Newbie looking for help and tips on a complete solar setup

sargcj
sargcj Registered Users Posts: 13
Hello there everyone. I'm new here and I'll be straight forward, I'm no electrician, and I don't know much of anything about solar. I have been researching for the past couple weeks and have picked up on a few things, but I don't know nor understand much more than your basic electric stuff.

What I'm wanting to do:
I have a (mobile concession) business idea that I'm working on planning out. With this I'm looking to be self-reliant, completely off grid, or at least as much as possible...
I have been told that it is probably not possible to be completely self reliant on solar. The Idea I have for my system is solar, battery, and a hookup for a generator as a backup/failsafe and/or peak times for the whole system.

Like I said I'm not an electrician so I'm not sure about the voltage differences and whatnot. I have seen some trailers for this kind of stuff outfitted with all DC stuff and a breaker box that links to a battery that everything runs off of, and sometimes a generator is needed for some parts or to help out...

The Primary equipment I need to power are as follows:
(All equipment will be similar to what I'll be searching for, and the exact ratings may change slightly.)
Mini refrigerator/drink cooler - 115v - 220 Watts, 2.8 Amps
*Block Ice Maker (Motor) - 115v - 5.1 Amps
(Condensing unit) - 115v - 8.1 Amps
Shaved Ice machine - 110v - 10.6Amps (on full load) {This can also come with a DC Motor}
Soft serve machine - 208/230v - 20Amp
*Chest Freezer - 357Kw per year. (I can't find voltage/amp info)
Phone & Tablet 2 port wall Charger: - Input:100-240V 150mA ; Output:DC 5V 2.1A or 10W (Two ports share 2.1A)
Receipt Printer - Average 1.6 Amp. Printing, 0.1 Amp. Standby
Wifi router - 12v 1 amp

On top of the above equipment the trailer will/should have:
-Interior florescent lights 1-3 fixtures. Est. 200-300 watts. {Can be AC(spec listed) or DC}
-Water pump - 115v .5-1 amp {Can be AC(spec listed) or DC}
-Instant water heater - 10 kw, 240 v {Can be AC(spec listed) or DC}
*--Would swapping to a small water heater lower the energy usage here? It usually says these are power savers, but I'm pretty sure that is compared to a large residential/commercial water heater, not a small/mini one that I would be squeezing into the trailer.?
-AC Unit - 110v Cooling: 14-14.7 Amps Heating: 16 Amps {Can be AC(spec listed) or DC}

(Some totals, assuming I did it correctly)
110v Amp total: ~26.6
115v Amp total: ~19.75 (Minus those I could not find Amp ratings for.)
208/230v Amp total: ~20
240v Amp total: N/A
+ a little headroom for good measure/other outlets if possible.

*Note: The Block maker/freezer, and the chest freezer may be interchangeable, such as I'll have only 1 and not both. Also the totals I figured up don't take this into account.

Limitations:
The trailer will be likely be a 6x12 or 6x14ft, and It needs to be fully/easily mobile. Most of the space I plan for solar would be the roof of the trailer. However some of the side windows that open while open for business will be upwards and may be potential space for smaller panels.


Notes about the trailer/business:
I will have a "home" spot where I take part in general/every day business, but I will also be at many of the local/regional events and fairs in my area that take place every year.
So If I was close to powering but needed an extra panel off to the side, as long as it is somewhat easy & quick to pack/unpack for moving that would be fine.


I really want to find a way to make this work. If it simply can't, then it can't, but I'm a hard headed person and I really want to find a way to be solar powered and mobile. If I can get at least 75% power from solar, that is enough to start out with and I would be satisfied with that, but my ultimate goal would be 100% Solar/Solar charged battery.

I will keep researching electricity/Solar, and my business, but I greatly appreciate any help, tips, etc you all could provide me. Maybe I'm not searching the right things or whatever, I just hope you fellas can point me in the right direction for my research, since I doubt there is a simple straight forward answer.

Comments

  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
    Re: Newbie looking for help and tips on a complete solar setup

    Welcome to the forum. I wont directly answer your question, however I suggest you go to a Honda, or similar, vendor that sells inverter generators and find out the size of generator you need to run you trailer an then look at the cost of a solar system to provide the equivalent power. I am sure you will be amazed and possibly dumbfounded at the costs of the 2 alternatives. My opinion is that you may end up with a hybrid of both.

    HTH
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Newbie looking for help and tips on a complete solar setup

    Welcome to the forum.

    Bought your equipment yet? Don't be surprised if the actual power any of it uses is far different from the specs given. This is why its a good idea to use a Kill-A-Watt meter and measure the power consumption for real.

    Your loads can be divided into two groups: 120 VAC and 240 VAC. No matter what little variations the specs say, these are the North American grid Voltage standards. That one machine at 208/230 sounds suspiciously like it is either 3-phase (big trouble) or European (another problem) power standard.

    Without doing the fine math, this looks like a whopping big power user. You've got motors, you've got refrigeration, you've got heaters. You couldn't ask for a worse mix for off-grid powering. The other missing number is how long these power demands go on, as you have to come up with a Watt hour amount to supply.

    Let's go at it from the other direction: you've got 6 feet by maybe 14 feet to fit panels in. That is not going to be a lot of panel (think 5' x 3' or thereabouts) even with monocrystaline (most efficient, most expensive). You might get 1000 Watts in that space. In terms of Watt hours AC on a battery-based system that would be roughly 2kW hours (with some variation based on length of day and quality of insolation). Most likely the solar could help keep the batteries up, but probably could not run the whole deal. Inevitably you would end up plugging in to grid power overnight to recharge.

    Again the missing number is the time factor. If we could rationalize some quantity of Watt hours it would be possible to pick a system Voltage (24 or 48 in this case due to the high demand items) and size a battery bank. Then we'd know how effective any panels might be.

    As a rule, solar electric power is pretty expensive especially in its off-grid form. Think $1 per kW hour. I wouldn't abandon the idea just yet, but it is necessary to work out a few more details. The solar panels on the roof could be a merchandising help, if nothing else. Just don't tell anyone you plug the trailer in at night to really recharge. ;)
  • sargcj
    sargcj Registered Users Posts: 13
    Re: Newbie looking for help and tips on a complete solar setup
    Welcome to the forum.

    Bought your equipment yet? Don't be surprised if the actual power any of it uses is far different from the specs given. This is why its a good idea to use a Kill-A-Watt meter and measure the power consumption for real.

    Your loads can be divided into two groups: 120 VAC and 240 VAC. No matter what little variations the specs say, these are the North American grid Voltage standards. That one machine at 208/230 sounds suspiciously like it is either 3-phase (big trouble) or European (another problem) power standard.

    Without doing the fine math, this looks like a whopping big power user. You've got motors, you've got refrigeration, you've got heaters. You couldn't ask for a worse mix for off-grid powering. The other missing number is how long these power demands go on, as you have to come up with a Watt hour amount to supply.

    Let's go at it from the other direction: you've got 6 feet by maybe 14 feet to fit panels in. That is not going to be a lot of panel (think 5' x 3' or thereabouts) even with monocrystaline (most efficient, most expensive). You might get 1000 Watts in that space. In terms of Watt hours AC on a battery-based system that would be roughly 2kW hours (with some variation based on length of day and quality of insolation). Most likely the solar could help keep the batteries up, but probably could not run the whole deal. Inevitably you would end up plugging in to grid power overnight to recharge.

    Again the missing number is the time factor. If we could rationalize some quantity of Watt hours it would be possible to pick a system Voltage (24 or 48 in this case due to the high demand items) and size a battery bank. Then we'd know how effective any panels might be.

    As a rule, solar electric power is pretty expensive especially in its off-grid form. Think $1 per kW hour. I wouldn't abandon the idea just yet, but it is necessary to work out a few more details. The solar panels on the roof could be a merchandising help, if nothing else. Just don't tell anyone you plug the trailer in at night to really recharge. ;)

    As to the first reply, a hybrid would be fine to start out, but I'd like to go as much solar as I could get (and afford).

    To the 2nd reply, thanks I can tell you're very knowledgeable about the subject. Part of the off grid system is to not have to worry about ever having to find a plug-in. I would like the capability to go virtually anywhere, which is why I wouldn't mind a solar/battery/generator hybrid system. But I would like to get as much as possible on the solar end because that will help save on gas/electricity in the long term, and reduce the emissions/noise issues that are generally related to a generator.

    In relation to the voltage ratings: I thought those were the standards, but the listings had me sort of confused, so I listed the specifics just in case. (That was actually from an email I sent.)
    For the oddball, here are two similar models with what looks to me like options for the electrical hookups. If someone would check these PDFs out and let me know I would be very thankful.
    1: http://www.dvorsons.com/taylor/softserve/pdf/taylor_152.pdf
    2: http://www.dvorsons.com/taylor/softserve/pdf/taylor_161.pdf


    And no I haven't bought anything yet. I'm a very detailed/know it all kind of person when I buy stuff, I do in depth research in just about everything I buy, especially on something I haven't bought before such as this. I'm currently just working on learning about it and how to plan for the system and what I can do in reality.

    All the cooler/freezers will likely be run at basic power level 24/7 for the storage of drinks, ice, etc. The rest will pretty much be on-demand use, but I do understand that there is always some "stand-by" power consumption if it is plugged in.

    I can guesstimate that the Lights, AC, & gen. electronics such as the IPAD PoS system, printer & cash drawer, wifi setup, etc will run from 5-12 hours(I can set the smaller electronics on a strip and cut the strip off when not in use to conserve power). I don't know if that really gives you anything to help, but I figure it is a start.

    I won't be open 7 days a week, at least not starting out. I'm considering focusing on a Wed-Sun or Tue-Sat sort of schedule, The longest days I would say would probably be 10am to 10pm, with most days ranging from 9-11am to 7-9pm. I figure peak sales will likely be sometime between 2-6pm. I have realy only grazed the top with my research on the business itself as well.

    Back on calculating a good estimate, would you know of any good sites online to help me with this? I'm a full & half(1.5) time college student + work + research & planning for this business which will take 4-6 months easily, so I'm pretty busy and don't get the chance to get out for hands on/real world stuff as much as I wish too.

    I really appreciate your help with this. Also Part of my business is to be unique from the others in my area, I'll have an Ipad PoS system, wifi via a mobile carrier, and I want solar to be a big part of it to work with the "green" fad that is going on and because it is really a useful and handy(and even money saving over time for some) technology that seems underused in my area.

    Edit: Another question came to mind that I had not thought of yet. How tough & durable are most solar panels? Do they take damage easily? (I live in east tn and while we don't get bombarded with heavy hail and tornado very often, we do get occasional hail, and sometimes it can be pretty severe and damaging.)
  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
    Re: Newbie looking for help and tips on a complete solar setup
    sargcj wrote: »
    As to the first reply, a hybrid would be fine to start out, but I'd like to go as much solar as I could get (and afford).
    that is why I suggested you price out a generator and compare to a solar equivalent system, watts vs watts and Kwh vs Kwh

    sargcj wrote: »
    I can guesstimate that the ..... will run from 5-12 hours.
    One of the errors we are all guilty of at some time or other is overestimating the amount of PV (solar) and underestimating the loads.. Use hard numbers, dig them up or be generous in their estimation...ie use the maximum you guess at.

    What you are looking at will cost big time so you want to do it right. Members here are very cost conscious, possibly considered cheap at times, but we also want PV to succeed when it is the best/right way to go... we will try to steer you in the right direction, the choice is up to you.

    hth
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • sargcj
    sargcj Registered Users Posts: 13
    Re: Newbie looking for help and tips on a complete solar setup
    westbranch wrote: »
    that is why I suggested you price out a generator and compare to a solar equivalent system, watts vs watts and Kwh vs Kwh



    One of the errors we are all guilty of at some time or other is overestimating the amount of PV (solar) and underestimating the loads.. Use hard numbers, dig them up or be generous in their estimation...ie use the maximum you guess at.

    What you are looking at will cost big time so you want to do it right. Members here are very cost conscious, possibly considered cheap at times, but we also want PV to succeed when it is the best/right way to go... we will try to steer you in the right direction, the choice is up to you.

    hth

    Sounds like I should fit in pretty well then :D

    And When I'm doing stuff like this that I don't or can't get hard numbers on I always over-estimate on purpose. It can have its drawbacks, but I understand that. In other situations I'm very conservative for the same reason.

    I appreciate the direction/guidance 110%. The person I was emailing trying to talk and learn about solar from hasn't been very fast nor very forward about some of the problems I could have with working out a system, even if it is hybrid, so I'm happy so far what what help I have been given.
  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
    Re: Newbie looking for help and tips on a complete solar setup

    If you haven't already done so, avail yourself of the wealth of information in the postings on this site, you can pick up a lot of background info so that you can ask more detailed questions as you gather your info.
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • sargcj
    sargcj Registered Users Posts: 13
    Re: Newbie looking for help and tips on a complete solar setup

    I have been working on that when I can. You have a couple of suggestions related to Watts/Amps/Volts to help me in figuring up the usage? or even an external site that is a good source?
    I have been searching and will continue to do so, I just have found sometimes my search results aren't the best on forums.
  • Caveman
    Caveman Solar Expert Posts: 83 ✭✭✭✭
    Re: Newbie looking for help and tips on a complete solar setup

    I am new to this as well and am hoping to get an education. Looks like a good site!
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Newbie looking for help and tips on a complete solar setup

    Okay, I looked at the links for those units. They have me confused. The Voltage and frequency seem to be wrong-way 'round. Over here the standard is 240 VAC @ 60 Hz. In Europe the standard is 230 VAC @ 50 Hz. The only guess I can make is that the ones listed for 208-230 VAC @ 60 Hz are designed so that they can be used in a commercial establishment where 3-phase power may be available (but they would only tap 1/3 of the supply of course). I note the first link indicates a 120 VAC model available. This may be a better choice all around.

    Since all you can do is estimate power usage *shudder* work up the Watts each item takes and multiply it by the number of hours it will be used to get the Watt hours for each item. Then total the lot to see how many Watt hours you may need in a day. This number will be almost as accurate as taking a wild guess. :roll: BUT if you have a generator on hand you can make up for any nasty surprises that may come along.

    Solar panels are made with tempered glass, but it's still glass and they are still fragile. They don't like hail, that's for sure. Being able to cover or remove them in the event of a storm would be good. In fact you may want some additional panels that are mobile; many RVers use such a set-up so they can park in the shade and get power from the sun. You might have additional 'swing up' panels on the side of he trailer, for instance.

    BTW, this stuff is expensive. I know it's been said, but really it is. Think $1,200 just for panels, $500 for a charge controller, better part of $1,000 for batteries, and near $2,000 for an inverter-charger. That doesn't include a lot of little bits in between and is based on a fairly small power need (about 2 to 3 kW hours per day).
  • sargcj
    sargcj Registered Users Posts: 13
    Re: Newbie looking for help and tips on a complete solar setup

    Yea I saw that one second and decided to include it. I saw one showed a 240 or ??/240 on one of them then the other had a 110 or 120 option as you mentioned. the 110/120 would be best, but then I gotta go and see about finding one for a reasonable price in the real world. hah!

    As for figuring up the amounts, I just started working on that a short bit ago. Excel is such a handy piece of software, I'm sure I use it daily!

    I ran across something earlier talking about different types of equipment, I think it was on a calculator on the honda generator site. But anyways, it mentioned that some equipment have a high start-up power use, but then remain at a relative steady and lower power usage, such as freezers. Should I get as detailed as possible and try to figure up start-up power every x hours, or is there an avg % I could use to add and round all the watt ratings to help figure that in without too much trouble? And just to clarify,the watt rating is for 1 hour right? Because that seems to be implied.?

    As for the idea about swing up panels, that is awesome. I was thinking of some sort of collapsible thing(like a canopy of sorts) I can pull up in front of my serving area to be extra panels and a shady area for a sunny day... Though I have no clue about how to manufacture something like that, nor the hassles that may be involved with some setup/rig of such nature.
  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
    Re: Newbie looking for help and tips on a complete solar setup
    sargcj wrote: »
    And just to clarify,the watt rating is for 1 hour right?

    all useage should be referenced in Watts per hour.

    So 10 watts of use for 1 hour is stated as 10 Whr(s) (Watt hours) , or .010 Kwh (Kilowatt hours), for 2 hours it would be 20Wh
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • sargcj
    sargcj Registered Users Posts: 13
    Re: Newbie looking for help and tips on a complete solar setup

    You lost me a little bit. haha.

    I was asking if the watt rating you see on equipment specs is considered that watt hour? In other words, can I take that(The listed rating), turn it into KW and add everything up to the my hourly KW (roughly) use? Is that what you said, or just related to my question?
    westbranch wrote: »
    all useage should be referenced in Watts per hour.

    So 10 watts of use for 1 hour is stated as 10 Whr(s) (Watt hours) , or .010 Kwh (Kilowatt hours), for 2 hours it would be 20Wh
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Newbie looking for help and tips on a complete solar setup

    AC induction motors, such as used on refrigeration compressors, have nasty start surges. This does not make a big difference in the over-all Watt hours (there should be enough margin in the capacity to account for it) but it does place demand on the inverter size and battery bank capacity. Unfortunately you aren't going to find any numbers on it. Other than buying a very expensive Ammeter capable of sampling fast enough to catch this momentary current spike there just isn't any way to get it. So we estimate on the basis of the running Watts and application. The same size motor allowed to start against no load will draw much more current when it has to start against the load of a water pump or compressor.

    Watts is Volts * Amps and as such is a moment-by-moment reading. The quantitative power unit is the Watt hour: one Watt used for one hour or any mathematical equivalent.

    If you work the margins in the right directions the systems work. If you try to cut everything to the minimum you get disappointed. So figure the loads will be larger, the battery capacity smaller, the sun light less than expected. If you calculated, say, 1845 Watt hours daily use you'd round that up to 2kW hours. If the battery bank size works out to 197 Amp hours @ whatever Voltage, you size that up to the nearest available unit. That determines how large an array you need, and again it will come out to some number that isn't manufactured so you buy a bit more panel just to be on the safe side.

    No one ever regretted buying too much capacity, but many have cried over too little.
  • sargcj
    sargcj Registered Users Posts: 13
    Re: Newbie looking for help and tips on a complete solar setup

    Great help/info...
    I sent you a pm about helping me fully understand, but it doesn't show anything in the Sent.
    However, I found a paragraph that explained WPH, WH and Watt. I think I understand. In non-electrician terms (as to the meaning of the words) can you use watt hour as watts in an(or per) hour? If so I think I understand. Because in the example when it uses the actual Watts Per Hour, its talking about a change. But it uses Watt Hour, and gives an example of a 100 watt rated light bulb and says it is 100 watt hour(s).

    I apologize if I'm over complicating it or just simply not getting it xD.
    Watts is Volts * Amps and as such is a moment-by-moment reading. The quantitative power unit is the Watt hour: one Watt used for one hour or any mathematical equivalent.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Newbie looking for help and tips on a complete solar setup

    Got your PM and replied.
    For those of you playing at home .. :p
    Watt is a rate. A 100 Watt bulb uses 100 Watts while it is on. If it is on for an hour it uses the quantity of 100 Watt hours. If it is on for 30 minutes it uses the quantity of 50 Watt hours.

    There really isn't such a thing as "Watts per hour" because that is a rate-rate. Like saying miles per hour per hour.

    And for those who like the extended edition ...

    The base rate is Amperes (Amps). This differs from Watts in that the Voltage factor is not included. Therefor Amp hours is not a full quantitative amount whereas Watt hours is. Watt hours are thus equivalent, but Amp hours are not because the full amount of power needs to be expressed with the Voltage factor.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Newbie looking for help and tips on a complete solar setup

    Commercial food preparation requires a heck of a lot of power... Fryers, toasters, ovens, grills, hot water, coffee/hot drinks, etc. that can be powered by propane should be powered by propane (which you may not want to do for various reasons).

    For a portable setup--Electricity should be only that required that you cannot work without (computer, register, lights, fridge, etc.) and get down to the minimum amount of power you can use--If you want to use solar power.

    Here is an old thread for a person in Hawaii that wanted to do something similar:

    Battery Bank to Power Lunchwagon's Mobile Kitchen


    Regarding how rugged solar panels are--They are just like your single pane windows mounted on the roof of your home/trailer (they are tempered 1/8" glass--but still not "bullet proof" by any means). They are also large sail areas--So if you have a down gust and use fold out "wings/awning" type panels to add solar generation--You would want to calculate wind loading too (or may need a civil engineer to do the calcs).

    Regarding hail--Golf ball or smaller, can be OK... Larger, call your insurance company,

    Solar panel
    damage from hail storm


    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • sargcj
    sargcj Registered Users Posts: 13
    Re: Newbie looking for help and tips on a complete solar setup

    First, thanks for those links, I'm reading over them now.

    Secondly, I'm not prepping hot food, Its a mobile shaved ice/ice cream & snack vendor. So I don't think I will require AS MUCH power as the fella in that one link. My equipment was listed in the first post, although the specs are iffy on those.

    I will offer shaved ice, soft serve ice cream(the oddball machine in the first listing of equipment) cold drinks, and snacks/candy (Candy bars, occasional brownies or doughnuts that I'll probably get from a local bakery, stuff like that)

    And thus far in my spreadsheet my instant water heater is the biggest killer, but it is also an on-demand application too.. So I may throw some of that stuff out and plan for a smaller setup and see what of that I can put on solar and go from there.

    And I'll def. have insurance so thanks for that tidbit, actually thanks for everything. :)


    BB. wrote: »
    Commercial food preparation requires a heck of a lot of power... Fryers, toasters, ovens, grills, hot water, coffee/hot drinks, etc. that can be powered by propane should be powered by propane (which you may not want to do for various reasons).

    For a portable setup--Electricity should be only that required that you cannot work without (computer, register, lights, fridge, etc.) and get down to the minimum amount of power you can use--If you want to use solar power.

    Here is an old thread for a person in Hawaii that wanted to do something similar:

    Battery Bank to Power Lunchwagon's Mobile Kitchen


    Regarding how rugged solar panels are--They are just like your single pane windows mounted on the roof of your home/trailer (they are tempered 1/8" glass--but still not "bullet proof" by any means). They are also large sail areas--So if you have a down gust and use fold out "wings/awning" type panels to add solar generation--You would want to calculate wind loading too (or may need a civil engineer to do the calcs).

    Regarding hail--Golf ball or smaller, can be OK... Larger, call your insurance company,

    Solar panel
    damage from hail storm


    -Bill


    As to the below, I think understand now, but how does that relate to the power equation/formula you mentioned earlier?
    In other words, if you use the highest Amp rating and volt rating to get watts, is that just the Watt rating or watt hour?
    Also From what I'm kind of getting, the standard rating is convertible to a "single" watt hour(100 watt light bulb = 100 watt hours; for 1 hour it uses 100 watts.), or so in a sense anyways. In your PM example I understand that, and the watt hour is what I'm looking for.
    Also on the Amp part, the ratings on most things are simply amps, not amp hours.
    Got your PM and replied.
    For those of you playing at home .. :p
    Watt is a rate. A 100 Watt bulb uses 100 Watts while it is on. If it is on for an hour it uses the quantity of 100 Watt hours. If it is on for 30 minutes it uses the quantity of 50 Watt hours.

    There really isn't such a thing as "Watts per hour" because that is a rate-rate. Like saying miles per hour per hour.

    And for those who like the extended edition ...

    The base rate is Amperes (Amps). This differs from Watts in that the Voltage factor is not included. Therefor Amp hours is not a full quantitative amount whereas Watt hours is. Watt hours are thus equivalent, but Amp hours are not because the full amount of power needs to be expressed with the Voltage factor.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Newbie looking for help and tips on a complete solar setup

    The snow cone machine will probably not use that much energy... If you use a lot, there are DC servo motors that can be a lot more energy efficient (approximately 1/3rd less energy vs a brushed motor, and probably even less than a typical induction motor).

    Just as an FYI--The major tool manufacturers are now offering brushless motors for their cordless tools (here is a Makita link about their brushless motors).

    Freezers--I assume you are going to have a storeroom/large freezer where everything is "pre-cooled"--And if it is industrial/commercial type, you can probably cool well below 0F and your portable freezers won't run much (if at all) as long as they are shaded from direct sun.

    In the end, you have two paths to choose from:

    First, would be to measure all of your loads in actual conditions (use a genset or grid power, and a Kill-a-Watt type meter--or other type power meter if you need 120/240 VAC). Then we can size the system based on usage, amount of sun (and season), and array.

    The other would be to calculate the maximum practical size of array (sq.ft., $$$$), estimate how much battery/power such an array would support--Then that gives you your electrical power budget--And you have to shoehorn everything into that budget.

    The hot water heater--Electrical on demand/instant type water heaters are not very practical for homes (they draw huge amounts of power and cause dimming/flickering light issues for many homes).

    So--You are either left with a tank style RV/under stink water heater (still not great for a small off grid solar power system). Or a hybrid tank water heater (basically heat pump integrated into the water heater)--Which while 2+ times more efficient, is still not very practical for a smaller off grid / portable power system.

    Is propane hot water out of the question? There is solar thermal, but even that is probably not practical for commercial use without backup (propane/etc.) hot water source.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • sargcj
    sargcj Registered Users Posts: 13
    Re: Newbie looking for help and tips on a complete solar setup

    I was actually just researching some water heaters... Due to the space constraints I would like an instant style or a very quick heating mini tank water heater.
    I ran across some suggestions pointing towards propane, but I'm not sure it it would be better due to the facts that I'll need to run lines for the propane and find a place to store the tank as well. However the electrical versions use a lot of electricity.

    As for freezers, I think I decided my block maker will likely be at my house, which will also serve as an office since it will be a mobile business. With that I can have the chest freezer. It is suggested for the best results of the ice to let the ice sit at I think it was 8-12 degrees. I may or may not put candy in there for overnight storage. The main use of the freezer is simply to hold the blocks of ice I will use throughout the day. I won't be using any industrial freezers at the house though, with the exception of the block maker of course.

    I will have a freshwater tank, a gray water tank, and either a small tank hot water heater or and instant. The only reasons I need hot water that I can really think of are for cleaning/dishes and to pass local health codes. (I'm looking into those, apparently the local health dept's website is useless for commercial information.) So it likely won't be a heavy user, but I will require hot water.

    And before I forget the shaved ice machine has a dc option. I think part of the my original question was the 120v vs DC style equipment and what would be better, but I wasn't exactly sure how to ask it and put it into context with the rest of the post at the time.

    Info on the shaved Ice machine I'm looking at if you're intersted: http://shaved-ice.com/southern-snow-machine.htm
    the DC motor is a 12v option that adds a little to the upfront cost. But if it would warrant it and I could tie it in to a hybrid system with some AC components that would work too if it would be better. As I mention that I want to say that some of the stuff such as the lights, AC Unit(I think) and various other equipment do have DC options.

    Edit:
    Also I want to mention. If I take out the Block Ice Maker and instant water heater and use a chest freezer, based on the specs I could find I have a peak usage of ~6.5KW.(I threw in an extra 500 watts in the core calculation that came to 6.4, before is 5.9) That is everything running at once, and I used the max/peak usage on equipment that listed it, such as the shaved ice machine. My estimated 24hr is at: ~104KW, with some as 24 hour, and others at 12 hours constant running. Realistically, I would hope it wouldn't be quite that much, but I could be way off target here.

    Easier to read form:
    As is currently:
    KW:5.984
    24hr total: 97.128KW

    With 500watt extra for good measure & Rounded up:
    KW: 6.5 (6.484)
    24hr total: 104KW ( 103.128 )
    (Note: I have adjusted/changed some equipment from the first post.)

    BB. wrote: »
    The snow cone machine will probably not use that much energy... If you use a lot, there are DC servo motors that can be a lot more energy efficient (approximately 1/3rd less energy vs a brushed motor, and probably even less than a typical induction motor).

    Just as an FYI--The major tool manufacturers are now offering brushless motors for their cordless tools (here is a Makita link about their brushless motors).

    Freezers--I assume you are going to have a storeroom/large freezer where everything is "pre-cooled"--And if it is industrial/commercial type, you can probably cool well below 0F and your portable freezers won't run much (if at all) as long as they are shaded from direct sun.

    In the end, you have two paths to choose from:

    First, would be to measure all of your loads in actual conditions (use a genset or grid power, and a Kill-a-Watt type meter--or other type power meter if you need 120/240 VAC). Then we can size the system based on usage, amount of sun (and season), and array.

    The other would be to calculate the maximum practical size of array (sq.ft., $$$$), estimate how much battery/power such an array would support--Then that gives you your electrical power budget--And you have to shoehorn everything into that budget.

    The hot water heater--Electrical on demand/instant type water heaters are not very practical for homes (they draw huge amounts of power and cause dimming/flickering light issues for many homes).

    So--You are either left with a tank style RV/under stink water heater (still not great for a small off grid solar power system). Or a hybrid tank water heater (basically heat pump integrated into the water heater)--Which while 2+ times more efficient, is still not very practical for a smaller off grid / portable power system.

    Is propane hot water out of the question? There is solar thermal, but even that is probably not practical for commercial use without backup (propane/etc.) hot water source.

    -Bill
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Newbie looking for help and tips on a complete solar setup

    3/4 HP is a lot of motor for a portable solar power system... But it really depends on how long/often the motor runs too.

    If it runs for 1 minute out of every 15 minutes--That is only 4 minutes per hour:
    • 1,000 watts (est) * 4min/60min = 67 watts "average" load
    • 10 hours * 67 watt load = 670 WH per day.

    I did not see any details on the DC version. It is probably a "brushed" universal motor. Brushed motors have been around for ever (electric drills, mixers, etc.). They are fine for intermittent use, but not great for continuous use (may have to replace brushes every 6 months, turn the commutator every XX months, etc.).

    But if they use less power, and my duty cycle estimate was way off--Then it may be worth it if you decide to go solar...

    Note, a Honda eu2000i will supply 400 watts for ~9 hours on a gallon of gasoline (~$1,000 generator, +$4 per gallon gasoline per day).

    If you decide on 12 VDC for the equipment--You can always use a DC Converter like those used in RV's and other applications (basically an AC to DC battery charger).

    It may be somewhat less efficient, but if you are plugged into utility power--you really don't need to worry too much (if your solar system generates 2kWH per day--that is only $0.20 to $0.40 worth of electricity--So even if 50% efficient, that is only an extra $0.20 to $0.40 in power costs).

    There are DC AmpHour/WattHour meters too... There are these used by RC model makers. And there are true Battery Monitors too.

    Just measuring current (or power) is only part of the problem... You need to also log current/power with respect to time--AH/WH meters do that for you (i.e., the duty cycle of your ice shaving machine/refrigerator/freezer/etc.).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Newbie looking for help and tips on a complete solar setup
    sargcj wrote: »
    Edit:
    Also I want to mention. If I take out the Block Ice Maker and instant water heater and use a chest freezer, based on the specs I could find I have a peak usage of ~6.5KW.(I threw in an extra 500 watts in the core calculation that came to 6.4, before is 5.9) That is everything running at once, and I used the max/peak usage on equipment that listed it, such as the shaved ice machine. My estimated 24hr is at: ~104KW, with some as 24 hour, and others at 12 hours constant running. Realistically, I would hope it wouldn't be quite that much, but I could be way off target here.

    Easier to read form:
    As is currently:
    KW:5.984
    24hr total: 97.128KW

    With 500watt extra for good measure & Rounded up:
    KW: 6.5 (6.484)
    24hr total: 104KW ( 103.128 )
    (Note: I have adjusted/changed some equipment from the first post.)
    That is a lot of power... 6.5 kW genset (probably 10+kW rated) would use ~1-2 gallons of fuel per hour (if gasoline, a diesel unit less, a propane unit more).

    In California, that kind of commercial utility power usage would probably (very roughly) in the range of $700 to $1,000 per month or so.

    If using a genset--That would be around 12-24 gallons of fuel per day.

    I am not sure I really understood your needs/estimate here... 6.5 kW is for the block ice maker? The instant hot water unit is not even practical for off-grid operation unless you are willing to pour $50-$100 worth of fuel into your genset every day--But I am probably misunderstanding your needs.

    Get yourself a Kill-a-Watt type meter (I think Home Depot sells them too) for $30 and start measuring some of your appliances (home fridge, etc.) and get a feeling for average/peak power usage and duty cycle for various devices (fridge, microwave, coffee maker, TV, computer system, etc.).

    Very roughly, you pay around $0.10 to $0.20 per kWH (guess) and off grid solar power (or even genset power) costs around $1-$2+ per kHW--or almost 10x the cost of utility power. So--You really have to understand your power needs and be able to justify spending that kind of money for your electricity.

    Being portable is just than much harder (weight of battery bank, how to mount and travel with solar array, etc.).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • sargcj
    sargcj Registered Users Posts: 13
    Re: Newbie looking for help and tips on a complete solar setup

    The 6.5KW is everything running at their spec sheet rating, or if available at their peak power usage.
    I'm using that to hopefully be over estimating it.
    Erase the block ice maker from your thoughts. that 6.5KW is for everything in the trailer. Reference below.

    The equipment that will be in the trailer is:
    Chest freezer
    Drink cooler/refrig
    Shaved Ice Machine
    Soft serve ice cream machine
    Ipad, charger & PoS system.
    Wifi related stuff
    Water pump
    AC unit
    Light

    I excluded the the Block Ice Maker, because I can store the ice in the freezer and make it at the house. I also excluded the water heater because I'm researching the options and whatnot related to it.

    Everything in the numbers I posted is 110-115-120 listing, so I'll call it 120v.
    I also added 500watt as a safety net, so to speak in that.

    From what I understand, if I understand it correctly, of the ratings & math related to this stuff, this would be 6.5 KWatt hours (1 hour duration) (or 6.5KW)
    The total of 24 is 103-104KWatt hours. , some equipment I multiplied it by 24, others by 12 and added those for the total aprox 24 hour usage.

    In reality for the shaved ice machine, you will run it for a few seconds per cup.
    http://www.youtube.com/watch?v=qj5OFKcAT3E
    Judging by that video and the large one, You would likely run it for ~30 seconds, maybe 45 until you get really good with it for a large. I anticipate most sales will be smaller and medium sizes however.

    I'm open for a hybrid setup though.


    Edit: I'll list the equipment and what the specs say, maybe that will help.
    Again this will be ONLY for what is in the trailer/ on-location.
    Which is what I calculated up above.
    The * is not times, it is a notice. for notes.)

    Drink Cooler/refrig. - 115 V - 1.3 A - 93 W *1
    Shaved Ice Machine - 110V - 10.6A - N/A *2
    Soft Serve Machine - 115V - 16.0A - N/A *2
    Chest Freezer - N/A *3
    Ipad Charger(PoS) - 100-240V 150mA ; Output:DC 5V 2.1A or 10W *4
    Printer & Drawer(PoS) - Average 1.6A. Printing, 0.1 Amp. Standby *5
    Wifi Stuff - 110v - .5 A - N/A*2
    Water pump - 115V - .98A - N/A *2
    AC Unit - 115v - 14.7A - N/A *2
    Lights - 115v - N/A - 160 watts *6
    ---
    Notes:
    *1 The listed Watt rating doesn't match with the formula, is there something I'm doing wrong or mis-understanding here? Because the formula with those amps & volt comes to 149.5. Or is it simply because of the cycle problem you have with equipment like this. If that is true then, while it is running it uses 149.5, but doesn't run for the full hour, is that correct?
    *2 I used the formula to figure up watts for these.
    *3 I was provided with a KW PER YEAR total, I divided by the total of (365*24) for an aprox watt.
    *4 I believe I should use the input, but just to be safe I think I used the 10watt output in my calculation.
    *5 Another one with missing info, I use the printing rating for calculation.
    *6 - I can't find the electrical specs of the ballasts/light fixture, however the recommended bulbs are 32 watts each. It holds 4. So I'll use 5, which comes to 160 watts.

    Also I want to mention that I found a few typo's & made some adjustments in my calculation and they updated to this:
    From Listed: 5.140(5.5KW)
    24hr: 90.132(91KW)

    With extra 500watt cushion:
    5.9(6KW)
    24hr: 96.132(97KW)
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Newbie looking for help and tips on a complete solar setup

    Sorry to confuse you: the Amp hours rating is a reference to battery capacity, which in this case is where you want your power coming from.

    Although 90 kW hours isn't going to work considering the size of the footprint you have.
    Example: 90,000 Watt hours / 48 Volts = 1875 Amp hour 48 Volt battery. This is forklift battery territory, especially as you need about double that to keep from discharging below the point where you can recharge. If you had to buy that lot new it would be like $32,000.
    Recharging would be another problem because that trailer would never hold the 18kW of panel necessary for a full recharge.

    You probably will not use the full 5kW for 24 hours, though. But even at half that it is a massive amount of power.

    To tell the truth it looks like a good generator is the only sensible solution here. There's just too much power demand for solar to be practical.
  • sargcj
    sargcj Registered Users Posts: 13
    Re: Newbie looking for help and tips on a complete solar setup

    Ok, well that isn't exactly what I was hoping to find out, but it is what it is...

    I still have some questions though.
    From what you can tell, does my math add up correctly. I don't mean the arithmatic, but rather how/what I did? I'm wanting to make sure I did that correctly.
    And I'm curious how the relation of the panel rating is to the watt hours and battery ratings. I remember running across something where you don't want your battery to drain more than like 50% I think. But how does 18kW of panels power/recharge that kind of demand/use on those batteries? Would I not need to match and/or exceed the use? Or is this a matter of other factors such as the volts/amps that go into the panel and when converted come out different? I'm rather curious on that.

    Back on the main topic, About how much Solar power/battery power do you think would be realstic for a 6x14' trailer with this kind of power use? Like I mentioned earlier I would not mind a hybrid setup.

    What kind of equipment would I need to setup a solar/battery & Generator hybrid? And what are the best solutions to that?

    I can think of solar & Generator goes towards charging batteries, and everything is drawn off of the batteries.
    --Though I think, depending upon the generator that would be more wasteful for any AC appliances because you may be inverting that power twice first to DC then back to AC, depending on the setup and generator of course.

    You could do a Solar/Battery setup and a generator setup and maybe have a load balancer or something that I don't know about setup with the breaker box to split the power load or you could set everything to draw from battery until a certain % of drainage(maybe 50%?) and then kick the generator on. (or alert you to start the generator since I probably won't have an auto start generator.)

    These are must theories from what I understand and imagine, so please work with me here.

    But even with that solar, every little bit helps save in the long run, and I can still market as trying to be more efficient and "green", as well as the fact it would be unique. If I manage to get 2kW that is 2kW less I have to generate or pay for repeatedly in the long term.

    And again I appreciate all of the help. Hopefully sometime in the future I'll be able to do some Real World testing on measurements and re-do my calculations to see how off I am.
    Sorry to confuse you: the Amp hours rating is a reference to battery capacity, which in this case is where you want your power coming from.

    Although 90 kW hours isn't going to work considering the size of the footprint you have.
    Example: 90,000 Watt hours / 48 Volts = 1875 Amp hour 48 Volt battery. This is forklift battery territory, especially as you need about double that to keep from discharging below the point where you can recharge. If you had to buy that lot new it would be like $32,000.
    Recharging would be another problem because that trailer would never hold the 18kW of panel necessary for a full recharge.

    You probably will not use the full 5kW for 24 hours, though. But even at half that it is a massive amount of power.

    To tell the truth it looks like a good generator is the only sensible solution here. There's just too much power demand for solar to be practical.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Newbie looking for help and tips on a complete solar setup

    The only 'flaw' I see in your math is taking a shortcut on the hours used. At this point it is impossible to tell how long each device will be on. Some will be in operation only "as needed" and others will turn on/off according to thermostatic demands while still others will have some constant power demand cycling up and down as their use necessitates. On the whole taking the short-cut approach is the only way to keep your sanity. :D

    To that end, if you only used 1/4 of that 90 kW hours you still would have massive power demands: 22.5 kW hours is no trifle. It's enough to power an entire house for a day.

    The array size calculation is based on a 10% peak charge rate (another shortcut) 48 Volts with typically 77% efficiency. If the battery bank is 2880 Amp hours (fudging for the ability to discharge to 80% if necessary) you need 288 Amps @ 48 Volts (13,824 Watts) plus factoring the efficiency = 17,953 Watts. And even that might not be enough, as system inefficiencies can cut the daily Watt hour 'harvest' down considerably (18kW * 5 hours is 90kW hours but depending on how much can be used from the panels and how much needs to be stored you could end up needing a much larger array). Pretty horrible, isn't it?

    If you go for a big inverter-charger that can handle all the power needs and utilize the generator for load sharing you'd have to pick either the Outback Radian 8kW unit or the Xantrex XW 6kw unit. Then you'd need a fairly substantial but not unmanageable battery bank to back it up. The amount of solar you can put on the trailer will limit its contribution to charging, so the generator would have to be counted on for some of that as well.

    If we look at roof space alone as I said before you've got room for about 1kW of panels. In 5 hours that would contribute slightly less than 5kW hours directly (conversion & efficiency losses) or about 2.5 kW hours if all stored in battery.

    Another option is to divide up the loads, putting the heavy loads strictly on generator and/or putting the constant (and lighter) loads on solar.

    Otherwise you would have the inverter starting the generator any time the batteries got below a certain Voltage, which would mean quite a lot of cycle of the batteries.

    I can see quite a number of different ways of setting this up, any one of which would work. Trying to determine which is the most practical is something of a poser.
  • sargcj
    sargcj Registered Users Posts: 13
    Re: Newbie looking for help and tips on a complete solar setup

    Shortcuts when done properly/ at the right time can be a very useful and helpful option...

    As to the potential setup from here...

    I was thinking of the latter where its all shared/balanced. I really like that idea but you bring a good point up and that is the wear/cycling of the batteries. I'm assuming a higher frequency is less than ideal, especially for any kind of long-term life. And I'm going to assume the (deep cycle right?) batteries I would need are not very cheap either. I obviously haven't gotten far enough to research that much.

    But I like the all in 1 deal because lets say I have some days where the solar just isn't up to par with charging the batteries/powering the specific equipment on it, the generator could make up for that on those days. And on days where solar is great and everything is working at it's absolute best for the longest possible duration, then more could run off of the solar/battery part and save on the gas/generator wear & tear. I'm not sure I know enough to really evaluate that though.
    Maybe I could do the separate system with a bypass shutoff switch/breaker in case I have a problem with the solar/batteries and put an inverter to DC(if I'm using only DC on the solar/battery system) inline for it to run from the generator as a backup, is that doable?

    I could split it up if that last part was easily and practical to do. Because If I'm not mistaken I can get DC Lights, DC water pump, DC Shaved Ice maker/machine, My Ipad/Phone chargers I can get car charger versions that would be DC. That is probably 1/3 of my equipment, and actually(though it was the AC calculations) is nearly 1/3 of my power use.

    But with that being said, I would "like" to have the capability to invert that excess power to AC to save on gas, but I guess I'll have to think and come to an agreement with possibilities from a financial and practical standpoint.

    Edit:An Issue I just thought of though, is my freezer & cooler. I can empty the ice cream machine at the end of the day if I have to, but if I still have stuff in my freezer and cooler overnight, I will need to keep those going. I don't know that I can get those in DC forms either so an inverter would be a must there. That goes back to the dual system, or at least some kind of a dual system for those specifically. However the issue with that is overnight I'm not going to be there to check gas and all of that. I don't mind setting up something like making sure the batteries are charged at the end of the day for overnight use, but that may require the use of the generator to charge them for a little while with the solar. Any advice on this one?

    I'm trying to think of scenarios here that I may run into and try to plan and prepare for them and set up the most practical system. xD


    The only 'flaw' I see in your math is taking a shortcut on the hours used. At this point it is impossible to tell how long each device will be on. Some will be in operation only "as needed" and others will turn on/off according to thermostatic demands while still others will have some constant power demand cycling up and down as their use necessitates. On the whole taking the short-cut approach is the only way to keep your sanity. :D

    To that end, if you only used 1/4 of that 90 kW hours you still would have massive power demands: 22.5 kW hours is no trifle. It's enough to power an entire house for a day.

    The array size calculation is based on a 10% peak charge rate (another shortcut) 48 Volts with typically 77% efficiency. If the battery bank is 2880 Amp hours (fudging for the ability to discharge to 80% if necessary) you need 288 Amps @ 48 Volts (13,824 Watts) plus factoring the efficiency = 17,953 Watts. And even that might not be enough, as system inefficiencies can cut the daily Watt hour 'harvest' down considerably (18kW * 5 hours is 90kW hours but depending on how much can be used from the panels and how much needs to be stored you could end up needing a much larger array). Pretty horrible, isn't it?

    If you go for a big inverter-charger that can handle all the power needs and utilize the generator for load sharing you'd have to pick either the Outback Radian 8kW unit or the Xantrex XW 6kw unit. Then you'd need a fairly substantial but not unmanageable battery bank to back it up. The amount of solar you can put on the trailer will limit its contribution to charging, so the generator would have to be counted on for some of that as well.

    If we look at roof space alone as I said before you've got room for about 1kW of panels. In 5 hours that would contribute slightly less than 5kW hours directly (conversion & efficiency losses) or about 2.5 kW hours if all stored in battery.

    Another option is to divide up the loads, putting the heavy loads strictly on generator and/or putting the constant (and lighter) loads on solar.

    Otherwise you would have the inverter starting the generator any time the batteries got below a certain Voltage, which would mean quite a lot of cycle of the batteries.

    I can see quite a number of different ways of setting this up, any one of which would work. Trying to determine which is the most practical is something of a poser.