Solar Panels for my home

Discussion in 'Prime Main Forum (2017-Current)' started by Jnbrown, May 16, 2017.

  1. MikeDee

    MikeDee Senior Member

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    Why don't you go back and read some of his other posts to me and some of others in other threads instead of just this one? Further, look at your own posts as well.

    I have a 7.5 kw solar system on my home. However, I'm not being a zealot about it.
     
  2. Zythryn

    Zythryn Senior Member

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    If you are going to hold a grudge against anyone that has, in the past, written a snarky post, discussion will become impossible.
    And I know about some of his other posts. I have been on the receiving end.

    But when someone makes a rational post, without ad hominin attacks or other fallacies, I think it is best to respond rationally rather than degrade the conversation.
    I apologize if you have taken offense at any of mine, I do work hard at trying to be rational and not rise to the bait when provoked.

    I am glad you aren't being a zealot about it.
    You asked me upthread how I calculated lifetime solar production. I replied, did you see zealotry in my method, or would you do so differently?
     
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  3. MikeDee

    MikeDee Senior Member

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    What fallacies?

    I'm not calling you a zealot. I do think your calculation is wrong though and overly simplistic (no offense meant). When I look at my Solar Edge web page showing what my system produced, I have questions like where is this being measured? Is this peak, average, RMS power and how I'd this related to what the power company uses? Is it DC or AC power? Did it account for conversion losses? I'll question my installer or Solar Edge.

    Also, I financed my system by pulling money out of my retirement account. Consider the return rate I'm losing if I had left that money in.

    Most people do not stay in their homes for 30 years. Will I recover my investment if I have to sell? Uncertain that is. My property taxes also went up slightly because this was an improvement and CA taxes it.

    My electric bill isn't zero either. My system over produces but I'm still being charged 2.3 cents per kwh for every kwh I buy from the grid. I don't know what your utility charges.
     
  4. Zythryn

    Zythryn Senior Member

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    Glad to hear you weren’t referring to me. You left your label rather open ended so I wasn’t sure.

    No offense taken, constructive criticism allows me to refine and improve my calculations.
    We have three methods of measurement. Solar Edge, our production meter and our eGauge monitoring system.

    Our production meter measures AC power after the DC has been converted to AC, same with our eGauge. I am not certain about the Solar Edge as I rarely use it.

    Cost of financing is definitely a factor you should include, as is the increasing costs of electricity for your own calculations.
    We did not finance, so I did not include any costs for that.
    However, I also don’t include calculations for the increased price of electricity. I mainly do this just to err on the side of too conservative, rather than too optimistic.

    Anyone planning to sell within 5 years would likely be better off waiting on the solar, or investing in a community solar garden. A valid point. In our case we do plan to remain in this house for more than 30 years. Hopefully I live that long:)
    I’ve studied that issue, it seems that, on average, the presence of solar is increasing the sale prices of houses.
    Prior to paying off the panels, this would be a mitigating factor. Afterwards, it is simply frosting on the cake.
    Minnesota does not allow the presence of solar panels to affect the taxed property values, which is why I didn’t include it.
    As yours did, I would definitely include it in your calculations, as long as you also consider the increased sale price if you do sell.

    For overproduction, our utility pays us the retail price plus 0.1 cents. Due to our overproduction, our annual bills including all fees and taxes have zeroed out, although this fluctuates from month to month.

    Anything I missed, or aspect you feel should be handled differently?
     
  5. fuzzy1

    fuzzy1 Senior Member

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    This isn't an audio system. Anything tied to the utility grid should measure power as AC RMS, either at the grid tie point or the AC side of the inverters.

    For my system, I see two measures of energy: the production meter installed by the utility, and the number reported by the individual microinverters, separated from the utility meter by a long run of wire. After five years of operation, I can easily see a small difference caused by the wire resistance loss (assuming both measures are accurate).
    Yikes. I paid for mine with other cash, swiped from budget for future utility expenses. I hope you have a path to funnel your utility savings back into your retirement accounts, either through increased payroll 401K contributions or annual IRA contributions. Being jobless (retired), I'm passed those.
    Property improvements here have a grace period (five years??) before being taxed. Of course, someone in the tax office has to learn of it first. Without a reporting process or building permit (not required for PV), assessors do periodic walk-around inspections, apparently less frequently now. And mine is easy to miss that way.

    But I don't think of housing as an 'investment'. It is an expense. While some folks are geographically lucky to realize a serious investment gain after inflation, the bulk of the population does not. And property taxes here are high enough to tax away the entire value of a home over one's lifetime. That is part of the reason we stayed in our 'starter home', never moving to something bigger. Without kids, this home turned out to be 'big enough', we didn't need any more space. Plus, larger homes have increased operating costs, and serial house trading involves major transaction costs that consume a fair chunk of the supposed investment gains.
     
    #185 fuzzy1, Jun 4, 2018
    Last edited: Jun 4, 2018
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  6. benagi

    benagi Active Member

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    Did I miss something, who are you talking about?
     
  7. fuzzy1

    fuzzy1 Senior Member

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    Here is my complete production, through today:
    PV_lifetime_2018Jun.GIF

    Peak production this year is off a bit, probably because I haven't been up yet to scrub off the winter grime and spring pollen layers.
     
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  8. MMBH

    MMBH Member

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    I totally agree about the price gauging from the electric utility companies! PGE sounds like NG in the east here!
    Speaking of — * Does everyone pay more for delivery than they use each month? We have always paid more for delivery than what we use!

    Although. one thing I can say about being grid connected, at least you can net meter and recoup your costs quicker! (I'm looking at having to live off grid as it's probably going to cost a little more for us to have it run to our property than it would to just go off grid, even with a larger solar PV array and batteries. And we don't get any state incentives or rebates because we are not connecting into the grid.) ;(
     
  9. ForestBeekeeper

    ForestBeekeeper Active Member

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    In 2015 I got quotes from three licensed solar installers here in Maine. And a fourth company came through our area offering a 30-year service contract thing.

    In all cases, the upfront cost of installing a net-metering system was more than the cost of installing an off-grid system with battery-bank.

    I live on a farm. Nearly everything on a farm is tax deductible. The IRS requires that solar systems depreciate over a lifespan of seven years, 1/7th each year.

    My solar-power system depreciates 1/7th of its total cost each year for 7 years. So there is no way possible for the infamous 'pay back' to be longer than seven years.
     
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  10. GregersonIT

    GregersonIT Member

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    So, if you can maximize your time of use or generation of power. Ideally, you would have East and West facing panels to maximize your early morning and late evening generation so it's not so much of a duck curve in power generation. Some utilities are giving out better rebates for systems built this way as well. It's not so much that you'll see a greater return on investment but you will see a smoother power generation curve going from crack of dawn morning until as late as 830pm at night during the summer months.
     
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  11. Salamander_King

    Salamander_King Senior Member

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    I find your statement very hard to believe. Everywhere I have looked, the grid-tide PV system is about half the price of the same KW PV system with battery either off-grid or grid-tied with battery back-up.

    For my situation, the solar panel system's upfront cost is way higher than potential savings. After very careful analysis, I decided to save money in an investment account and let the money grow instead of spending it on the PV panels on my roof. Instead of spending a large sum of money now, I signed up for a community solar farm share. It will save me some electricity costs and contribute to renewable energy effort.
     
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  12. MMBH

    MMBH Member

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    Not so if there isn't any power close enough in proximity to begin with at the property line, as is our scenario! Although if power is there already, then I agree that hooking into the grid will typically be less expensive.
     
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  13. Salamander_King

    Salamander_King Senior Member

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    Yeah, if you include the cost of bringing the line to tie to the grid. But @ForestBeekeeper already have the grid connection. Compearing the cost of the PV system alone, the grid-tied system is much less than the off-grid (or grid-tied with battery back up) due to the cost of the battery. In my case, the difference is close to $15K.

    10.9kW Grid-Tie Solar Power Kit with SolarEdge Inverter
    9.1kW Grid-Tie Solar Power System with Battery Backup
     
  14. GregersonIT

    GregersonIT Member

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    Sometimes it works out that way. Though, a lot of people miss the utility escalation math as well as the summer/winter rates. Typically utilities go up on average around 2-3 percent a year and they typically give you smaller tiers during the summer. That's where the Solar starts to make a ton of sense because you basically lock in the rate you are paying for power year round and after rebates the typical low end payback rate is 10-20% annually. I tell everyone avoid anything that escalates and get multiple quotes as there can be big price differences between installers.
     
  15. Salamander_King

    Salamander_King Senior Member

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    The problem is that in our states, solar panel generated electricity is bought back at wholesale price and will get paid back only as a credit toward the actual electric use. The credit is good for only 12 months on a rolling basis. So, even if I generate 100% of our electricity use, I can only save that much not anymore. For a $35K upfront investment, the payback period is almost 17 years. It just makes no economic sense to use the money for something that takes so long to break even.
     
  16. hill

    hill High Fiber Member

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    OUR area - like most - credit backfeeding the grid at the rate that the meter runs when it's going forward. IE; ~20¢/kwh at tier One (1st 600kWh's) ~28¢ at tier 2 (next 150kWh's) - tier 3 at 38.5¢/kWh.
    Before any of our plugins, we were actually getting credit for tier 2 power back.
    But at the end of the year? If we had several hundred kWh's Surplus credit? They only paid us at 1.2¢/kWh . . . . which the utility then turns around & maybe sells it to another customer for an average of 30¢/kWh.
    Moral of the story is never have too much excess or your payback/ amortization time frame will take a longer time. Even if you're just knocking off one or two price tears, you are saving a boatload.
    .
     
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  17. Salamander_King

    Salamander_King Senior Member

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    At least you are getting something back for the excess production. We have no tiered price for a residential customer and the price does not change often, usually only once a year. It is one standard offer price if it's from the utility, although the supply part of the electricity can be purchased from any wholesale, and that is the price they will credit for any solar panel production back to the owner up to a year on rolling base. If the panel makes more than I can use, I give away the electricity for free. I had an installer measure the solar exposure and seasonal variation for our 1000kWh/mo usage. To cover 100%, they proposed to install a 12kw grid tied system completely turn-key operation, but the price tag was $35K. Even after a 26% tax credit this year, it is still a $26K price tag. That's still 13 years for the payback period only if the panel does produce as much electricity as promised. Anything less, the payback period will just get longer. I can probably reduce the price tag on the initial investment if I DIY, but I just don't have the skill. Any way I slice it, there just does not seems to be any money-saving in this scheme. I signed up for the community solar contract which guarantees a 15% discount on our utility bill. This is without any upfront payment. Do the math, I am in for the 15% saving and contributing to the renewable energy shift.
     
  18. fuzzy1

    fuzzy1 Senior Member

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    Our net metering program is essentially the same here, except that I will get 0.0¢/kWh for any excess credits that expire after a year. Fortunately, my unused excess is also small, and we have significantly lower retail prices to begin with.

    Under the production incentive program, I received an incentive payment for all production, including the excess, but that program expired June 30, so only net metering remains.
    I was willing to assign a decent chunk of the installation cost towards putting my money where my mouth is, with respect to doing my part to address Anthropogenic Climate Change. So I didn't demand a full economic payback.

    But being able to DIY, I was able to hit Net Zero Energy with $17k of hardware (before incentives) and permits, half of your estimated cost (though needing less capacity too). That made it easier to justify than in your situation.

    I was happy to hit Net Zero here in part to poke a stick in the eye of detractors who claim that solar isn't practical in the Seattle region. I did it despite a Zillow Sun Number score in the mid 50s, much lower than Seattle's median score of 69, and national median of 78. Neighboring trees dragged my score even lower than our poor climate norm, significantly boosting the amount of hardware required. Yet it still works when paired with reasonable conservation measures, such as heat pump space and water heating and not-too-expensive building envelope improvements.

    FWIW, I built in three stages, so had two years of production history to help tune the sizing of the final stage.
     
    #198 fuzzy1, Dec 2, 2020
    Last edited: Dec 2, 2020
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  19. Salamander_King

    Salamander_King Senior Member

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    Net Zero is wonderful if you can achieve it, but for my sentiment, as long as I am tied to the grid I remain to be a slave to the utility for energy dependence. My ideal set up would be a 100% off-grid with no reliance on the large utility company. Unfortunately, that goal is not very realistic for our current residence and lifestyle. The battery bank large enough to store enough electricity would be cost-prohibitive. As far as doing something about climate change, over 70% of our state electricity is already from renewable sources, and currently working to get to 100% renewable by 2030. I already pay an optional contribution to renewable electricity sources on my monthly electricity bill. My feeling is that there is a better way to spend money to help this cause such as supporting a larger Mega Watt community solar farm projects than to spend and tie up a large sum of my money upfront to install PV panels for such a small amount of electricity produced. That being said, I will continue to explore other options. As solar energy becomes more popular and widely used, the price will decrease. In near future, even after the incentives run out, a smaller unit may become affordable enough for me to try without breaking the bank.
     
  20. hill

    hill High Fiber Member

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    In the realm of wide variations between SoCal cool summers & rainy/short winter days, our 2 SunPower Inverters will generate a low of 5kWh's to a high of 50kWh's - AC.
    Averaged over 24 months, our usage wood generate a bill of $225. That was 11 years ago, whereafter we have paid virtually nothing for transportation Fuel & home cooking, Heating, and Lighting. Each gear utility gets approved for an average of a 3% increase in electricity costs. Accordingly our electric bill would have gone up 3% per year for the past 11 years. Can anyone get that kind of payback on that initial $30,000 capital outlay (for our system) that would otherwise be money sitting in your federally insured, safe, checking account?
    .
     
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