Solar Kit question?

msta999msta999 Registered Users Posts: 11
Hi, I'm new to this forum and to solar. Looks like a great forum with lots of info.

My question: I am building a 1200 sq ft home next summer and am looking at a 2000 watt system. I contacted Grape solar and this is what they recommended:

8pcs GS-S-250-Fab5
8pcs MC4 cables 15’
4pcs MC4 cables 1’
4pcs 15A Breakers
1pc MNPV6 combiner box
1pc Outback FP1-1
4pcs Outback 200Ah batteries
Haticon Direct mount racking

I have to admit, I am not really sure what I'll need as far as wattage. I am guessing 2K will work for me. 24Volt system
They told me: Based on your location, a single 100W panel mounted at 50 degrees to the south will generate about 346Wh/day in June and 64Wh/day in December.
Since the panels will be 250 watt, the shortest days should produce about 1360 Wh's a day, which I'm thinking I'll have to use a generator to keep the batteries charged.....but I am not really sure how to figure out how many Wh's I'll need per day.....can someone help me figure this out and what kind of loads I might not be aware of??
I am also considering DC powered refrigerator and freezer, which I read uses very little power.

Comments

  • waynefromnscanadawaynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: Solar Kit question?

    Welcome to the forum "msta".
    What you are thinking about is what many of the solar gurus on here refer to as "FIRE, READY, AIM". In other words, like you hinted at in your post, purchasing a system BEFORE you know your needs. Sellers of course will encourage any potential sale be completed as soon as possible.
    Re the DC fridge and freezer, there was a time when there was indeed a big difference between their consumption and the standard AC units. Today however, the Energy Star standard home units are very efficient and in my opinion you'd be much farther ahead to go that route and put the ton of money saved on an extra few panels. PLUS, when they have come to the end of their lives, you won't have to remortgage the house to replace them. Keep in mind though that added features like built in ice makers will drive up consumption considerably.
    I'm sure the resident Gurus will offer much more info and advice, so stay tuned. :D
  • vtmapsvtmaps Solar Expert Posts: 3,738 ✭✭✭✭
    Re: Solar Kit question?
    msta999 wrote: »
    I have to admit, I am not really sure what I'll need as far as wattage. I am guessing 2K will work for me. 24Volt system

    Welcome the forum.

    You're asking the wrong question. Its not about what you'll need for solar panel wattage. The MOST IMPORTANT (and most difficult) decision you must make is choosing your battery bank. Once that is done, the rest of the design of your system is really quite simple: Just buy enough panels, generator, and electronics to keep the batteries happy.

    In order to choose your battery (and system voltage), you must know your loads. You must know your average load, your peak load, the duration of your peak loads, and the time of day of your loads. You must be fairly precise about this... after all, engineering and design require precision.

    If you're not precise, you will end up with the wrong system for your needs. Sort of like buying a half ton pickup truck when you need a one ton truck (or vice versa). Buying the wrong truck (either too large or too small) is an expensive mistake and there is no way to convert one to the other. If you buy the wrong solar power system, you will be surprised to find out how little of it is usable when you redesign your system.

    Getting back to your loads... consider my situation... I built a system that requires load shifting. That means, as a practical matter, that I must do laundry or vacuum only when the sun is shining or the generator is running. The payoff is that my (expensive and always deteriorating) battery bank is half the size it might otherwise be. Do you plan to live like that? If the system you build is to meet your needs, you MUST know your needs. Precisely.
    msta999 wrote: »
    I am also considering DC powered refrigerator and freezer, which I read uses very little power.

    Wayne is correct about the DC fridge, with one possible exception... Conventional fridges need substantial inverters to handle the startup surge. If your system could get by with a much smaller inverter, except for the fridge, then a DC fridge might make sense.

    by the way, another load to think about is your water pump. Most conventional submersible pumps have huge startup surges and may be a defining factor in the design of an off grid system. Some folks have spent much extra for a soft starting, more efficient pump... the payoff being a smaller power system.

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • solar_davesolar_dave Solar Expert Posts: 2,356 ✭✭✭✭
    Re: Solar Kit question?

    Is the grid not available? Grid tie is much more cost effective.
  • msta999msta999 Registered Users Posts: 11
    Re: Solar Kit question?

    The grid is available, but it is powered by generators in the winter and runs over 55 cents a KW, cheaper in the summer. Not sure how stable it is. I think the power station is down by Valdez somewhere.
    Thanks for the info on the frig/freezer, I'll look into an efficient AC set.

    To determine the load, do I just read the wattage on the back of my items? I bought a tool to see how much an appliance is using, but I have to leave it on for 24 hrs to see what something uses in a day, otherwise it tells you what the item is using to run.
  • solar_davesolar_dave Solar Expert Posts: 2,356 ✭✭✭✭
    Re: Solar Kit question?

    Do they let you grid tie? That is the most cost effective method and no battery maintenance.
  • BB.BB. Super Moderators, Administrators Posts: 30,177 admin
    Re: Solar Kit question?

    A Kill-a-Watt type meter is popular here.

    Yep--Pretty much read the "peak" watts and run the meter for ~24 hours to get an estimate on your kWH per day usage.

    Of course, you can run longer/different times and convert to 24 hour energy usage:

    ABC kWH used * 24 hours * 1/actual hours used = EFG kWH per day

    So if you used 3.3 kWH in 54 hours:

    3.3. kWH * 24 hours * 1/54 hour measurement period = 1.47 kWH per 24 hour period = 1,470 Watt*Hours per day

    For DC loads, you can get a DC AH/WH meter like one of these.

    Or get a DC Current Clamp meter to estimate larger loads. However, just measuring current is a bit difficult if you have something that cycles (a refrigerator may run 15-30 minutes per hour, and longer in hot weather).

    You basically need to create a list of the power usage for each appliance/load:

    Name, Watt Peak, Watt average, kWH per day, PF (average power factor)

    You add all of the loads up that you use at the same time (i.e., clothes washer during the day, lights at night, refrigerator 24 hours x 7 days a week, etc., laptop computer, TV, etc.) and size your system to meet those needs.

    Of course, off grid power is expensive, so you need to pick very energy efficient appliances and keep the loads load. Note that 24 hour per day smaller loads can be as bad or worse than big loads (i.e., a laptop computer running 24 hours per day may use as much power as a full sized refrigerator, and a microwave used 20 minutes a day may use much less energy overall then either the computer or fridge).

    Just to give you some very rough idea of energy usage:

    1 kWH (1,000 WH) per day--LED/CFL lights, laptop computer, cell phone, water pump to pressurize home, radio, efficient TV.
    3.3 kWH per day--Add a full size refrigerator, well pump, clothes washer (you have to be very careful of energy usage)
    10 kWH per day--Almost a full/normal grid electrical system (add a microwave, washer/drier, more electronics, more computer usage, etc.).
    33 kWH per day (~1,000 kWH per month)--North American average home usage. Some A/C heat pump use, hot water from heat pump, etc.

    Each of the above systems is about 3x larger than the next--And ~3x more expensive to build. A 3.3 kWH per day system is something that many people can swing (cost, self install, maintenance wise). Larger systems are scary expensive and will give most people a heart attack.

    3.3 kWH per day system--Maybe USD$10,000 (very rough guess).

    The labels on the back of appliances are, many times, not very helpful for planning your energy usage.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • vtmapsvtmaps Solar Expert Posts: 3,738 ✭✭✭✭
    Re: Solar Kit question?
    BB. wrote: »
    You basically need to create a list of the power usage for each appliance/load:

    Name, Watt Peak, Watt average, kWH per day, PF (average power factor)

    Depending on your budget and energy lifestyle, you might consider the time of day that these loads occur... load shifting is a way to save on system costs. Also, are there any occasional, but large loads (shop tools, etc)? If so, you might consider running the generator for them, rather than super-sizing your entire system to run them.

    Do you know what you will be doing for water pumping?

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • msta999msta999 Registered Users Posts: 11
    Re: Solar Kit question?

    I just spent the last half hr/45 min (typing), answering questions and asking more, but the thread strings on this forum drive me nuts! so I try'd a different one and lost everything I typed! Why can't this forum be like all others on the net, just start with 1 (the first post) and go on from there! There are only 3 options: Switch to linear mode, Switch to hybrid mode and threaded mode.
    It's almost 2am now, so I'll try to retype everything again later.
  • ILFEILFE Solar Expert Posts: 364 ✭✭
    Re: Solar Kit question?
    msta999 wrote: »
    I just spent the last half hr/45 min (typing), answering questions and asking more, but the thread strings on this forum drive me nuts! so I try'd a different one and lost everything I typed! Why can't this forum be like all others on the net, just start with 1 (the first post) and go on from there! There are only 3 options: Switch to linear mode, Switch to hybrid mode and threaded mode.
    It's almost 2am now, so I'll try to retype everything again later.

    There are any number of reasons to cause you to lose your post. It could be your internet connection, gremlins in the software, whatever. Trust me, it isn't just vBulletin, which is a higher end forum software, by the way.

    Anyway, a suggestion would be to type it up in word, notepad, or other text editor. Perhaps one with an auto-save feature - although vBulletin will perform similarly for you. Anyway, then copy / paste your post into the text box and post the reply.

    HTH
    Paul
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Solar Kit question?

    when doing a reply it is better to do that in a word processor and when finished just copy and paste it into the space you are currently typing into for replies.

    i think what the guys wanted to know is if you have utility power at your place now or not and not necessarily if the power can be brought to your place with an expensive connection from a currently distant pole. if you have reliable utility power then go with a grid tie system. if the grid is unreliable then a hybrid system also known as gt with battery backup is good. only if there's no grid then an off grid system with batteries is warranted and makes reliance on a large battery bank more necessary.

    determine your daily consumption if you want an off grid system or if you need to determine capacities for backup power. the size of the inverter is determined by the max power consumed at one time and that includes surges.
  • msta999msta999 Registered Users Posts: 11
    Re: Solar Kit question?

    I plan on looking into a well after the house and shop it build. the two wells I know of, in the area, are 160 ft deep and very good water. I will probably start out with a holding tank and hauling my water to begin with, so it should take much to operate that pump.

    I had planned on using a generator for the big loads.

    If I can run a AC frig and freezer on solar, that would be ideal. I was planning on propane, until I found out they made DC ones. I’m going to look at what I can get.

    I am checking the watt usage and peak watt of devices, but I am trying to figure out what to take…..

    I just talked to a guy I know up there and the cost of power in the winter months, when they are powering the grid with generators, is 65 cents a KW. The grid is within 2 or 300 yards of my property and they would have to cross a highway.

    “Some folks have spent much extra for a soft starting, more efficient pump... the payoff being a smaller power system.” Thanks vtmaps, didn’t know there was such a thing. I’ll keep it in mind if I put in a well.

    I’m still having trouble trying to figure out what all to check. I think I’m missing a bunch of electrical devices, that I should be checking. Have to make a list, of mine and the girl friends stuff and a lot of stuff will only be used once in a while, so I'm not sure adding everything up is a good way to do it.....the blow dryer and the toaster won't be used at the same times....and so on.

    I do plan on have some kind of ventilation system to circulate the heat....I think. Seems like I'd have to get heat to the other rooms somehow. Would just leaving the doors open be good enough? There will be a up stairs that will be at least half the size of the down stairs. I don't think I would want all the heat to go up stairs, so.....have to figure that one out.

    I do have rough plans of the house. I'm going to take them to a pro so he can make sure I build it right and have prints to work off.
  • waynefromnscanadawaynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: Solar Kit question?

    Just a thought re "looking into a well after the house and shop are built", what are your backup water supply plans if after the fact you don't get a good water supply, truck water in? Not being sarcastic. In my part of the world it's required to prove you have water, as well as a properly installed and inspected sewage handling system before the building permits will be issued. And for good reason.
  • msta999msta999 Registered Users Posts: 11
    Re: Solar Kit question?

    No permits are required here, except for connecting my driveway to the DOT's road. Many in the area haul water, they have a water station at the fire station to get water.
  • jcheiljcheil Solar Expert Posts: 722 ✭✭✭
    Re: Solar Kit question?
    msta999 wrote: »
    No permits are required here, except for connecting my driveway to the DOT's road. Many in the area haul water, they have a water station at the fire station to get water.

    Curious as to where you are?
    Off-Grid in Central Florida since 2005, Full-Time since June 2014 | 12 X Sovello 205w panels, 9 X ToPoint 220w panels, 36x ToPoint 225w panels (12,525 watts total) | Custom built single-axis ground mounts | Complete FP2 Outback System: 3 x FM80, 2 x VFX3648, X240 Transformer, FLEXnet-DC, Mate-3, Hub-10, FW500 AC/DC | 24 x Trojan L16RE-B Batteries 1110ah @ 48v | Honda EU7000is Generator and a pile of "other" Generators | Home-Made PVC solar hot water collector | Custom data logging software http://www.somewhatcrookedcamp.com/monitormate.html
  • msta999msta999 Registered Users Posts: 11
    Re: Solar Kit question?

    There are lots of places like this in Alaska. they are in areas where there are no or little services.
  • msta999msta999 Registered Users Posts: 11
    Re: Solar Kit question?

    Has anyone delt with this company or kit?
    http://www.theinverterstore.com/5k-48v-80a-off-grid-solar-kit.html#

    looks like the inverter in this kit is a modified sine inverter....as I understand it, I should have a true sine inverter, if I want to plug in electronics....does that sound right?
    It is also about 2K cheaper than the 1st system I posted, but I have read some solar panels are not very good...don't know if that applies to these.
  • BB.BB. Super Moderators, Administrators Posts: 30,177 admin
    Re: Solar Kit question?

    I guess it is a "reasonably price" kit--If you look up the hardware.

    It is a 5kW @ 48 volt Aims MSW inverter--Only $700 or so. And it is an Aims 80 amp MPPT charge controller (don't know anything about it). Aims, in general, was well known around here for selling 12 volt 4-5 kWatt AC inverters--Which is very impractical and usually resulted in the inverters having difficulties meeting their specifications.

    In the end--You need to know your loads (how much, how long) and type (refrigerators, induction motors, etc., many times, do not do well with MSW inverters).

    Batteries are AGM--In some ways, AGMs are close to the ideal Lead Acid battery type. Very high surge current, no need to add water, much cleaner than flooded cell batteries. Down sides usually include, more sensitive to overcharging, may last a few years less than similar quality flooded cell batteries, and something like 2x more expensive vs flooded cell.

    Until you know your actual power needs and have gotten used to managing your battery bank, a large AGM back can be expensive if you make an "oops" taking care of them or if the bank is too small (or too big) for your needs.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • msta999msta999 Registered Users Posts: 11
    Re: Solar Kit question?

    I'm still working on figuring out the load, it is harder than I thought it would be. Some items I don't have yet.

    Thanks for the info.
  • BB.BB. Super Moderators, Administrators Posts: 30,177 admin
    Re: Solar Kit question?

    I forgot to say that was a 4-5 kW 12 volt DC input AC inverter.

    There is (was?) a poster from Hawaii here that used a lot Aims inverter for his fabrication operation--And he was very happy with them (used the higher battery voltage units).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • msta999msta999 Registered Users Posts: 11
    Re: Solar Kit question?

    Why would there be a problem if I bought something a little bigger than I need??
  • vtmapsvtmaps Solar Expert Posts: 3,738 ✭✭✭✭
    Re: Solar Kit question?
    msta999 wrote: »
    Why would there be a problem if I bought something a little bigger than I need??

    Are you talking about the Aims inverter? Usually its not a problem. The problem is the specs... there is no reasonable way to draw 5000 watts from a 12 volt battery... 5,000 watts at 12 volts is over 400 amps DC. What sort of cables and circuit breakers do you think can handle that current?

    I have no personal experience with Aims inverters, but I wouldn't trust anyone who told me that their 12 volt inverter can handle 5,000 watts. Also, I thought you wanted a true sinewave inverter.

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • msta999msta999 Registered Users Posts: 11
    Re: Solar Kit question?

    Due to the electronics, I was asking if I should have a true sine inverter, from what I read it sounded like that is the case.........

    The last link I posted should have been a 48 volt inverter. I don't think the first link had a 12 volt inverter, didn't want anything under a 24 volt inverter......I must be missing something....

    I did find a check sheet to help check the loads of different devices I should have in the house. I still have to send the plans for my house to an Architect to have him look at it, he can also tell me if I'm missing anything. Somethings I still have to buy yet, like the frig, freezer, gas dryer....those items, that I have now, I'm not taking.
  • vtmapsvtmaps Solar Expert Posts: 3,738 ✭✭✭✭
    Re: Solar Kit question?
    msta999 wrote: »
    The last link I posted should have been a 48 volt inverter. I don't think the first link had a 12 volt inverter, didn't want anything under a 24 volt inverter......I must be missing something....

    No, I was missing something... I saw BB's post but didn't check your original link. --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • BB.BB. Super Moderators, Administrators Posts: 30,177 admin
    Re: Solar Kit question?

    I should clarify--Yes the original Kit/AIMs inverter link was for 48 volt at 4kW MSW inverter...

    My comment was that AIMs had a lot of high wattage inverters at 12 volts--Which was not really a good idea and most people could not get rated output from BIG inverters on 12 volt battery banks.

    My fault.
    -Bill :blush:
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • msta999msta999 Registered Users Posts: 11
    Re: Solar Kit question?

    I figure I'll just wait till the house is built, then pick some of the appliances that use less watts, then build the solar system around the house....kind of like some said here. That way I don't have to worry about it till later. I will keep reading though, that should help out later.

    Thanks everyone.
  • phillipallisonphillipallison Registered Users Posts: 1
    Re: Solar Kit question?

    Where to buy online Solar Kit?
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