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I did my part. I just wrapped up installing a 7.3kW system on my roof at 49.5°N. Yesterday was the highest day of output so far, 50.17 kWh I'm extremely happy

• stavros 2y ago
  I really like rooftop solar, as an idea. It might not be the cheapest way to generate electricity, but it's good to know you aren't as dependent on the grid. It's like having your own vegetable garden. Hopefully, with advances in battery technology, homes can become completely independent of the grid.
  • blondie9x 2y ago
    I wish it was this simple. All energy is still borrowed. Mining and producing and disposing of solar panels is still very energy intensive. Renewable energy is a piece of what needs to be a much larger effort to fight climate change.
    • stavros 2y ago
      Sure, it's energy intensive, but if that energy comes from the sun, who cares? I don't understand we keep using "energy intensive" as a euphemism for "emits carbon". The two aren't synonymous. Energy-intensive processes aren't a problem at all, the problem is dirty energy generation processes. Fix your energy generation, and there's no problem.
      • cogman10 2y ago
        There's a (diminishing) correlation that shouldn't be ignored. I'm not saying we should abandon solar because of that correlation but it should at least be factored in. For example, I think it's a dumb idea to turn every road into a "solar road" just because "who cares".
        • stavros 2y ago
          I was replying to a specific argument: That producing solar panels is energy-intensive, and thus bad (this part was implied). My counterargument is that energy-intensive is irrelevant when you've got basically-free, clean energy. If your energy is dirty, fix your energy. Don't make downstream consumers feel bad instead.
          • cogman10 2y ago
            I don't disagree, just taking the conversation a slightly different direction as I think you'll agree that the "it takes energy to make renewables" argument is generally made in bad faith. I think there is irresponsible consumption of solar panels, particularly when it's done more as a performative action rather than actually producing power to be used.
            • mlyle 2y ago
              Yah. I am glad we are deemphasizing residential solar. Utility-scale solar has better capacity factors and installation economics. I think it's going to be barely possible to keep our current quality of life and reach a low-CO2 economy. We have limited resources, and even if a residential solar panel "pays back" its energy in 2.5 years, we are better off putting it in a desert where it will pay back that energy in a year.
              • mulmen 2y ago
                What about the economies of scale? Does/did residential solar create enough demand to ramp up utility scale production?
                • mlyle 2y ago
                  > did I think residential solar was a decent bridge to get things going, and the installed capacity we have is helpful. Now, though-- at midday we have a glut of power. Residential installations are more expensive per kilowatt hour and don't do as well in reaching into the late afternoon when we need power most. There's no need to add more capacity like this. Better for those panels to go somewhere else. There are still times that non-utility scale solar make sense-- it's usually when you get some kind of non-normal-generation related benefit that tips it over into worthwhile, e.g. - getting a shade structure for a parking lot as part of the rollout - if you want power backup for your house, adding a bunch of storage and solar etc.
      • XorNot 2y ago
        The oil companies all rebranded themselves as energy companies over a decade ago, my presumption is it was a convenient part of a long term promotional plan to mix up the definitions to get the environmental movement to fight itself. Same as how the idea of a "carbon footprint" was sponsored out into the world by the same people. The trick to good propaganda is to create something that makes you say "well I know it's propaganda, but this doesn't seem so wrong..."
    • dgacmu 2y ago
      Yes, you have to analyze the embodied energy, but solar panels are energy positive within 1-2 years these days: https://www.quora.com/How-much-more-energy-do-solar-panels-produce-in-their-lifetime-than-is-used-to-make-them-How-does-this-energy-return-on-energy-investment-compare-with-other-technologies https://www.quora.com/How-much-more-energy-do-solar-panels-p... It's really a no-brainer up to a certain amount of your grid mix (and that amount can be quite high).
    • cogman10 2y ago
      This is an old trope that's not longer accurate pretty much across the board for renewables/batteries. Also.. Mining for solar panels has never been the major energy cost. Solar panels are primarily silicon (re: sand). The actual energy expensive part for them is/was melting the sand into glass. Even the next major element, aluminum for the brackets, accounts for far more energy expenditure than the mining of the doping agents. Even for windmills, the major energy cost isn't mining, it's the smelting the steel for the tower. Renewable energy is a piece of the puzzle and not everything. It's a major and important piece. Switching the grid away from fossil fuels accounts for a huge portion of emissions and renewables are some of the fastest and cheapest to deploy solutions currently.
    • mrshadowgoose 2y ago
      It is that simple. "Energy intensive" is irrelevant. On average, a solar panel will capture more energy in its lifetime than the amount used to create and eventually recycle it. So please stop repeating that useless whine.
      • sitkack 2y ago
        This is easy to refute. Take the commercial price of power for the location of manufacture and divide your retail price by that amount. The result will be the upper bound in MWh that could have possibly gone into the creation of that panel. Chinese solar panels cost less than 15 cents a watt. In the NW with residential prices at 10 cents per KWh, it takes 1500 hrs to break even. With 4hrs of "full sun" per day on average at PNW latitudes, about a year. This is just the panel not the system. The BS that panels take more energy to produce than they generate is disproven. https://www.alibaba.com/product-detail/In-Stock-TRINA-Vertex-Solar-Cell_1600995276082.html?spm=a2700.galleryofferlist.p_offer.d_title.1308596fd9fgIx&s=p https://www.alibaba.com/product-detail/In-Stock-TRINA-Vertex... The tariffs on solar are stupider than the Iraq war. If China can produce panels at 10 cents a watt wholesale, we should give them billions of dollars to make as many as they can. Train everyone in the military to install them.
    • nine_k 2y ago
      Energy-intensive is fine, as long as the energy is renewable. Smelting aluminum and silicon or mining aluminum and iron ores with electricity produced by solar and wind is ideal: else that energy of light and air motion would be wasted. Steel and concrete are harder to produce in an emission-free ways, but steel smelting in arc furnaces is very much a thing, and can be powered by renewables, at least partly.
    • blondie9x 2y ago
      A lot of misunderstanding about this comment. I think adding solar energy capacity to the energy supply mix is helpful. What I want to clarify is this, adding all energy supply has costs. Rare earth metals and other mining and habitat destruction that goes into increasing renewable supply needs to be considered. Like I said all additional energy supply has a cost. The real problem is we need to reduce consumption. We also need to rework our energy supply chains with renewables when appropriate as well as nuclear that isn't vulnerable to meltdowns.
  • redserk 2y ago
    It’s interesting seeing the difference in how solar is usually talked about versus backup generators. Whole-home generators are expensive and get used rarely but are often justified as a “just in case”. Solar doesn’t enjoy this kind of leniency, unfortunately. Being less dependent on the grid has many benefits that get ignored over a perceived return on value.
    • briHass 2y ago
      At least around here, backup generators are for outages that happen when solar would be mostly useless: heavy storms or during Winter. Cheap and safe batteries paired with solar will help, but the capacity will likely still be an issue for extended outages.
      • epistasis 2y ago
        An islanding solar system with storage is not useless during storms or the winter, it still generates during the day. Not sure where your "around here" is, though.
        • nine_k 2y ago
          Do solar panels ever get trapped under large amounts of snow the day after a strong snow storm?
          • timschmidt 2y ago
            Sure, but with a couple inches of snow on them, mine still generate power. And in areas which regularly receive snow, roof pitches are generally steep enough to encourage it to slide off else the building would suffer overloading. Worst case a push broom or squeegee with a very long handle works wonders. Also fairly trivial to rig up a resistive heating system for melting the snow in cases where the above isn't possible. Even possible to automate it based on time of day and expected power input.
            • 2y ago
  • epistasis 2y ago
    Once you add in the costs of additional transmission needed for utility scale solar, rooftop solar is extremely competitive. Especially as transmission capital costs start to skyrocket, and solar capital costs plummet. I have yet to see an economic argument in favor of utility scale solar over residential solar that takes into account the T&D upgrades necessary from utility scale solar.
    • bobthepanda 2y ago
      We will need both, or at least something else, since not every building has a rooftop that can generate sufficient solar.
      • epistasis 2y ago
        Agreed. I think we will also start to see lots of industrial sites that have their own utility scale installs that don't even feed back into the grid, and are used directly, and coupled with thermal or chemical storage.
  • HPsquared 2y ago
    It's a testament to how inefficient "the system" is that rooftop solar is economical for a lot of people.
    • jameshart 2y ago
      Why? Sunlight falls everywhere. It’s not obvious to me that there should be efficiencies in capturing solar power centrally and then moving the energy over transmission lines. If you want one rooftop’s worth of electricity, you can either pay someone else for a rooftop’s worth of real estate and have them run solar panels on it, and transmit the power to you over wires, or you can put solar panels on the rooftop-sized area you already own at zero marginal land cost, and have the electricity already right where you want it. That that works out economically doesn’t seem like a surprise.
    • grecy 2y ago
      > It's a testament to how inefficient "the system" is that rooftop solar is economical for a lot of people. Solar panels are rapidly falling in price, and now I'm generating the power right where I'm using it - so no transmissions losses, no power transmission infrastructure, no transformers, no poles to replace when they get old, no lines to replace when trees fall on them, no trees to trim. No accounts to maintain, no billing, no credit card fees, no taxes. In fact, to get power to my house for the next ~30+ years requires absolutely zero labor from anybody. Of course it's economical, it would be baffling if it wasn't.
  • energy123 2y ago
    I'm surprised more conservatives in the West don't like it. It's the ultimate individual independence from the government and corporations. Individual sovereignty over your energy needs. Instead they want to rely on a foreign dictator and government-funded transmission lines. Bizarre.
    • mulmen 2y ago
      This isn’t an interesting line of thinking because it depends entirely on your definition of conservative. There’s nothing surprising (or interesting) about a straw man.
    • HPsquared 2y ago
      Same with EVs. You can generate your own electricity a hell of a lot easier than making your own gasoline.
      • wdh505 2y ago
        There are two attitudes that you skipped over: "dependability" and if it works, then don't fix it. Between those two and people who have tried an electric or hybrid vehicle and had it turn out poorly (totaled because the battery went bad in the heat and it isn't worth replacing). There is a degree of wisdom to the advice "chemical energy storage is more convenient, dependable, and cheap for intermittent to constant daily use". I look forward to on site residential solar powered propane production and liquification for this reason.
        • mulmen 2y ago
          How will onsite propane work? Do you mean carbon capture? That would be great but isn’t it similar to flying cars where it’s not feasible around humans because you have to move a LOT of air?
          • wdh505 2y ago
            1) it takes co2 from the air and water to produce propane hydrocarbons (mostly theory with some promising lab results) 2) not quite. Well, it is a form of carbon capture, but with the intent of releasing again soon. 3) 4% co2 is everywhere (open a window and turn on a fan and you have almost infinite). Water is everywhere humans are. I think it is a lot more an engineering problem than a feasibility problem
  • lobochrome 2y ago
    i think - when the grid goes down, your rooftop solar will go down too. Without grid generation there is nothing that can keep your inverters synchronized…
    • MaKey 2y ago
      There are inverters with a power outlet that can be used in case of a grid outage. Supplying your whole home with power when the grid goes down is possible too with the right hardware.
  • thelastgallon 2y ago
    It is probably cheaper or at least equivalent to utility scale, if we consider the cost of transmission and distribution, neither of which are needed with rooftop. Of course, it is grid tied, but it uses existing power lines to the home without requiring any new lines to be installed. And the indestructible resiliency of distributed power production from tens of millions of rooftops is unparalleled.
  • richie-guix 2y ago
    A 50KW battery is <$10,000. Sounds like he is allowed to sell excess back to the grid and payback period would be <20 years. They are warranted for longer. If financing is available it is basically free. ;) Big if that but more realistically the real kicker here is that all of that is about x3 larger than what most households need. I get that not everybody has $10k laying around to plop down on panels/batteries all in one go but if you do you can get off the grid now.
• Sytten 2y ago
  How expensive is the electricity in your area? I think here it is so cheap that might not be worth the installation cost (though that did drop a whole lot lately).
  • zdragnar 2y ago
    That's the trick. On one of the longest days of the year, OP got ~$5 worth of electricity where I live. The payoff can be long, and people often forget to account for the added cost to home insurance to cover the panels in that. OTOH, if where you live electricity is more expensive or labor is cheaper, it can be a really nice addition without too long a wait to make it back. The company I talked to said I get too much shade to be worth installing (150 foot tall trees near my house) so I'll be waiting awhile before I get mine even if electricity prices go up, sadly.
  • Retric 2y ago
    The ROI calculation can be a little tricky because solar can be a low risk leveraged investment with tax free returns. Remember money you don’t need to spend isn’t taxable. So for most home owners it’s easily worth it. While from a worker safety, economic, and even environmental standpoint rooftop solar is terrible compared to grid solar as an individual homeowner you can often get subsidies.
    • bumby 2y ago
      >So for most home owners it’s easily worth it. Can you elaborate on how you arrived at that conclusion? At least where I live, the math didn’t work out. It seemed like smarter conservation was a much better alternative. A couple portable/window A/C units that pay for themselves within a year or two made a heck of a lot more sense than $30k of solar on a roof already at half it’s life. Maybe when it’s time to replace my roof I’ll reconsider, but the payback didn’t seem there. (FWIW, I probably average < $100/mo in electricity.) I know conservation can go against human nature, but it sure seems like the better option for me.
      • Retric 2y ago
• sponaugle 2y ago
  That is awesome. I live in the PNW (Oregon,45°N) and the summers here are fantastic for solar power. I have a 20.2kW system on my roof and crank out 100-120 kWh a day in the summer months. I can store 42kWh, and push the rest back to the grid at full cost return.
  • sitkack 2y ago
    Thank you for saving our water!
  • kylehotchkiss 2y ago
    20kw on the roof is awesome! Do you have anything high load in your house or property or is it more just to sell back the excess to grid?
    • sponaugle 2y ago
      Well.... yea.... I do sort of have some high load... but not too much! https://www.youtube.com/watch?v=-b3t37SIyBs https://www.youtube.com/watch?v=-b3t37SIyBs
• Waterluvian 2y ago
  Very exciting and satisfying! What’s the current break even date?
  • grecy 2y ago
    I'll need to see a whole 12 months of output before I can be sure. I suspect winter production will be well down, especially on heavy snow weeks (we get a lot here). Roughly, it looks like it will make about $1000 worth of power per year, and the price of power here is already locked in to go up between 5% and 12% per year, basically forever. I'm right on $8k out of pocket, which is on a 10 year interest free loan. So if I just put the savings from my old electricity bill into the loan, in 10 years it will be gone, and I'll just free power for 20 or so years after that. One day I'll build a garage, cover that in solar too, then get an EV so I don't have to ever buy gas again.
    • Waterluvian 2y ago
      That’s a phenomenal ROI if you’re in it for the long haul. Thanks for sharing the details.
      • grecy 2y ago
        And I'm in the rocky mountains in Canada, where basically everyone says "Solar will never work here". In my experience, solar works everywhere. TONS of friends in Alaska and Yukon have been off grid since ~2010.
        • Waterluvian 2y ago
          My MSc research at UWaterloo involved mapping photovoltaic viability in Canada. The data was somewhat uninteresting because the conclusion was: pretty much everywhere.
    • SoftTalker 2y ago
      Where do you get a 10 year interest-free loan for solar?
• lttlrck 2y ago
  Ooh that's pretty good at 49.5° 49.7kWh in San Diego yesterday. We take a hit from the from the prevailing temperatures in the Summer. Peak this year so far was 53kWh back in May.