Where to Start: RV and Solar Power

SystemSystem Posts: 2,511 admin
With that being said,Goodmorning,my name is Guy and I am about to venture into the possibilty for powering up an RV on a powerless lot in New Mexico. I am very spanking new to all this,where do I start. I'd appreciate any help and suggestions.
At the moment I am still searching for the right used RV but when I set it up I would like to have power. The power lines are three 6 acre lots away from mine and I'd like to keep it that way,and I'd like to be able to (future build) around my trailer to make it my last project I build. So this Solar Power would converted to the home later,I am not even sure where to start but for now I just need enough juice to keep me warm,tv,fridge,lights at 7500 feet. Where do I start? I totally agree,let there be nothing but SUN and the Wind:D
Thank you
Guy:confused:

Comments

  • mike95490mike95490 Solar Expert Posts: 8,470 ✭✭✭✭✭
    Re: Where to Start: RV and Solar Power

    To get power for space heating, you need the utility grid. Trying to harvest it with solar is futile. Also, a RV may not be insulated well enough, to keep warm, it may leak heat faster than you cold generate it. Either propane or solar heated gycol loop with a 500 gallon tank might work.
    Power for lights, TV, computer and microwave, is doable.
    Fridge and heat, require propane, or plan on 1,0000w of panels for your fridge alone.

    I guess you are looking at either ground mounting your solar, or a carport with the solar on the roof.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • BB.BB. Super Moderators, Administrators Posts: 29,712 admin
    Re: Where to Start: RV and Solar Power

    Guy,

    I moved your post to its own thread in the Beginners forum.

    Our general suggestion for getting into solar PV electricity:
    1. Conservation--Reduce your power needs by changing to LED/CFL lighting, Energy Star Appliances (computer, TV, etc.), and just turning things off. For AC devices--get a Kill-A-Watt meter to measure their draw.
    2. Know your loads--You need to measure your loads... Watts*Hours (average power * time) or Amps*Hours (for 12 volt / DC loads). Average usage per day and by season (more sun in summer, less in winter -- same for PV power). This is where you set your expectations for your solar power system. Generating the solar power is expensive (~$1.00 TO $2.00+ per kWhr vs $0.10 per kWhr for utility power).
    3. Design the System--This part is pretty straight forward. Define your location, season(s) of use, mounting of panels (fixed, flat or tilt, how much space, etc.). Generator backup power, battery monitoring equipment, how much you want to spend (range of solar panels, charge controllers, inverter, battery types, battery monitor, etc.).
    Here are some frequently asked questions that will help you with the understanding the basic issues:

    All About Charge Controllers
    Read this page about power tracking controllers
    All About Inverters
    Choosing an inverter for water pumping
    Deep Cycle Battery FAQ
    Solar Radiation Tables for US
    PV Watts--Simple Solar Power Calculator Program (use Derating=0.52 for off-grid systems)

    Here is a nice thread with video from Keven in Calgary Canada that shows designing and installing solar PV in a small RV trailer.

    Our host is Northern Arizona Wind & Sun (Flagstaff Az) and they have a webstore with a good selection of components to build your own solar system. You do not have to purchase from them--but it is a handy place to find reliable products at reasonable prices to layout your system.

    If you have questions about those products, or others from different vendors--please ask. We are all volunteers here with no connection to NAWS (except for Windsun, the Admin from NAWS) and are happy to help.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • icarusicarus Solar Expert Posts: 5,352 ✭✭✭✭
    Re: Where to Start: RV and Solar Power

    Hey Bill,

    Remember the conversation that we had about a "cheat sheet" that I was lobbying for and agreed to write? You just did it in the previous post. Save it, and move it as a sticky and bold it!

    Nice job,

    Tony
  • BB.BB. Super Moderators, Administrators Posts: 29,712 admin
    Re: Where to Start: RV and Solar Power

    Votes? Edits? :confused: :roll:

    -Bill

    PS: I can see adding more on the "solar thermal" and solar shed links. And a recommendation to use propane, wood, alternative power for heating.
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • System2System2 Posts: 6,290 admin
    Re: Where to Start: RV and Solar Power

    You have all giving me plenty to start with,I know this takes alot of planning,that is why I am starting now. All I have is the lot at 7500-7800 feet,in the El Malpais National Conservation Area. I just purchased 6 acres there and it is beautiful,peaceful,and where I will retire. Since I am on a military pension,this will be low budget for awhile and I know most of the equipment isn't exactly low budget material. Batteries,panel,hard wire etc,the panel(s) will be mounted on top of the RV for now with extra wiring for a later move as I plan on building over this RV as monies allow. A generator is only short term power supply,I need a more perminent alterative sollution.
    I saw all this in action at another home in New Mexico,totally awesome,he had his battery house along with panels just outside of it on a mountain side but he was also connected to main power lines which he switched over to while away.
    Realizing this power has to be managed correctly,esp the fridge because I don't wish to drive 35 miles to the nearest town for supplies(Grants,NM) I am 7.5 miles in on dirt roads,and they are not exactly Van social,more like 4x4 only in spots, so I have to plan every trip carefully.
    I thank you for the beginning lessons,is there any books on building your own system available?
  • BB.BB. Super Moderators, Administrators Posts: 29,712 admin
    Re: Where to Start: RV and Solar Power

    For many of your loads, you have the choice of solar PV electric or alternative power sources (the biggest choice is probably the fridge on electric or propane power)...

    If you live there 9 months or more of the year--then usually the choice is to pick an Energy Star fridge (even frostless in-door water, etc.) is a good one (around 400-800 kWhrs per year)... Propane, over the long term is probably a more expensive solution (cost of fuel, smaller/more expensive propane fridge, etc.).

    ENERGY STAR government's home page

    Off-Grid power, at least for planning purposes (assuming costs are spread over 20 years or so) still will cost you around $1-$2.00+ per kWhr. So--that "low power" fridge/freezer still will cost you between $400-$1,600 a year).

    Note that small refrigerators are seldom energy efficient. A 2 cuft "bar fridge" may use 250 kWhrs per year. A 18-20 cuft fridge/freezer will use around 400-500 cuft per year. 2x the power for 10x the storage.

    Looking at a fridge designed for off-grid use (solar or propane) are usually very expensive and have few "features" (not frost free, smaller than a standard fridge, etc.). Can be difficult to get service.

    There are alternatives for many of the "power hungry" appliances out there... One of the neatest solutions is to take a chest freezer and change the thermostat over to one that will work in the "fridge" temperature range... Can get down to 0.25 kWhrs per day (instead of 1-2 kWhrs per day).

    Chest freezer as a chest refrigerator

    Solar Thermal can be a nice source for space heating and hot water... And usually is "cheaper" per kWhr/BTU vs Solar PV Electric. Also, Solar Thermal lends itself very well to do it yourself projects. Note, these are plumbing projects and have their own issues (leaks, pump failures, installation issues trapping air, anti-freeze, storage, heat exchangers, etc.):

    Solar Shed and other Solar Thermal Links

    A good place to start reading is Home Power Magazine... They have a free past issue online--and have a lot of articles you can read for free. I don't always agree with them and their reviews--but they are a fun and enlightening read:

    Home Power Mag


    You have not asked yet about wind power... At this point, I would suggest you forget installing a wind turbine until you have everything else up and running. Wind may seem cheap, but it is expensive to maintain and few turbines out there will last very long or generate very much power. I can add links--but won't unless you ask... Sort of feel like beating a dead horse (and I am not a pro-wind guy anyway--so it may look like I am being negative).

    In the end, measure / quantify the power usage of every thing you will be feeding energy, work out its cost vs your needs, then plan the power system required to support it.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • icarusicarus Solar Expert Posts: 5,352 ✭✭✭✭
    Re: Where to Start: RV and Solar Power

    A couple of thoughts just to augment Bill's great thead.

    As you are calculating your loads, remember loads will grow with time, try to budget for that. Second, Pv will produce LESS than you calculate net/net out of the wire in most cases. Most people over estimate production and underestimate loads.

    To get started, eliminate all resistance electric heat sources, toasters, hair driers, waffle irons, coffee pots etc. There are alternatives to ALL these and more. Consider a LP fridge which can be run fairly efficiently while reducing Pv costs. (Long term an energy star fridge will be cheaper net/net, but is short term cash is king then LP is the way to go.

    Design your system to grow as your budget, but be advised that some things grow better than others. Many large inverters don't run very efficiently with small loads, same with charge controllers. Battery banks don't grow very well either, as new batteries shouldn't be added to existing strings.

    Remember, off grid is going to be about twice as expensive per kwh as grid tie, something in the range of ~$10/AC watt. You really have to figure if it makes sense to bite the bullet and string grid power.

    The best advise I can give is, do you homework, read all you can here and elsewhere, and avoid the "ready, fire, aim" syndrome that plagues so many newbies.

    Good luck,

    Tony
  • System2System2 Posts: 6,290 admin
    Re: Where to Start: RV and Solar Power

    ;)1st I wish to thank you all for getting me, well lets just say nervously informed,since this is a next spring venture,I am now getting the tools ready for application.
    I saw the kits on EBAY,I have no idea what sized panels,inverters etc I'd need,as things change,my plan now is to build a small cabin,I'm going with a wood stove for heat,LP Fridge as suggested. Now for the rest of the house poop,lights,as few as possible,I'm a low light person,tv and stereo,that is about it,can you suggest what sized panels I would need to power all that. Also, if I run one of those cheapo kits with say,9) 15 watt panels,run in a series,can I also run my charging batteries in a series or is that a laughable question. I'd like to run at least 4 batteries charging all the time,how many panels,of what size would I need.
    Again,thanks to all of you for this first timer info,for starters I am building a 12x14
    camp house just to get inside before winter,one wall will be very moveable,only screwed down because it's movin the following spring until I get where I want to be. Now with my camp built in the center of my newly added deck, I will have my porch with walk around room on all sides except the front,,,4-6 feet of porch,got to have some place to kick back and rest. On the far right,only 1 foot of removeable decking so I can add to my floor joists and continue to add more rooms as needed. This is where I am retiring and most likely rest my bones,but for now it's;NO MORE RENT,NO MORE CABLE BILLS,ALL CAN NOW GO TOWARDS MY SOLAR POWER AND HAPPIER DAYS.
  • icarusicarus Solar Expert Posts: 5,352 ✭✭✭✭
    Re: Where to Start: RV and Solar Power

    A 15 watt panel is, as you say, "a laughable question".

    First off, 15 watts is to small for ANYTHING except for possibly maintaining the float charge on a battery. Secondly, you probably pay way more than $3/watt for the 15 watt panel. "Real" name brand panels with real out put and real warranties can be had for under $3/watt right now.

    My suggestion is to spend as much time as you can, learning your loads using a Kill-a-watt meter. Once you have an accurate idea of how big (or small) you loads are, THEN and only then can you begin to ask yourself (and us) how big your Pv and battery systems need to be.

    Two observations that experience has taught me. Most people grossly under estimate their loads, and over estimate their "good" sun hours, leading to a dramatically undersized system.

    To avoid the ready, fire, aim, read and understand all that you can, asking questions as needed.

    Tony

    PS Just for example, in our 600 sq ft house we use ~.6kwh/day. That is for lighting , radio, computer/modem water pumping. We have no TV which helps alot. We keep a nice balance between draw down and recharge with 300 watts of panels and 450ah of 12 v battery. I would suspect that we are about 1/2 the "average"user in a similar situation. If that be true, the double everything.
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Where to Start: RV and Solar Power

    stay away from those kits as you will not get what you think from them. many have gotten their feet wet with these, but they move on to get the better pvs. also, do not think the small pvs are smaller in their cost per watt because these are usually higher in $/w.
  • mike95490mike95490 Solar Expert Posts: 8,470 ✭✭✭✭✭
    Re: Where to Start: RV and Solar Power

    Look at some of the "sample" quotes at our hosts store:
    http://store.solar-electric.com/capr.html
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • BB.BB. Super Moderators, Administrators Posts: 29,712 admin
    Re: Where to Start: RV and Solar Power

    BC,

    First, thank you for your service.

    Second, define your needs and your loads... My first thoughts--a "small" system for a few lights and small TV/Computer/etc.

    A 12 volt system with a very nice 300 watt True Sine Wave inverter could be cost effective.

    The other question is tools? Power saws, pumps, etc.... Those require much more power (solar panels, batteries, inverters). And while you can save some costs (use flooded cell deep cycle batteries, Modified Square Wave Inverters to power hand tools--not the battery chargers though)...

    In the end, you will still probably need a genset--and there, I would suggest the Honda eu2000i as quiet, small, and very fuel efficient at less than 50% rated load (Yamaha also makes similar ones, including propane configured--but I think the Honda is still more fuel efficient).

    If the eu2000i would be too small for some loads (pump, big table saw, etc.)... Get a second genset (5kW+) that you only run when those loads need power.

    For solar--you are going to need to conserve electricity... The 1,200 watt microwave running 6 minutes a day takes about the same amount of power as a laptop running 2 or so hours per day...

    Those smaller loads running many hours per day can be real killers in terms of total power consumption.

    Tony/Icarus is in a similar setup as you (cabin in Canadian wilderness). Take a look at his sig. Some of his larger loads are a bit off-beat (old gas engine powered washing machine)--but they work well.

    You will be in a New Mexico--so have lots of sun and solar will be nice. But "real" loads + room for expansion will help you design a cost effective system.

    And--understand that solar systems are very hard to expand. As you move up in size, need new/bigger charge controllers, bigger batteries (not usually recommended to add new batteries to an old bank), and larger inverters, etc...

    Build out a small off-grid system and plan to use it for a year or three--and once you approach your final build-out--then budget and size your "final system". Probably the only thing you could salvage from your first system is the solar panels an, perhaps, the charge controller (if you get a 60+ amp MPPT controller). Usually, the larger systems will be 24 or 48 volts--so a new inverter, pumps, etc. will be needed too.

    As a rough guide, less than a 1,000 watt load--12 volts is OK. For systems less than 2,000 watts--24 volt is OK. And for larger systems (especially those over 4,000 watts), 48 volts is almost mandatory.

    We can help you in two ways... Tell us how many solar panels you want to buy -- and we can tell you how much solar power a day you will get...

    Or, tells us how much power you will need (per day, by season, and where the system will be)--and we can give you some guidance on system sizing/design.

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