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I am going solar

Discussion in 'Gen 1 Prius Plug-in 2012-2015' started by usbseawolf2000, Feb 16, 2015.

  1. fuzzy1

    fuzzy1 Senior Member

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    Congrats on going live. Did you get much 'testing' :) during the utility delay?

    Also, all those panels should add a lot of shade to the roof. I've been surprised how much cooler my attic is running since my system expansion four weeks ago. A remote thermometer up there has been running only 17 F warmer than the north porch, better than ever before. Before the reroofing / improved venting / starter solar system two years ago, it was running 40-something-F higher than ambient. That initial project dropped the temperature rise to about 30F. Two solar expansions later, it is down even more.

    Combined with upgraded attic insulation last fall -- most importantly, finding and fixing about 100 square feet of completely uninsulated ceiling -- there seems to be much less heat radiating down. Despite the current record-setting June heat wave, we have not yet turned on our AC. (I should note since getting a heat pump with AC six years ago, we have needed to use the AC only half the summers.)

    Have you noticed any similar change inside your home?
    My Enphase microinverters will go all they way down to 1 watt per module, finding enough light to stay active from scattered light around sunrise and sunset (which happen well behind the modules this time of year). Yesterday the system was producing under 100 watts for the first 40 minutes in the morning, and last 55 in the evening. But tree interference means no direct sunlight on the system for 3 hours in the morning, and more than 4 hours in the evening. Other trees in other seasons make this microinverter topology essential here.
     
    #261 fuzzy1, Jun 29, 2015
    Last edited: Jun 29, 2015
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  2. usbseawolf2000

    usbseawolf2000 HSD PhD

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    I tested two full days. Since I had nonreversible meter, my overproduced kWh kept rolling forward. I ended up paying for them.

    I did notice notably cooler attic. I did not measure like you but upstairs bedrooms are cooler and needed less AC.
     
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  3. fuzzy1

    fuzzy1 Senior Member

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    The best reason there is to not keep testing.

    My old analog meter did turn backwards, so there was no reason to stop. But they still swapped it for a modern digital meter.
     
  4. usbseawolf2000

    usbseawolf2000 HSD PhD

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    I was curious so I checked this morning playback from 5:30am and the lowest I see was 0.06 Watt from one of the panels.

    As of 7:30am, it has generated 1.33 kWh so far. Today is sunny but 40% chance of rain. We'll see how it turns out.

    5-30am.png
     
  5. Potorap

    Potorap Active Member

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    Congratulations USB. You will be very happy with the results. Enjoy!
     
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  6. 3PriusMike

    3PriusMike Prius owner since 2000, Tesla M3 2018

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    My system has been running for ~5 weeks.
    I have 12 panels facing west for a total of 3.1 kw AC. In the first 30 days I generated 560 kw-hr or about 19 kw-hr/day, which is >2x what I typically use. (Thus I just got a Leaf to help use more than just with my PIP).
    The most has been about 20.5 kw-hr. I had one day where it rained most of the day and still got 10 kw-hr!
    (yes, we had one rainy day in CA in the last 2-3 months)

    On a couple of mostly cloudy days I got 13-17 kw-hrs...most of the rest of the time it has been very sunny.
    I have just one inverter and I've seen 15 - 25 watts still being generated at 8pm.

    I got my first PG&E bill a couple of days ago. I was surprised to find out the with net metering the tiers also work in reverse. When I exceed negative tier one quantity they start crediting me at tier 2 rates!

    Mike
     
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  7. usbseawolf2000

    usbseawolf2000 HSD PhD

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    Today was a good day for production. Made 41 kWh with intermediate clouds.

    I could put 160 EV miles with my PiP :D

    Screenshot_2015-06-30-21-44-34.png
     
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  8. giora

    giora Senior Member

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    If your neighbor had a plug-in I wonder if you could make some barter deal with him... :cool:
     
  9. jzchen

    jzchen Newbie!

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    Mine must be the exact same as rxlawdude's. We're also SCE. I remember the dreaded $0.32/kWh. Funny, but the rates were supposed to increase but it seems the same from two years ago when we got our solar. I definitely remember the $0.32/kWh but am not sure about the others. I was able to get the total use for a year and dividing into 12 months got an average of low $300s/month.

    Congrats USB! I remember reading a story on a solar forum how something went wrong and SolarEdge refunded them the cost of the lost electricity. While this made me a little nervous, at least they made things right. So far nothing like that has happened to us. Two years and going...

    MT2L03 ?
     
  10. 3PriusMike

    3PriusMike Prius owner since 2000, Tesla M3 2018

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    But this is the peak for the year. In winter I'll generate less than I use, besides the PIP and Leaf.

    Mike
     
  11. inferno

    inferno Senior Member

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    That's why over generation is crucial now :p lol. Go on vacation and let your house work a couple days without you hah.
     
  12. el Crucero

    el Crucero Senior Member

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    Mike, this is exactly the same as my experience with 13 panels here in SoCal and I've been up and running for 6 months. GO GREEN!
     
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  13. usbseawolf2000

    usbseawolf2000 HSD PhD

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    37 kWh on a partly rainy cloudy day. I can get used to it :).

    Not sure how to read the net meter. It was flipping between two numbers. One seems to be kWh drawn from grid and another being the net number.

    I think I have -57 kWh net.
     
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  14. lensovet

    lensovet former BP Brigade 207

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    can you explain how this works? my understanding was that unless you've completely disconnected from the grid – which you haven't – there are minimum distribution charges that you must pay every month?
     
  15. fuzzy1

    fuzzy1 Senior Member

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    In my service area, production credits can offset not just energy charges, but account connect charges as well.

    In the first two years, my system never had enough overproduction to see if the local utility gives credits on the second tier. But that changed with my system expansion that went live a month ago. Billing here is on a two month cycle, so I won't see how it is handled until early August.
     
  16. macman408

    macman408 Electron Guidance Counselor

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    Yes, there are minimum charges per month from PG&E. Currently, about $5/month, but they're trying to change it to $10/month (and reduce the number of tiers to 2, and make the lower tier more expensive and the higher tier less expensive - they say to improve the fairness of pricing, but I think they're trying to take away as many incentives to get solar as they can).

    I've only had mine for 6 months, so I have yet to reach the annual "true-up" bill, but as I understand, this is how it works:
    You pay $5 every month for 11 months. They keep track of how much electricity you use; generally, positive in the winter, and negative in the summer. They multiply your net use(/generation) by the applicable rate - whether a higher tier, or Time Of Use. (I enrolled in the Time Of Use program - if I produce a 1 kWh surplus during midday summer peak hours, it earns me enough credit to offset about 2.5 kWh of off-peak winter use.)
    The credits accumulate, but if they end up negative, that doesn't mean you'll get a payout from PG&E; that just means you don't owe anything for energy usage. You still owe the minimum charge. On the other hand, if you don't get enough credit to have a negative balance after 12 months, I believe the $5/month minimum charge is applied towards the energy you used. If you still owe a balance after that, then your bill in the 12th month will cover it.
    The last piece of the puzzle is the Net Surplus Compensation. As I mentioned, just having a negative balance (PGE calls it "Net Energy Metering Charges") doesn't mean they'll pay you any money. Because of Time Of Use rates, tiered rates, and other things, it's possible to have a negative Net Energy Metering Charge at the end of 12 months, but still have used more electricity than you generated. On the other hand, if your total kWh used over the course of that year is less than the total kWh produced, THEN they will give you a payout - but not at the fat rates that they charge their non-solar customers. They will only pay you the average wholesale price for electricity generation; currently, that's about 4¢/kWh.

    So in my case, as of last month, I have net charges of -$25; that means I can use $25 worth of electricity in the winter without having to pay anything besides the minimum charge. I also have net usage of -101 kWh, so if I still had that much after 12 months, they would pay me $4 (which wouldn't even offset that last month's minimum charge, so I'd still have to send them a check).

    I was a little surprised to see 3PriusMike say that PG&E credits the tiers in reverse too (I don't use or produce enough to get out of Tier 1, but I do see the Tier 1 threshold as negative on my bill), but it makes sense; if you're producing that much surplus in the summer, there's a pretty decent chance that you'll have just as much shortfall in the winter, so it seems fair to credit it to you at the same rate. In any case, if you *don't* have that much shortfall, it won't result in them paying you that amount anyway, so it's not really that big of a problem for them.
     
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  17. inferno

    inferno Senior Member

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    You may have the same net meter we have. Does your show #s 4 and 10? Those are codes, one is usage and one is generation back to the grid. I forget which is which. As far as I know though, that outside meter will actually not count the energy that is being used by your house which is at the same time being generated by solar. IE, your solar will directly feed your house and the excess will count as generation toward the grid, while the opposite can hold true (your generation toward the house may not exceed what you actually use).

    So if you have -57 kWh usage, your solar may have actually produced you more. As for our state (MA), we have a service fee every month of $6 to be connected to the grid. That cannot be waived, but our over generation will allow a credit toward it. And any credits (overgeneration) is kept permanently, although we have an option to give it to another customer as well.
     
  18. usbseawolf2000

    usbseawolf2000 HSD PhD

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    It flips between 100 and 101. I have GE I-210+C netmeter.
     
  19. el Crucero

    el Crucero Senior Member

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    I don't know about PG&E, but Southern California Edison charges us a "billing fee" of $1.50 to $2 per month (they do monthly billing) even when we are generating twice as much as we use! :mad: In other words they are charging us to tell us we don't owe anything! This isn't a big deal, but it is irritating.

    I have friends with homes in very remote areas of Baja California that are completely off grid because there is no electric service of any type in their area. They use solar and batteries and live very comfortable lives, right down to satellite Internet.

    In my opinion, it is only a matter of time when we will have the resources here in California to go completely off-grid at an affordable cost.
     
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  20. inferno

    inferno Senior Member

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    Well, to be fair, you are using the grid's lines for overgeneration right? In a way they pay you for overgeneration and send bill someone else (the same price luckily). So there is a service charge because it is using the lines...

    I think this is better than off grid, why? Because what about those people who are offgrid and overgenerating to the point where their batteries can't hold anymore power? Grid-tied is true peer-to-peer sharing of energy....
     
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