sunsei 130w solar panels

homerramirez Solar Expert Posts: 102 ✭✭
I guys. I'm new to solar and this forum, so , knowing that the eficiecy of solar panels still is very shy considering the cost, I decided to gave it a try and purchased the following:

9 Sunsei 130w solar panels
3 Sunsei 100w panels
3 Sunsei 25Amp. charge controllers
1 Sun Force 30Amp. charge controller
1 Sunsei voltage/amp monitor
4 200AH ea. 12v NAPA AGM deep cycle batteries (Power Cycler).
1 1200w continuos 2400w peak Motor Trend MSW inverter

Do you guys know any thing about those Sunsei panels? are they any good?, before I got'em I'd tried to find reviews about it but couldn't found any, I been reading your forum and nobody mention the Sunsei brand, is there any reason why ?

I installed all those panels on my roof facing South with nothing blocking the sun exposure all day, I wired this array @ 12v paralell, this way how long will take to charge my battery bank ? is there any other better way to do this installation so it can produce the most electricity I can?

I'm not cosidering to connect or get off grid but alternate so I can run our 3 bedroom + livingroom tv's and or lights, you know, after my wife and I get off work and my 2 kids (12 and 13yrs.) get off school pus weekends and holidays.

We live in Van Alstyne Tx. ( 40mi. N Dallas, Tx.)

On this system it will not be refrigerator, microwave, washer or clothes drier,

How realistic I'm.?, or do I need more Batteries?.

any help is apreciated.


  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
    Re: sunsei 130w solar panels

    The easiest to figure out how much power, on average, you will get from your solar array is to use this solar calculator. Since you are using batteries and, I assume, probably an inverter, use a derating factor of 0.52 and enter your solar panel wattage in kWatts (1,470 watts = 1.47 kWatts).

    Picking Fort Worth, we get:

    Month     Solar Radiation
    (kWh/m2/day)     AC Energy
    (kWh)     Energy Value
    1      4.32          98        9.51   
    2      4.77          97        9.41   
    3      5.50          121        11.74   
    4      5.98          124        12.03   
    5      6.02          127        12.32   
    6      6.26          124        12.03   
    7      6.39          128        12.42   
    8      6.31          126        12.22   
    9      5.83          114        11.06   
    10      5.56          118        11.45   
    11      4.43          95        9.21   
    12      4.10          92        8.92   
    Year      5.46          1365        132.41

    Between 90 kWhrs per month to ~120+ kWhrs per month (or about 3 kWhrs to 4 kWhrs per day--assuming default values for a fixed array)...

    Battery wise, several ways of figuring out the best match for panel to battery capacity...

    One is to take between 5%-13% of the 20 Hour Rate battery capacity (below 5%, not enough current to charge the battery; above 13% you may "toast" your battery).

    (1,470 watts / 17 volt panels) * 1/0.10 = 865 Amp*Hours at 12 volts (assuming 10% in example).

    Another way is to look at how much power you can generate in a day, and multiply by 6 (3x for 3 days of no sun, 2x for 50% maximum battery discharge level)... Sizing for summer day of ~4kWhours per day (4,000 watt*hours per day):

    (4,000 watt*hours / 15 volts) * 6 = 1,600 Amp*Hours (rough value)...

    So--you can look at supporting a battery bank of ~800-1,600 Amp*Hour capacity (12 volt battery bank).

    Don't know anything about the panels or the controllers... But, your next solar charge controller should be a Outback, Xantrex, or some other MPPT type charge controller... Putting together several small PWM controllers is not really the most efficient (power and cost wise) way of doing things.

    The simple charge controllers you have purchased appear to be missing a Remote Battery Temperature Sensor and are probaby single stage chargers... Typically, your batteries may not last very long, and your batteries will not be accurately charged.

    Also, you have a very expensive set of AGM Batteries... I highly recommend either Trimetric (less expensive) or Xantrex (more expensive) battery monitors...

    AGM batteries are sealed, so it is difficult to know how well they are charged. A proper battery meter will take all of the guess work out of running your battery bank (and will probably save you, or others, from running your batteries dead and/or under discharging them).

    You should read a few of the FAQ's in our host's online store. There are FAQs for batteries, charge controllers, and such... Much more than I can type here in a short amount of time and space. Just look through the major headings and look for FAQ's down near the bottom.

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: sunsei 130w solar panels

    well bb has roughly figured out what you can produce with that system, but that has no bearing on what you use. you can use more, the same, or less than what the pvs produce for you. what you use depends on the appliances' wattage consumption and the time you use each appliance. conservation plays a big role in making many systems work and is good to do even without a pv system.
  • Windsun
    Windsun Solar Expert Posts: 1,164 ✭✭
    Re: sunsei 130w solar panels

    Aside from the fact that you probably paid too much for those, they are not UL approved for residential use. That is probably a main reason you have not heard much about them. They simply do not meet the specs that any of the major brand panels are required to.

    The Sunsei website shows almost no real specifications for them, such as actual output voltage and amps, so it is difficult to make any recommendations for upgrading your charge controller or batteries.
  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: sunsei 130w solar panels

    As I often say,,, do the math. Bill has "done the math" on the charging side. As Niel suggests,it is up to you to do a load calculations to see what you expect to use on an average day/week/month etc.

    I would suggest that you read all you can, both on this site, as well as other sources, about PV Solar. This will help you avoid the "Ready, fire, aim," syndrome that seems to suck so many in.


    PS. The fact that you couldn't (easily) find much information on the Sunsei hardware should be considered a warning sign. If the reputable, long term suppliers A: don't carry an item, and B: don't know anything about any given product take it as a sign that either the hardware is brand new and therefore one set of risk(s) or it is of substandard quality. Buyer beware!
  • homerramirez
    homerramirez Solar Expert Posts: 102 ✭✭
    Re: sunsei 130w solar panels

    Thanks guys, Yeap, all of you got it right, and I looked for the UL logo on boxes and there is none, I was told that this panels were made in Germany and sold thru canada therefore UL does not aplies for selling in Europe, canada or Mexico, I admit that I made the mistake of going too fast on getting my system started before winter beguin so, they are here, this panels while I first tested on short current gave me 22 amps. and and just a little over18 v, the controllers were made to be used with those panels by Sunsei and are 2 stage charge controllers PWM, I know that the outback controllers are one of the best in the market but at this point my main concern is the power inverter, this Chinase made Motror Trend start to scream for help after 3.5 hrs. of use and I know is not my batteries because the monitor reads 12.4, can you guys recomend any particular brand of pure sine wave, my wife will like to run couple loads on her Sears Kenmore 700 series (one Year old) clothes washer during peak full sunny hours, I know my MSW can't handle this load plus the MSW tend to over heat... any sugestions?;)

    By the way, this panels are sold By Amazon for 1,299.00 ea., I got'em new on the box for 600.00 ea.
    the charge controllers and minitor were free new still sealed on it's pakages with the exeption of my 30A. Sunforce from Amazon at 52.00 dlls.
    my invertor from Don @ $114.00, that's why I need to replace it.

    I have about 150 watts on CF lights aroud the house , a desk top computer and three 25 in. tv's, the comment about the washer machine is because my wife will like to try it. any recomendations on the power inverter?

    Thanks again
  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
    Re: sunsei 130w solar panels

    I have not used any of them... But I would start here (reading FAQ and reviewing Mfg.).

    And review this brand and their products.

    To a degree--how far do you need to go with this... Is this a full off-grid situation or are you "learning and playing" (not a bad thing) with your grid connected home...

    Short answer is that Grid Power and Conservation will be much cheaper in the near and far term than full off-grid solar ever can be...

    As a hedge against inflation--look at Grid Tied Solar as an alternative (not near as expensive per kWhr as you have no batteries, chargers, or replacements to purchase--plus you gather probably 2x or more useful power with grid tied vs off grid solar). Down side is that Grid Tied Inverters/connections are not allowed by all utilities.

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: sunsei 130w solar panels

    i do see one problem you can encounter due to all of your little 12v controllers and that is that you can't arrange your batteries or pv wiring for higher voltages that could save on losses and wiring costs. this also presents 12v only for use on any inverter and will have greater currents flowing, also presenting higher losses unless extra large wire is used to compensate. as i had mentioned before, you have to know what everything will draw for power or you can't even think of which inverter to get, assuming you want it all on one inverter. it is possible to split loads between an msw and sw inverter as the msw can power less critical items like your cfls. this would also take some of the loads off of your sw inverter possibly lowering the wattage you may need for it. to me that's not as much important to stay close to your usage as the inverter ratings should be much higher anyway for future uses and a buffer to allow for cooler operations of the inverter.
  • homerramirez
    homerramirez Solar Expert Posts: 102 ✭✭
    Re: sunsei 130w solar panels

    Hi guys ., well , yes we are grid connected, but it will be very naive to think that if we set up a grid tie solar power system we will get paid for selling it back to the power company, if someone does it , I bet they will still have to report to IRS as income plus a world of money sepent on inspections and meet local gov. restrictions, I'll not call it playing solar with our grid tie home, is more about being prepared, I rather try to be self reliable than expect any monetary return on a technology that has not improved after 20 yrs. of trying?, however most of us do it for the feeling of independence?.

    Going back to my Sunsei controllers, those 25 A. can be used on 12 and 24v., but since I do not want to get involved with the power company on this project, wiring my system to 24v will de-rate my battery bank from 800ah.@ 12v. to 400ah. for 24v., other than reduce the wire size and the use of only 2 controllers, I really do not see the benefit, I will need to buy 4 more 200ah. at the price of $260.00 ea. just to get the the same 800ah. or is there any other reason to wire at 24v.?

    I'd wired my solar panels (130w) paralell on sets of 3, just to be in the controller recomended range, I installed a 30a. fuse @ the combined wiring of ea. sets of panels and a 20a. fuse after each controller, this will keep my electrical components from causing any trouble, also, I grounded all panels with #8 awg wire (bare) to a separate from grid 8ft. ground rod. do you guys think this way is safe enough? or m'I missing something?

    On the power inverter, I think a 2500w. continuos 5000 peak true sine will handle our cloth washer, those Xantrex and Outback are very expensive on that wattage range for a guy on a budget like mine, is there any other good (aceptable) quality inverters at lower price?

    we been using our solar power system on weekends on a sunny days and everething seems to work just fine, with the exeption of my power inverter, I know Imust upgrade, any suggestions outthere?
  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: sunsei 130w solar panels

    You do know that if you double the voltage of a battery and half the amp hour capacity you still have the same amount of useable power?

    Volts X Amps = Watts Double one, half the other and the product is still the same.

    The advantage is of higher voltages is less line loss and the ability to use smaller wire gauges. I still encourage you to do some more homework.


    PS I think one of the previous posters point was that watt for watt, a grid tie system is less than half the cost of a battery based system. In the real world, if you are looking simply for long term preparedness a generator is much cheaper, and gives a much bigger useful bang for the buck. If you are worried about doomsday scenarios where the grid will be "gone for good" then your system is too small to give much benefit with out major reductions in the loads. If you are looking for a short to mid term power outage situation,,, a generator will, as I said,, give way more bang for the buck.

  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
    Re: sunsei 130w solar panels

    Remember power is:


    So, if you double V from 12 to 24 volts, I goes down by 1/2... With Amp*Hours, it is a bit confusing, because Volts is not part of the equation... But:

    P=800Amp*Hours * 12 volts = 9,600 Watt*Hours = 9.6 kWhrs of energy storage
    P=400Amp*Hours * 24 volts = 9,600 Watt*Hours = 9.6 kWhrs of energy storage

    So--from a simple point of view, both setups (24 or 12 volt) store the same amount of energy...

    However, looking at the energy you want to deliver... Say, you want to deliver 5,000 watts peak... All of that energy (plus some due to conversion losses--assume 85% efficiency for now) need to come from the battery bank:

    I=P/V=(5,000 watts * 1/85%) / 24 volts = 245 amps
    I=P/V=(5,000 watts * 1/85%) / 12 volts = 490 amps

    So, a 12 volt system delivering 5,000 watts peak would need wiring (and batteries) capable of delivering almost 500 amps for some 10's of seconds (i.e., a well pump starting load, etc.).

    A 48 volt battery system:

    I=P/V=(5,000 watts * 1/85%) / 48 volts = 122.5 amps

    So, just from a wiring point of view--it is a lot of copper to output 500 amps... A 48 volt inverter, on the the other hand, cost almost the same as a 12 volt inverter, but needs 1/4 the amount of current/wiring to operate at the same wattage.

    Typically, I would recommend to stay below ~100 amps for your wiring (wire, switches, etc.) are much smaller, and losses are much less... For a 12 volt system, roughly 1,000 watts maximum. For a 24 volt system, 2,000 watts max... And 48 volt system for larger installations.

    For example, self heating losses due to resistance go up with the square of the current:


    And voltage drop is much less of a problem with higher voltages (especially on longer wiring runs).

    The typical 12 volt device will turn off around 10.5 volts... or after a 1.5 volt drop in wiring.

    The typical 48 volt device will turn off at 42 volts--or a 6 volt drop... So, less current, and ability to operate with more of a voltage drop (due to wiring losses).

    Also makes it easier to find fuses and circuit breakers to make your system safe. (500 amp devices are not easy to find or cheap).

    And yes, true sine wave inverters are much more expensive than MSW type inverters... In many cases, people use a small TSW inverter for electronics, fridge, etc... And a big MSW inverter for well pump and other appliances. It is difficult to predict which appliances will work fine on a MSW inverter or need a TSW inverter for proper operation and long life.

    I gave a some links to units that have good reliability... And some of the more expensive ones may include internal battery chargers and multiple AC inputs (Mains, Generator) and auto-switch over in failure conditions (AC mains fail, switch over to generator, switch over to AC mains if batteries low, etc.--basically a large UPS).

    Regarding your grounding--check the NEC--but it may require a 6 awg solid wire for safety ground minimum (unless insulated?).

    Regarding selling back to the power company... I do that every day... I get between $0.09 and $0.30+ per kWhr with my 3.5kW grid tied solar system... I am paid retail up to the value of my yearly bill (I don't get paid actual cash, but I can cut my bill down to near zero -- actually about $6.00 per month minimum power bill).

    Not every power company / state support 1 year net metering (and I don't think that this is a good business for utilities--paying retail for electric power)--but it does happen for many people.

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • homerramirez
    homerramirez Solar Expert Posts: 102 ✭✭
    Re: sunsei 130w solar panels

    Thank you Bill & Tony, I did not know about dc voltage and some of the basic math since I work with most AC voltages ( 480/208 3ph. controllers, starters,strip heaters etc.) and understand that efficiency increses with higher voltages usually by 1/2, I did'nt know that also aplies to batteries. newby on this.

    said all this, my next steps is re-config. my panels to 24v., I also have a MSW 24v. power inverter, I bough it from EBAY @ $130.00 as spare, this inverter (Power Express, TM. 1200w cont. /2400 surge) claim to have SST technology, will that make it easy on our clothes washer electric motor?

    as you guys can see, I made the mistake that Tony always talks about it, ready, fire, aim. buying lower quality brands cost in the long run, so, I looked on EBAY today and there is a company that sell a Xantrex Pro Sine 2.0 (2000w cont. /4000 peak) charger/ inverter for $736.00 w/free catch? by Xantrex.....mmmmm, tempting.:roll:

    as suggested, I'm going to try the 24v. config.,and I probably get a Xantrex as money permits.

    Yes Mr. Tony, grid will always be cheaper, supply and demand is the only way to bring prices down, I forgot to mention that in my search for some sort of self reliance the first thing I bough was that cheap Motor Trend power inverter, then I purchased a small ETQ 4000 generator 3200 w cont. 120/240vac, even with the 11hrs. of running @ 50% load on 4 gal. of gasoline, grid still be cheaper, then I turned to sun...let's say, if I loose my job or get sick, it (might)come the time to choose between pay the mortage or pay the light bill, and keeping the house it will be priority #1, now we are getting more focus on conservation , something that we never thought before , and is a good learning lesson for our family, specially our early teen kids.

    The challenge is to make it happen without breaking the bank.

    what do you guys think about the remanufactured Xantrex, does it worth the try or is too risky? do you guys know about any techcnical flaws with the Pro Sine 2.0 ?....

    thanks again for your time.:D
  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
    Re: sunsei 130w solar panels

    The AC and DC voltage/current/power/etc. equations are all pretty much the same--without the complication of AC phases and phase angles. DC does have the issue of inductive kick (which can arc/pit contacts, blow electronic switches, etc. unless a snubbing cap/diode is added across the points).

    The big issue with DC is that it sustains arcs much better than AC... So fuses/breakers/switches are either rated for much lower values (max interrupt current, max voltage, etc.) or the DC devices are physically larger.

    A problem with anyone that tries to generate their own power (on-grid or off-grid) is stuff goes obsolete in 5-10 years and when the original stuff fails--a painful purchase and transition to the new products.

    If you can get the stuff really cheap (~10% of list price)--may be worth a gamble. If you are paying 50% or more (in my humble opinion) of list price (and no or questionable warranty support)--probably not worth the gamble...

    Looking at your generator fuel consumption... It is actually not easy to find a "small" genset that is very fuel efficient...

    The $500 5kW gensets can be pretty efficient at 100% power, but when you get down towards 50% of capacity and less--the fuel flow does not drop and you get terrible fuel economy...

    If you can reduce your power needs (conservation is almost always your #1 payback), the Honda eu2000i series is really nice (1,600 watts continuous--using spec. fuel consumption). Look at your fuel flows vs the Honda:

    ETQ 4000 (one spec sheet):
    3,250 watts * 50% * 13.5 hours / 4 gallons of gas = 5.48 kWhrs per gallon @ 1,600 watts--that is not bad.

    Your ETQ 4000 numbers:
    3,200 watts * 50% * 11 hours / (4 gallons of gas) = 4.4 kWhrs per gallon of gasoline @ 1,600 watts

    Honda eu2000i:
    1,600 watts * 100% * 4 hours / 1.1 gallons of gas) = 5.8 kWhrs per gallon @ 1,600 watts
    1,600 watts * 25% * 15 hours / 1.1 gallons of gas) = 5.45 kWhrs per gallon of gas @ 400 watts

    For me, I should be able to run my fridge/freezer and a few lights at 400 watts average... Lets me run on less than 2 gallons of fuel per day (and the Honda is really quiet).

    The larger generator probably still uses ~4 gallons per 11-13 hours even at 400 watts... So, for me, the fuel usage would be around 8 gallons per day (assuming 24 hours per day runtime)... 1/4 the fuel storage needed, or 4x longer runtime on equal amounts of stored food.

    My plan is to actually run my generator roughly 12 hours per day--just enough to keep my food cold/frozen and run a few lights in the evening--so down to ~1 gallon of fuel per day.

    But everyone's needs and situations are different.

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Moe
    Moe Solar Expert Posts: 60 ✭✭
    Re: sunsei 130w solar panels
    BB. wrote: »
    My plan is to actually run my generator roughly 12 hours per day--just enough to keep my food cold/frozen and run a few lights in the evening--so down to ~1 gallon of fuel per day.

    We ran both our refrigerators on our EU2000s for 9 days after Ike came through Ohio. Their compressors didn't want to start with the generators on "Eco-Throttle" so we ran without that. Each generator burned between 1-1/2 and 2 gallons per day, running about 4 hours in the morning and 4 hours in the evening with the refrigerator settings colder than usual (and powering a couple of lights, notebooks, and the DSL modem).

    We run about 1/2 gallon per four hours average every evening when boondocking with the Airstream... powering the converter/charger to recharge the batteries from vent fan use and to run 12VDC things like lights and water pump, while running 120VAC things like a small TV, microwave, and vacuum cleaner. The latter two start a little hard on Eco-Throttle, but work so we use it.

    You may want to "practice" with your generator before counting on small fuel use.
  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: sunsei 130w solar panels

    You haven't said, (or I missed it) how you charge the batteries. Why do you need a inverter charger like the Xantrex? How about this:

    The you could use a xantrex tc 20 or 40 for topping up the batteries from the grid or a generator.

  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Re: sunsei 130w solar panels

    One advantage Grid Tie gives you, VS batteries, is, that you can get FULL power from your PVs, all day long. (sun permitting) If running on batteries, you reach the end of Bulk charge (20 A) at noon, the rest of the day, you are only harvesting 4 or 5 A to top off the batteries. You can get really into it, by running your vaccum and washer at those times, but you may not complete you charge before sunset. Using Grid as your "battery" kicks the usefullness up a notch.
    Yes I read where you don't want grid tie, but I wanted to point this out.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    gen: ,

  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
    Re: sunsei 130w solar panels

    Thank you Moe,

    I don't really plan on 20 days on 20 gallons of fuel... I really plan on 5 days, then see what to do next... And have some extra fuel to drive out if possible (I presume, it will be the "big one" -- aka earthquake).

    Water and food are the big needs I plan for--electricity is just a nicety (our area is a temperate climate--and no big storms/winds/hurricanes/etc.). So far, we don't have any cyclical events (aka hurricanes, ice storms, hot weather AC/Power Failures) where it makes sense to plan for repetitive off-grid living--unless our state government is successful again and causes our power companies to go bankrupt again (and they are trying their darnedest again in Sacramento).

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • homerramirez
    homerramirez Solar Expert Posts: 102 ✭✭
    Re: sunsei 130w solar panels

    Hi guys, Tony has pointed out to charge my batteries with grid or generator, if I was to use grid, then why buy solar panels? top up the battery bank with a Xantrex 20 @ the price tag of $371.00 is painfull if I do not have a large enough battery bank, let's say, If I increase my bank to 1000ah. @ 24v how long can I run my refrigerator kenmore (2yrs. old )with an electrical rating of 4.50 amps @ 115v 60hz ?

    Instead Xantrex 20 , sice I need a true sine inverter, will it be the best to get the Xantrex Pro Sine 2000w cont., 4000w peak (inverter/charger) for $736.00 remanufactured by Xantrex?....

    Mike just described what's going on with my solar power system, by noon my batteriers start to float (4.5a) and if I start to use when in bulk my batteries might never get fully charged and this will reduce the life on my battery bank, is not a bad Idea to go fully off grid if I have to do it. but if someone help me to figure out what is the optimal battery bank for running my refrigerator it will be just great to run the generator just about 2 hrs running my refrigerator while fully charging my battery bank....

    Guys, please remember that this is on a no money to pay light bill situation, which I want to be prep. for.

    thanks for yout good advice, please reply.:D
  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
    Re: sunsei 130w solar panels

    Off-Grid solar is rarely going to be the solution to a "no money to pay the light bill" situation... Maybe for a few months, but as the seasons and years drag on, everything from a string of bad weather, to worn out batteries, softball sized hail, to unexpected hardware failure--something is going to eventually happen that will require more money than a $10 per month electric bill would have cost.

    Back to your question... You need to get a kill-a-watt meter and see now much power (average power consumption, and kWhrs per day/week/etc.) you will need.

    For the sake of discussion, assume your small "emergency" fridge uses between 1-2 kWhrs per day (~365-730 kWhrs per year--a full featured and/or older fridge is going to use more).

    Typically, the recommended battery bank allows for 3 days off-grid and 50% maximum discharge of the battery bank--for longer battery life. So, assuming 85% efficient inverter:

    2,000 Whrs per day * (1/0.85 inv eff) * 1/24 volts * 3 days * (1/0.50 batt dischrg) = 588 Amp*Hour battery bank (@24 volts)

    Typically, everything you can do to reduce power usage will be a big help... Shopping for a very energy efficient fridge will help both in an off-grid situation, as well as for day to day living/reduction in power bill.

    Take a look at the chest freezer conversion into a fridge--people get down to 0.5kWhrs per day with one of those (and they are very happy with how it works as a fridge).

    Anyway--the solar panel are generating ~1,365 kWhrs per year... At $0.15 per kWhr, that is only $204 per year, or ~$17 per month.

    A $700 inverter will give you over 3 years of "free power" vs what your solar panels are capable of producing.

    Don't get me wrong, I like to have some preperation for an emergency--but this is not a cost effective way to prepare for a shortage of funds type situation.

    Your entire solar panel output would run 1-2 fridges during the year (depending on season)---unless you get more efficient fridge or install more panel$, batterie$, inverter$, etc...

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • homerramirez
    homerramirez Solar Expert Posts: 102 ✭✭
    Re: sunsei 130w solar panels

    Thanks BB., so do you think my 24v MSW with SST, will not harm our refrigerator compressor or our clothes washer?
    how many more watts of solar panels and batteries do I need?
    thanks again.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
    Re: sunsei 130w solar panels

    Don't really know if your appliances will work fine or not with your inverter... Perhaps some others here have had experience with MSW Motor Trend inverter... Probably an 80-90% chance that all will work OK with MSW. There is also a smallish possibility that timers in some of your appliances (defrost timer on Fridge, cycle timer on washer) will not work correctly because of the MSW waveform (timers sometimes run at 2x speed because of the square wave from the inverter).

    Regarding how many panels do you need... You really need to measure your loads with a kill-a-watt meter (see link one of my earlier posts) and add them up.

    The fridge/freezers tend to be the bigger users (excluding A/C, electric hot water, electric heat, electric drier, electric stove... you get the idea). My washer takes about 250 Watt*Hours per load, and so does our gas drier.

    I also gave you the link and example of how much power your system produces per month (average)... You can add up all your loads over the month and see how the fit vs the production numbers I have supplied (or use the link to make your own calculations).

    For example, if you need 2x the power produced (180 kWhrs per month vs 90 kWhrs produced--then you will need to double your panels--or make up the deficit with a generator). For my home, the solar calculator was pretty accurate (mine is a Grid Tied system and I used the default 0.77 default derating because I don't use a battery or DC converter).

    Your system will probably work fine for you--if you keep your loads and expectations low via conservation. Depending on the weather at your location--there may be times where you will simply have to use a generator to make up for bad weather--if you want power.

    When using a genset--that is probably the time to run your larger, optional loads, like clothes washing directly from the generator rather than going through the additional conversion steps of AC to DC battery charger, charging a battery, discharging a battery, DC to AC inverter, to your load.

    If you expect to use 2,000 kWhrs per month to power your home's AC system--it can be done, but it will not be cheap.

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset