First Time Thread - Aftermath of Sandy

IanB22IanB22 Registered Users Posts: 6
All,
there are a lot of Sandy stories on this site it seems, and mine is one of them. I am thanking the lord that this storm did not impact me the way it has impacted the NJ coast and NY and CT, however, I feel I may have dodged a little bit of a bullet, and not having anyway to generate power to run our oil burning stove, or keep our food cool in the fridge has me freaked out!

I have sold a bunch of video and audio equipment that I dearly loved after sweating bullets driving back on the turnpike and seeing long long 2 hr+ waits for gasoline to run generators and cars. I know storms like this 'shouldn't' happen, but honestly I am not convinced anymore. Anyway onto the solar stuff.

I realize that I can do this with a generator, especially a Honda one and get through even 10+ days without power, but honestly, in my heart I want to be able to go longer than that, and Electric Power is just to vital to me and my work to go without, even with a generator like that. So I have decided to go solar (stupid me, I know).

Just picked up some used telecom batteries (don't worry, everything else is on it's way too) for 600 AH at 12v for 505$ with the tax out the door. Not a bad deal I thought?
Everything else below is in the plan and in the 'buy it cart at Wind-Sun'

1. Xantrex XW MPPT 60 Amp Solar Charge Controller
2. (1) 415w Helios Panel (I can't add more than one, or the wife will get suspicious of how much this all 'really' costs)
3. Samlex 1,500 Watt 24 Volt Sine Wave Inverter
4. Classic Composition Mount
5. Z-Bracket RV Mounting Feet (set of 4)
6. 50 Foot MC4 Solarline 2, Extender Cable Male/Female
7. MRCB 150 Amp DC circuit breakers with switch
8. MidNite Solar 150VDC 15a Panel Mount DC Circuit Breakers
9. MidNite Solar 150VDC 70a Panel Mount DC Circuit Breakers
10. Midnite Solar MNEDC-Quad Enclosure for 1-4 Panel Mount Breakers

Cables and terminated battery cords and other misc small stuff is also there.

What do you think of this setup, the fridge (sorry, don't have a watt meter) is an LG side by side with an ice-maker 509 kw pr year so, and the oil heater I have no idea what it needs right now, but it runs off a 110v plug and is a Weil-Mclain something like this (http://www.pexsupply.com/Weil-Mclain-386-700-830-WGO-5-175000-BTU-Gold-Oil-Boiler-7209000-p)

Sorry for not having more details, but as you expect from where I am posting, this is a Newbie question. I know I don't have enough watts to fully re-plenish my batteries, but I wonder how many days I could go without having power before I am down to 50% battery.
Ian

Comments

  • H2SO4_guyH2SO4_guy Solar Expert Posts: 213 ✭✭✭
    Re: First Time Thread - Aftermath of Sandy

    If you have a 24 volt inverter and only 12 volts of batteries, you will not be able to power your inverter unless you can configure them to a 24 volt setup. What exactly are the batteries? I use retired (Read slightly over scrap value wise) telcom batteries to help run stuff and since I don't have a huge battery bank I split up the panels into smaller systems. Without a generator you will not be able to get near enough power to charge batteries and run many loads. Let us know more details.

    Skip
    12K asst panels charging through Midnite Classic 150's, powering Exeltechs and Outback VFX-3648 inverter at 12 and 48 volts.  2080 AH @ 48 VDC of Panasonic Stationary batteries (2 strings of 1040 AH each) purchased for slightly over scrap, installed August 2013.  Outback PSX-240X for 220 volt duties.  No genny usage since 2014. 
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: First Time Thread - Aftermath of Sandy

    Welcome to the forum, Ian.

    Are you any good at math? :D Let's do some!
    You have 600 Amp hours of 24 Volt battery? Minimum charge rate 5% (with no loads) is 30 Amps. Now, how many Amps can that panel put out? 13 Amps @ 24 Volts perhaps. Hmm. Problem. Especially if you're trying to get it to charge during a rainstorm. In fact with the rain falling down it isn't going to charge at all.

    Let's look at more problems. You're going to run a refrigerator? Try plugging it in to a Kill-A-Watt meter for a day. 509 kW hours per year / 365 days is 1.4 kW hours per day. 300 Amp hours (50% DOD) @ 24 Volts is 7200 Watt hours, not including losses and inverter consumption. An oil-filled radiator will be 500 Watts or more (up to 1500) and is thermostatically controlled so the actual power use is somewhat difficult to determine in advance. Use the lowest setting (often 600 Watts) for half the day and you've got another 7200 Watt hours. Whoops! Ran out of battery power in one go. Never mind running the refrigerator. And if the 'frige kicks on defrost, there's even more Watt hours you haven't got.

    The Samlex 1500 Watt is not a good choice for running a 'frige; it hasn't got good surge capacity and may have difficulty starting the compressor.
    Instead of the Xantrex controller I'd go with the MidNite: http://www.solar-electric.com/mnsolar.html It's a better controller.

    So the biggest problem is that the heater will just plain use too much power and the second problem is that the one 415 Watt panel isn't going to recharge 600 Amp hours @ 24 Volts on even a good day. Really you'd need closer to 2 kW of array for that.

    As far as running the 'frige alone is concerned, you could down-size considerably to get around 2 kW hours of battery power, but you'd still need more panel to recharge (about 1 kW in good sun). Solar for back-up power is expensive and not very efficient. Maybe a few days worth of battery power and an AC charger for when the power comes back on (or use with generator) instead?
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: First Time Thread - Aftermath of Sandy

    just kicking my thoughts around on this. get the generator anyway as it will go farther right now than the solar install will. don't get me wrong as you can still get the solar and the more backup you have the better.

    there could be some problems with the batteries as they are used. you don't know the condition to say if they are a good deal.

    of course you know that the 415w is on the low side of being able to keep a charge to the batteries so should you use them it will take some time to recharge them. unstand about the other half, but plan on buying more pv later.

    if you plan on using such a large pv then you may need more than 4 z bracket feet to mount it. that pv would be huge and very heavy.

    i'll advise against the xw controller as adding another like pv would exceed its ability. you will want a controller in the 80a and up class. the fm80 and the classic are candidates and i'll recommend the classic. you can get the extra current ability you need from a classic lite for a few dollars more or opt for the regular classic with the mngp display for a tad more than what the fm80 goes for.

    if the ac power you plan on feeding into ac circuits at your main breaker panel for the utility you have to be careful to get a inverter than can be neutral and ground tied. not sure of that one, but read up on these and be very sure of this or your inverter investment could go up in smoke.
  • IanB22IanB22 Registered Users Posts: 6
    Re: First Time Thread - Aftermath of Sandy

    Cariboocoot - The panel is actually 48v by 8 ish amps. More specs below
    STC Power Rating 415W
    PTC Power Rating 370.9W 1
    STC Power per unit of area 14.9W/ft2 (160.3W/m2)
    Peak Efficiency 16.03%
    Power Tolerances 0%/+3%
    Number of Cells 96
    Nominal Voltage not applicable
    Imp 8.43A
    Vmp 49.23V
    Isc 8.95A
    Voc 60.4V
    NOCT 45°C
    Temp. Coefficient of Isc 0.0
    Temp. Coefficient of Power -0.41%/C
    Temp. Coefficient of Voltage -0.193V/C
    Series Fuse Rating 15A
    Maximum System Voltage 1000V

    I don't want to recharge the entire battery bank in one day. I want to charge it 'enough' to get me to the next day. However, this idea you have mentioned about not enough Battery to even run the fridge seems a bit off to me (and this is probably my fault) but,

    300 AH *24v = 7200 Watts
    Fridge Runs on 1500 watt's, How do you not get a chance to run the fridge for even one day? It would seem to me, I could run it for at least 3 days without power or solar and use only 4500 watts?

    On the Oil Heater, it looks like I am fudged (edited as it was too close to the real swear word. family oriented forum. this is a warning. niel) there. However, I see 1500 watts as the normal use for a heater, and that supposed to be per day, so again, I feel like this should still get me a few days?
    Maybe at this point, I should consider picking up more batteries, so they are ready for the emergency (maybe 4 more) to get to 600 ah at 50%?

    Also, surge on the Inverter is 3800 watts, and continues is 1500, I am sure it can run the fridge? What about it prevents it from running the fridge is it the surge?

    One last thing, the batteries I planed to run in 24v configuration for the 'better' efficiency.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: First Time Thread - Aftermath of Sandy

    The panel specs, other than Watts, aren't what determines the output from an MPPT controller. 415 Watts @ 77% efficiency / 24 Volts = 13 Amps. That's a 2% peak rate in bright sunlight on a 600 Amp hour battery bank. That's maintenance, not charging.

    You can run the 'frige, but not the heater and the 'frige; the heater would wipe out that battery bank in a hurry. What's more you will not be able to recover power with that little amount of panel. This gives you net deficit charging. You'd have four, maybe five days before the batteries are dead (assuming they are capable of their full 600 Amp hour rating, which isn't likely for used batteries).

    Save the money on the panel/controller. Buy a generator and good inverter/charger. Run the gen during the day to recharge, let the batteries handle the loads over night. You could even stay with 12 VDC and 2kW inverter to keep critical loads going.

    My opinion is that for this application the solar is a waste of money.
  • IanB22IanB22 Registered Users Posts: 6
    Re: First Time Thread - Aftermath of Sandy

    Cariboocoot - You just aren't any fun ;)...

    No, it's not you, it's surely me. I am not doing what I need to keep things going like I want on here (at least not yet). However, do I need to bump up to the 80 amp when I am running on 48v from the panel? I thought I could run at least 2 or even 3 more panels on the 60 amp because it is a 48v panel?

    This 10 day + plan is going to he double hocky sticks!
  • westbranchwestbranch Solar Expert Posts: 5,163 ✭✭✭✭
    Re: First Time Thread - Aftermath of Sandy

    With what has so far been posted, I think it is time to pull out (look up) the manual for that CC to see what its strengths and weaknesses are. Your understanding will improve greatly I expect
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: First Time Thread - Aftermath of Sandy
    IanB22 wrote: »
    Cariboocoot - You just aren't any fun ;)...

    No, it's not you, it's surely me. I am not doing what I need to keep things going like I want on here (at least not yet). However, do I need to bump up to the 80 amp when I am running on 48v from the panel? I thought I could run at least 2 or even 3 more panels on the 60 amp because it is a 48v panel?

    This 10 day + plan is going to he double hocky sticks!

    Charge controllers are rated in output current @ system Voltage. So a 60 Amp controller on 12 Volts can take 720 Watts input or on 48 Volts 2880 Watts (this is for an MPPT controller). (note-this wattage increase also holds true for a pwm cc as you go up in battery voltage as well. niel)
    The panel Voltage will be adjusted to suitable output Voltage. Two of those 415 Watt panels (830 Watts total) would put out about 52 Amps to a 12 Volt system, 26 to a 24 Volt system, or 13 to a 48 Volt system.
  • IanB22IanB22 Registered Users Posts: 6
    Re: First Time Thread - Aftermath of Sandy
    Charge controllers are rated in output current @ system Voltage. So a 60 Amp controller on 12 Volts can take 720 Watts input or on 48 Volts 2880 Watts (this is for an MPPT controller).
    The panel Voltage will be adjusted to suitable output Voltage. Two of those 415 Watt panels (830 Watts total) would put out about 52 Amps to a 12 Volt system, 26 to a 24 Volt system, or 13 to a 48 Volt system.

    Yeah, I agree with you about the controller matching the voltage of the battery bank. So from your calculations I guess one panel will put 13 amps through the controller. Then if I added 3 additional panels it would put 13 amps x 4 at 24volts to give a total of 52 amps at 24 volts. The mppt is rated at 60 amps so is that to close to the rating?

    That makes sense to me,
    Ian
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: First Time Thread - Aftermath of Sandy
    IanB22 wrote: »
    Yeah, I agree with you about the controller matching the voltage of the battery bank. So from your calculations I guess one panel will put 13 amps through the controller. Then if I added 3 additional panels it would put 13 amps x 4 at 24volts to give a total of 52 amps at 24 volts. The mppt is rated at 60 amps so is that to close to the rating?

    That makes sense to me,
    Ian

    Pretty much.
    Four 415 Watt panels would be 1660 Watts. Usually an array & controller will average 77% of the 'nameplate' on an MPPT controller, or 1278 Watts. Divide by system Voltage and you get 53 Amps peak potential. Your actual maximum may be higher or lower due to individual characteristics of the particular system. If you had "too much" panel on the controller it will just 'clip' the extra current potential; the 'extra' power would be lost. As in: a 2000 Watt array @ 77% is 1540 Watts / 24 = 64 Amps maximum current, but the controller would limit output to 60 Amps.

    What you would have to watch out for with those panels is the Voc. It's probably 56 or so, and if you put two in series the resulting string Voc would be 112. That would work even in cold weather (maximum Voc would still be under 150). But you sure couldn't put a third panel in series on the Xantrex controller.
  • stephendvstephendv Solar Expert Posts: 1,571 ✭✭
    Re: First Time Thread - Aftermath of Sandy

    Hi,

    If it's backup you're looking for, then a generator is almost a must-have solution. You can then build the rest of the system around the generator and then it won't be that important how big the battery is or how much solar you have. So you have a spectrum of option, on the one side you have just a generator, which means you need lots of fuel. On the far other side of the spectrum you could have an enormous battery with 4kW of solar, which means lots of initial cost which may not be used very often. And you have a whole range of options in between these two extremes where you can have almost any amount of battery and any amount of solar for supplemental charging as long as you're prepared to rely n the gen for the bulk of the charging.

    The key elements to bear in mind are that the inverter/charger (must have a charger too to work with the gen) you choose should be able to support the peak power draw you need. That fridge seems extremely thirsty and starting compressors requires a lot of peak power, to run a grid tied house without problems I think a 3kW inverter/charger is probably the minimum. Any amount of solar will then supplement the generator charging and you can slowly add more panels whenever you can. When I last checked, an MPPT charge controller only starts to become economical at > 600W of solar, for smaller systems it's usually more economical to buy off-grid panels designed for your battery voltage and a cheaper PWM charge controller.

    Since this is a significant investment it would be great if you could take advantage of it for the 98% of the year when you don't have power outtage. Outback and Magnum make reasonably priced inverter/chargers that can sell to the grid, so you could save on your daily electricity consumption by using your installed solar and selling excess. The one caveat is that as far as I remember the outback grid inverters are very picky about their generator input, so you'd have to choose an inverter/generator like the honda EU series. These are a good choice in any case because they're quite economical to power house loads.
  • IanB22IanB22 Registered Users Posts: 6
    Re: First Time Thread - Aftermath of Sandy

    Ok, I will get the generator, but isn't it possible to just use it to recharge the batteries, rather than run it into the grid-tie portion of the inverter?

    Also, on the charge controller front, I am switching to the MIdnite 250 lite. It will have the VOC to handle up to four panels this size and do a good job charging and monitoring the system. Anyone see an issue with this charger in my system?

    I am also considering a second panel of the same size to increase my solar to 830 watts.

    Grid tie is not on my list of must haves right now, but how not to waste my inverter purchase this time around? Maybe a Xantrex GT 2.8 Inverter, 2800W, Grid Tied? Then it has everything all in one box, and I don't need the battery charger? (Darn, just checked, and it appears there isn't any battery charging options with this inverter. There is no free lunch in solar huh!)
  • IanB22IanB22 Registered Users Posts: 6
    Re: First Time Thread - Aftermath of Sandy

    Ok, I think I have the final setup. Right now with the size of my pv array, and the money I would need to spend to tie into the grid to 'sell back' my electricity is silly. Its like 600-700$ more to get the grid-tie UL certified stuff off ebay from Outback to do the sell-back to the utility company idea. With the size of my PV panel today, it would take FOREVER to pay that off.
    When I get more PV watts in the future, I will change out my inverter to something that can be grid-tied, or just run certain appliances and electronics off-grid.

    Now, here is where I am at:
    1. MidNite Solar Classic Lite 250 MPPT Charge Controller
    2. (1) 415w Helios Panel (I can't add more than one, or the wife will get suspicious of how much this all 'really' costs)
    3. Tripp-lite APS2424 for charging/inverting 2400 watt, peak 4800, and 24v (There is one on ebay, then there is a new one too http://www.frontrowelectronics.com/tripp-lite-aps2424-inverter-charger.aspx)
    4. Classic Composition Mount
    5. Z-Bracket RV Mounting Feet (set of 4)
    6. 50 Foot MC4 Solarline 2, Extender Cable Male/Female
    7. MRCB 150 Amp DC circuit breakers with switch
    8. MidNite Solar 150VDC 15a Panel Mount DC Circuit Breakers
    9. MidNite Solar 150VDC 70a Panel Mount DC Circuit Breakers
    10. Midnite Solar MNEDC-Quad Enclosure for 1-4 Panel Mount Breakers
    11. Gas Generator to charge batteries when they drain down to low in power outage situation.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: First Time Thread - Aftermath of Sandy
    IanB22 wrote: »
    Ok, I will get the generator, but isn't it possible to just use it to recharge the batteries, rather than run it into the grid-tie portion of the inverter?

    Depending on what inverter you have, you can either use the built-in charger (if available) or a stand-alone battery charger. The inverter does not have to be GT capable and the gen would not be grid-tied in any sense; it's just that with a battery-based GT inverter the gen can be connected as a substitute for the utility AC which then allows it to provide power for all the house circuits as well as recharging batteries for the 'critical' loads (providing it has sufficient capacity).
    Also, on the charge controller front, I am switching to the MIdnite 250 lite. It will have the VOC to handle up to four panels this size and do a good job charging and monitoring the system. Anyone see an issue with this charger in my system?

    MidNite Classics are the best charge controllers available at this point in time. They can not communicate with inverters the way 'all Outback' or 'all Xantrex' set-up would, but that isn't really a big issue on a single controller/single inverter system.
    I am also considering a second panel of the same size to increase my solar to 830 watts.

    Grid tie is not on my list of must haves right now, but how not to waste my inverter purchase this time around? Maybe a Xantrex GT 2.8 Inverter, 2800W, Grid Tied? Then it has everything all in one box, and I don't need the battery charger? (Darn, just checked, and it appears there isn't any battery charging options with this inverter. There is no free lunch in solar huh!)

    Most grid-tie inverters do not use batteries; they simply convert whatever power is available from the panels directly to AC fed to the house/grid. For battery back-up GT you need one of the more expensive hybrid inverters like Outback's Radian or Xantrex's XW series or SMA's Sunny Island.
  • stephendvstephendv Solar Expert Posts: 1,571 ✭✭
    Re: First Time Thread - Aftermath of Sandy

    To add to what 'coot said your options for a generator + battery + inverter + charger are something like:

    1. Generator with dirty output (big variations in frequency and voltage) + dedicated battery charger + plain inverter. All power will come from the inverter so it doesn't matter that the gens output is dirty. You have to make sure that the inverter can handle the whole load.

    2. Generator with clean(ish) output + inverter/charger. Power will come from the inverter when the generator is off. When the generator is on, the inverter/charger passes through gen power to the load and charges the battery with excess power. The gen output should be fairly stable to not affect sensitive loads. The transfer between inverter and gen is instantaneous (for all practical purposes) and will be controlled automatically by the inverter/charger. A good gen with AVR should be fine (it's what I use), or you could spring for an inverter generator like the Honda EU which is a very clean output (what 'coot uses).

    3. Generator with inverter quality output + inverter/charger. As above, with the addition that you'll have good fuel efficiency through all the charging stages. With a non-inverter gen, they run less efficiently at low loads, like when you're doing the absorb phase of the charge.

    3. Gen with good quality output + grid tied inverter/charger (the hybrid inverters that coot mentioned above). You get all of the above + the ability to sell to grid. In addition to the Radian, you can use the cheaper and lower output Outback "G" series inverters, but then you have to use an inverter generator. The other hybrid inverter/chargers don't care so much about gen output quality, but is have to be at least "good", e.g. with AVR.

    I didn't know about the additional costs to go grid tie in the US, but there must be some way you can take advantage of that solar without having it go to waste for 98% of the year. Even if you don't feed anything back to the grid, if you got an inverter/charger that was large enough to cover your daily use then you could run your whole house of the system and use the grid to charge the batteries. This would act a bit like a whole house UPS system. How much you choose to use the batteries will be entirely up to you as you can just tell the inverter/charger to connect to the grid whenever you want. E.g. if the batteries are less than 90% full, then connect to the grid and charge the batts. With some inverter/chargers you can also tell them to connect to the grid based on the power draw. E.g. a 2kW inverter may be able to pass through 4kW of power through it's internal transfer switch. So if you have a 3kW draw, then inverter will detect it, close the switch and pass through the grid power. With this configuration you won't be selling anything to the grid, but you will be running off the solar you produce. And you'll have instant backup for power failures. As long as you're not selling to the grid any inverter/charger will accept the grid as input you don't need one of the hybrid inverter/chargers listed above.

    The system would look something like the diagram below, except that with only 1 AC input, you'll have to manually switch between grid and generator for prolonged power cuts. And you'd only have 1 AC out which goes to the house.

    Attachment not found.
  • stephendvstephendv Solar Expert Posts: 1,571 ✭✭
    Re: First Time Thread - Aftermath of Sandy

    ...don't know anything about that triplite inverter, seems a bit cheap. 1 year warranty. AFAIK a similar output will cost more than double, but give you a 5 year warranty and is used by many many off-grid users. Guess the triplite might be ok for purely backup use.
  • techntrektechntrek Solar Expert Posts: 1,372 ✭✭✭
    Re: First Time Thread - Aftermath of Sandy

    I followed the generator + battery + inverter route about 4 1/2 years ago for emergency power. First got the generator, 12 kw. Not happy with the dirty output and with the desire to keep the basics going overnight (quietly), I bought a server-room class UPS (4 kw) and a 22 kw battery bank. This also brought the benefit of increasing my overall efficiency since I could load up the generator while it ran and use the inverter more than just overnight. Remember - a standard genset is most efficient fully loaded, but it is best not to load it beyond 80% for longevity and surge reasons.

    The big genset was very expensive. The battery bank somewhat expensive. The UPS was cheap since they can be purchased surplus on Ebay. Would I do the same thing again? No.

    If I did it all over again I would buy a 2 or 3 kw Honda inverter-genset and a cheap 10 kw construction screamer. I need the big guy for my well pump and water heater a few hours per day. The rest of my loads would be handled by the inverter genset. Clean power, low fuel use overnight for the base loads, and quiet while running those base loads. Also cheaper than what I did the first time around and no batteries to maintain. I've actually done something similar already (see the link in my signature).

    Bottom line, for emergency power PV will be much more expensive to get the same functionality (wattage) as using generators - as other here have already said.
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
  • st2288st2288 Registered Users Posts: 9
    Re: First Time Thread - Aftermath of Sandy

    I just got a APC UTS6H Universal Transfer Switch. The beauty of this switch is it has dual input (Generator or UPS) in case there is a blackout. I will connect a Xantrex prowatt pure sinewave inverter to the UPS input and attach 2 deep cycle marine batteries. (I may buy two more later on) And then attach a MPPT charge controller to the batteries.
    Turn the breaker off the micro-inverter. Use the Y-cable for 2 or 3 panels and tie them parallel to the charge controller. This way I can use the solar during daytime (I average about 4kw hr during the blackout), and use a honda su2000i inverter generator at night. My panels are 200 w each. I am still not sure if I can do that. The worst case is run an extra set of cable to the PV. If blackout hits, I just disconnect the micro-inverters and connect the extra cable back to my charge controller.

    Once the gird comes back on, the APC transfer switch will auto switch back to grid. then I can shut down the inverter and charge controller. (using a boat battery switch) . Reconnect the micro inverter cable and Power the micro-inverter breaker back on.
  • Eric LEric L Solar Expert Posts: 262 ✭✭
    Re: First Time Thread - Aftermath of Sandy
    Once the gird comes back on, the APC transfer switch will auto switch back to grid. then I can shut down the inverter and charge controller. (using a boat battery switch) . Reconnect the micro inverter cable and Power the micro-inverter breaker back on.

    One thing to consider is that the batteries will still need a float charge between the times you use them for power outages (which I expect will be infrequent). Perhaps consider a small dedicated solar panel that you could connect to the controller during the times when the grid is up to keep the batteries in float. Make sure it's sized appropriately for whatever voltage your battery bank is.

    Also, if you go this route do occasionally partially discharge, cycle, and equalize the batteries to keep them healthy.
  • st2288st2288 Registered Users Posts: 9
    Re: First Time Thread - Aftermath of Sandy

    you read my mind.. I have a 20 watt panel i can use to maintain the batteries.
  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: First Time Thread - Aftermath of Sandy
    st2288 wrote: »
    you read my mind.. I have a 20 watt panel i can use to maintain the batteries.
    I reiterated in a post on your other thread that your plan is good as long as your PV's are functioning and something else doesn't get you.

    What I didn't post was that shortly after the electricity went out that the city sewers started backing up, because they didn't have electric to make the pumps function. With sewerage backing up into the house it wasn't a place you'd want to stay, the city left the water on, people used it and bingo a man made flood. In my case I installed a gate valve in the sewer line outside so I could cut them off next time. The point is, you have to consider many things to make your plans work, one flaw and your wasting your time.
  • st2288st2288 Registered Users Posts: 9
    Re: First Time Thread - Aftermath of Sandy
    I reiterated in a post on your other thread that your plan is good as long as your PV's are functioning and something else doesn't get you.

    What I didn't post was that shortly after the electricity went out that the city sewers started backing up, because they didn't have electric to make the pumps function. With sewerage backing up into the house it wasn't a place you'd want to stay, the city left the water on, people used it and bingo a man made flood. In my case I installed a gate valve in the sewer line outside so I could cut them off next time. The point is, you have to consider many things to make your plans work, one flaw and your wasting your time.

    I just picked up a 200 w panel. so I am good now.. no need to tap into my other PV /w microinverter...but I will try out one panel and see if I use the Y-cable just to test it out...
  • inetdoginetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: First Time Thread - Aftermath of Sandy
    stephendv wrote: »

    I didn't know about the additional costs to go grid tie in the US, but there must be some way you can take advantage of that solar without having it go to waste for 98% of the year. Even if you don't feed anything back to the grid, if you got an inverter/charger that was large enough to cover your daily use then you could run your whole house of the system and use the grid to charge the batteries. This would act a bit like a whole house UPS system. How much you choose to use the batteries will be entirely up to you as you can just tell the inverter/charger to connect to the grid whenever you want. E.g. if the batteries are less than 90% full, then connect to the grid and charge the batts. With some inverter/chargers you can also tell them to connect to the grid based on the power draw. E.g. a 2kW inverter may be able to pass through 4kW of power through it's internal transfer switch. So if you have a 3kW draw, then inverter will detect it, close the switch and pass through the grid power. With this configuration you won't be selling anything to the grid, but you will be running off the solar you produce. And you'll have instant backup for power failures. As long as you're not selling to the grid any inverter/charger will accept the grid as input you don't need one of the hybrid inverter/chargers listed above.

    A good description of the options.
    With US power prices, the cost of running everything through the UPS will be much higher than the direct cost of power, when you factor in the reduced battery life and resulting replacement cost. In addition to using more grid power for the same load power.
    Any system that shares your house loads between PV and grid using GT or hybrid inverter will have to go through the full grid-tie permitting process in the US even if you do not intend to sell back power, so you might as well go to fully interactive Grid Tie and reduce the cycle load on your battery bank, which will now be used for backup only.
    SMA SB 3000, old BP panels.
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