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To: Tell It Right

That sounds like a great system. Did you design it?
What do you do for work?

I have heard that solar panels have come down in price quite a bit recently.
I have considered building my own free standing static array. I have an open south facing field. My wife HATES the idea though. Especially since it would face our bedroom window. I also would do all the trenching to run the conduit to my house/garage(about 200’). Then hire my local electrician to hook it up. We have net metering here in NH locked in at $.06/KWH.


28 posted on 05/07/2024 9:54:32 AM PDT by woodbutcher1963
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To: woodbutcher1963
Thanks. I'm a software engineer mainly on the back-end data. To me everything is about the real world data and analysis and ignoring the hype, then seeing if it'd be optimal to utilize something and how to optimize it for my clients. Thus I use those skills for my family and church.

IMHO, ignore net metering in your overall design. That means both in a cost/benefit analysis (pretend your benefit is entirely on lowering your grid pull costs) and also in picking your inverters (choose inverters that allow you to optionally turn off the grid sell feature, sometimes it's called having a "no output" or "zero report" feature). That way if your state changes the regulations you're not left hating your system. Go solar only if your ROI is based only on saving your power bill (or if you want comfort in being less dependent on the overly regulated energy market). Then if you decide that selling power is good for you, it'll be like gravy on top.

That's what I did. Alabama doesn't do net metering. I avoided the "solar fee" by not selling power to the grid for a while. After doing the upgrade in Phase II and having it for a year, seeing how much power I pulled and how much excess power I would have sold to the grid, I determined that the tiny sell rate per kWh my utility gives us for selling power is a hair above the extra fees that come with it. Thus I've been selling power for half a year. If the fees change or the regulations change, I'll cancel my contract, change a few inverter settings, quit selling power to the grid, and go back to being a normal power consumer like everybody else except that I buy a lot less power from the grid.

Do a real analysis on your power consumption habits and how much you can do to save power in your home without solar. Extra insulation, sealing cracks, etc. I did that.

Then use this tool to see the average daily peak solar hours in your area and how that changes per month. I found that tool to be spot on for my area. Look at each of your past 12 months of power statements, how much power you pulled from the grid that month, and divide it by the 30 to get it per day, then divide it by the peak solar hours per day that month. This will give you on average, how many kW of solar you need to on average meet your needs that month. On sunny days you'll take in more power, on rainy days you'll take in less. Also, try to estimate how much of your power consumption is at night (battery storage) and much of your power consumption is bursty with many appliances running simultaneously (inverter capacity to meet the load). See how much it'd cost for those, subtract from that 30% for the solar tax credit (10% more if made in the U.S.), but know that the tax credit is non-refundable but does carry forward. So if you're willing to pay that much minus the credit and count it as a good ROI, then proceed.

In Phase I don't buy that much solar/inverter/and battery capacity up front. Buy enough to play with it for a year, test it to make sure it works as well as you think, track it month by month to see how much it changes in the seasons and if those changes conform to your power changes in the seasons. Be sure to have it installed in a way that can be added onto later if you like it. (i.e. inverters can work in parallel, thus in Phase I my inverter choice was one that I could later add a 2nd inverter in Phase II knowing they'd work in concert.) And, my personal preference, pick an inverter that tracks a lot of telemetry that you can export and study. The Sol-Ark inverters record in 5-minute candles how much power it has to put on each leg of your electrical panel to meet your homes needs at that moment. And how much solar is coming in. How much excess solar is stored to the battery bank. How much power is pulled from the battery bank. And how much power is pulled from the grid.

After running solar in Phase I for a year I did a deep dive in the numbers. It worked as good as expected. I was able to see which parts to upgrade and by how much in Phase II (I anticipated doubling battery stack and tripling solar panels, but the numbers showed me it'd be better to double solar and triple battery). This dive in the numbers after having solar in your area is where the real power is in figuring out how much you need of what to get the best ROI. You're looking for the sweet spot between taking advantage of the Economies of Scale, without trying to fight the Law of Diminishing Returns.

29 posted on 05/07/2024 10:34:41 AM PDT by Tell It Right (1st Thessalonians 5:21 -- Put everything to the test, hold fast to that which is true.)
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