X
 
  • Time
  • Show
Clear All
new posts

  • sunpoweredev
    replied
    Originally posted by NJturtlePower

    Wow! That's the ridiculous wholesale rate I've been hearing about. Including the fees I think my retail rate with JCP&L is about 14.5 cents per kWh last bill I checked.

    I had nothing banked in Feb. but the end of the month was my Anniversary/true-up as well.

    Currently I'm at 1.116MWh this month with a few days remaining so I should be seeing some banked kWh very soon...

    I believe my meter read date is set for 3/30. Fingers crossed they won't pull the old "estimated bill" in their favor with all the craziness going on in NJ right now.
    Since I never received a mailing from JCP&L acknowledging my anniversary change, I contacted them again and was basically told don't worry about it Contacted once again and insisted on a written acknowledgment and looked like the agent typed up a PDF in a hurry (typo and grammar) to shut me up lol. I will see real soon if how far off the numbers are this month. According to my consumption meter, as of right now I've banked 500KWh for March. Every month since start of winter, my billed kWh from JCP&L has been at least 300kWh more than what my consumption meter says. Last month I expected to be billed 160kWh but was billed 480. It was an actual reading. I took a couple of readings on a fully sunny day this week. This past Friday by 6PM, per the consumption meter I generated 60kWh in surplus, and the 40 reading on the JCP&L meter had gone up by exactly 60, so I have no doubt as to the accuracy of the consumption meter.

    Very pleased with the production for March even with the many rainy and cloudy days. Max production in a day was 71kWh. The max on a single day was 76kWh in August last year when my system was first up. Perhaps in another month's time I will see >80 in a day?

    Leave a comment:


  • NJturtlePower
    replied
    Originally posted by njdealguy
    Received my PSEG bill today based on the anniversary date that was set for last week of February. For a net meter anniversary credit for about 22 kWh, have been paid a 51 cents or just 2.33 cents per kWh (vs retail rate of about 16.5 cents per kWh). What a joke, hope to use all the power we generate before the anniversary dates hit!
    Wow! That's the ridiculous wholesale rate I've been hearing about. Including the fees I think my retail rate with JCP&L is about 14.5 cents per kWh last bill I checked.

    I had nothing banked in Feb. but the end of the month was my Anniversary/true-up as well.

    Currently I'm at 1.116MWh this month with a few days remaining so I should be seeing some banked kWh very soon...

    I believe my meter read date is set for 3/30. Fingers crossed they won't pull the old "estimated bill" in their favor with all the craziness going on in NJ right now.

    Leave a comment:


  • njdealguy
    replied
    Received my PSEG bill today based on the anniversary date that was set for last week of February. For a net meter anniversary credit for about 22 kWh, have been paid a 51 cents or just 2.33 cents per kWh (vs retail rate of about 16.5 cents per kWh). What a joke, hope to use all the power we generate before the anniversary dates hit!

    Leave a comment:


  • Ampster
    replied
    Originally posted by J.P.M.
    ........

    Why do you seem to be implying I don't appreciate several viewpoints and opinions about a subject ? .........

    While all opinions are to be respected, that doesn't make them equally correct or safe. .....
    To call out errors in expressed opinions that may be wrong/dangerous/just plain B.S. or lead to bad outcomes, personal injury or worse. ......
    ..... but not all opinions are based on reality. ...........
    Your own words and the tone and style of your comments speak for themselves. I am happy to correct any mistakes of fact.
    No doubt we have different realities but isn't reality just an opinion? I am sure there are bad outcomes that we can agree upon but some opinions of bad outcomes are just opinions. Or, as Mike says, different strokes for different folks.
    Last edited by Ampster; 02-10-2020, 01:06 PM.

    Leave a comment:


  • Mike90250
    replied
    All, Different strokes for different folks. Many ideas seem straightforward, but practical field experience nearly always beats lunch time napkin notes.

    Ya'll can have your opinions and say, but we will often call someone out on bad or dangerous ideas. I find my self sometimes just rolling my eyes, as folks contemplate taking used batteries from various sources and slamming them into a charger and thinking its going to be fine, As fine as looking down the bore of a light saber and then switching it on.

    Leave a comment:


  • bcroe
    replied
    Originally posted by J.P.M.
    Bottom line on all this: What happens with multiple orientations done for the purpose of spreading out the harvest so that inverter sizes might be reduced is that while inverter sizes may be reduced, the required array sizes in terms of total panel STC wattage will increase. That is, the average annual output per STC panel W (or m^2 of panel) will decrease, requiring corresponding increases in array costs due to increased array sizes required to meet the same duty including costs for panels and B.O.S material costs and any non DIY labor costs as expressed per installed STC W. At least to my experience those panel and B.O.S incremental are usually greater per STC W than the incremental material acquisition cost increases of inverters as expressed per nominal W increase in inverter capacity.
    What is new here, seems like we already agreed that work here is only remotely tied to money?
    Each application is unique, my methods being simply an option, not a definition of RIGHT. A
    clean sheet design is nice, but reality makes the problem much more complex.

    My first upgrade put to work most of the 14KW of extra solar panels previously on hand, using
    a very cheap double sided mount, and better utilized the rest of the system without overloading
    anything. Later, mounting panels to minimize snow clearing efforts was somewhat costly, a
    price I was glad to pay, and half the supports were aluminum left over from other work. Bruce Roe

    Leave a comment:


  • Ampster
    replied
    Originally posted by bcroe

    ...... Lately the experiment seems to be closer to the end than
    the beginning, with my list of goals being met. ..
    Meeting one's goals is an important issue in any system design. Thanks for your contribution to this body of knowledge. Many people with less than optimum sites or weather will benefit.
    Last edited by Ampster; 02-09-2020, 01:45 PM.

    Leave a comment:


  • J.P.M.
    replied
    Originally posted by Ampster

    It is pretty obvious there is a lot of difference between the weather in snowy cloudy Illinois and the deserts of California. Therefore it is no surprise optimal systems might be designed differently. More importantly the goals and cost structures, as well as the cost of the land and capital are different as well.

    Let me offer another opinion, not to say that you are wrong, but simply to point out that there are often several viewpoints and opinions about a subject. The value of forums like these, is the various opinions offered by people with different perspectives. That way the viewers and lurkers can form their own conclusions, whether they are in the Midwest or the Desert.

    The thing that I admire about Bruce's system is that it generates almost 2000 times the AC capacity of his inverters. I have yet to see a solar farm in the desert that rivals that.
    Having grown up in central NY state (a place with possibly marginally worse winters than Buffalo) and spending 25 yrs of my adult live in/around Buffalo, NY, I appreciate the winters here in N. San Diego county - which, BTW, and to not let you (or anyone else) either by ignorance or intent, or design or anything else infer by your desert reference, while drier and sunnier than a lot of places, is most certainly not desert, although I've lived in the desert as well.

    I'm not picking on you and certainly not Bruce, but I've lived in dryer sunny, winter climates including several years in Albuquerque, besides the 20+ yrs. of what many consider the goldilocks climate in N. San Diego county and places with what many consider brutal winter climates. Can either of you say that ?

    I've also designed PV and thermal systems as well as several residential housing designs and retrofits for both climate types. Can you say that ? I appreciate the design differences imposed by both climate types and other climates as well. Many of the same principles I learned and practiced while designing and stamping power and process system designs for the power, petrochemical and chemical process industries carry over to alternate energy system design, including dealing with the design requirements (and tradeoffs) imposed by environmental considerations in various climates.

    So, I'll chalk up your blinding flash of the obvious statement about climate variation and its importance in PV system design to your ignorance. I forgot more about the subject than you might ever know.

    To say or write to me or anyone who has the capability to design systems, or for that matter anyone who has ever lived in either type of climate you mention - including readers, members or lurkers here - that it's no surprise optimal alternate energy systems might be designed differently for different climates is not only no surprise, but a blinding flash of the obvious.

    However, one thing that is common to most all PV and solar thermal systems is that for stationary, flat plate solar energy devices there is one orientation that optimizes the integrated annual POA irradiance on the device. That orientation will almost always lead to the optimal operating efficiency and greatest annual energy harvest. Other orientations will, by definition, harvest less.

    1X/a while, but I'd suggest rarely, there may be practical aspects to an application where there is more than one orientation that maximizes annual POA irradiance. If they exist, I've not seen one.

    However, that's not to say, and I never meant to imply (although others it seems want to infer and so ascribe it to what I've written) that other design considerations that can and probably will most likely change the system orientation from the one that gathers the most energy to one that better meets other design requirements do not need to be considered. The impact of TOU tariffs on system cost effectiveness being one such example.

    After designing, running and managing engineering projects for a long time and doing so while trying to keep 10-20 balls in the air simultaneously and trying not to drop any of them - including cost/budget considerations, optimization and client perceptions as well as profit considerations my bosses may have - I think I appreciate managing priorities and design comprises more than at least some others.

    Why do you seem to be implying I don't appreciate several viewpoints and opinions about a subject ? IMO, a good, that is to say sizeable part of the value of forums such as this is indeed the opportunity it affords to offer opinions.

    While all opinions are to be respected, that doesn't make them equally correct or safe. Some are dangerous when expressed or acted upon. That leads to another good part of the value of these forums: To call out errors in expressed opinions that may be wrong/dangerous/just plain B.S. or lead to bad outcomes, personal injury or worse. I cite your temporary banishment some time ago as an example.

    All folks are to be respected, but not all opinions are based on reality. Those opinions that are incorrect or needing clarification need to be identified and called out. Peer reviewed literature does that quite nicely for the most part. Here, IMO only, we suffer fools all too much to the detriment of the forum credibility.

    Bruce's opinions are based on reality and experience, and as I've written several times, I pay a lot of attention to what he writes and feel I ignore his opinions at my peril.

    However, to Bruce:

    Take this FWIW, and meant respectfully but just as seriously. It looks to me that you're under some misapprehension(s) about the solar resource. One such misapprehension may be that, while environmental considerations may and probably will require orientation changes, it looks to me that you have a notion that, base on annual harvest per installed STC panel W, using several panel orientations will improve the annual harvest of your system(s), or that maybe it'll be more economical or cost effective. That may be correct, but based on what I think I might know, I doubt it. I asked for your orientations and array sizes for the purpose of doing some work w/PVWatts/SAM/my private stuff. While I note your use of multiple tilts to improve harvest and help with snow mitigation, I also note such adjustments are also possible with single orientation arrays.

    Not that it matters much, but if/when I design an array for a ground mount application where there's usually a fair degree of orientation flexibility, I start with a duty (load) and find the optimum orientation based on the solar resource availability. I then base the first design iteration on that orientation and modify the design as site conditions/constraints and project goals dictate with the goal of meeting all or as many of the design goals and constraints as possible while keeping as close to the max. output orientation as possible. Roof applications devolve to a rating type design based on picking the best, that is, most productive orientation among the available but probably more limited orientation choices. In such cases, multiple orientations are sometimes necessary to meet a duty, but, like life, they're not perfect, just the best available for that application and seldom optimal. Another of many reasons why ground mounts are usually better if given the choice.

    Even with few environmental constraints - no snow, sunnier climates, different temps., it looks to me that you are of the opinion that using orientations based on the idea that making a flatter output curve for sunnier days over a year will be better both for system efficiency and cost effectiveness. It also seems to me that you've come to that conclusion, or at least landed upon the notion that using the ratio of your annual harvest to your installed inverter capacity is a useful figure of merit. I am of the opinion that's not a good or maybe even valid criteria for measuring either system collection efficiency or for economic optimization.

    Annual harvest per installed STC (panel) W is a better metric, both for system efficiency (annual utilization) in terms of kWh/yr. harvested per installed STC panel W, or (and with a slightly different azimuth but similar tilt for TOU systems) average annual bill reduction per installed STC W.

    If one design goal is broadly defined as most bang for the buck, size the array STC wattage to the duty that gives the lowest LCOE mix of PV and POCO power and size the inverter with an eye to the max. panel array power output. Sometimes the inverter size limits can control a design for such things as off grid applications or for battery charging rate considerations or POCO demand rates if applicable and maybe some other conditions, but not usually or most often for common residential grid tie applications.

    I don't think I've read where you've written you have such imposed limitations (If I'm wrong or missed something on that, I apologize).

    Other environmental site conditions, limitations or application mandates or goals may require more than one orientation. But to be clear, while those other conditions may very well mandate off optimal orientations, and maybe even - although unlikely from my experience - splitting orientations, for most applications, I can't see a way that spreading out (lengthening) average daily average harvest times can, in and of itself, create a high(er) probability of improving system efficiency or cost effectiveness for most any residential grid tie application, pretty much regardless of climate.

    To restate, the one thing I've found to be most common to all active solar energy systems, PV or thermal - that there is almost always one orientation for PV panels or thermal collectors, active or passive, that optimizes yearly integrated POA irradiance on a flat plate solar device. And, maximizing annual POA irradiance is the surest and easiest way to get a leg up on system optimization.

    Parenthetically, and a bit off topic, for the PV/TOU rate considerations, there is also and usually a single (and probably different) orientation that optimizes the system cost effectiveness with respect to the system's ability to offset part or all of a residential electric bill that's different from the orientation that maximizes annual system output per STC W.

    Bottom line on all this: What happens with multiple orientations done for the purpose of spreading out the harvest so that inverter sizes might be reduced is that while inverter sizes may be reduced, the required array sizes in terms of total panel STC wattage will increase. That is, the average annual output per STC panel W (or m^2 of panel) will decrease, requiring corresponding increases in array costs due to increased array sizes required to meet the same duty including costs for panels and B.O.S material costs and any non DIY labor costs as expressed per installed STC W. At least to my experience those panel and B.O.S incremental are usually greater per STC W than the incremental material acquisition cost increases of inverters as expressed per nominal W increase in inverter capacity.

    Leave a comment:


  • bcroe
    replied
    Originally posted by J.P.M.
    Bruce: Thank you.
    I'm sorry my question was not stated well. My question was not how many kW if inverter capacity you have
    installed. My question was: How many STC kW of solar panels do you have installed ?

    What are your array orientations and panel STC array sizes and what are the corresponding array sizes
    as f(array orientations) ?

    Other considerations aside (but not forgotten) for a moment, usually, the most cost effective grid tie designs
    are ones that have the greatest POA irradiance on them over the course of a year. That goal is most often
    met by a single optimal orientation, particularly when there is flexibility in orientation as is often the case
    with ground mounts.

    Multiple array orientations do not meet that criteria. The integrated POA irradiance will always be less for a
    multiple orientation system than a system optimized for greatest annual POA irradiance. As a result, more
    orientations for a system require more panel area for the same performance as a single optimal orientation.

    As for larger arrays producing more electricity under cloudy skies, it's still not cost effective. Production under
    clouds is better thought of as a nice surprise.

    System cost effectiveness is affected by the site clearness index, lower clearness index, lower cost effectiveness
    and longer paybacks. Best anecdotal evidence I've seen to folk's awareness of that is when recently circling two
    airports, Chicago, and San Diego, and noticing all the array on roofs in one area and finding a lot fewer arrays
    on roofs in the other.

    I appreciate what you've done and continue to do, but don't kid yourself. Systems with multiple orientations
    are seldom more efficient or more cost effective than systems that use one optimum orientation.
    Respectfully,
    No doubt a lot more panels can be seen in southern CA than in cloudy Chicago, where we
    can buy all the KWH we want for $0.116 with tax and transmission, no tiers or times.

    I would pretty much agree, except the surprise of energy under clouds. I contend that
    it is entirely dependent on HOW cloudy it is. You might say that it is inefficient to even
    build PV solar in areas with frequent snowfall and a lot of clouding. I have made that
    argument at many zoning meetings, where carpet baggers want to make a quick profit
    and leave a lot of white elephants here on our prime farm land. However my 5 acres
    are not suitable for farming, and I can afford to run my latest science experiment to see
    if it can be made to work. Lately the experiment seems to be closer to the end than
    the beginning, with my list of goals being met. Someday someone may figure just how
    inefficient it may be.

    The original STC rating of the panels here is the AC inverter rating (15KW) multiplied
    by the DC:AC ratio (2.33). After much of a decade they may have slipped a bit. The
    annual AC output is taken from the inverters total to date I recorded, on anniversary
    dates. The actual DC collected would be more like 30,500 KWH before inverter and
    DC wiring losses. Here are 4 different panel alignments, some subject to semi annual
    adjustment. I do not have them precisely recorded, clearly most are not in what I now
    consider optimum position. Bruce Roe
    Last edited by bcroe; 02-08-2020, 03:49 AM.

    Leave a comment:


  • Ampster
    replied
    Originally posted by J.P.M.

    Bruce..............
    I appreciate what you've done and continue to do, but don't kid yourself. Systems with multiple orientations are seldom more efficient or more cost effective than systems that use one optimum orientation.
    It is pretty obvious there is a lot of difference between the weather in snowy cloudy Illinois and the deserts of California. Therefore it is no surprise optimal systems might be designed differently. More importantly the goals and cost structures, as well as the cost of the land and capital are different as well.

    Let me offer another opinion, not to say that you are wrong, but simply to point out that there are often several viewpoints and opinions about a subject. Tha classic south facing array is a no brainer. The value of forums like these, is the various opinions offered by people with different perspectives. That way the viewers and lurkers can form their own conclusions, whether they are in the Midwest or the Desert, or they have East-West facing roof faces.

    The thing that I admire about Bruce's system is that it annually generates almost 2000 times the AC capacity of his inverters. I have yet to see a solar farm in the desert that rivals that. That is a reason system designers should be flexible and consider site specifics in their designs.
    Last edited by Ampster; 02-08-2020, 07:58 PM.

    Leave a comment:


  • J.P.M.
    replied
    Originally posted by bcroe

    For a couple of years have done 29,000 KWH from 15KW of inverters at some 96% efficient. To do that under
    these clouds the DC:AC ratio is 2.33. Bruce Roe
    Bruce: Thank you.

    I'm sorry my question was not stated well. My question was not how many kW if inverter capacity you have installed. My question was: How many STC kW of solar panels do you have installed ?

    What are your array orientations and panel STC array sizes and what are the corresponding array sizes as f(array orientations) ?

    Other considerations aside (but not forgotten) for a moment, usually, the most cost effective grid tie designs are ones that have the greatest POA irradiance on them over the course of a year. That goal is most often met by a single optimal orientation, particularly when there is flexibility in orientation as is often the case with ground mounts.

    Multiple array orientations do not meet that criteria. The integrated POA irradiance will always be less for a multiple orientation system than a system optimized for greatest annual POA irradiance. As a result, more orientations for a system require more panel area for the same performance as a single optimal orientation.

    As for larger arrays producing more electricity under cloudy skies, it's still not cost effective. Production under clouds is better thought of as a nice surprise.

    System cost effectiveness is affected by the site clearness index, lower clearness index, lower cost effectiveness and longer paybacks. Best anecdotal evidence I've seen to folk's awareness of that is when recently circling two airports, Chicago, and San Diego, and noticing all the array on roofs in one area and finding a lot fewer arrays on roofs in the other.

    I appreciate what you've done and continue to do, but don't kid yourself. Systems with multiple orientations are seldom more efficient or more cost effective than systems that use one optimum orientation.

    Respectfully,

    Leave a comment:


  • SunEagle
    replied
    Originally posted by njdealguy
    With the way the month is going so far and forecasted in NJ, having doubts will even get to half of the total I generated in January and perhaps just one third of what PVWatts gave as estimate for Feb! Hope the later months makes up for some of this
    The weather is changing so I expect a lot of people will have less production from their pv systems then what they got in the past. I also think that pvwatts will need to update their data base to be closer to the new reality that we should expect more clouds and less solar production.

    Leave a comment:


  • njdealguy
    replied
    With the way the month is going so far and forecasted in NJ, having doubts will even get to half of the total I generated in January and perhaps just one third of what PVWatts gave as estimate for Feb! Hope the later months makes up for some of this

    Leave a comment:


  • sunpoweredev
    replied
    Originally posted by NJturtlePower

    So like I said I had an estimated bill this month, but in checking it was actually pretty close...Billed for 338 kWh. Came to $46.54

    Correct me if I'm wrong, but your SREC meter should be different than the 40-reading on the utility meter since the SREC meter counts ALL solar energy generation while the 40 Output reading is only the excess going to the grid not self-consumed.

    Anyways, February is not looking like much of a pro-solar month in NJ according to the latest weather forecast....

    Untitled.jpg
    I think I figured out the discrepancy. My November billing was an estimate. They put 250kWh in the bank which shouldn't have been there. The two subsequent readings were actual and it finally caught up.

    Can't argue with mother nature, but I am quite thankful that this winter has been quite mild. All this rain we've had could easily have been snow.

    Originally posted by robstrash
    What did you end up doing for selling your SREC's? I know previous posts recommended Flett Exchange as GPE did not offer direct deposit. I just received my SREC confirmation emails from the state and GPE so need to decide what I want to do. It looks like GPE uses SRECTrade and they indicate they have direct deposit and fees can be found here. The fees are VERY high at 5% management plus 2% transaction for 7% total fees for systems from 0-50 kW which I would think fits all homes. I'm thinking I'll just create my own account at GATS and just do it myself for $5 via Flett Exchange. Is that what everyone else does? If SREC price is $220 the 7% fee is only around $15 which isn't bad but might as well save myself $10 and do it myself.

    On a side note, I have been surprised how much solar I get on very cloudy/rainy days. I got 7.5 kWh yesterday and it was crappy weather all day long. I was telling my parents that I now get mad on cloudy days as those clouds are costing me money!!

    Update: looks like Flett Exchange also offers SREC Manager option for 3% (currently $6.75 for NJ) for full service or do it yourself transfers for $2.50. Now I'm wondering if I should be lazy and automate for only a few dollars.....
    Not that I was interested, but I asked GPE when I initially got all my SREC related stuff approved and was informed that they no longer handle SREC trades. I too used NJSREC. "No fees" from NJSREC, but they give you a lower dollar figure which still works out to be the cheapest of them all. I don't remember which, but one of the recommended services from GPE they want complete control of your system (they take control of your PJM-EIS account). No thanks. Very easy with NJSREC. You don't even have to create an account with them. You just transfer your SREC certificates from PJM-EIS GATS to them and you will receive a check in the mail in a few days. I will be doing that again soon as I've just accumulated another 3 certificates

    Same, when my system was first up and running, I was pleasantly surprised how much power it makes even on a fully cloudy day.

    Leave a comment:


  • Ampster
    replied
    Originally posted by bcroe

    For a couple of years have done 29,000 KWH from 15KW of inverters at some 96% efficient.
    That high DC to AC ratio works together with the orientation of the panels economically. That is a capacity factor of almost 2000. Better than I am getting in California.(1200 to 1400)

    I am not sure "capacity factor" is the correct term for the relationship between installed capacity in kW and actual or predicted annual output in kWhrs.
    Last edited by Ampster; 02-08-2020, 11:44 AM.

    Leave a comment:

Working...