1st system. need suggestions.

toppertopper Solar Expert Posts: 113 ✭✭✭✭
K here we go.
Looking for a grid tied system with a battery backup.
Peak load approx 6KW. that is stove and dryer.Dryer will not be backed up. Stove may not be either.

After much thought and info from all of you, Wind power is out. SWWP scares me now. No helecopters or boomerangs allowed in residential either.;)

Looking at starting with 1-2 KW PV.

XW 4024 or 6048??? For some reason these XW's have caught my eye.
Outbacks?
which way would you go if given the choice? I need room to expand as time goes on so 24V or 48V?

Batterys? Trojans, Surret, Huge industrials, FLA, AGM, lead/Calcium(there are literally pallets of these things sitting for free. Are they worth it?)

Generators. Are hondas worth it?
I have seen numbers of people here talk about their ES2000s and nothing bad so far.

If given the chance to build it once and do it right, what would you buy and install.
Please spend my $$ freely while daydreaming.

Comments

  • BB.BB. Super Moderators, Administrators Posts: 29,883 admin
    Re: 1st system. need suggestions.

    Hate to sound repetitive--Know your loads (peak kW and kWH per day, by season, etc.). And conservation... Converter every heating source you can to propane or whatever alternate fuel (camp stove for emergencies, etc.).

    A 1,000 watts of panels for an off-grid/backup system may generate roughly 2-3kWH per day (depending on where you live, what the weather is like, etc.)...

    That would run one element on your stove for an hour maybe...

    Call it $10,000to $20,000 per 1,000 Watts of solar panels + inverter + battery bank + installation + backup genset + etc...

    Can you run an electric home (cooking, hot water, heating, A/C, etc.) on off-grid solar power... Yes--But be prepared to pay (very roughly) around $1-$2+ per kWhr you use for off grid power...

    A nice size for an off grid home is around 100 kWH per month (3.3 kWH per day)... The typical US home (depending on where you live and how you live) uses around 600 to 2,000 kWH per month... At $0.10 per kWH, that is not much money... At $1-$2+ per kWH, that is a heck of a lot of cash (this is assuming that your take all of your capital costs + battery replacement costs and divide it by 20 years worth of kWHr for the estimated power costs).

    The Xantrex XW system is very nice and many people here use it. The 6048 is probably the way to go (not that much more than the smaller units). However, batteries+panels are going to make the whole system fairly expensive.

    Do you have a location, an idea of how many kWH per month you want to run from solar, and an idea of how much you would want to pay to install such a system? Do you plan on this being a backup system for emergencies, a full grid tied system to reduce your power bills, or intend to go off grid and leave the utility behind?

    Generator wise, the Honda eu2000i is a nice portable unit for cabins and small homes as a backup genset---but it is not a replacement for an 1,800 RPM prime mover diesel/LP genset if you plan on 20+ kWHr per day of energy usage.

    What is your neighborhood like--can you run a genset for several hours a day (when needed) without having to hid from the neighbors (noise and fumes)?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • toppertopper Solar Expert Posts: 113 ✭✭✭✭
    Re: 1st system. need suggestions.

    In my mind, starting as a primarily backup system with a little solar to start with to offset
    I just don't want to start too small and run out of room for future expansion.
    ie: The price difference between a 4024 and 6048 is a mere $150.00-$300.00
    Batteries, well Double the voltage. Double the price. Spend it once and treat them well. They should last till I retire.
    Solar panels. Drop a couple G's a year and eventually I should have what I want.
  • BB.BB. Super Moderators, Administrators Posts: 29,883 admin
    Re: 1st system. need suggestions.

    It is sort of difficult to slowly add batteries--Old and new (and different model/brands of) batteries don't play well together...

    Peak power is one requirement for the battery bank (basically, a minimum of 600 Amp*Hours at 48 volts) to get grid tied system stable to sell at 6kW.

    The other issue is how much energy (KWH) you will use in a day (grid tied and off-grid). The more KWH you use, the larger the battery bank and more solar panels you will need... If this is for emergency backup power, you should plan on only powering they stuff you need rather than running the whole home as normal...

    Of course, you could run the whole home as normal, but that will dramatically increase your battery bank size and solar panels....

    If you want to do this in steps--Your better bet is to run with 600 AH battery bank (using less expensive batteries) and a backup generator (for longer term power outages).

    Then increase solar panels until you hit your requirements (GT and Off-Grid use)... In 3-7 years, you will need a replacement set of batteries and you can size the bank to your needs....

    You may choose not to increase the battery bank size beyond 600 AH if this will be for backup power -- rather than full-time off grid use... It will just force you to use the genset more if the outage lasts more than 24 hours and/or the outage occurs during bad weather.

    You can probably adjust the price of the system by a range of 2-4x depending on how you answer those questions.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: 1st system. need suggestions.

    topper,
    why don't you just forget the pvs and get the batteries and inverter that suit you now? you will have the full backup of the grid and then you can save for the pvs, controller, etc. you may even have a few $ to get maybe the controller and a few pvs now and you could hook it up, but i'd imagine the charge rate could be too low for bulk charging, but it could float it i'm sure. it would be easier this way as you can add pvs as you can afford them without hurting the battery bank with high loads during an outage or mismatching them by age later. remember the inverter has a charger in it and go for the 6048 as you indicated the need for up to 6kw and it's better when 1 inverter can fill the bill.
  • Ralph DayRalph Day Solar Expert Posts: 898 ✭✭✭✭
    Re: 1st system. need suggestions.

    3.3kwhr/day??!! That would be in an ideal world, starting from scratch with few amenities (in my opinion). I have lived off grid for 6 years and average 6-7kwh/day. The only off-gridders I know at Bill's suggested level of consumption won't make toast unless it's a sunny day, don't have a deep freeze unit, won't have a generator so Nov and Dec are scary!

    No disrespect intended Bill, but pure off grid with a generator backup/charging source (mine runs 100-150 hours per year) is easy to do at 7kwh/day. Over that and youre looking at a lot of pv or running a genset daily or weekly and that's too much.

    Ralp;h
  • BB.BB. Super Moderators, Administrators Posts: 29,883 admin
    Re: 1st system. need suggestions.

    Topper was looking for a Grid Tied backup up system, not a pure off-grid (at least as I understand).

    The 100 kWH per month was an aim point--I run around 200-250 kWH per month and I am on grid (but, I have natural gas for all my normal cooking/heating needs).

    The real question is how much power does Topper use today and how much does he want for emergency backup power.

    Running an electric stove and electric drier (I guess it is electric, not really clear--could be gas/propane)--and perhaps other electric appliances (hot water, heat, etc.)... Those are a lot of electric loads for an off-grid / emergency backup system with 1-2kW of solar panels and a 6kW inverter.

    Without knowing the total monthly kWH power used (or planned for an outage) and where the system will be installed--we really do not know how much battery/solar panels will be needed.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • icarusicarus Solar Expert Posts: 5,399 ✭✭✭✭
    Re: 1st system. need suggestions.

    Ralph,,

    You profligate waster you! 6-7 kwh/day! I don't make toast with electricity, even on a sunny day!

    I suspect as I keep at it, my loads will grow to near BB's estimate, but we are pretty exceptional ( not a compliment, just an observation) in what we use,, and we do make up for it by using a bit of Propane for the fridge(s) (freezers) as well as gasoline for the shops.

    I can't imaging living a "normal" life with under ~5 kwh day.
  • BB.BB. Super Moderators, Administrators Posts: 29,883 admin
    Re: 1st system. need suggestions.

    Topper also seems to be sensitive to costs (aren't we all) "...Solar panels. Drop a couple G's a year and eventually I should have what I want..." -- So, I would suggest keeping the system small/power use to a minimum to keep costs lower too.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • loreleclorelec Solar Expert Posts: 200 ✭✭✭✭✭
    Re: 1st system. need suggestions.
    Ralph Day wrote: »
    3.3kwhr/day??!! That would be in an ideal world, starting from scratch with few amenities (in my opinion). I have lived off grid for 6 years and average 6-7kwh/day. The only off-gridders I know at Bill's suggested level of consumption won't make toast unless it's a sunny day, don't have a deep freeze unit, won't have a generator so Nov and Dec are scary!

    I'm with Tony on this...don't make toast with electricity ;). I get by with probably a little over a kWh on the worst of days. And that's powering a computer, sat modem, radio, lighting, and an assortment of test equipment including soldering irons. The only thing I consistently use a generator for is pumping water, and usually keeping the batteries full once a week or so in the worst of the winter. During the summer months, the batteries are full by 11am, and remain in float all day long unless I happen to plug in a tool that really drags things down. I do use propane for all the "heavy" items (including the generator).

    Marc
  • icarusicarus Solar Expert Posts: 5,399 ✭✭✭✭
    Re: 1st system. need suggestions.

    You know,, I could get rich if I could build a nice automatic propane toaster. Mine is a catalytic Coleman heater that hasn't been made in years. ~6X8" rectangular,, just enough for two pieces of toast!

    I also have a butane soldering iron, and I have seen butane steam irons, and I have even heard of butane hair driers!

    Tony
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: 1st system. need suggestions.

    We have an electric refrigerator and a microwave and an electric toaster.
    We don't use the toaster unless the generator is running; it uses more power than any other single item, including the microwave and the 1 HP digester pump!

    Our system, described in my sig line, produces about 2.4 kW hours per day. It's amazing what ou can do with a little careful load managing. We are still way under 100 kW hours a month. About half that, in fact. (Unless I start working on something and use a lot of power for tools.)
  • toppertopper Solar Expert Posts: 113 ✭✭✭✭
    Re: 1st system. need suggestions.

    Ok. To answer some Q's as to my situation.
    I AM GRID TIED.
    Economics aside, yes I know it is expensive to "waste" power.
    I'm working on it. In any case, no matter the cost, it will eventually pay itself off even if it's 30 yrs from now. At any rate it is more of an investment like our home reno. We have put in $80k+ in the last year in eco refits. Insulation, HVAC, basement finally finished so the kids can run wild. Solar hot water is comming soon to help cut our gas usage and hopefully give us some additional winter heat.
    It all adds to home Equity. Our 80k investment has increased our home value by $110 000 easily (because I work cheap).

    At any rate the heart of any system is the batteries and inverter.
    ie. A Primary backup system.
    Approximately $3-5K for inverter.
    Approximately $4-5K for batteries.I was thinking of about 1000Ahr 24 volt or 500 ahr @ 48 volt. 20% DOD = 4800 watts less line losses. Enough to get by in a severe outage.

    Batteries and inverter I do not want to skimp on. I would like to size them large enough that I don't have to worry about out growing them and buying a battery bank and inverter twice.
    Grand total 10 K more or less.

    Solar is expandable at any time. As long as I start with enough to keep the batteries up. Say 1-2 KW I can always expand the array as time goes on. It is an investment.
    Even at 1-2 KW starting it's enough to cut my grid usage by 10-20%.
    In the mean time I can work on cutting power consumption.

    My ultimate dream would be to get off grid but I can't see it happening anytime soon. Learing to live without is a steep slope. In the meantime I have to get started and it's been a long time since I've done anything for ME.
  • BB.BB. Super Moderators, Administrators Posts: 29,883 admin
    Re: 1st system. need suggestions.

    Sounds like you are working hard on the conservation side of the equation... Very good deal.

    What kind of inverter are you looking for? You can get a pure Off-Grid inverter or you can get a Hybrid inverter that can do both Grid Tied and Off Grid power.

    With a small array--Even if you have a Hybrid Inverter, it may not make sense to go "Grid Tied" with all of the hassles (GT permits and utility approvals) until your installed solar array is >3,000 watts (just a guess--you need to do your own research for your area).

    And, if you ever go Grid Tied, normally it is a requirement that the system be installed by a licensed electrician/installer with all approvals. Also, usually that is the requirement to get the 30% Federal Tax credits and other local rebates/credits.

    Pure Off-Grid system, many times, are not eligible for rebates/credits--So it may be worth installing a large GT connected hybrid inverter+battery bank and small solar array just to get the credits.

    Sizing the battery bank really depends on the loads you want to support (or in the GT case, the size of the solar array and inverter power levels).

    Batteries tend to be the "expensive" over time part of the system... They not only consume power (loss in efficiency), they also require maintenance, and replacement (every 5-10 years or so).

    You could have a "large hybrid inverter" but wire it (for now) with smaller emergency backed-up loads and a smaller battery bank with an inexpensive battery bank--and 3-7 years later, install a larger (and better) bank, more panels, and transfer more loads to the protected circuit breaker box.

    I am still doing a lot of hand waving here--Really need to, at some point, talk real numbers... Depending on what you need--there are limitations to what can be done with which hardware. (remember to estimate how many square feet of solar panels can be installed on a south facing roof/ground mount--shading and/or non-south facing panels can severely restrict energy production).

    In the end, you will probably have to do several costed paper designs and see which is the best bang for the buck for your situation.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • toppertopper Solar Expert Posts: 113 ✭✭✭✭
    Re: 1st system. need suggestions.

    BB you got it on the head this time.
    I'm getting more interested in the XW series.
    I can grid tie(import only) if I should decide and avoid all the true grid tie bull with the power company. then any excess generation can be funneled to household loads (back-up panel) Back-up panel would supply all but the most severe power users.
    The stove, dryer, A/C, would all be dedicated to grid power only.(generator in the future)

    Hopefully my logic/understanding of the XW's capabilities are good.

    If not, speak your minds guys. I am here to get the flat out truth with no candy coating.
  • toppertopper Solar Expert Posts: 113 ✭✭✭✭
    Re: 1st system. need suggestions.

    Well I'm kind of a loser today.
    Our current usage is +/- 20KW per day down from 40+ ten years ago.

    If I only backed up our critical loads, I'd say max surge around 2-3 KW.
    My biggest Surge loads are the furnace's hot surface igniter, fridge, deep freeze and water heater's hot surface igniter. I got them all to fire at the same time a while ago and if memory serves I was just under 3 KW on my DMM.

    Constant usage of 300 watts with lights and TV on. If I unplugged all of our toys, we'd be down to near 0.

    Funny isn't it. 10 years ago it was myself and the Mrs. 40+ KW.
    Now 3 kids, 2 TVs 2 computers, lights always left on and only 20 KW. Something just ain't right here.

    Edit: In addition I have 630 sq ft of unobstructed roof. South facing but only a 4/12 pitch = 18.4*. The only shading I get is one spruce tree in late afternoon 3-4 PM
    in late fall/winter/spring.
  • BB.BB. Super Moderators, Administrators Posts: 29,883 admin
    Re: 1st system. need suggestions.

    Topper,

    I will give one caveat about what you are asking for...

    I do not believe there is any Grid Tied inverter (at least that I am aware of) that is capable of being setup to never back-feed the utility.

    The only way you can use the XW + solar panels would be to set it up to never do the Grid Tied operation but simply go to "off-grid mode" and run your loads from the battery bank + solar panels (and, probably from the grid via the internal battery charger).

    Not to say that the XW could not be factory programmed to have this function (and, this is a stretch that a Grid Tied inverter could be connect to the utility power but not need utility approval because it never back feeds the grid)...

    I know that the previous generation of SWxxxx inverters had a capability where you could program them to charge from solar then go off-grid and discharge the battery bank (to save grid power)--Perhaps the XW has a mode like this--you would have to read through the operations manual to find out.

    In any case, I am not sure that running an XW hybrid inverter to solar charge the battery bank during the day and discharging at night to supply the home is really cost efficient... You probably are looking at $0.15-$0.30 per kWhr because of wear on the battery bank (and early wear out) and costs to replace the bank... You can play with the costs and the energy shifted and come up with the figure for your installation pretty easily.

    Grid Tied inverters are just so much more cost efficient (pure GT or Hybrid + Battery Bank). The efficiency and the "virtually unlimited" storage capability of the grid vs the losses and costs of batteries---Make it very difficult to make a case for home based power shifting via lead acid batteries.

    Either go through the work to get the Grid Tied properly installed and approved... Or just build a nice emergency power system (basically a solar+genset powered whole house UPS) and leave it at that.

    If you ever get enough solar panels installed--then it may be worth getting Utility / Building Department approval for the GT connection/operation (but, the whole building permit process is usually a two step process; rough + final inspection--difficult to bypass that rough and just get a final several years later).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • toppertopper Solar Expert Posts: 113 ✭✭✭✭
    Re: 1st system. need suggestions.

    Thanks Bill.
    My understanding through reading the XW manual.
    With grid support enabled and Sell mode diabled, the XW will pass through power from the grid until XX preset battery voltage is reached. Then it would put the extra battery power to help support household loads on the backup panel.. Not to grid.

    Reguardless I guess I better go see the power company and see what permits are required. I've gone through one major electrical inpection already (Home Renos and complete basement) and passed, so it can't be that bad. Permits were only a couple hundred.

    Thanks for all the info.
    Research and knowledge is invaluble for all us nubees.

    Thanks again. I'll get back to you all when it all starts getting under way.
  • BB.BB. Super Moderators, Administrators Posts: 29,883 admin
    Re: 1st system. need suggestions.

    That is good to hear---Perhaps I confused pure Grid Tied inverters (no batteries and cannot throttle back output to prevent "selling to the grid") with the functions available in the XW...

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • toppertopper Solar Expert Posts: 113 ✭✭✭✭
    Re: 1st system. need suggestions.

    Well looks like I am in a 1 Year holding pattern.
    I've rethought everything. New plan. I will do an 8'X16" addition on the front of our house.(green house/ sunroom) south facing @ 180*. I can house an underground solar hot water storage tank, battery bank, and inverter as well as have room for all of our plants. We've grown into gardeners along the way. Love fresh veggies in the winter.
    At this point in time I have also decided rather than expanding slowly, Just do it once and be done...
    2-2880 watt arrays.
    Uniracks with 6" standoffs by easyrack
    2-4 position combiners
    2-Mppt Charge controllers
    1-XW 6048 inverter
    1-Inverter distribution panel
    1-System control panel
    1- remote gererator start controller
    24-L16RE-2V 1110 Ahr batteries
    1-Honda ES 2000 genset
    GRAND TOTAL: About $30,000. I have gotton quotes for 17-20K plus batteries.

    This is going on in my head right now but we'll see next year when I go for it.

    OK Time to beat me up. Thoughts and words of wisdom are always welcome.
    Thank-you
    Ken
    EDIT:
    As well this gives me another year to work on the conservation end of things.
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