        you are running on solar generated power almost year round, except for those long
        periods of no sun in winter (usually). If you can supplement your charging sources
        with wind or microhydro, you may never need the generator. If I had to choose a fuel
        type for a generator, I'd use propane. Less energy value per pound than gasoline or
        diesel, but much easier to deal with. Biodiesel might be a choice if you grew
        something to make it where you lived.

        > > It's expensive to produce power with PV panels. Refrigeration uses about 20%
        > > of the power in a typical home. We have a large side-by-side refrigerator that
        > > uses 913 kwh/year. If you plug this into my solar sizer tool, it comes up with
        > > these figures on a system to run the refrigerator.
        > >
        > > Location -Houston TX, 24V system / 5 day backup
        > > Refrigerator 250whr * 7hr/day = 2.5 kwh/day @ .08 per kwh (HL&P) = $73/yr.
        > >
        > > Needed: 8 - 6V, 350 ahr lead-acid batteries @ $169 ea., 8 - 100W PC panels @
        > > $479 ea., 1 1500W inverter @ $739 ea,
        > > 1 60A charge controller @ $269 ea.
        > >
        > > System production: 2.66 kwh/day System load: 2.48 kwh/day
        > > Total system cost $6700
        > > Total paypack time @ .08 per kwh = 94.63 years
        > >
        >
        > The obvious response to this is that you need the fridge that NASA has developed
        > that does not need battery back up to make it through the night. I am designing
        > my place to use far less electricity than a "normal" home. One of the tactics
        > that we are looking at is using pumps that run on DC current for the hydronics and
        > other parts and hooking them to small PV installs. This avoids the cost, both
        > environmental and financial of a large set of batteries that must all be replaced
        > at once.

        This is the crux of using renewable energy sources. Normal houses, electronic
        equipment, and consumer attitudes are all geared toward not caring about how much
        energy is wasted in the home. Switching to more energy efficient appliances and
        lighting, eliminating phantom loads, and exercising conservation in general is
        something we all can do right now, no matter where we live. It's a lot cheaper to
        reduce the load than to buy PV panels. To power my house with PV right now with no
        changes would probably need a system that would cost $60-100K. You can buy really
        efficient DC-powered refrigerators, well pumps, and lights right now.

        > > Here's a quote from an article in Home Power magazine
        > > #64 written by James Udall and one from William Lord's website that sums up my
        > > feelings pretty well on the payback issue:
        > >
        > > "If PV systems get to $2 watt, everyone will do it and won't ask why. Today,
        > > though, we've got to wrestle with the economics. "What's the payback?"
        > > probably got its start after the first oil crunch, when some builder was
        > > trying to figure out whether it made sense to add fiberglass insulation to his
        > > next 2 by 4 shell. Duh. Twenty years later, "what's the payback?" has become a
        > > mindless chant. In no other realm does this mentality prevail. Your wife's
        > > pregnant!? Jeez, I'm sorry, kids aren't cost effective. Honey, let's buy a new
        > > sofa. Have you done a cost-benefit analysis? We've been brainwashed, infected
        > > with bean counter disease."

        > While this is an interesting comment on financial planning, when there is a finite
        > amount of money available, the decision of what to buy has to be based on
        > something....

        Agreed, and for me, especially lately, the motivation and choices have been personal
        and environmental. My wife and an increasing number of children I know of are getting
        or already have asthma. It's damn sobering to know exactly how much CO, CO2, SO4,
        VOC's, and fine particulates are put out by your lawn equipment, and realizing that
        you could walk in and tell your wife just how much junk you personally put into the
        air today for her and the neighbors kids to breathe. That's how my solar lawn
        equipment project got started. I needed to make better choices, and invent them if
        necessary.

        > > Solar Capital of the World!: Yes, Maine has been the cat's meow during the
        > > month of June, 1999 as the American Solar Energy Society held its annual
        > > convention in Portland...and I got to speak about "Living Well with Solar in
        > > Maine." It was an impressive gathering. Most notable was Steven Strong's
        > > answer (my architect) to the question about pv payback? "Engineers in
        > > Switzerland have meticulously attempted to measure the electrical output of
        > > asphalt shingles and other conventional roofing material, " he noted. "Because
        > > there is no current flowing, there appears to be no payback on most roofs
        > > throughout the world...unlike a solar roof," he concluded with a sly grin.
        >
        > The pay back on the roof is lack of damage. Ask me I know. I have been living
        > with a leaky roof since a tornado hit my place last June. The real pay back is
        > being able to sleep through the night, not listening for a storm. There is
        > nothing wrong with trying to save money and the environment at the same time. By
        > going to an alternative building method, our finished home will have cost about
        > 1/4 of a normal stick frame shell.

        The only reason the pay back issue is a sore spot with me is that it is used a lot to
        discourage PV use. There's no pay back on necessities, you buy them because you need
        them, pay back or not.

        > > > I am still interested in solar cooking but find that the wind is a major
        > > > problem. I would like to correspond with anyone who is doing solar
        > > > cooking, but at present I cannot join another group in Houston.
        > >
        > > I have the same problem. My cooker can't handle moisture or wind. I decided
        > > that I wasn't going to solar-cook on a regular basis until I could build a
        > > unit that could stay outside all the time because that's the only way it would
        > > be useful.
        >
        > Does anyone have any design ideas to make a solar cooker convenient? I do most
        > of my cooking outside in the summer months, [May through Oct.] and have placed my
        > auxiliary kitchen on the NE side of my building for comforts sake. The real,
        > indoor kitchen is therefore on the same side of the building to make life
        > convenient. A solar cooker needs the south or SW exposure. This leads us to the
        > problem of carrying food either through the building or around the building.
        > Carrying hot food through doorways, [auxiliary kitchen is screened] leads to
        > accidents.

        If I wanted an indoor unit, it would have to be something like what you would find at
        this site: http://solarcooking.org/walloven.htm
        I'm accumulating ideas for a new outside unit, but nothing definite in writing yet.

        Ok, that's enough for now. My fingers hurt from all this typing :-)

        James Ferrill
      • Chuck Wright
        ... Nice to have this interaction going on! Tell us more about your solar lawn equipment project... Chuck Wright
        Message 3 of 9 , May 11, 2000
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          James Ferrill wrote:

          > That's how my solar lawn
          > equipment project got started. I needed to make better choices, and invent them if
          > necessary.
          >

          Nice to have this interaction going on! Tell us more about your
          solar lawn equipment project...

          Chuck Wright
        • James Ferrill
          ... Hey Chuck, What I have observed is that although solar technology has advanced, no one other than a few interested people have actually made use of solar
          Message 4 of 9 , May 12, 2000
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            Chuck Wright wrote:

            > James Ferrill wrote:
            >
            > > That's how my solar lawn equipment project got started. I needed to make better
            > choices, and invent them if necessary.
            >
            > Nice to have this interaction going on! Tell us more about your
            > solar lawn equipment project...
            >
            > Chuck Wright

            Hey Chuck,

            What I have observed is that although solar technology has advanced, no one other than a
            few interested people have actually made use of solar energy in a practical way. If I
            went to my neighbors and poured my guts out all day about why they should be doing more
            with solar, the conversations would always end up focused around 2 questions, "How much
            will it cost?" and "Where do I get the stuff?". This is where the equation always breaks
            down. How to answer the question, "How do you implement use of solar power for XXXXXXX
            in a suburban environment?".

            I've reasoned that I need to start by doing a small project that everyone can relate to
            and that would make a difference that mattered to my neighbors. The project I came up
            with is a solar recharged lawn mower. If you know how much pollution lawn equipment
            emits, it's a sickening feeling when you walk outside on a weekend and see all your
            neighbors mowing, edging, and leaf blowing with poorly maintained, dirty, polluting
            equipment in Houston (which is now the pollution capital of the US, it seems). What made
            it so important to me is that I know a number of people and friends that have asthma,
            including my wife. That kinda makes it personal because I'm using the same bad
            equipment.

            I knew that the only things I would have to buy are a standard cordless lawnmower, a
            charge controller, and solar panels. That's it. The mower can be something like the
            cordless Black and Decker CM1000, 5 hp, mulching mower which is in stock at any Home
            Depot. The other two items are also stock items that I can order online from any number
            of vendors. I'm going to put an hour meter on the mower so I can log how much time it
            has spent mowing. Maybe I'll paint it gaudy colors and stick on solar stickers to
            attract attention too :-)

            After I started working on this, I decided to expand the project so that my shed and
            everything in it or plugged into it would be solar powered. This way I would be able to
            power my weed eater and leaf blower as well as the lawnmower, run the shed interior and
            exterior lights, and have a demonstration system that people could come and see how
            solar is utilized. My old physics teacher lives in my neighborhood, and I envisioned
            being able to let him bring students over to see how solar can be used for real and not
            just read about it in a book.

            After the equipment is built and tested for a time, the project needs to go on the web.
            I want to start with a domain name like suburban-solar.org or .com and make it a base of
            information of my journey to put solar energy to use at my suburban home. Along with the
            main page, I want to have a page for each project. I can put all the information on this
            page that anyone could want, like specs, runtime, charge time, principles of operation,
            etc. And the best thing I want to put on there and update on a regular basis is the
            amount of time this mower has been running and a list of how much pollution has been
            eliminated in detail. I can get people to visit the web site to see what can be done. I
            think it would really make an impact on my neighbors to see and realize just how much
            NO2, CO, CO2, SO2, and VOC's that they and everyone else are spewing into the air and
            into their kids lungs. I can provide a link for people to email me so that I could
            answer any questions they might have. I had sent a similar letter to Greg about getting
            TXSES to host the web site and domain, and it didn't sound like a problem. I figured I
            would tackle this project in phases:

            1) Acquire the lawnmower and research it's internal circuitry to see how the charger can
            be alternately powered.
            2) Acquire and install an hour meter and connector for access to the internal battery.
            3) Build battery cabinet for the shed. I already had 4 golf cart batteries. Expand as
            needed.
            4) Acquire the solar panels and install on the shed roof.
            5) Acquire a charge controller, 1500W inverter, and related hardware. Create a power
            distribution board to mount these components.
            6) Create circuit to recharge mower or simply run power cube off of inverter as needed.
            7) Create web site using documentation and notes kept as project has progressed.
            8) Spread the word.

            Phases 1 and 2 have been completed. I cut two holes in the lawnmower shell and mounted a
            small digital hour meter and connector to the internal battery. I have 2.4 hours of
            runtime on the mower so far. I talked with David Shaver in Canada, the man that actually
            designed the electronics in that mower for B&D and he gave me details on how it worked.
            Based on the strict current limited requirements of that small internal battery, I
            decided first to charge it normally using the original power cube running off the
            inverter and work on a direct DC-DC charger later.

            Phase 3 is 80% completed. I'm over-building the battery cabinet so that it's capacity
            can easily be expanded or the voltage changed from 12 to 24 volts. I've used 1.25" x 1"
            buss bar and 2/0 battery cables to minimize loss in the system. Two small fans in the
            bottom push any fumes or hydrogen produced during charging out a 2" PVC vent at the top
            to the outside. The box is 5' tall, 3.5' wide, and 2.5' deep, with two levels that can
            hold 8 golf cart batteries each for a total of 16 batteries max. Starting out with 4
            golf cart batteries will provide 220 Ah @ 24V or 440 Ah @ 12V. I'm designed enough
            headroom in there so that a larger, better battery can be used later, such as the Trojan
            L16's or equivalent. They're the same size, just taller than my current batteries.
            There's some serious framing in this cabinet since 16 batteries would weigh 1280 pounds.
            I can see my shed sinking into the ground already :-)

            I bought 2 Solec 90W panels and a Morningstar Sunlight series charge controller 3 weeks
            ago. After I finish the battery cabinet, they will be mounted on the shed roof (phase
            4). I've been taking pictures of each step as I build/add something new, and these will
            be scanned in later for the web site. If I get them scanned sooner, I'll email out some
            samples. That's where the project stands right now.

            James Ferrill
          • Chuck Wright
            This link has several papers about oil. I looked at the first one, and it is most interesting. http://www.simmonsco-intl.com/web/html/matt.asp?thispage=simple
            Message 5 of 9 , May 14, 2000
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              This link has several papers about oil. I looked at the first one,
              and it is most interesting.

              http://www.simmonsco-intl.com/web/html/matt.asp?thispage=simple

              Cuhck Wright

              --
              Chuck Wright
              http://www.chuck-wright.com
            • Ewert, Mike
              This is fantastic James! You definitely deserve an atta boy from HREG. We ll reward you by electing you secretary/treasurer at the next meeting (A little
              Message 6 of 9 , May 15, 2000
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                This is fantastic James! You definitely deserve an 'atta boy' from HREG.
                We'll reward you by electing you secretary/treasurer at the next meeting (A
                little selfish on our part, I know).

                Q: When you say "Based on the strict current limited requirements of that
                small internal battery", do you mean that a normal charge controller set on
                either sealed or flooded would allow the voltage to go too high or low?

                -----Original Message-----
                From: James Ferrill [mailto:jferrill@...]
                Sent: Friday, May 12, 2000 3:14 PM
                To: hreg@egroups.com
                Subject: Re: [hreg] Workshops and threads


                Chuck Wright wrote:

                > James Ferrill wrote:
                >
                > > That's how my solar lawn equipment project got started. I needed to make
                better
                > choices, and invent them if necessary.
                >
                > Nice to have this interaction going on! Tell us more about your
                > solar lawn equipment project...
                >
                > Chuck Wright

                Hey Chuck,

                What I have observed is that although solar technology has advanced, no one
                other than a
                few interested people have actually made use of solar energy in a practical
                way. If I
                went to my neighbors and poured my guts out all day about why they should be
                doing more
                with solar, the conversations would always end up focused around 2
                questions, "How much
                will it cost?" and "Where do I get the stuff?". This is where the equation
                always breaks
                down. How to answer the question, "How do you implement use of solar power
                for XXXXXXX
                in a suburban environment?".

                I've reasoned that I need to start by doing a small project that everyone
                can relate to
                and that would make a difference that mattered to my neighbors. The project
                I came up
                with is a solar recharged lawn mower. If you know how much pollution lawn
                equipment
                emits, it's a sickening feeling when you walk outside on a weekend and see
                all your
                neighbors mowing, edging, and leaf blowing with poorly maintained, dirty,
                polluting
                equipment in Houston (which is now the pollution capital of the US, it
                seems). What made
                it so important to me is that I know a number of people and friends that
                have asthma,
                including my wife. That kinda makes it personal because I'm using the same
                bad
                equipment.

                I knew that the only things I would have to buy are a standard cordless
                lawnmower, a
                charge controller, and solar panels. That's it. The mower can be something
                like the
                cordless Black and Decker CM1000, 5 hp, mulching mower which is in stock at
                any Home
                Depot. The other two items are also stock items that I can order online from
                any number
                of vendors. I'm going to put an hour meter on the mower so I can log how
                much time it
                has spent mowing. Maybe I'll paint it gaudy colors and stick on solar
                stickers to
                attract attention too :-)

                After I started working on this, I decided to expand the project so that my
                shed and
                everything in it or plugged into it would be solar powered. This way I would
                be able to
                power my weed eater and leaf blower as well as the lawnmower, run the shed
                interior and
                exterior lights, and have a demonstration system that people could come and
                see how
                solar is utilized. My old physics teacher lives in my neighborhood, and I
                envisioned
                being able to let him bring students over to see how solar can be used for
                real and not
                just read about it in a book.

                After the equipment is built and tested for a time, the project needs to go
                on the web.
                I want to start with a domain name like suburban-solar.org or .com and make
                it a base of
                information of my journey to put solar energy to use at my suburban home.
                Along with the
                main page, I want to have a page for each project. I can put all the
                information on this
                page that anyone could want, like specs, runtime, charge time, principles of
                operation,
                etc. And the best thing I want to put on there and update on a regular basis
                is the
                amount of time this mower has been running and a list of how much pollution
                has been
                eliminated in detail. I can get people to visit the web site to see what can
                be done. I
                think it would really make an impact on my neighbors to see and realize just
                how much
                NO2, CO, CO2, SO2, and VOC's that they and everyone else are spewing into
                the air and
                into their kids lungs. I can provide a link for people to email me so that I
                could
                answer any questions they might have. I had sent a similar letter to Greg
                about getting
                TXSES to host the web site and domain, and it didn't sound like a problem. I
                figured I
                would tackle this project in phases:

                1) Acquire the lawnmower and research it's internal circuitry to see how the
                charger can
                be alternately powered.
                2) Acquire and install an hour meter and connector for access to the
                internal battery.
                3) Build battery cabinet for the shed. I already had 4 golf cart batteries.
                Expand as
                needed.
                4) Acquire the solar panels and install on the shed roof.
                5) Acquire a charge controller, 1500W inverter, and related hardware. Create
                a power
                distribution board to mount these components.
                6) Create circuit to recharge mower or simply run power cube off of inverter
                as needed.
                7) Create web site using documentation and notes kept as project has
                progressed.
                8) Spread the word.

                Phases 1 and 2 have been completed. I cut two holes in the lawnmower shell
                and mounted a
                small digital hour meter and connector to the internal battery. I have 2.4
                hours of
                runtime on the mower so far. I talked with David Shaver in Canada, the man
                that actually
                designed the electronics in that mower for B&D and he gave me details on how
                it worked.
                Based on the strict current limited requirements of that small internal
                battery, I
                decided first to charge it normally using the original power cube running
                off the
                inverter and work on a direct DC-DC charger later.

                Phase 3 is 80% completed. I'm over-building the battery cabinet so that it's
                capacity
                can easily be expanded or the voltage changed from 12 to 24 volts. I've used
                1.25" x 1"
                buss bar and 2/0 battery cables to minimize loss in the system. Two small
                fans in the
                bottom push any fumes or hydrogen produced during charging out a 2" PVC vent
                at the top
                to the outside. The box is 5' tall, 3.5' wide, and 2.5' deep, with two
                levels that can
                hold 8 golf cart batteries each for a total of 16 batteries max. Starting
                out with 4
                golf cart batteries will provide 220 Ah @ 24V or 440 Ah @ 12V. I'm designed
                enough
                headroom in there so that a larger, better battery can be used later, such
                as the Trojan
                L16's or equivalent. They're the same size, just taller than my current
                batteries.
                There's some serious framing in this cabinet since 16 batteries would weigh
                1280 pounds.
                I can see my shed sinking into the ground already :-)

                I bought 2 Solec 90W panels and a Morningstar Sunlight series charge
                controller 3 weeks
                ago. After I finish the battery cabinet, they will be mounted on the shed
                roof (phase
                4). I've been taking pictures of each step as I build/add something new, and
                these will
                be scanned in later for the web site. If I get them scanned sooner, I'll
                email out some
                samples. That's where the project stands right now.

                James Ferrill



                ------------------------------------------------------------------------
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              • James Ferrill
                ... Thanks for that info, Chuck. I downloaded all those pdf files and read them oldest to newest. Fascinating and scary at the same time. Based on the facts
                Message 7 of 9 , May 15, 2000
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                  Chuck Wright wrote:

                  > This link has several papers about oil. I looked at the first one,
                  > and it is most interesting.
                  >
                  > http://www.simmonsco-intl.com/web/html/matt.asp?thispage=simple

                  Thanks for that info, Chuck. I downloaded all those pdf files and read them
                  oldest to newest. Fascinating and scary at the same time. Based on the facts
                  they presented, it seems unlikely we would have an embargo of any kind, except
                  from maybe Iraq. But if OPEC keeps the production down, we are basically
                  facing demand exceeding supply, with prices going way up and probably gas
                  lines again. One interesting fact that I gleaned from that report was the
                  question of how do you enforce or even do gas rationing since many stations
                  are totally automated with no attendant to enforce the rules. Answer: you
                  don't, it's every person for himself :-)

                  James
                • James Ferrill
                  ... The charge controller I bought was almost the same one on that electric car, a 24V, 20A unit by Morningstar.. The two solar panels I have can charge my
                  Message 8 of 9 , May 15, 2000
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                    "Ewert, Mike" wrote:

                    > Q: When you say "Based on the strict current limited requirements of that
                    > small internal battery", do you mean that a normal charge controller set on
                    > either sealed or flooded would allow the voltage to go too high or low?

                    The charge controller I bought was almost the same one on that electric car, a
                    24V, 20A unit by Morningstar.. The two solar panels I have can charge my battery
                    bank at 5.25 amps at the most. For maximum life, you limit the maximum charge
                    current of a lead-acid battery to the C/20 rate, which is the amp-hour rating of
                    the battery divided by 20. My set of golf car batteries have 220 Ah, so the C/20
                    rate is 11 amps and thus cannot be overcharged by my panels. But the internal
                    battery of the mower is 17 Ah, with a C/20 rate of .85 amp. So connecting the
                    same controller/panel setup would result in shortened battery life and probable
                    battery failure due to overcharging. The solution is to limit the charging
                    current, which is why they selected a power cube for the mower with a max output
                    of .8 amps. It limits itself. For the time being, I'll just use the factory
                    power cube and run it off of the inverter.

                    James
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