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Discussion in 'Environmental Discussion' started by bwilson4web, Nov 24, 2024.

  1. bwilson4web

    bwilson4web BMW i3 and Model 3

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    So this is how the project begins:
    upload_2024-11-24_12-38-51.png

    Requirements:
    • Maximum billing, $0.12/kWh, reduction not taxable
    • Minimize power to grid, $0.05/kWh, taxable income
    • Expandable
    Proposed $61,000 solution:
    • 6 kW
      • 400 W panels
    • Integrat with existing emergency generator
      • 16 kW, $0.45/kWh
      • natural gas fueled
      • 30-35 seconds startup
    • Load managing, smart breaker panel
      • 5 kW battery, 16 ms (one cycle) switch to support house load
      • EV charging, work shed, water heater, oven+stove - OFF
      • Lights, gas heater, refrigerator, communications - ON
      • All on when 16 kW generator comes online
        • Solar reduces generator fuel consumption
    I have contracted with "SOLAR Alternatives" for a turn-key solution. Yes, it would be fun to "roll your own" but I am paying extra for their expertise and warranty. Furthermore, at age 74, I really shouldn't be scampering up ladders, laying my own power lines, and replacing the breaker box. They come with integration skills including with the Generac emergency generator.

    Bob Wilson
     

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    #1 bwilson4web, Nov 24, 2024
    Last edited: Nov 24, 2024
  2. tochatihu

    tochatihu Senior Member

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    First thing I notice is trees shading the roof.
     
  3. bisco

    bisco cookie crumbler

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    solar companies run computer models of your location and sat photos to show how much power you can produce throughout the year, including average cloud cover and tree shading.
    cutting or pruning may help if they are your trees. some people prefer the shade
     
  4. tochatihu

    tochatihu Senior Member

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    Some leaves on the roof also :)

    ==

    Selected contractor will find that this retired engineer will be more 'involved' than average client. Hope they see that as a positive.
     
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  5. bisco

    bisco cookie crumbler

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    okay, that got a laugh
     
  6. bwilson4web

    bwilson4web BMW i3 and Model 3

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    There are two "ground stumps." The larger one nearest the camera held a former pine tree, ~56 years old. The smaller one in front of the BMW i3-REx was some "red berry" tall tree about the same age. I had both removed and hauled off. I have not removed the legacy pine needles since their installation staff can borrow a broom.
    [​IMG]
    The remaining pine tree on the right shades the master bedroom and two smaller ones. The photo was taken on Friday, November 21, about 30 days ahead of the winter solstice, December 21.

    Here is their initial, proposal:
    upload_2024-11-24_22-15-11.png

    My spreadsheet model and NREL web pages project an annual cost avoidance of ~$1,000 per year. So I've transferred the profits of my former TSLA stock to get a recurring, $1,000 per year payback. One I can enjoy more than whoever would have gotten my TSLA after I'm gone.

    I have gas heating so summer solar for air conditioning is more important than in the winter. Not shown, the back of the house has no shading trees on my property. Fortunately, my property is over one meter higher than the back yard properties. There is a ridge line to the east that delays sunrise by about 1/2 hour.

    I anticipate moref panels will be on the eastern side to maximize summer solar power. But I leave that to their design teams after a site inspection. They appreciated my photos but I emphasized a site survey brings eyes and experience that I lack. The more information they have, the better the final project.

    I sent them names of three hotels, 2 miles away, and a contractor motel walking distance from my house. I volunteered to let them use one of my two cars, Tesla or BMW i3-REx during their visit. I also named and offered dinner at better restaurants in Huntsville.

    Before they arrive, I'll run a Cat-6 ethernet from the breaker closet to the TV room where the cable modem is located. I've got a Cisco switch ordered to free up ports for the "SPAN Panel." I'll also run a #6/3, NMC, from the breaker closet to the corner where I want to mount my Tesla Universal charger. I will probably run a Cat-6 line from the TV room to the Tesla charging demarcation for more reliable and faster WiFi for the Tesla and 'she shed.'

    I have a fine appreciation for letting the technically skilled do their best while showing an appreciative interest. So I visited their shop in New Orleans returning home. They liked my Starship photo. But more importantly, we have a good sense of each others skills, abilities, and commitment.

    Bob Wilson
     
    #6 bwilson4web, Nov 24, 2024
    Last edited: Nov 25, 2024
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  7. bwilson4web

    bwilson4web BMW i3 and Model 3

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    A recent skeptic of home solar, Michael Shellenberger, claimed at a Ted Talk that "home solar costs twice as much as from a solar farm." Of course comparing retail home solar installation versus a utility grade solar farm is somewhat of an Apples to Oranges as each has different economies of scale. The engineering and design for my 6 kW solar takes more per kWh than say a 600,000 kW solar farm. But he misses the point:
    • $0.12/kWh - is what I pay, retail for every kWh and is not taxed
    • $0.05/kWh - is what the utility will pay me for every extra kWh and it becomes taxable income
    Whether or not home solar makes sense for you, compare your retail cost of electricity to the wholesale price from the utility. That is what drove my sizing decision has I want cost avoidance. No extra electrons buys me anything but the privilege of becoming a volunteer, wholesale electricity generator. The utility can go buy their own solar farm as they and their larger customers are already doing.



    Bob Wilson
     
    #7 bwilson4web, Dec 5, 2024
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  8. bisco

    bisco cookie crumbler

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    Idk anything about solar farms, but we are offered clean electricity at a rate higher than our current 40 cents per kWh
     
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  9. bwilson4web

    bwilson4web BMW i3 and Model 3

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    Eliminate the middle man casting a shadow between you and that great fusion reactor in the sky. <GRINS>

    Bob Wilson
     
  10. tochatihu

    tochatihu Senior Member

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    Huntsville and Boston solar power potential are more similar than I guessed (I looked). Both are about middle compared to 48 states' range. Overall, the middleman that cannot be eliminated is Mr. Cloud.
     
  11. bwilson4web

    bwilson4web BMW i3 and Model 3

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    That is why it is important to have a battery buffer to store excess noon electricity to offset evening and night loads.

    There is a good, online modeling tool: PVWatts Calculator

    Bob Wilson
     
  12. tochatihu

    tochatihu Senior Member

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    OT, and shut it down if desired.

    Geoengineering is a climate-repair strategy getting current attention. It is tempting to put sulfate aerosols in upper troposphere or lower stratosphere. They enhance Mr. Cloud and cool things down. One aspect not getting a lot of talk is negative effect on photovoltaic power generation.
     
  13. bwilson4web

    bwilson4web BMW i3 and Model 3

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    Agreed. A recent report claims that mechanical drill bits can be replaced by directed energy at the drill pipe end. But that is a research project, not a product.

    Bob Wilson
     
  14. tochatihu

    tochatihu Senior Member

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    Some agency (forgot which and where) is looking at temperature maps to detect 'rogue' geoengineering projects. My guess is it will be hard to prove because weather is so variable. But rogues would have airplanes with 'sulfate shooters' installed. Do some ramp checks.
     
  15. tochatihu

    tochatihu Senior Member

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    If you're doing laser drills here, I'll assume that OT is OK :)
     
  16. davecook89t

    davecook89t Senior Member

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    $61k seems like a lot to me for what you are getting, but I've never gotten to the point of getting a price for a solar installation that we had been considering for our house in the Bronx. Having dabbled in solar power for our travel trailer and a small system to keep our refrigerator powered on during storms at our house in Florida (unoccupied during the summer), I'm familiar with the cost of DIY components, which at this point in time can be surprisingly inexpensive. I fully realize that the Tesla Power Wall is not DIY, and as such is several times more expensive than a DIY battery with the same capacity. But even taking the price of $13.6k that I see online for their inverter and a 13.5 Kwh battery (are you sure yours is only 5 Kwh, that does not seem to be the standard battery for a PW3?) along with the cost of your solar panels at less than $3k (currently on sale at Portable Sun for $132 per panel), the total cost of the main components would be around $16k. Allowing a few thousand more for racking and wiring, I would guess the parts could all be purchased for less than $20k, meaning that the labor cost would be about double that. Maybe that is reasonable, but given how cheap solar panels are currently, I wonder if it might be worth loading up your roof with panels, since you are getting some credit for excess power generated at least.

    For what it's worth, I would have jumped into solar with both feet in either NY or Florida, particularly since I believe they both still offer full net metering, and our roof in NY actually needed to be replaced, but my wife calls the shots for that property and she does not see the point of making a huge investment in solar, when at 70 years of age, we will probably not be around long enough realize the full benefit. The house in Florida (where I have a little more input) will supposedly not need a roof for a few more years, but when it does, I intend to cover it with solar panels.
     
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  17. tochatihu

    tochatihu Senior Member

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    There are many PV power (average) maps available. But I don’t see PV power intermittency maps. They could be derived from monthly sunshine days data. Those are available for locations (pretty much) everywhere, but have not been geospatially redrawn. To my knowledge.

    PV power guides decisions on collector area required. PV intermittency guides decisions on battery capacity required. If this is clever, offer it freely to your contractor. Maybe you can get a biiig discount.

    This
    Huntsville weather by month: monthly climate averages | Alabama

    does not have the 'monthly sunshine days' metric I sought, but that must be elsewhere, and it tells a lot. Nov though Feb are your system-sizing months. The low-power months are also high-intermittency months.
     
  18. tochatihu

    tochatihu Senior Member

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    @davecook89t hit something interesting. Older people have accumulated wisdom, but that includes knowledge that payoff times can exceed life expectancy. This type of home upgrading might be viewed as a multi-generational thing.
     
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  19. bisco

    bisco cookie crumbler

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    exactly. my quotes were around 25k after all credits. because of latitude and neighboring trees, it's a ten year payback. plus another 25k for a new rood that does not need replacing yet, but is recommended before installation.
    at 70, we probably won't be here to enjoy it.
     
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  20. bwilson4web

    bwilson4web BMW i3 and Model 3

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    Good points, let me share my thinking:
    • This is the second attempt at home solar. The first attempted to use a Tesla recommended supplier out of North Carolina but they also work on "Elon time" and "Musk communications" skills.
    • The "$61k" also struck me as high but it is for a house the County and 'cold call' real estate buyers values about 3-4x more, $180,000 to $240,000. I pay taxes on the valuation.
    • Do it yourself solar does work and much more affordable but tends to be bought and installed by less skilled individuals. There is a reason why electricians are licensed and insured. My contractor has checked off the engineering skills I learned when I was working. So having visited the contractor's office in New Orleans, their compact, dozen skilled people impressed me with their expertise ($$$) and resources. For example, I asked about the pending Chinese tariffs and they answered, "We already have the panels in stock."
      • In 2016, I paided $8k for a 16 kW, automatic emergency generator, fueled by natural gas. In either years, I've had two service calls to diagnose a corroded starter battery cable and most recently, a failed oil pressure sensor. I want a maintainable solar system with good engineering skills applied.
      • One of my younger brothers did his own solar for his mobile home. I admire his work and engineering but I wanted to buy the contractor's skills.
    • They offered a PowerWall solution but it had no ability to integrate with the existing, emergency generator.
    • I continue to see technical improvements in solar panels and did not want to "load up" with soon dated panels. But at 74 years and 6 weeks to the next administration, today's 'old technology' is better than waiting for perfection.
    Bob Wilson
     
    #20 bwilson4web, Dec 6, 2024
    Last edited: Dec 6, 2024
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