tips/tricks, how to get better with what i have

HunterDon
HunterDon Registered Users Posts: 4
Heres what i'm looking at

Current Equipment (in use)
2x 1000w Grid Tie Inverters (1000 watt max 22-60v input)
1x 260 watt panel (37.8v open, 30.7v rated, 9.01a short, 8.5a rated)
4x 90 watt panel (21.6v open 17.0v rated, 6.1a short, 5.4a rated)
Total of 620 watts

current setup:
4x90 to Inverter A (averaging about 1.20kwh/day)
1x260 to Inverter B (averaging about 1.00kwh/day)

the 4x90s are wired as a pairs in series to get them above 22v (21x2=~42) and then the pairs as parallel to inverter A
the 260 watt panel is direct wired to inverter B

currently, if i'm not running anything in the house, but the normal standby stuff, fridge, nobody home, etc... without solar i'm using on average 0.40 per hour (big fridge), with solar applied, that comes down to around 0.02 between 11am and 2pm, the current solar pretty much covers my base usage (of not really using anything) for some of the day, I'm happy with that. with that being said, if i were to add another 260 watt panel (parallel with the existing 260), those base usage hours during the day would be exceeded, taking the usage if it could to below 0, meaning the generated power would go to waste during that time as i do not 'sell back' to the utility.

the questions:
with that in mind, i would like to add just a bit of battery power along with the additional panel, and allow off-grid options
Considering this and the fact if grid goes down so do i, I cannot currently use the solar to power my house without the grid, i want to make it where i can work off-grid
can i use a charge controller before the grid tie inverter for battery charging,

and allow the batteries to feed the grid tie inverter for just a little bit each evening, after the sun goes down, to offset those hours and, be able to flip a switch or something, that lets me use the solar power off grid during the day and utilize the battery power at night (assuming grid is down). Ideally, i'm looking for something that is relatively easy, costs as close to nothing as possible, does not require a electrician, easily done by someone that is not an electrician.

i currently have about 280ah of 12v, so 140ah at 24v that i could start with, no, it wont last long, but i just want to get started and add on as i can

I also have 2 20 watt panels (16.7v, 1.2a) i 'could' use for charging the 280ah worth batteries.
also, have a SunSaver 10 and couple SunSaver 6 (i think)

i am also thinking of buying 4 245 watt panels (10V/30A) which would 
change to
4x90 to inverter A (retain 1.2kwh/day)
4x245 to Inverter B (hopeful of 3.5kwh/day)

move the 260 to a charge controller for my 24v/140ah battery bank, if the controller will handle 30Volts, if not I will switch out Inverter A instead, and change it to 12V battery bank, changing the 12v panels to parallel to the battery bank.

any ideas/thoughts on what i'm doing

Comments

  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Welcome to the forum Don,

    HunterDon said:
    Heres what i'm looking at

    Current Equipment (in use)
    2x 1000w Grid Tie Inverters (1000 watt max 22-60v input)
    1x 260 watt panel (37.8v open, 30.7v rated, 9.01a short, 8.5a rated)
    4x 90 watt panel (21.6v open 17.0v rated, 6.1a short, 5.4a rated)
    Total of 620 watts

    current setup:
    4x90 to Inverter A (averaging about 1.20kwh/day)
    1x260 to Inverter B (averaging about 1.00kwh/day)

    the 4x90s are wired as a pairs in series to get them above 22v (21x2=~42) and then the pairs as parallel to inverter A
    the 260 watt panel is direct wired to inverter B

    Guessing you are around Salinas, CA?

    What brand/model of GT inverters are you thinking of using? The ones that sort of match your specifications are not usually UL/NRTL Listed devices--And for a "legal" GT Installation, you would need both Building Department and Utility approval--Not likely to happen with your configuration (smaller solar panels may not be UL/NRTL listed either).

    Generally, in California, to setup for Net Metering (where you "bank" energy on sunny days for use a night, during winter and/or summer A/C seasons). You can connect up a "guerilla/rogue" GT installation and as long as you do not feed power backwards through the meter to the utility--It can work. If you feed excess power to the utility, the meter may "flag" the utility you have a solar install (not on file--they can pull your meter), or it may charge you for excess power you feed back to the grid.

    I will not encourage you to do an "illegal" GT install (and I would highly try to discourage you from doing this)--But I/we can answer general questions.

    There also have been some issues with "illegal" GT inverters--Some have been unreliable--Others have run hot/overheated (running risk of fire). There are also issues with "plug and play" GT inverters that are plugged into normal multi-outlet branch circuits.

    currently, if i'm not running anything in the house, but the normal standby stuff, fridge, nobody home, etc... without solar i'm using on average 0.40 per hour (big fridge) [do you mean 0.4 kW or 400 Watts?], with solar applied, that comes down to around 0.02 between 11am and 2pm, the current solar pretty much covers my base usage (of not really using anything) for some of the day, I'm happy with that. with that being said, if i were to add another 260 watt panel (parallel with the existing 260), those base usage hours during the day would be exceeded, taking the usage if it could to below 0, meaning the generated power would go to waste during that time as i do not 'sell back' to the utility.

    There are different meter configurations... Some will "not turn backwards" (free power to utility). Others that will actually "run forward" (charge you for feeding power to the utility--Sometimes call "revenue guard" to stop people that would install meters "upside down" for 1/2 a month). And, now with remote reading power meters--They can look for "reverse power" and signs of GT inverters to notify the utility that you are doing this (and you risk the utility pulling your meter).

    With most homes in California now having "smart meters"--It is much more difficult to "hide" un-permitted installations.

    However, I have yet to read any articles about utilities/building departments going after "illegal" installations.

    And even if you are able to sneak this installation in--There are significant fire and safety hazards to your home (inverter catches fire, possible overloading of house branch circuits with "plug and play" GT inverters, and other things like lightning/roof fire/etc.). For example (and this was a permitted/inspected install done with non-UL listed solar panels:

    http://forum.solar-electric.com/discussion/3375/panel-fire-question/p1

    Would your home actually have a fire from such an installation or have the utility knocking at your door? Probably not. Would you want to run the risk? Your-choice (and possible lost of fire & liability insurance coverage if the worst does happen).

    the questions:
    with that in mind, i would like to add just a bit of battery power along with the additional panel, and allow off-grid options
    Considering this and the fact if grid goes down so do i, I cannot currently use the solar to power my house without the grid, i want to make it where i can work off-grid
    can i use a charge controller before the grid tie inverter for battery charging,

    No--A standard GT inverter is designed with anti-islanding circuits--It turns off if the grid voltage/frequency fails.

    You can design a "hybrid" solar power system with a battery bank+Hybrid inverter (or pure off grid inverter)+AC transfer switch+a "protected" subpanel (run a few of your smaller 120 VAC loads when utility power fails).

    There are lots of AC inverters that can do some pretty amazing things out there--Or you can use a "pure off grid" inverter plus (manual or automatic) AC transfer switch (grid power when up, "fail over" to AC inverter power when grid fails). Lots of options (there are even some non-battery GT inverter options that will give you "some backup power" when the sun is shinning).

    However, Off Grid and Hybrid Inverters (Hybrid inverters can do both GT and OG inverter functions+battery bank) systems are not cheap and will not save you money (typically battery based Hybrid and Off Grid power systems cost 5-10x $$/kWH vs utility power (depends on where you live).

    Pure GT solar systems can save you money--But utilities are starting to change the regulations (along with State PUC) to make GT solar less cost effective (or non-cost effective such as Nevada did a few months ago). Utilities do not make money with GT Solar systems and Net Metering Plans. There are lots of rate payer/tax payer subsidies involved.

    and allow the batteries to feed the grid tie inverter for just a little bit each evening, after the sun goes down, to offset those hours and, be able to flip a switch or something, that lets me use the solar power off grid during the day and utilize the battery power at night (assuming grid is down). Ideally, i'm looking for something that is relatively easy, costs as close to nothing as possible, does not require a electrician, easily done by someone that is not an electrician.

    Batteries cost money to cycle and standard lead acid batteries only last ~500-2,000 cycles before you have to replace them (2-5-8 year life typical--depending on "quality of battery" and how you use it).

    It is almost impossible to save money with Battery + GT inverter systems and feeding power back into the grid. In some places (like California Edison--So Cal--It is "illegal" (un-permitted) to install hybrid battery equipped GT back-feed capable systems (in recent times, utility will not issue approval).

    i currently have about 280ah of 12v, so 140ah at 24v that i could start with, no, it wont last long, but i just want to get started and add on as i can

    I also have 2 20 watt panels (16.7v, 1.2a) i 'could' use for charging the 280ah worth batteries.
    also, have a SunSaver 10 and couple SunSaver 6 (i think)

    i am also thinking of buying 4 245 watt panels (10V/30A) which would 
    change to
    4x90 to inverter A (retain 1.2kwh/day)
    4x245 to Inverter B (hopeful of 3.5kwh/day)

    move the 260 to a charge controller for my 24v/140ah battery bank, if the controller will handle 30Volts, if not I will switch out Inverter A instead, and change it to 12V battery bank, changing the 12v panels to parallel to the battery bank.

    any ideas/thoughts on what i'm doing

    At best, you are getting around $0.15 to $0.30 per kWH (cost avoidance). Or $9 to something like $45 per month.

    If you want to save money, I would go on a conservation spree. Get a Kill-a-Watt meter (for your 120 VAC appliances) and/or a whole house meter (for whole house/240 VAC appliances) and figure out what your major loads are.

    And look into replacing older appliances (refrigerators, Air Conditioners), any electric heating devices (hot water, electric drier), etc... And look into adding a bunch of ceiling/air duct insulation/weather stripping/etc. (if you have an older home).
    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • HunterDon
    HunterDon Registered Users Posts: 4
    edited July 2016 #3
    yes, 0.40 kwh or 400 watts.
    the GTI is the plug and play style (Sun 1000g), i'm not trying to feed the grid, or sell back, or reverse the meter or anything like that, i just want to save where I can. i ran across a really good deal on the inverters (free, due to the other guy upgrading) and a decent price on some panels to get started.
    my costs are like 0.40/kwh in the upper tier
    I have a few kill-a-watt meters now, 2 are monitoring the grid-tie things. they only work with grid, so wont back feed, i would assume the power company doesnt allow it anyway. 
    most stuff is gas, except drier, which pulls like 4+kw when running, . i still have florescent tube lights, that i'm trying to replacing as possible. fridge is simply big, for its size it is energy efficient. 
    I have reptile, so some heat lamps that i'm trying to figure a way to get 200 watts worth of heat without using 200 watts, using probably 2.5kwh/day, I may put that on its own circuit and run as off-grid, its sounding like i might just want to try to put more circuits off-grid
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Obviously, a natural gas drier would be a help (depends on how much you use the drier--Our old house had an electric drier and did not run our bill up that much--We line dried most of our clothes and did not do that many washes).

    I was going to recommend trying heated rocks--But a quick web search shows that is probably a bad idea (burns, does not heat the air).

    You can plug your GT inverter into a Kill-a-Watt meter and it will log the power generated (as far as I know, a KaW meter is not capable of detecting direction of AC power flow--Just plug in GT inverter to KaW and meter will log kWatt*Hours through the meter).

    I have started using LED "tube" lamps (4 foot bi-pin tubes from Costco)--And they seem to work much better that standard florescent tubes (as bright, or brighter, start almost instantaneously, full brightness immediately). Even tried a few LED retrofit tube lights in existing fixtures. Working great (old fixture ballast may still hum). Have not measured power consumption to know if retrofit tubes use more/less/same amount of electricity. And the LED tubes should last longer (my house came with florecsent lamps on garage/shed lights which are turned on/off quite often--Bad for florescent lamps.

    I don't know anything about the Sun 1000 GT--It appears that some of the "good" Asian brand GT inverters seem to work OK.

    In general, if you are trying to save money, a Solar+charge controller+battery bank+Off Grid AC inverter will not ever save you money. The electronics can last ~10+ years and the batteries 3-8 years (depending on brand/quality of batteries you purchase). All told, OG solar comes to around $1-$2+ per kWH (at least one person here have gotten their costs down to $0.50 per kWH--But you have to work at that). Ruin one battery bank (over/under charging, forget to water, leave inverter on during winter/bad weather, etc.)--And your battery bank is toast. Most folks "murder" their first battery bank (in months or a year or so). A "cheap" battery bank (golf cart "training batteries") for your first off grid system is generally a good "investment".

    In general, conservation is a much better investment. Using less power saves money without additional costs (smaller solar power system + maintenance costs).

    The refrigerator--How large is it? The typical "efficient" ~17-20 cuft fridge is around 400-500 kWH per year (or ~1.1 to 1.4 kWH per day). 400 Watt*Hours per hour? 400Watt*24 hours per day = 9,600 = 9.6 kWH per day--That is a lot of power for any typical in-kitchen fridge (if I understand you correctly)..

    Even 200 Watts * 10 hours per day (heat lamps) ~ 2,000 WH = 2 kWH per day--that is also a significant load:
    • 2 kWH per day * 30 days per month * $0.40 per kWH = $24 per month
    I still would try to dissuade you from going Rogue GT inverter install (safety, legality)... If nothing else, try calling a solar installation company and get a quote--They are getting pretty cheap these days (even less if you go with the solar leasing option--not that I recommend leasing).

    What is your energy usage from your power bill (kWH per month)? Is it higher/lower by season (more drier use in winter, more fan/fridge/Air Conditioning use in summer)?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • HunterDon
    HunterDon Registered Users Posts: 4
    great BB, I was wondering about those LED tubes at Costco, those are like 7watts right? When i first looked at trying it, the guy at home depot said i would have to change the entire fixture. that particular lighting is the primary light source for the family room, just the way the house is designed, that's the closest lights, so they tend to stay on a LOT. and those are 3 fixtures, 2 tubes per, so 6X40watts or 240 watts on quite often, they are hard wired so difficult to put a KaW on them. but i'm sure changing those out would be good, 240 down to what 42, would certainly help, 
    i have small rocks in the terrarium now, he lays right on them, and he has other choices for where to lay at so i dont think the rocks are too hot for him.
    fridge is 26cube, it can hold 6 gallons of milk in the doors, its big, i was meaning my house 'at idle' uses about 0.40kwh, i think a lot of that is due to the fridge, also have a thing for those 5 gallon jugs that cools and heats the water. i figure with 3 xboxes/big TVs, computer and such, all in standby modes, still taking a trickle of electricity all contributes, the fridge being the most.
    no AC, the heaviest usage is in December, when the heater is on, i think that is the blowers actually, its a gas heater, typcial usage was about 600kwh/month, so around 20kwh/day tier pricing, the first 200ish is at like 20cents, then the next 100 is 30ish, everything above that is at about 40cents/kwh, 
    yes, i really need to do something about those heat lamps, I may consider your "training batteries" idea and do an off-grid solution for just the terrarium. which leads me to the next question? I am only suppose to use like max 20% of battery capacity, or something like that, so, if i have a battery bank of 280ah, is that saying I can only use about 55 of it

    I have a KaW on the GTI's thats how i know they are providing an average 2kwh/day

  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Costco sells both complete fixtures (tubes are not replaceable) and 4' bi-pin tubes (that appear to fit any standard bi-pin fixture, regardless of original tube diameter/rating). One caution--There are plastic bi-pin protectors that, when you pull them off, can pull the end cap and let you rotate the entire bi-pin cap (caps are held in by "spring pressure", not glued or heat sealed). You pull the end cap and rotate it back into position if you do that.

    From what I read, hot rocks can still burn the reptiles. And they will stay on the rocks if the "hot side" of the cage air is too cool (even if the rocks are too hot).

    If you do the math, many times, the 24x7 standby and "small" loads are a major portion of your power bill. Your 600 kWH per month is not bad (average or a bit below US average household power usage of 600-1,000 kWH per month):
    • 600 kWH per month * 1/30 days per month * 1/24 hours per day = 0.833 KWatt = 833 Watts average load
    So--Even at a 400 Watt "idle home" load (fridge should take near zero when "off", ~120 Watts with compressor running about 1/4 to 1/2 that time, and ~500 Watts when auto defrosting 1-2 hours every 12-24 hours per day--Do not disable auto defrost, after ~24 hours the evaporator will ice up). That is about 1/2 of your monthly power bill. Looking at standby loads can save you quite a bit of energy (modern appliances have much lower standby loads--I have an old stereo that runs 40 Watts standby and 80 watts turned on--Now that is on a switchable power strip). And computers systems can be real energy hogs too (desktop left on, Sat. Receivers and DVRs can take 25 watts each when "off").

    More or less, for flooded cell lead acid batteries, the math works out to 1-3 days of storage (bad weather) at 50% discharge (for longer battery life). The "optimum" (cost/performance) usually works out to 2 days of storage and 50% maximum discharge--Or your battery should be ~2x your average daily load (if this were a full off grid home).

    With a battery powered Off Grid Solar power system, you will (at best) about "break even" at your $0.40 per kWH rate (and most people run closer to $1.00 per kWH). In general, off grid solar only makes sense if you do not have grid power near by (or use so little power, that your fixed monthly charges are are the major component of your bill. My PG&E bill is now $10 per month for fixed electric charges--Was $4 per month not long ago. People that have seasonal cabins are now disconnecting from the grid and going solar because their monthly fixed bills are approaching $20-$48 per month in some regions now.

    Battery backed solar can make sense if you have unreliable power (some countries, or if you are at the end of the power line in a remote area). But unless you have 2+ week outages once or more per year, a genset usually is more cost effective (I have a small 1,800 watt genset and 20 gallons of fuel+stabilizer that I replace once per year--Honda eu2000i). I could never justify an off grid solar power system (last power outage that lasted more than 2 hours was >50 years ago).

    My emergency prep recommendations is to go "camping" (fuel stove, water storage/hot water heater, LED flash lights+batteries, battery powered radio, sleeping bags, dried/canned foods, etc.). In cities, if you lose power more than a few days--The cities may become unsafe (lost pumping for sewers, city will turn off fresh water to prevent sewer flooding, etc.). Cell phone/cable internet may be lost on power failure or after a few hours (small battery/genset backup utility backup, if you are lucky, for cell towers and cable systems).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • HunterDon
    HunterDon Registered Users Posts: 4
    yes, i calculated the usage, and found that, even if I am gone for a month, my usage will go into tier 2 (which is now like 28/29cents i think) in about 20 days (tier 1 is the first 200 hours) just at idle with nobody home.  the 0.40kwh usage figures, as i could easily tell that was the minimum hourly usage for months, nothing dipping below that hardly at all. it was in that range at times when nobody was home and/or a few hours overnight, that and, if i turn off everything, meaning everything that should be turned off if i am gone for the day,  and go look at my meter, its showing somewhere close to 0.400watts, 
    i agree, all my idle power usage is from the standby modes of everything, the fridge contributing the most to it. then the water cooler probably, then all the xbox/tv sets, then computer. router/wifi, i also have cameras taking a bit of power. reviewing the hourly usage from the power companies website, 
    our idea for power outage is camping also, i store bulk of my camping stuff for easy accessibility just for that reason. but now since i have solar, it would be nice to have basic power if grid is down. if i was to do any off-grid circuit, it certainly would not include my kitchen/family room lighting, and i'd probably need a small fridge to transfer stuff to from the big fridge. i also have a couple 7to14ah 'ammo can' power supplies that the batteries are charged via solar, for charging small batteries and phones and such, made for camping, but work for power outages too. i charge my kindle only with a goalzero guide 10 (7watt) panel, its never seen grid power.
    if you recall, a few years back we had the rolling outages, during those times power was out more than a couple/few hours at times. I'm city, and with all these unlicensed drivers never learning that hitting a power pole isnt very smart, we get those on occasion knocking out our power also, for those its typically more than a few hours too.