New Poster with DIY questions about solar

rtcy2998
rtcy2998 Registered Users Posts: 7
[clip posts from this previous thread: http://forum.solar-electric.com/showthread.php?14217-250w-grid-tie-inverters-on-E-bay -BB]
solar_dave wrote: »
I think you should buy 6 of them and plug,them all into a single 15 amp household circuit and see what happened when some one plugs a 1500 watt hair dryer and a 1500 watt space heater into the same circuit. Guess what the breaker won trip.

BTW tells us how long before the fire breaks out.

I just read this entire thread and found it, informative and left me with many questions. I went to the trouble of copying each post that gave me questions, and was going to make a massive post with questions, but seemed very complicated , so I will ask each poster instead and hope i don't seem to over whelming

Q: so if a person has a empty hole in their 200amp panel and sets up a isolated circuit breaker and runs a line to where the micro-inverters(using one of micro-inverters talked about in here as being "safe" and "approved" will connect, will this be a "ok" way ? I know I need to specify capacity of the inverter output capcity, but that is up in the air for now, as I REALLY want to make at least one or 2 panels myself and my son wants to do it really bad too. ( we have fun these way ;) )

off topic:(thinking outloud) this web site is driving me batty. it reminds me of the old BBS. I set my preferences so I see a thread from start to end, but keeps reverting back to showing me the last posts first, and I'm loosing my place so i can keep following it and making questions as the posts progress. also if there's a way to make the box when you set it to hybrid go away it would be great as I want to go chronologically only.

Comments

  • rtcy2998
    rtcy2998 Registered Users Posts: 7
    Re: 250w grid tie inverters on E-bay
    solar_dave wrote: »
    Well instructions are all fine and dandy, but unless the circuit is Designed and added to prevent other uses some ones teenager or wife will come along and overloaded. And if it is built and added to the panel to prevent it why not use something like Enphase and do it right and pull the permits and provide thE proper hard wire attachment.

    I am under the understanding (and I need corrections if I'm wrong), that using micro inverters from a PV panels and feeding that AC current into the panel it would offset the incoming load.
    does it not also mean that if you hook it up to a isolated breaker as discussed, then it gets used by the house loads and any other excess loads would get pulled from the street?
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: 250w grid tie inverters on E-bay
    rtcy2998 wrote: »
    Q: so if a person has a empty hole in their 200amp panel and sets up a isolated circuit breaker and runs a line to where the micro-inverters(using one of micro-inverters talked about in here as being "safe" and "approved" will connect, will this be a "ok" way ? I know I need to specify capacity of the inverter output capcity, but that is up in the air for now, as I REALLY want to make at least one or 2 panels myself and my son wants to do it really bad too. ( we have fun these way ;) )

    Legally, a solar GT circuit breaker can be installed in the "far slots" (away from the main breaker) and be 20% of the panel rating (0.20 * 200 amps = 40 amp double pole breaker). There are other rules, but that is probably enough for the moment.

    You are more than welcome to make panels yourself. However, beware that there can be issues with starting fires if something goes wrong.

    Panel Fire Question
    (this was not a UL/NRTL listed panel and never would have passed NRTL--but unknown if "home made" or cheap factory made/supplied)

    And, here is a good series on Do It Yourself solar panel construction (don't recommend, but if you want to try):

    http://fieldlines.com/board/index.ph...,144982.0.html
    http://fieldlines.com/board/index.ph...,144995.0.html
    http://fieldlines.com/board/index.ph...,145004.0.html

    Home made solar hot water/hot air heating is usually a better bang for the buck:
    BB. wrote: »
    Everyone,

    I have trimmed these posts from another thread and intend to put everything together in a Stick FAQ/Thread... Please feel free to add suggestions and update information as you see fit.

    In a few days, I (or anyone who wants) can cut and past everything into one post (and post edit).

    -Bill

    If you want a do-it-yourself kit... This one appears to be hard to beat:

    www.solarroofs.com

    Solar Guppy has many years experience with a system from them and has been pretty happy. It does require proper maintenance to keep running well and to prevent problems (like freeze damage).

    There have been a few threads here that link back to several extensive home projects--right down to installation photos, and documentation of mistakes and corrections...

    Link 1
    Link 2
    Link 3
    www.arttec.net/Solar/BarnHeat.html (also sells battery based Differential temperature pump controller).

    Follow the off-forum links. The several projects/websites highlighted are very educational.

    And this one is a bit more low tech home made heating system. Also very interesting and informative.

    Between the two above links, they probably give the best detailed explanations of how to do a major home heating/domestic hot water project that I have seen.

    The second one is, by itself, probably not practical for a city home system--but both give great ideas of the scope of such projects.
    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • rtcy2998
    rtcy2998 Registered Users Posts: 7
    Re: 250w grid tie inverters on E-bay
    What they're doing isn't legal. You can not have GT without co-operation of the utility and local AHJ. Got to be UL listed equipment and have all permits and inspections in place.

    That doesn't mean they aren't doing it, but such guerrilla installs have problems. For instance if something goes wrong and the equipment is there it (and the owner) will be blamed whether or not it is the cause. Anti-islanding or not, the insurance companies can refuse to pay and the utility can pull the power if they find it (even if there is no problem).

    Chances are they won't find it because the size is so small it will merely off-set some of the household use. But should its output exceed the household use at any time and it does actually back-feed the grid another problem will arise: if you don't have the right kind of meter this production will be read as consumption.

    Just my opinion, but only arrogant idiots do this.

    ok I understand just so no one gets uncomfortable with my questions, that this should be done with permits, BUT , as I want to play around and make a couple of panels and hook up a( "gismo" I bet you guys love that phrase) , meter to see how much I'm putting back in , I want to start out with a PROPER inverter on a isolated line to the main box, fused and see at what point I can remain in stealth mode and hope Edison does not see ANY juice being back fed into their system.

    again this is using one of the approved inverters that disconnect when street power is cut , so no lineman gets hurt.

    Ps: we just had all our transformer replaced not long ago, and we have the "call home" meters that report instant usage and so forth

    as part of what you should know about me, is that I made a room addition to this house and doubled the size, at that time I installed a new 200amp box with a new roof pole about 2 feet from the old 1950's box with just 4 circuit breakers and a 8 foot buried ground rod just below the new main box, as I always like to OVER spec my stuff I used 12 gauge wire throughout the house with GFI's in the required places like bathrooms and kitchen

    this is what it says right now, actually i picked 2 days ago as it was in blue and seemed higher, yes we use a lot of energy at midnight til 3 am as my wife and son are insomniacs and do all the laundry and dish wahers and stuff like that.

    Comparing your usage year over year helps you see how changes affect your costs.
    Billed Month Usage (kWh) Amount
    in $
    Jul '10 1,966 $316
    Jun '11 1,501 $195
    Jun '12 1,704 $237
    Daily Usage

    Making smarter energy choices can help decrease the amount due on your next bill.
    Usage On Jul 20 2012 Usage (kWh)
    12am 3.2300
    1am 3.1200
    2am 1.8600
    3am 1.5900
    4am 1.8600
    5am 1.5800
    6am 1.6400
    7am 1.9000
    8am 1.8000
    9am 2.2500
    10am 2.2000
    11am 1.8200
    12pm 1.2900
    1pm 1.4600
    2pm 1.3200
    3pm 1.2800
    4pm 1.2900
    5pm 1.3500
    6pm 2.8600
    7pm 3.2500
    8pm 2.8100
    9pm 2.7500
    10pm 2.6300
    11pm 2.7000
    This website provides the most recent data available as of 07-21-12 and is subject to update at any time. Projected next bill estimates are based on your average daily usage and do not include credits or other applicable charges, and will differ from your actual bill.
  • rtcy2998
    rtcy2998 Registered Users Posts: 7
    Re: 250w grid tie inverters on E-bay
    BB. wrote: »
    Legally, a solar GT circuit breaker can be installed in the "far slots" (away from the main breaker) and be 20% of the panel rating (0.20 * 200 amps = 40 amp double pole breaker). There are other rules, but that is probably enough for the moment.

    You are more than welcome to make panels yourself. However, beware that there can be issues with starting fires if something goes wrong.

    Panel Fire Question
    (this was not a UL/NRTL listed panel and never would have passed NRTL--but unknown if "home made" or cheap factory made/supplied)

    And, here is a good series on Do It Yourself solar panel construction (don't recommend, but if you want to try):

    http://fieldlines.com/board/index.ph...,144982.0.html
    http://fieldlines.com/board/index.ph...,144995.0.html
    http://fieldlines.com/board/index.ph...,145004.0.html

    Home made solar hot water/hot air heating is usually a better bang for the buck:


    -Bill

    Bill thanks. the more info and links the better , funny I should ask this, since I understand why and how, this is important in battery hook ups, but not sure I get it in a AC hookup , but still i will put it at the very bottom of the panel (fardest poles). not sure what you meant by 20%.

    I just started to contemplate the construction of the panel (my son has been bugging me about this for a while) and my oldest son also is very interested even though he rents in Santa Cruz, CA. I guess we all inherited the tinker bug from my DAD the perennial tinkerer just cause we think it's fun. your mention of solar water heater make me think of the "good old days", when I arrived in the USA in 1969 most if not all the homes in Miami , (before we Cubans "beautified" it NOT ) had solar water heaters, these were homes going back to the 1920's and they were very self sufficient in that area. the water was scalding hot and there were no holding tanks or pumps, just a box on the roof with copper tubing about 4'x8' , you got hot water well into the early evening, dear old dad used to turn off the water heater in the summer and it was ok
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: New Poster with DIY questions about solar

    RTCY,

    I have created a new thread for you and moved your posts here. Feel free to guide the discussions anyway that makes sense for you here.

    Many (most/all?) of us here are big believers in conservation. It appears that you may have electric hot water and other relatively high power needs.

    Have you looked at the new appliances and such out there that can reduce electric usage (if not using propane/natural gas/etc.).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: New Poster with DIY questions about solar

    One thing you have to understand: homemade panels are a "no-go" for a GT system. They are not listed and thus deemed not safe (sometimes with good reason).

    That does not mean you can't build one or two and use them to power something, but it will have to be "off-grid" entirely. That means either a direct DC drive something, or a battery-based AC system.
  • rollandelliott
    rollandelliott Solar Expert Posts: 834 ✭✭
    Re: New Poster with DIY questions about solar

    well if you really want to conserve you can get rid of that electric dryer. Heating with electricity is about the inneffcient way you can use it. Ditto for the dish washer which has a huge heating element as well.

    Don't waste your time making a panel, it typically takes severla years to just break even on a solar panel installaiton. And your homemade panel will fail in a few years and you will Actually LOOSE money, not save any by the time you figgure everything out.

    If you want to make a panel, make a hot water panel, if made out of metal they will last just as long as a commercially made one and work great for years and years and years.

    and if you really must make a PV panel, make a small 10 ro 20 watt one and hook it up to a direct drive pump to circulate the water in your solar water heater.
  • rtcy2998
    rtcy2998 Registered Users Posts: 7
    Re: New Poster with DIY questions about solar
    BB. wrote: »
    RTCY,

    I have created a new thread for you and moved your posts here. Feel free to guide the discussions anyway that makes sense for you here.

    Many (most/all?) of us here are big believers in conservation. It appears that you may have electric hot water and other relatively high power needs.

    Have you looked at the new appliances and such out there that can reduce electric usage (if not using propane/natural gas/etc.).

    -Bill

    Hi Bill and thanks for separating me, this way i can ask some things that may be off topic on the other thread. to answer your question, yes we have changed all the lighting in the house to LED's and that lowered the bill by 60.00 a month, have gone through a few models of LED's as you probably know, they get dim with time, for a while there the gent at lights of america exchanged the bulbs as they got dim and full of humidity inside. nice you caught that electric dryer. yes that was a topic of much debate, they are indoors and the gas one seemed to cause a lot of allergic / headaches for wife, problems no matter how well vented to the outside and kept clean they were. we no longer use the wall gas heater either, I bought those radiator looking room heaters, but we like cold, so hardly use those too.

    my wife is the architect of that project and I remain happy to not know how much she has spent on LEd and it probably is the same ration as PV versus just buying it from Edison. (just a tad of exaggeration there)

    we do have energy star appliances, and I installed a tank less water heater , that also saved a bunch on the first gas bill. if you saw my consumption ,then you know we use a lot. but it probably is not too high for 7 people in this house including grand kids that run computers day and night. that's a fight I no longer fight as my kids and grand kids just love to consume. my father must be turning in his grave LOL this was the man that turned off the small electric heater in his mobile home the last 20 years of his life and would only turn it on 20 minutes before showering. can't get away from extremes I guess LOL.


    this is for anyone in the forum not just you, What would you do if you were me and was given a 1500 watt inverter made for mobile equipment, meant to be hooked up to batteries and has 2 outlets and provides up to 1500 watts ? the reason i ask is I would like to have access to power in outages for my wife's CPAP machine . how many 6 volt deep cycle batteries needed to produce 1500 watts for 8 hours max. would 4 batteries do it. I forget the watt hours in 6 volt batteries, and have not changed any in a while (electric pallet jacks and some liftagates) as i recalled 225?

    here is the manual http://www.vanner.com/wp-content/uploads/2011/01/INVERTER-MODEL-VLT12-600.pdf

    the newest CPAP machine says 12v 5 amp or 2.1amps in 120v ac
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: New Poster with DIY questions about solar
    rtcy2998 wrote: »
    this is for anyone in the forum not just you, What would you do if you were me and was given a 1500 watt inverter made for mobile equipment, meant to be hooked up to batteries and has 2 outlets and provides up to 1500 watts ? the reason i ask is I would like to have access to power in outages for my wife's CPAP machine . how many 6 volt deep cycle batteries needed to produce 1500 watts for 8 hours max. would 4 batteries do it. I forget the watt hours in 6 volt batteries, and have not changed any in a while (electric pallet jacks and some liftagates) as i recalled 225?

    here is the manual http://www.vanner.com/wp-content/uploads/2011/01/INVERTER-MODEL-VLT12-600.pdf

    the newest CPAP machine says 12v 5 amp or 2.1amps in 120v ac

    Okay, a 1500 Watt inverter does not necessarily have to be able to produce 1500 Watts per hour for 8 hours; it only has to be able to supply the load.

    The CPAP says 5 Amps @ 12 Volts? That is 60 Watts. It also says 2.1 Amps @ 120 VAC? That is 252 Watts. Bit of a discrepancy there. This is where you plug it in through the Kill-A-Watt meter and see what it really uses.

    Batteries come in different capacities. A typical "golf cart" battery is about 220 Amp hours. Two in series to get you 12 VDC, and you have about 1kW hour AC from the inverter (depending on how much it consumes and how efficient it is in conversion).

    If we take the 60 Watt reading of the CPAP for 8 hours you get 480 Watt hours, which is easy to achieve. If the number is closer to the 252 Watts * 8 hours you get over 2kW hours which is a bit more difficult to come by. That's why accurate, real-world power consumption numbers are essential. The data they put on the equipment ... I don't know where they get it from. Flight of fancy I suspect. :roll:
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: New Poster with DIY questions about solar

    1,500 watts for 8 hours on 12 volt "forklift" type batteries (discharge to 20% of capacity):
    • 1,500 watts * 8 hours * 1/0.85 inverter eff * 1/12 volt battery bank * 1/0.80 max discharge = 1,471 AH @ 12 volts

    Such a battery here:

    Crown Industrial Battery - 12 Volts, 1500 Amp-hours Price: $3,365.35

    • 12 Volts
    • 1500 Amp-hours at the 20 hour rate
    • Dimensions: 29.13"L x 12.94"W x 26.25"H
    • Weight: 1122 pounds
    Warranty: 1500 cycles to 80% DOD for five years full replacement.

    Will do it very nicely for many years to come.

    If you where going to charge such a battery bank from solar... We recommend 5% to 13% rate of charge... Use 10% as a "healthy" number:
    • 1,500 AH * 14.5 volts charging * 1/0.77 panel+controller derating * 0.10 rate of charge = 2,825 Watt Solar Array

    In terms of how big of solar array for recharging such a load on a daily basis--Assuming you get a minimum of 4 hours of "noon time equivalent" of sun per day for ~9+ months a year:
    • 1,500 watts * 8 hours * 1/0.77 panel+controller derating * 1/4 hours of sun per day = 3,896 Watt Solar Array

    So, notice that there are two drivers for the minimum size of a solar array... One based on battery capacity and the second based on hours of sun per day and energy used... In this case, you have "small" battery capacity relative to your kWH of load per day--So such a system would (guessing) need almost 4kW of solar panels to power such a load for around 9 months per year (and use grid/generator for other ~3 months per year--assuming most of continental US).

    Now--I would not recommend building a system like this (things are "out of balance"--But this is what was asked for.

    In the end, there are two major ways to design a system... First is based on your load requirements.

    A second is to pick something (a certain sized battery, can only fit YYYY Watts of solar panels on roof of RV, etc.), then design the rest of the system around the core requirement predict how much energy you can generate per day...

    Note a 1,500 watt load running * 8 hours per day is 50% more energy than my grid connected home with four people uses per day.

    In the end, energy use is very personal choice--And we will help you with whatever you decide is needed for your home/family (i.e., if spouse is allergic to combustion gases--You are forced to use other methods... However, for home heating/cooling, the modern mini-split AC systems and heat pump type water heaters are about 2x as efficient as pure "resistive" electric heat). In the end, anything you can do towards conservation is almost always cheaper than trying to generate the power.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • rtcy2998
    rtcy2998 Registered Users Posts: 7
    Re: New Poster with DIY questions about solar
    BB. wrote: »
    1,500 watts for 8 hours on 12 volt "forklift" type batteries (discharge to 20% of capacity):
    • 1,500 watts * 8 hours * 1/0.85 inverter eff * 1/12 volt battery bank * 1/0.80 max discharge = 1,471 AH @ 12 volts

    Such a battery here:

    Crown Industrial Battery - 12 Volts, 1500 Amp-hours Price: $3,365.35




    Will do it very nicely for many years to come.

    If you where going to charge such a battery bank from solar... We recommend 5% to 13% rate of charge... Use 10% as a "healthy" number:
    • 1,500 AH * 14.5 volts charging * 1/0.77 panel+controller derating * 0.10 rate of charge = 2,825 Watt Solar Array

    In terms of how big of solar array for recharging such a load on a daily basis--Assuming you get a minimum of 4 hours of "noon time equivalent" of sun per day for ~9+ months a year:
    • 1,500 watts * 8 hours * 1/0.77 panel+controller derating * 1/4 hours of sun per day = 3,896 Watt Solar Array

    So, notice that there are two drivers for the minimum size of a solar array... One based on battery capacity and the second based on hours of sun per day and energy used... In this case, you have "small" battery capacity relative to your kWH of load per day--So such a system would (guessing) need almost 4kW of solar panels to power such a load for around 9 months per year (and use grid/generator for other ~3 months per year--assuming most of continental US).

    Now--I would not recommend building a system like this (things are "out of balance"--But this is what was asked for.

    In the end, there are two major ways to design a system... First is based on your load requirements.

    A second is to pick something (a certain sized battery, can only fit YYYY Watts of solar panels on roof of RV, etc.), then design the rest of the system around the core requirement predict how much energy you can generate per day...

    Note a 1,500 watt load running * 8 hours per day is 50% more energy than my grid connected home with four people uses per day.

    In the end, energy use is very personal choice--And we will help you with whatever you decide is needed for your home/family (i.e., if spouse is allergic to combustion gases--You are forced to use other methods... However, for home heating/cooling, the modern mini-split AC systems and heat pump type water heaters are about 2x as efficient as pure "resistive" electric heat). In the end, anything you can do towards conservation is almost always cheaper than trying to generate the power.

    -Bill

    that's a lot of info, I'm getting old and the brain just seems to be sulfated like a lot of batteries I deal with at work!. but working from the point, that the inverter is brand new and FREE , AND that the last 3 times our power went out , the wife who suffers from insomnia had to sleep in her yukon, running , with the CPAP hooked up to the cigarette charger , I figured this is a no brainer, I also figured I would make a few homemade solar panels, over spec the amount of cells a bit to compensate for nasty plexiglass and create a bit of juice and back feed say 16 volts into a bank of group 31 used but good batteries and use it for those "emergencies", hell it may even produce enough to last 2 or 3 days, but of course I have a huge roof free and sun bathed all day so I could use the south facing side and put up a few panels.

    this is all just talk right now off the top of my sulfated brain. need to re-read your post and do the math until it gels into the brain.

    i do want to keep reading and learning until I can make a intelligent decision on what panels to buy to do a GT system to lower my bill, in my current monetary situation I will have to wait to do a GT, for now though I will be doing a re-insulation of the front half of the house with blown in cellulose insulation to keep those air conditioners at bay. the rear room addition is all r-30 roof and whatever the walls is r-11 or r-13 as I recall per California code.

    as you gents said , conservation is the first step to going green and solar / wind.

    oh I forgot one more motivation for having a GT someday is Edison likes to "accidentally" pull our medical certification from our bill putting us faster into tier 4 and tier 5 rates, last year they did this and our bill went up tp 700.00 dollars for one month.
    every 2 years they send a re-certification letter EXCEPT our first copy NEVER comes, so now this year they pulled the same game again, except this time the SECOND notice also wanted a DOCTOR to sign the CERT and be back in 10 day to them, anyone that deals with Kaiser Permanente knows getting a doctors appointment in that time can be hard, I had to once again file a complaint with the PUC.
    their PUC representative called us, just like she did 2 year ago and said they had sent us a first notice, but not true, but this time when we got the "second" notice dated 15th , postdated 21st and we received on 23rd, saying we had 10 days.
    this time having been thru hell last time, I sent it registered to their post office box. and filed the complaint at once, when she called she asked why we filed? since they had not YET removed our medical cert?. we answered her that they would just like last time and remove both our discounts and she proceeded to ASURE us this would not happen.

    I asked her if she had received the new letter I sent registered with the re-certification letter from Kaiser Permanente (knowing they had) and was told by her no.
    I then told her the FACT "they" had 3 days earlier. she called a few days later telling us once again it was handled , "don't worry" sure enough 5 days later the new bill showed up online. medical cert was gone(the other discount we get was still there this time) bill 100.00 dollars higher, called her , she had no answer, but told us NOT to pay it, she would take care of it.

    she ended up doing it , and we payed the bill 10 day late. can't wait to see our next bill, it probably have a new LATE fee or such thing.

    anyways, being as I'm one of those conspiracy guys, it just seems weird that 3 times in a row they claim to have sent a fist letter, but we never got it. funny thing is, about 6 months ago we did get a letter from them letting us know they were upgrading the grid in our area and we would be without electricty , (another night she slept in the yukon with engine idling) that letter we got. so now I put us back on PAPER billing just to see how those letters get tome. and sure enough you all know the bill WILL get to me.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: New Poster with DIY questions about solar

    Look at the same numbers again with a 150 watt load (CPAP machines are around 60 watt or so--There are some people use for camping with DC inputs too, I think).

    Then look at my Battery Bank/Solar array/etc. sizing as 1/10th the size.

    All of a sudden, much more reasonable.

    Regarding building solar PV panels. Understand the draw of DIY. And for small panels for "playing around"--Why not.

    But for anything you will rely on and permanently mounted (home, over brush, etc.). Home made panels will typically last a few months in the weather (sun/rain/etc.). And as they fail, the chances of something getting hot and starting a fire is not zero.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: 250w grid tie inverters on E-bay
    rtcy2998 wrote: »
    Bill thanks. the more info and links the better , funny I should ask this, since I understand why and how, this is important in battery hook ups, but not sure I get it in a AC hookup , but still i will put it at the very bottom of the panel (fardest poles). not sure what you meant by 20%.

    I just started to contemplate the construction of the panel (my son has been bugging me about this for a while) and my oldest son also is very interested even though he rents in Santa Cruz, CA. I guess we all inherited the tinker bug from my DAD the perennial tinkerer just cause we think it's fun. your mention of solar water heater make me think of the "good old days", when I arrived in the USA in 1969 most if not all the homes in Miami , (before we Cubans "beautified" it NOT ) had solar water heaters, these were homes going back to the 1920's and they were very self sufficient in that area. the water was scalding hot and there were no holding tanks or pumps, just a box on the roof with copper tubing about 4'x8' , you got hot water well into the early evening, dear old dad used to turn off the water heater in the summer and it was ok
    You are very welcome...

    The 20% in the main breaker panel for Grid Tied Solar... Basically, we are all familiar with a main panel that may have a 200 amp breaker at the input, and a bunch of one or two pole load breakers connected to branch circuits around the home. A single energy source (main breaker) and a bunch of loads (branch breakers).

    With Grid Tied Solar, we have now added a second current source to the main home panel. There is 200 amps from above, and (20%) 40 amps from the GT Solar Inverter... There has to be some limit so that the other breakers don't pull a total of more than 240 amps and over heat the bus bar/main box.

    Also, if you place the GT breakers at the top next to the 200 Main Breaker, you now have 200 amps + 40 amps flowing in a bus bar set rated at 200 amps (in this example). If you place the GT breakers at the "bottom" of the box, then no point on the main bus bar will be carrying more than 200 amps to the other distributed loads.

    Yes, there is a lot of history with solar hot water/heating in the US... But once natural gas and electricity became "cheap and plentiful", the solar heating stuff "went away".

    Today, they use "tempering valves" to mix extra hot solar heated water with cold water to make sure nobody gets scalded.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: New Poster with DIY questions about solar
    rtcy2998 wrote: »
    oh I forgot one more motivation for having a GT someday is Edison likes to "accidentally" pull our medical certification from our bill putting us faster into tier 4 and tier 5 rates, last year they did this and our bill went up tp 700.00 dollars for one month.

    That is why I got GT Solar--We don't use much power (and no medical exemptions), but I too fear that our northern California power company (PG&E) will keep jacking up rates (right now from ~$0.10 to $0.50 per kWH -- the more you use, the more you pay).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • ggunn
    ggunn Solar Expert Posts: 1,973 ✭✭✭
    Re: 250w grid tie inverters on E-bay
    rtcy2998 wrote: »
    ok I understand just so no one gets uncomfortable with my questions, that this should be done with permits, BUT , as I want to play around and make a couple of panels and hook up a( "gismo" I bet you guys love that phrase) , meter to see how much I'm putting back in , I want to start out with a PROPER inverter on a isolated line to the main box, fused and see at what point I can remain in stealth mode and hope Edison does not see ANY juice being back fed into their system.
    Not a good idea. Backfeeding your electrical service without an interconnection agreement with your utility is illegal, even if you never get your meter to "spin backwards". Also, in most (all?) jurisdictions your interconnection has to be installed by a licensed electrician.
  • Blackcherry04
    Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: New Poster with DIY questions about solar

    Not to mention that if you have a " Smart Meter " it will probably ADD to your KWH usage shown, rather than subtract from it. My utility had a 8 day lag on changing my meter after it was approved, during that time I produced about 300 KWH that was added to my usage by the old meter smart meter until the new net meter was installed. Obviously I never got credit for it.