6 ms·

Why are you treating 10 years as if it's infinity? Lots of houses last longer than 10 years.

zemvpferreira 6y ago
It's just a bad rate of return for an investment. Put the same amount of money in a better investment vehicle (say the stereotypical index fund) and you'll be able to afford buying the same amount of electricity from the grid as the panels would generate and have enough spare to go out to dinner every week.
- mortehu 6y ago
  You have to compare to investments with similar risk profiles. For example, 10 year treasury bonds only recoup 11.4% of their cost after 10 years. That doesn't mean nobody will accept that return. Not everyone is in a situation where equity index funds make the most sense as a marginal investment.
  - zemvpferreira 6y ago
    Are you also expecting your bonds to be worth literally zero after around 15 to 20 years?
    - deleted 6y ago
      [deleted]
    - ClumsyPilot 6y ago
      When you sell a house, do take it apart brick by brick and sell the bricks, door and windows on ebay? Obviously you sell the entire house and all improvements are reflected in increased value of the house. So no, the value of solar is not zero at the end of 10 years.
      - zemvpferreira 6y ago
        Are you betting on your solar install to last forever? What do you estimate the useful life span is for the average solar panel installed?
        ClumsyPilot 6y ago
        The argument doesn't even make sence - which part of a house lasts forever? A roof lasts 15 years, you can buy solar panels with 50 year warranty. Don't bet or estimate, we have mountains of data on this: https://www.nrel.gov/docs/fy12osti/51664.pdf https://www.nrel.gov/docs/fy12osti/51664.pdf
- ogre_codes 6y ago
  This ignores the other benefits of solar. The fact that I'll stay powered up when everyone else is black is important in rural areas even on-grid. The fact that you know your power is green. It also ignores the possibility that energy costs will go up over those 10 years. Essentially you are fixing your energy costs indefinitely. Of course I'm not-quite normal kind of guy regardless. I paid too much for a very efficient house. I own my house. I own my cars. To me, the idea of turning unknown future costs into known present costs is fantastic. Not a lot of people agree with that concept.
  - zemvpferreira 6y ago
    There are absolutely other benefits to solar other than return on investment, but this thread was about solar being 'worth it' financially. Also worth it to add in this context that the 5 or 6 solar-dependent/off-grid homes I've seen built and lived in have been anything but reliable. It seems to take a while to fine tune the system to the point of not having a blackout every 3 months.
    - ogre_codes 6y ago
      > There are absolutely other benefits to solar other than return on investment When you are talking about a purchase which you live with day to day for 10+ years, "Return on Investment" is never going to be a straight financial calculation. People don't buy a house based on straight ROI, nor are most home improvements based purely on ROI. I don't see why solar should be the exception.
      - zemvpferreira 6y ago
        Maybe it shouldn't, but ROI seems to be the particular topic in this discussion.
  - yablak 6y ago
    At least here in CA, if you are on the grid but don't have a battery then you will go black with everyone else even if you have solar. This is a safety measure for the technicians from the electrical company fixing the issue. According to another comment the additional cost of a battery is between $6,000 to $10,000.
- FabHK 6y ago
  10% annual yield is great for an investment. In real terms, the S&P 500 price return was about 3.2% p.a. since the peak in 1968, 5.2% since 1988, and less than 3% since 2000. Real total (ie with dividends) return p.a. over a decade has been between -4% and 17%, with an average of around 7%. As things stand currently, I'd not plan on more than 6% total return in real terms over the next two decades.
  - zemvpferreira 6y ago
    Please don't disregard that with investing in solar panels, you're eventually losing your principal. It's only after the 10-year payback that you actually start making yields i.e. for a 15-year life span, those hypothetical panels are only making 50% back over 15 years - a 3% return at best.
    - toomuchtodo 6y ago
      Inverters usually have a 12 year warranty you pay a fee to extend to 25 years. Panels have a 25 year warranty, and we'll produce at 90% of rated power after that point.
inglor_cz 6y ago
The question is if the panels last longer than 10 years without major degradation.
- gilrain 6y ago
  And the answer is yes.
deleted 6y ago
[deleted]

It's just a bad rate of return for an investment. Put the same amount of money in a better investment vehicle (say the stereotypical index fund) and you'll be able to afford buying the same amount of electricity from the grid as the panels would generate and have enough spare to go out to dinner every week.

mortehu 6y ago
You have to compare to investments with similar risk profiles. For example, 10 year treasury bonds only recoup 11.4% of their cost after 10 years. That doesn't mean nobody will accept that return. Not everyone is in a situation where equity index funds make the most sense as a marginal investment.
- zemvpferreira 6y ago
  Are you also expecting your bonds to be worth literally zero after around 15 to 20 years?
  - deleted 6y ago
    [deleted]
  - ClumsyPilot 6y ago
    When you sell a house, do take it apart brick by brick and sell the bricks, door and windows on ebay? Obviously you sell the entire house and all improvements are reflected in increased value of the house. So no, the value of solar is not zero at the end of 10 years.
    - zemvpferreira 6y ago
      Are you betting on your solar install to last forever? What do you estimate the useful life span is for the average solar panel installed?
      - ClumsyPilot 6y ago
        The argument doesn't even make sence - which part of a house lasts forever? A roof lasts 15 years, you can buy solar panels with 50 year warranty. Don't bet or estimate, we have mountains of data on this: https://www.nrel.gov/docs/fy12osti/51664.pdf https://www.nrel.gov/docs/fy12osti/51664.pdf
ogre_codes 6y ago
This ignores the other benefits of solar. The fact that I'll stay powered up when everyone else is black is important in rural areas even on-grid. The fact that you know your power is green. It also ignores the possibility that energy costs will go up over those 10 years. Essentially you are fixing your energy costs indefinitely. Of course I'm not-quite normal kind of guy regardless. I paid too much for a very efficient house. I own my house. I own my cars. To me, the idea of turning unknown future costs into known present costs is fantastic. Not a lot of people agree with that concept.
- zemvpferreira 6y ago
  There are absolutely other benefits to solar other than return on investment, but this thread was about solar being 'worth it' financially. Also worth it to add in this context that the 5 or 6 solar-dependent/off-grid homes I've seen built and lived in have been anything but reliable. It seems to take a while to fine tune the system to the point of not having a blackout every 3 months.
  - ogre_codes 6y ago
    > There are absolutely other benefits to solar other than return on investment When you are talking about a purchase which you live with day to day for 10+ years, "Return on Investment" is never going to be a straight financial calculation. People don't buy a house based on straight ROI, nor are most home improvements based purely on ROI. I don't see why solar should be the exception.
    - zemvpferreira 6y ago
      Maybe it shouldn't, but ROI seems to be the particular topic in this discussion.
- yablak 6y ago
  At least here in CA, if you are on the grid but don't have a battery then you will go black with everyone else even if you have solar. This is a safety measure for the technicians from the electrical company fixing the issue. According to another comment the additional cost of a battery is between $6,000 to $10,000.
FabHK 6y ago
10% annual yield is great for an investment. In real terms, the S&P 500 price return was about 3.2% p.a. since the peak in 1968, 5.2% since 1988, and less than 3% since 2000. Real total (ie with dividends) return p.a. over a decade has been between -4% and 17%, with an average of around 7%. As things stand currently, I'd not plan on more than 6% total return in real terms over the next two decades.
- zemvpferreira 6y ago
  Please don't disregard that with investing in solar panels, you're eventually losing your principal. It's only after the 10-year payback that you actually start making yields i.e. for a 15-year life span, those hypothetical panels are only making 50% back over 15 years - a 3% return at best.
  - toomuchtodo 6y ago
    Inverters usually have a 12 year warranty you pay a fee to extend to 25 years. Panels have a 25 year warranty, and we'll produce at 90% of rated power after that point.

inglor_cz 6y ago

The question is if the panels last longer than 10 years without major degradation.

gilrain 6y ago
And the answer is yes.

deleted 6y ago

[deleted]