Help with getting started

JimNAZ
JimNAZ Registered Users Posts: 26 ✭✭
Hello! I just found this forum and this is my first post.

My wife & I will soon be moving onto off-grid land. It will be just outside Ash Fork Arizona in case anyone is close by. There is no shot for electric, cannot drill so have to truck in water, and will have to truck in propane. (Not sure if our situation is considered completely off-grid). Our long term goal is to build a small home using Earthship concepts. However, for the next year or more we plan on buying a used RV trailer and live in that.
I am struggling right now with not knowing the best way to go with everything, and when I try to figure out what we would need for solar, I get completely lost. The more I search, read and click on links, the more I feel I have no idea about anything. I hope I can explain everything properly and thank you in advance for any help. I am happy to do more research/reading if anyone wants to point me in the best direction.
I need to create/build/establish a power system for us to use to live. I am thinking of the present (living in an RV) and future house set-up. We are fortunate enough to have just sold our house so we will have some money to invest. I share this because if it is a matter of spending a little more now and be better set for the future, I would like to know about it.

Some of the things I am struggling with:
Most RV's have the option to run fridge & heaters on electric or propane - which will make for a better setup? Propane here is about $19 for a 20# tank or ~ $4 gal. *The land came with a 155 gal tank.
I know we will need a generator - so is gas or propane better for this? Would a stand by generator be better than a portable (thinking long term for building and house living)? (Gas here is about $3.50 for 87)
We will have a water tank at ground level to feed the RV etc. so either will need an electric pump or a manual pump (?)

I know we will need to learn to conserve on our electric/gas use however ideally we would like to have some sort of washer/dryer, use of a microwave and watch TV/movies etc. along with anything else to live. * We are all for changing out lights to LED. We have no cell service so will need some sort of booster for that and not sure power draw for it. One major thing we will not be able to avoid is the use of a chest freezer. Our dog is fed raw food and given the cost and drive time, we need to buy in bulk. (Propane/electric?)
We will also need (albeit not immediately) some power for our greenhouse. This could be a separate system.

So, any suggestions on how to set up for the RV? I am open to using all solar or mix with propane
The previous owner of the property left us with ~125 solar roof tiles. They are currently just stacked in a pile. I am hoping we can use them for something. Here is the info for each tile:
Peak Power - 34w
Voltage - 4.80Vdc
Current - 7.09A
Open circuit voltage - 6.07Vdc
Short circuit current - 7.76A
Maxium series fuse - 15A
Max system voltage - 600Vdc
I do not understand most of all that but they are all separately wired with individual pair of wires on each tile. They have a male/female plug on each pair.

On a side note -something I am struggling with for the future is our appliances. Would a propane stove be better than electric? Should the fridge/freezer be AC, DC or propane? I read that you lose power with an inverter

Sorry if this was all over the place - hopefully it makes sense.

Thanks again for any help

Comments

  • JimNAZ
    JimNAZ Registered Users Posts: 26 ✭✭
    Re: Help with getting started

    A couple other things:
    The solar for the RV is not meant to be installed on the RV, so lots of room for ideas. Also, I am not sure about whether it is viable or not where we are at but we are open to some sort of wind generator too.

    Thx
    Jim
  • Plowman
    Plowman Solar Expert Posts: 203 ✭✭✭✭✭
    Re: Help with getting started

    First thing you should do is write down all the loads you're expecting to run, then determine how much power they draw. Get a Kill-A-Watt to measure the appliances you already have (chest freezer, TV, computers, etc.), then estimate the rest. Once you've figured out how many amp hours per day @ 12V (or 24V/48V), you'll have an idea as to how big your battery bank and solar panel array should be.

    You don't want to run an RV fridge on AC if you're off grid, they're serious energy hogs on 120V. When run on propane my RV fridge uses roughly 4.5 ah @ 12V per day---this just powers the controller. It uses about 100 times that if run on 120V! Not feasible to run these on a battery bank---if you want an electric fridge, I'd convert a chest freezer using a Johnson controller.

    I doubt an electric stove would make any sense unless you are willing to spend $$$ on solar electric. Together my propane stove and RV fridge use about 0.25 gals/day propane. That's about 75 cents a day.

    Re. the water pump, this is some sort of external tank that you'll feed into the RV? I would think a small 12V pump would work fine for this as long as you're not trying to pump water 100 feet uphill or something. I also have to haul water to my home site, I use 55 gal barrels and use a little Seaflo pump to transfer water from barrels in the back of my truck into barrels I have outside the RV. The Seaflo only draws a couple amps @ 12V when running, but takes ~45 mins to empty a barrel. I use gravity to transfer water from the barrels into the RV's internal tank since the former are situated higher than the latter. The larger pump in my RV draws ~4.4 amps @ 12V.

    See my signature for my little off-grid RV system. My system is on the small side since I live alone and I've cut my electricity use to the bone. I use propane for refrigeration, cooking, and hot water. I keep a chest freezer in a neighbor's barn. I use the generator to run large loads (power tools mostly) and to charge the batteries when needed during bad weather. Running a generator gets expensive real fast.
  • AuricTech
    AuricTech Solar Expert Posts: 140 ✭✭
    Re: Help with getting started

    As a general rule, in an off-grid setup, you want to avoid using electricity to generate heat if at all possible. A propane stove would definitely be more efficient than an electric stove. As for refrigeration, if you want to go with an electric refrigerator, you'll want to replace the RV's absorption refrigerator (the one that can run on propane or electricity) with an Energy Star electric refrigerator. That's because an absorption refrigerator relies on a heat source to function. Again, propane is much more efficient than electricity at creating heat.

    As for the rest of your system, what I was told when I first started asking questions on this forum is to start with figuring out what your power load requirements are, then work from there.
  • Plowman
    Plowman Solar Expert Posts: 203 ✭✭✭✭✭
    Re: Help with getting started

    Another thought: What are you going to do about air conditioning? I grew up in Arizona, gets a bit warm there.

    Even here in Oregon my RV became an oven during the summer when I had it in full sun, it was regularly >100 degrees inside when I got home from work---luckily I had grid power to run the AC.

    Last fall I moved off grid and set up the RV in a spot with almost full shade. Hopefully that will be enough to keep it cool this summer. Main drawback is that I had to set up my solar panels about 100' away. But there's no way I could power the RV's air conditioner with my little system.
  • zoneblue
    zoneblue Solar Expert Posts: 1,220 ✭✭✭✭
    Re: Help with getting started

    Those tiles sound interesting, they are most likely amorphous. If i get that right thats Wp= 4.2kW.

    vmp 4.8V
    isc 7.09A
    wp 34.032W
    qty 125
    total wp 4254W

    How old are they, i think those sort of thing were made fairly recently, so there shouldnt be any worrys about cell degredation just yet.

    When you get a moment make a test rig with a pair of matching conectors, so you verify the voc, and isc for each cell. Given their unknown origin this is a must. That way you can bin anything out of spec, that might be damaged internally.

    The final design will obviously need to be long strings of say 15 modules to get the sort of Vmp needed for mmtp charge controllers.

    As others said it all starts with your loads. However you can do it backwards and design around a 4kWp system. You will obviously need a surface to mount the modules on. You could start by building a shed exactly the right size for the modules. Use that to store building materials, later workshop whatever.
    1.8kWp CSUN, 10kWh AGM, Midnite Classic 150, Outback VFX3024E,
    http://zoneblue.org/cms/page.php?view=off-grid-solar


  • solar_dave
    solar_dave Solar Expert Posts: 2,397 ✭✭✭✭
    Re: Help with getting started
    Plowman wrote: »
    Another thought: What are you going to do about air conditioning? I grew up in Arizona, gets a bit warm there.

    Even here in Oregon my RV became an oven during the summer when I had it in full sun, it was regularly >100 degrees inside when I got home from work---luckily I had grid power to run the AC.

    Last fall I moved off grid and set up the RV in a spot with almost full shade. Hopefully that will be enough to keep it cool this summer. Main drawback is that I had to set up my solar panels about 100' away. But there's no way I could power the RV's air conditioner with my little system.

    Ash Fork is up pretty high so the temps I bet rarely go triple digit.
  • AuricTech
    AuricTech Solar Expert Posts: 140 ✭✭
    Re: Help with getting started

    If you do a Web search for "rv evaporative cooler 12v", you'll find some options designed for the RV application, such as the TurboKOOL, which fits on a standard roof vent opening. While it's not as effective as an air conditioner, it's much less of a power hog.... 8)
  • Plowman
    Plowman Solar Expert Posts: 203 ✭✭✭✭✭
    Re: Help with getting started
    solar_dave wrote: »
    Ash Fork is up pretty high so the temps I bet rarely go triple digit.

    It only has to be in the 80s-90s outside to be 100+ degrees in an RV in full sun. They're poorly insulated metal boxes. Add cooking inside, heat generated by appliances, etc., and it can become downright uncomfortable.

    I'd site the RV in the shade if at all possible and/or be prepared to sleep outside.
  • JimNAZ
    JimNAZ Registered Users Posts: 26 ✭✭
    Re: Help with getting started

    Thank you for the replies/suggestions so far!
    I really was not planning on replacing anything in the RV so propane it is for the heater/fridge.
    I was kick'n around the idea of an on demand water heater - thoughts?

    I have a 250 & 500 gal water tanks to use how I want. I can try to raise it off the ground to elliminate the need for a pump to the RV, but either way the tank will be close to the RV.

    The chest freezer will be outside so in the winter that will be great but not so much for the summer. I have read people put them on timers so they do not run so much (???)

    The RV will be parked in a somewhat shaded area and I plan on adding a porch which will keep the south side out of direct sun. Although I agree about the opportunity for a hot box/freezer with those things! Since I was not going to use the roof to place the solar panels on I thought I could possibly put something up there to help reflect the heat.

    What type of generator (gas or propane) and what size would you suggest?

    I do not know how to "test" those roof tiles. Can you point me in the right direction to learn?

    Although I still have not determined how big my setup needs to be - can you suggest the best products to use? Unless I can determine that those roof panels can be used, I will just get new panels for the RV and use the roof tiles for other things. Should I buy over sized equipment now, knowing I will need more for the house, or just get what I need?

    Thanks again
    Jim
  • jcheil
    jcheil Solar Expert Posts: 722 ✭✭✭
    Re: Help with getting started
    JimNAZ wrote: »
    The chest freezer will be outside so in the winter that will be great but not so much for the summer. I have read people put them on timers so they do not run so much (???)

    I keep my chest freezer (10cf) in a small out-building here in central Florida and the temp in the summer in there is well into the upper 90's.
    I am sure it would be more efficient if it was in air-conditioned space but that is not going to happen. It still uses just under 1kwh per day. And I thought I read somewhere that having them in the cold (not sure at what "cold" point) is actually worse than having them in the hot?

    As far as buying over sized, you will find that it is very difficult to "expand" a system once you design it. Panels you can buy today may be unavailable and finding ones that will work tomorrow with your existing ones may be difficult.
    As others have stated, you need to define your LOADS (including future loads) first, as complete as possible and then design a system around that.
    In some cases, you could build a system with room for expansion within say 6 months (1 year at the most). But after that you risk issues with installing new batteries with old batteries, etc.

    Trust us, we've all been there. I myself have wasted more $ in the past 5 years "upgrading" when I should have just done it right (and completely) from the beginning.
    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
  • Plowman
    Plowman Solar Expert Posts: 203 ✭✭✭✭✭
    Re: Help with getting started
    JimNAZ wrote: »
    Thank you for the replies/suggestions so far!
    I really was not planning on replacing anything in the RV so propane it is for the heater/fridge.
    I was kick'n around the idea of an on demand water heater - thoughts?
    I'm supposed to be getting an Eccotemp L5 delivered tomorrow. It's replacing the leaky water heater in my RV, which I haven't used in many months. It'll be nice to have hot running water again.

    My understanding of little on-demand heaters like this is that they will only heat the water ~30 or 40 degrees above starting temperature. I've heard pressure can also be an issue. But most folks are happy with them over all. Larger units, I believe, will heat even really cold water to 100+ degrees. On-demand heaters like this need to be installed outside, I plan on putting mine on a 4x4 post and covering it with a small sheet metal roof.
    I have a 250 & 500 gal water tanks to use how I want. I can try to raise it off the ground to elliminate the need for a pump to the RV, but either way the tank will be close to the RV.
    Wouldn't hurt to elevate the tanks if you can, that way you don't have to use electricty to run the water into the RV. It'll take a fair bit of pumping using a 12V pump to move 250+ gals of water.
    What type of generator (gas or propane) and what size would you suggest?
    For an RV you don't need a giant generator. I have a 3500 and it's bigger than I need. A Honda EU2000 would suit my needs better, be more efficient given the loads I'm running, smaller, less of a gas hog, etc. Once I finish my solar electric system, I'm hoping to only run the generator for power tools and the occasional battery charging during winter.
    I do not know how to "test" those roof tiles. Can you point me in the right direction to learn?
    I know nothing about these (they sound neat, got any pictures?), but I'd just put them in the sun and test them with a multimeter for open circuit voltage.
    Although I still have not determined how big my setup needs to be - can you suggest the best products to use? Unless I can determine that those roof panels can be used, I will just get new panels for the RV and use the roof tiles for other things. Should I buy over sized equipment now, knowing I will need more for the house, or just get what I need?
    I'm glad I started out a bit small, better to make mistakes on a small system than a big system. And I've made a lot of mistakes. Tons.

    But as Jcheil said, expanding an existing system isn't always easy. I was worried that the Dmsolar panels I have were no longer available since neither Amazon nor my local supplier had any for a couple months. Luckily they're back, but I'm thinking of getting two more ASAP just in case.
  • inetdog
    inetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: Help with getting started
    Plowman wrote: »
    I'm supposed to be getting an Eccotemp L5 delivered tomorrow. It's replacing the leaky water heater in my RV, which I haven't used in many months. It'll be nice to have hot running water again.

    My understanding of little on-demand heaters like this is that they will only heat the water ~30 or 40 degrees above starting temperature. I've heard pressure can also be an issue. But most folks are happy with them over all. Larger units, I believe, will heat even really cold water to 100+ degrees. On-demand heaters like this need to be installed outside, I plan on putting mine on a 4x4 post and covering it with a small sheet metal roof..

    The maximum temperature rise is inversely proportional to the flow rate, given a maximum power input. The nominal temp rise for a particular unit will be at the nominal flow rate.

    Pressure itself is not a problem but many of the units have built-in active flow restricters to try to hold the set output temperature. That gives the appearance of a pressure problem when you open a sink, shower or tub valve wide open.

    The larger units will give you a higher flow at the same set temperature.
    One of the characteristics you need to look for when shopping is how well the unit can cut back on its burn rate to keep from overheating the water at low flow rate.
    At some low flow rate the unit will just shut off for safety and you get cold water.

    Even very big on-demand units using propane as fuel can be mounted inside a house or garage if properly piped, but they may not meet the requirements for a modular home or RV.
    SMA SB 3000, old BP panels.
  • JimNAZ
    JimNAZ Registered Users Posts: 26 ✭✭
    Re: Help with getting started

    Ok - I need to measure my usage and guess-timates. What gadget do I use for the measuring and where do I get this?

    It sounds like I need to build this for final use (bigger than I need now) so I do not come across any challenges. However, is it common to have more than 1 system and does that even make sense?

    Can anyone recommend a propane generator and what size (consider backup for RV, power tools and possibly to run a washer/dryer)

    Thx
    Jim
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Help with getting started

    You might end up with a large/inexpensive/noisy generator for large loads and backup for a smaller quiet generator for battery charging/small portable usage.

    Regarding propane, how large of tank were you thinking of? Running for hours on cold days can"freeze smaller tanks.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • JimNAZ
    JimNAZ Registered Users Posts: 26 ✭✭
    Re: Help with getting started
    BB. wrote: »
    You might end up with a large/inexpensive/noisy generator for large loads and backup for a smaller quiet generator for battery charging/small portable usage.

    Regarding propane, how large of tank were you thinking of? Running for hours on cold days can"freeze smaller tanks.

    -Bill

    Currently we have a 155 gal tank on the property along with a few 20's