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Re: [hreg] Workshops and threads

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  • James Ferrill
    ... There are two types of PV solar electric systems, stand-alone and utility-intertie. Stand-alone systems are exactly that, a set of panels charging a set of
    Message 1 of 9 , May 8 7:43 AM
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      Kim & Garth Travis wrote:

      > Hi,
      >
      > I would like to suggest a topic for a thread. I would like to
      > understand more about net metering. I know the the group in Austin has
      > it on the web site, but like many such sites, it does not answer basic
      > questions. Could we possibly have a net metering for dummies?
      > Something in the practical range of if I normally pay x for electricity,
      > how long would it take to pay off a PV system that costs y and has no
      > batteries? Some batteries?

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

      Stand-alone systems are exactly that, a set of panels charging a set of
      batteries with a charge controller. An inverter draws the stored power from
      the batteries and converts it to 120V AC that your house uses. If the power
      goes off, you are unaffected as long as you have power in the batteries. Such
      systems are typically designed to have a 3-5 day autonomy, at which point a
      backup generator is used to charge the batteries. The generator is usually
      only needed during long periods of insufficient sun, typically during the
      winter.

      Utility-intertie systems have no batteries and require the utility grid to
      operate. A set of panels feeds power directly to a intertie-style inverter.
      The inverter matches its output to the grid supplying your house and reduces
      the incoming power by the amount it happens to be producing at the moment. If
      you are producing more than you are actually using, the utility meter will run

      backwards. 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.

      Net metering refers to the type of setup where you have only one meter and the

      utility company allows the meter to run backward. Billing is typically
      arranged so that you are charged on an annual basis for your net use or
      credited for your net production, hence the term "net metering". Some
      utilities in California and the Northeast have taken active steps to try and
      prevent people from affecting their monopoly on electricity by requiring
      expensive disconnects, two meters instead of one, or million-dollar insurance
      policies, all paid for by the homeowner. This is why net metering, supported
      at the state regulatory level, is so important since it ensures that the
      cheaper, single meter setup is used without undue burden on the residential
      power producer. I am unaware of anyone with a residence that has a intertie
      system doing net metering in Houston, although net metering is the official
      policy of Texas. In many states where utilities have fought to prevent people
      from using intertie systems, a grass-roots effort known as "solar guerrillas"
      has sprung up. These people typically build a system and operate it without
      notifying the utility, which won't know any different as long as you always
      produce less each month than you consume.

      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

      This estimate did not include labor, PV mounting rack, wiring, etc. A
      real-life install would cost $12,000 and stretch the payback time out to 164
      years. PV cannot compete in the marketplace because carbon-based power is so
      heavily subsidized. If people had to pay the real cost of carbon-based power,
      PV would be competitive. If you want to use PV, it usually for personal or
      environmental reasons. 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."

      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.

      > 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
    • 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 2 of 9 , May 11 7:43 AM
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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 3 of 9 , May 11 10:06 AM
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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 4 of 9 , May 11 6:16 PM
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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 5 of 9 , May 12 1:14 PM
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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 6 of 9 , May 14 3:28 PM
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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 7 of 9 , May 15 8:45 PM
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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



                  ------------------------------------------------------------------------
                  Best friends, most artistic, class clown Find 'em here:
                  http://click.egroups.com/1/4054/0/_/58590/_/958162477/
                  ------------------------------------------------------------------------
                • 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 8 of 9 , May 15 9:40 PM
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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 9 of 9 , May 15 9:57 PM
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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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