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General Thoughts on what timeframes to opt into Receive #OhmHours for solar production

c1courtneyc1courtney El Dorado Hills, CAPosts: 35Member

So all Solar Producers curves are going to vary some, as well as how things tail off at end of day, and how much consumption estimation there would be.

The question I have given mine is mostly West facing, I've got a long tail. From 5-6pm this time of year I'm producing about 3.4kWh typically, 6-7 2.0kWh, 7-8 about 0.75kWh and after 8pm pretty much nothing. But there's the possibility of getting a cloudy day where any of these drop down to Nothing.

So I'm wanting to make sure I'll be 'Safe' or not have a 'Negative' any projection, which as we know may not be achievable based on weather.

So, Is there a way to determine ahead of time if/when any of these will be negative, or below a certain threshold so I can ensure I don't break a streak, or is it, I need to wait until 8pm at this time of year period.

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Answers

  • UkiwiSUkiwiS San DiegoPosts: 1,577Member, Moderator
    edited July 2018

    @c1courtney You could download your actual utility data and go through the exercise of creating your own forecasts using the same methodology. That'll use real data. OR...you should be good for 6pm and onwards..... assuming you have some usage to counter the generation while still producing. What you are trying to eliminate is the cloudy day that wipes you out entirely.

    There's been some discussion in the past on the forum. Search for the word"solar" here and have a look around:
    https://forum.ohmconnect.com/

  • cwiedcwied San MateoPosts: 131Member

    If you know the parameters of your solar system, such as DC size, orientation, etc., you can use the PVWatts calculator (https://pvwatts.nrel.gov/) to give you an estimate of production for every day and hour of the year. You can download a CSV of this data. If you combine this with your average consumption, you should be able to get an idea of your exposure.

  • c1courtneyc1courtney El Dorado Hills, CAPosts: 35Member

    Yeah, I've got PVWatts data and I can pull my PG&E data (actually used a spreadsheet, multiple panel layouts, orientation, 5 different TOU vs my usage (yes I did time adjust the PVWatts for PDT as it was all in PST and that would have thrown things off) ... to figure out what was optimal.

    That said, I don't know what exactly they use for forcasting this. I've only had Solar in for 40days, and the first one they scheduled me on was a -2,458Wh for today 5-6pm. I could have easily beaten it during a normal sunny day, but forecasts has it partially cloudy, which as any Solar owner knows could be anything from no to full production.

    So they aren't using data from a year ago. Sounds like they may have been using June's data, but that's a SWAG. June was unseasonably cool here, and most of the days I managed to get by w/o AC at all, just whole house fan overnight to bring temps down, and the air never got above 78. And now, the AC has been cycling from at least noon onwards, but the -2,458Wh wasn't representative of this when my Solar averages putting out 3,400Wh during this time, and my household is usually consuming 1,000Wh w/o the AC.

    I'll look around for threads on their forecasting methodology, for now I have it at 6pm-6am, I want to at least see what they're asking for on a 6-7pm timeframe.

  • frankhacfrankhac Sunnyvale, CAPosts: 49Member

    Assuming your priority is not to lose your streak, I think what you need to decide is how close you are willing to barely meet your forecast. How much stress are you willing to put on yourself. Keep in mind that when you are really close to meeting your forecast you're not going to be getting much points. The only benefit is that your streak increases by one. As your streak goes up, it's more important not to lose it. At that point I want almost a guarantee that I have OhmHours only when I can beat it.

    Let's assume you are using 1 kWh consistently during an OhmHour. You can then look at your actual usage and determine when your net usage is 0 kWh, meaning that will be your forecast. If there is a cloudy day and you generate no electricity, then if you can actually turn off everything, you will be have an actual usage of 0 kWh. Let's say this is from 5:00 - 6:00 pm. At this time, you will be right at the point of beating your forecast but it's not guaranteed. If you set your availability to be 6:00 pm or later and assuming you still consistently use 1 kWh, then your forecast will be higher then 0 kWh, maybe 500 Wh. You should then easily be able to beat this even if it's cloudy and don't generate anything.

    Basically, if you are available at 5:00 pm or later, you may be able to beat your forecast but you'll be stressing out over it. If you set your availability to 6:00 pm or later, you won't stress out.

  • cwiedcwied San MateoPosts: 131Member

    One erratum in the FAQ on baseline scheduling: the calculation skips any day on which you received an OhmHour, even if it was a different hour than the scheduled OhmHour.

    One number you should try to estimate is how much you can reduce during an OhmHour. If you can't consistently reduce your usage by 750 Wh from 7-8pm, I would recommend setting your availability to after 8pm. In the long term your streak is key to getting points from an OhmHour, so you want to do what you can to avoid losing it.

    With your availability set so late, you might lose out on some OhmHours, but when the days get shorter again you may be able to include 7pm. This matches what my availability is set to, and I got 8 OhmHours in June (all between 7 and 9 pm).

  • c1courtneyc1courtney El Dorado Hills, CAPosts: 35Member

    Thanks guys, I looked back at the FAQ (thanks UkiwiS for posting) and did the math and got fairly close to their projections. Had a lot of days were the AC hadn't kicked in yet before 6pm, that that hit, and days where the family was in the pool from 5-6pm and the house was pretty much at baseline so it skewed everything. Now it's hitting AC every day, If i had it over the previous 5 days (including weekends) it would have had me solid in the positive usage, but take out the weekend and extend it the 10 weekdays and it was solid in the negative. It actually adjusted to -2,059 from the -2458 the day of the event, so I guess it grabbed the most recent day and dropped the end production day, which was about +1kWh added on one side and -3kWh dropped on the other side making a +4kWh -> +400Wh increase in the difference.

    I only wished PG&E had an API I could use to pull data directly instead of needing to download it manually every time. I'd set up a Google Spreadsheet to pull it and calculate my projection rates. I may end up doing it with my Solar and Wattnode data instead.

  • jserramcjserramc Posts: 299Member

    I have a mega hour tomorrow Tuesday July 17 from 8-9 PM. (I finally figured out how to change my hours and did so last week). So my mega is zero while my goal is a manageable 0.3. If I truly throw the breaker vs just unplugging major electric hogs, how will it affect my solar system? One breaker (30 amp) is dedicated to solar and the monitor on the wall which shows usage etc is regular 110. plug. Anyone have ideas on what happens to solar systems when power is lost either because of a blackout or actually flipping breakers? Is it harmful to the system? Not something I would do on a regular basis. Also I do have solar but expect very little if any power generated at 8 PM. thanks for your input.

  • UkiwiSUkiwiS San DiegoPosts: 1,577Member, Moderator

    @jserramc said:

    It's not harmful to the Solar PV system to flip the breaker, I've done it a few times. You could always have a dummy run in 30 minutes to see what will happen with your usage. Yesterday 8 to 9 I generated 0.003 kWh. The two days prior exactly 0.000. My panels are mounted flat on a flat roof so not optimal but I doubt you'd generate much even with a West orientation. The point is, if you want the Mega you will have very little offset from the Solar if you don't flip the breaker. I would think for you to meet the Mega goal, you will need to flip it.

  • jserramcjserramc Posts: 299Member

    I don't have stuff to read my usage until PGE posts it. I can read my (exterior) solar meter but it does not indicate anything under one kwh. the (interior) reader will likely show that 0 panels are active at this hour so I don't have any way to know stuff. Since I started tracking usage with certain things unplugged, for this hour, 8-9 PM my usage has been .-0.008 June 26 so a few days after summer solstice. Only solar was on for that event. I probably made power hence the negative number. Thu July 5 unplugged fridge and tvs and usage was -0.011. Fri July 13 , fridge and tvs unplugged usage was 0.01. For tomorrow,, even just unplugging vs flipping breaker-- I would meet my regular goal (and keep streak) but mega, maybe not...

  • c1courtneyc1courtney El Dorado Hills, CAPosts: 35Member

    You could flip every breaker but the solar breakers. Note that you usually will have at least two solar breaker - the Main one which is a feed to the system and the one that actually provides grid power to operate the panel (and it observes the voltage level from - though this could be a second one)

    I'm in the same boat as UkiwiS in my W facing. I can get about 0.008 - 0.015kWh from solar this time of year from 8-9. That's not enough for me to kill my phantom power of 0.220kWh which I haven't really worked on yet. I would kill all the breakers but the solar, wait until the solar stopped producing and then kill them (there is a small drain from the inverter staying powered, and if you have a consumption meter, that would have a small draw as well.)

    Luckily for me, I got the 7-8pm Mega hour tonight. I produce about 0.75-0.80kWh of power typically in this time period. Time to chill in the pool with the family.

  • frankhacfrankhac Sunnyvale, CAPosts: 49Member

    @c1courtney, you brought up a point that I didn't know or even thought of. If you kill the solar breakers, you're saying that your solar would not be putting the electricity back into the grid. So as a solar use and if you plan on flipping breakers, you should only flip the solar breakers when you're not generating electricity.

  • c1courtneyc1courtney El Dorado Hills, CAPosts: 35Member

    Just to clarify there are two things here.

    1.) Solar Main Breaker - Trip this and there's no path to the grid for solar to feed.
    2.) Solar Sensing and Control Panel Power - Normally has at least one separate breaker for this - (want available 24/7) and should be installed as separate from Main Breaker - Trip this and there's no control or voltage sensing required (i.e. see's as a black-out and grid tie should disconnect)

    There may be another separate breaker - I've got two more one for a GFCI outlet mounted by the Inverter that powers my Ethernet Power Adapter, and one for powering Consumption Meter. So that makes 4 - Main, Sensing, GFCI and Consumption Meter. One can probably do the last three with one, but you don't want one of the other two tripping the sensing and killing the Solar generation.

    A good installer will have labeled this well in the breaker box.

    I'll try to remember to take a picture of my breaker panel tonight.

  • jserramcjserramc Posts: 299Member

    I flipped all but the solar breaker last night. This includes the wall mounted monitor that tells me the unit is on. Stay tuned for results....

  • c1courtneyc1courtney El Dorado Hills, CAPosts: 35Member

    Yeah, this was my first #OhmHour (well I had one that they immediately stuck in at 5pm before I had even a chance to change my settings, which I did immediately to set my times.) It was looking like a cloudy day, plus my family wasn't ready to do this, so I opt'd out. Now regretting not opting back in, as while it was cloudy, it was good enough to have met the goal, plus the 2 days of data that got added, took it from a -2.5kWh to a -1.5kWh as they were high AC days. I could have easily gotten that as I produced over 3kWh in the 5-6pm timeframe.

    Looks like the overall target is going to be 2.156kWh (based on the last day which OC doesn't have data for but I have) and I should be about -0.570kWh in usage (based on my Inverter and Consumption meter data.) Looks like I produced about 0.75kWh and was consuming 0.18kWh. Well see what the exact numbers come out. I have wondered how accurate the time was on PG&E smart meters for TOU.

  • jserramcjserramc Posts: 299Member

    If you don't have a streak or just a few events, if you don't opt out and see what happens, at least the worst that can happen is you don't earn and you lose your streak. Which might be nothing anyway. Only down side is, from what I've experienced, is if you don't opt out and you go over and you get negative points. those negatives might be there for more than one future event. A few weeks ago, with a streak of high 50s, I had a mega event of zero but a regular event of something like -0.3. It was a cloudy day and I had not yet set my hours to avoid solar making time. (I finally figured out how to set my hours --FYI there is an "edit" tab on the settings that I did not see until now). I made my mega of zero but missed the regular with something like -0.01. I got dinged 44 points but made 500. I argued about the mega being more than the regular even though their info page says "Mega hours are ALWAYS less than regular hours". So they gave me back my streak and I'm still trying to get something done about the -44. Anyway you may be surprised at how much you might earn even if you think you won't A few recent posts talk about this. And early on so a cheap learning tool. Also gives you a chance to see what happens depending on what you unplug.

  • c1courtneyc1courtney El Dorado Hills, CAPosts: 35Member

    Grrr.... PG&E is showing Estimated power consumption in the 7-8pm Mega OhmHour Time frame.

    Note that Solar Edge only outputs it at 15min intervals and then smooths the curve, apparently when the AC kicked back on was just at a snapshot window time frame but the electric consumption was flat lined at about 180W the entire hour.

  • jserramcjserramc Posts: 299Member

    what is solar edge?

  • c1courtneyc1courtney El Dorado Hills, CAPosts: 35Member
    edited July 2018

    SolarEdge is a brand of Inverters, Power Optimizers, Consumption Meters.... https://www.solaredge.com/us/ They also provide monitoring for the equipment so you can see what you're producing and consuming: Real time, Daily, Weekly, Monthly, Annually....

    They're the most popular Power Optimizer brand out there, and likely the most popular Inverter brand - Sunnyboy is about as popular, but Solar Edge has them beat (and pretty much everyone) on monitoring abilities.

    https://www.solaredge.com/us/products/pv-monitoring#/

  • UkiwiSUkiwiS San DiegoPosts: 1,577Member, Moderator
    @c1courtney I use a virtually free solution that incorporates usage data too and I can check in and compare with others nearby and around the globe.

    https://pvoutput.org/intraday.jsp?id=41203&sid=39052
  • jserramcjserramc Posts: 299Member

    my system has individual inverters on each panel (so if one goes out they don't all go out) and the panel that shows me stuff is envoy. Because I'm not online at home I am unsure if I could access something like this. Ideas?

  • c1courtneyc1courtney El Dorado Hills, CAPosts: 35Member

    I use PVoutput as well - Here's the day https://pvoutput.org/intraday.jsp?id=67355&sid=59864&dt=20180717

    But Solar Edge only puts out in 15min intervals

    You can see the 7:45pm estimate at 3,585Wh must be normalized data captured at a specific point from the AC kicking back in after the true Ohmhour. The AC just kicked back on at 8pm, must have grabbed it from the previous point, or clocking is a little off...

    That SmartMeter should have the true data measured every 8s, but that's right now giving an Estimated 6.66kWh

  • c1courtneyc1courtney El Dorado Hills, CAPosts: 35Member

    Data pulled directly from API

    This XML file does not appear to have any style information associated with it. The document tree is shown below.

    QUARTER_OF_AN_HOUR
    W


    Consumption


    2018-07-17 18:45:00
    4780.153


    2018-07-17 19:00:00
    184.83875


    2018-07-17 19:15:00
    176.76997


    2018-07-17 19:30:00
    181.61674


    2018-07-17 19:45:00
    177.77325


    2018-07-17 20:00:00
    6990.798




    Production


    2018-07-17 18:45:00
    1716.2267


    2018-07-17 19:00:00
    1482.4711


    2018-07-17 19:15:00
    1131.329


    2018-07-17 19:30:00
    605.7401


    2018-07-17 19:45:00
    248.81999


    2018-07-17 20:00:00
    54.219982




  • UkiwiSUkiwiS San DiegoPosts: 1,577Member, Moderator

    @c1courtney What exactly are you asking?

  • c1courtneyc1courtney El Dorado Hills, CAPosts: 35Member

    Was really complaining about PG&E doing an estimated power consumption of 6.66kWh from 7-8pm during this Mega #OhmHour. I put in a different thread where I was asking if people thought I should contact PG&E now, or wait and see if it resolves itself.

  • UkiwiSUkiwiS San DiegoPosts: 1,577Member, Moderator
    edited July 2018
    I responding to that thread. Feel free to escalate it with them, if you have a ton or time and if banging your head on a brick wall is appealing. ;)
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