Solar + Powerwall: One Year Review

August 20, 2019

This should be geeky enough for the most hard core. And good news about zombies.

16 Responses to “Solar + Powerwall: One Year Review”

  1. mboli Says:

    So the good news is that if you are paying a $185/month in electric bills (what the bleep?), earn in the neighborhood of $200k per year (his marginal tax rate was about 30%), have enough other deductions (the pedestal), and have $32k to drop on installation (I’m guessing he didn’t include the new roof), and ignore the time value of money, this thing will pay off in 11 years.
    For many of the rest of us mortals however….
    Last time I costed this out it would have been about 30 year payback (ignoring the time value of money), which means never.
    I’m thinking that I might install such a system a few years down the road when they are a bit less pricier. Certainly a smaller one. It would be part of my personal contribution to the effort.
    But regular readers of Climate Crocks see every now and then the levelized cost of new generation, produced by Lazard. Which shows residential rooftop solar is about the most expensive way to produce electricity. Utility-scale solar is about 1/4 the price of residential rooftop solar.
    If we, as a society, are plunking down beaucoup bucks for residential solar, it is a sad comment on our energy economic policies. We could be eliminating four times as much GHG for the same price.

    • rsmurf Says:

      How do you figure his income, there is a 30% tax credit on the cost!!!

      • mboli Says:

        Whaddya know! I didn’t know that. Thanks.

      • J4Zonian Says:

        And usually reduced transmission costs, sometimes considerably reduced. In some places–increasing?–there’s some effort to create micro-grids, a good decentralizing move for resilience. And in a country or state that refuses to act rationally, household, commercial, and non-profit PV is not only a wise thing to do, it can be a message to those around the insane people in charge, and those wishing to take over from them.

    • rsmurf Says:

      And I’m sure you apply this economic thinking to ALL your purchases, please elaborate on the payback for ANY car, thanks.

      • rhymeswithgoalie Says:

        From a personal perspective, solar vs. non-solar doesn’t affect your daily life.

        A car has a value based on personal opportunities it offers. Even if the days’ temps didn’t range from a low of 80&def;F to > 100°F, my damaged knee means that walking+bus for errands is not an option. My two experiences with lyft were (1) meh, and (2) not available at that time of day.

        God, I miss walking without pain….

        • rsmurf Says:

          Sorry about the knee, but your discussing mobility we all need it. The point I was making no matter how necessary a car is NO ONE EVER weighs the pay back of even one car over an other. So when I produce my electricity co2 free I still don’t understand the necessity of a PAYBACK.

  2. Brent Jensen-Schmidt Says:

    Private PV panels cut down GHG, and if they save you money, usually do certainly mine, its win win. Do not care if they are not the absolutely perfect optimum.
    Batteries are being seriously pushed and subsidized here in Oz as a Public power backup. Details are hard to extricate from propaganda and sales pitches. Otherwise, batteries are uneconomical, at present cost, in urban areas. at this time.

    • rsmurf Says:

      Yea but it sure would be nice to be the only one with power when the grid goes down, I would smile like a Cheshire Cat!

      • Brent Jensen-Schmidt Says:

        No worries there. Apart from the upfront costs, I receive around 150% input tariff from my panels. So input into a battery instead of the grid would cost me heaps without any environmental benefit. There is a limit to my personal indulgences. Would love to indulge though.

        • rsmurf Says:

          I assume you mean you get paid for electricity you feed to the grid in excess of what you use! Is that correct? Here I don’t get anything for excess, they get it free. And I get charged a minimal usage fee if I don’t buy any electricity from them in a month of $5.00. And that doesn’t go away if I buy 1 watt from them it goes away after I have purchased $5.00 of watts from them.

          • Brent Jensen-Schmidt Says:

            Have limited familiarity with USA rates, LFaD, not other countries.
            Here in Sth Oz, (about) electricity costs. First tranch 37 cents KwH, 2nd 40 cents. Connection fee, $12 month. Standard solar input to grid today is 12 cents KwH. I receive 56 cents KwH due to early installation.
            If my excess went to a power outfit for free, would install batteries out of shear ‘aggravation’.

          • grindupbaker Says:

            My understanding is that electric meters will run backwards during power being delivered from the nominal demand side of the meter to the nominal supply side of the meter but fact check me on that because it was just an assumption I’ve always had.

          • rsmurf Says:

            Yes they do. I have a smart meter keeps track of everything. But they still don’t pay for anything they get.

          • grindupbaker Says:

            Ah, ignore my comment. I gather it’s about the fixed line provision fee and non-proportional cost/income pricing.

          • Brent Jensen-Schmidt Says:

            Old meters with a revolving disk, last for ever, do run backwards and so are anathema to utility companies. Pre PV digital meters (mine unfortunately) did not recognize power direction and many poor sods were charged full tariff for their power given to the grid. Modern meters are sexy.

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