What do I buy next ???

So far all I have is 1 deep cycle marine battery ( 100 AH ) and a small charger that I plug into the wall. I would slowly like to keep adding batteries, solar panels, inverter, etc... so I can use my battery ( more then 1 battery eventually ) for backup power and eventually power the whole house if I can ever afford it, lol. Should I buy a small inverter now so I can power some small appliances and then maybe a small solar panel, more batteries, etc... ? What should be my next step ?

Comments

  • VicVic Solar Expert Posts: 3,145 ✭✭✭✭
    Re: What do I buy next ???

    Mad,

    Here is a strikingly similar question, and some good answers ...

    http://forum.solar-electric.com/showthread.php?t=819

    Generally, you need to study what your needs are/will be,
    buy the batteries at one time to support this need, Most of the other items can be expanded as needed.

    Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH [email protected], 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
  • BB.BB. Super Moderators, Administrators Posts: 32,609 admin
    Re: What do I buy next ???

    One suggestion... Monitor the charging voltage & current from your wall charger. Also, get a good temperature compensated hydrometer too (assuming this is a flooded cell battery).

    The typical wall charger will boil the battery dry in a few months as they do not typically have a very sophisticated charge profile--but tend to just "trickle charge" the battery. And unless there is some load (or the trickle charger is quite small compared to the size of the battery), you may not be too happy with the results.

    Personally, I and my in-laws' have a couple cars that are not driven too often and because of on-star, low-jack, keyless entry systems, and such--they need a trickle charger to keep the batteries from going flat.

    In one case, the draw on the battery is about 0.185 amps--That works out to ~4.4 Amp*hours per day. Inside of two weeks, the battery is already being significantly discharged beyond recommended margins (about 20% discharge maximum is recommended for an automotive style starting battery--or typically around 20 amp*hours).

    My problem was the the "maintenance chargers" you get from the local auto parts store does not properly float charge the battery--but instead boils it dry.

    So, I just used a lamp timer to turn on the charger (in the in-laws' case) ~4-5 hours per day... Makes up for the load, and the battery does not boil dry (supposed to be a Maintenance Free battery). My car, I have set it to ~1 hour per day.

    One of the most difficult things to imagine is the amount of "work" it takes to keep a battery (and battery bank) happy. Seven years ago, I certainly did not realize this (and have had to replace more than my fair share of lead acid batteries).

    Regarding where to go next--basically, with solar and renewable energy--conservation is the number one goal. In virtually every case, it is worth spending the money first to ensure that you have the most efficient/lightest load(s) possible for your system...

    So, that usually means, with small systems, starting with 12 VDC appliances. Radio, small LCD TV, lighting (LED, CFLs, etc.). Just enough to survive the emergency (I would plan on 5 to 14 days of being "on your own"). Try not to plan on cycling your standard flooded cell storage battery to more than 50% discharge (~50 amp*hours in your case). And try to recharge the battery relatively quickly after discharge--the longer it is stored with less than full charge, the quicker it will sulfate and lose capacity.

    As you get a larger system, a good energy star rated refrigerator would be a nice load to add (keep food fresh instead of going bad within a day or two). But, that will be a good size system (~1kWhr per day--or probably ~500 watts of solar panels+more batteries+DC to AC inverter).

    Then you will need an inverter--and you will probably have to get a "true sine wave inverter"... Yes, the Modified Square Wave Inverter (usually Modified Sine Wave Inverter in marketing speak) is much smaller and cheaper--but some appliances do not work on them very well (electronic loads work great, or overheat and die--and you can't tell which will do what).

    And electric motors (like refrigerator/freezers) don't like MSW inverters at all... So, check with a reputable supplier (like Wind-Sun's inverter page) for more information about good, reliable, and efficient models.

    When you start looking at actual solar panel useful ratings (vs data sheet ratings), battery charging losses, and inverter losses, you quickly find that you will need almost twice the wattage of panels that you thought--Nothing is wrong--it is just the nature of collecting, storing, and inverting energy with a solar system. Hence the first recommendation about conservation.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • System2System2 Posts: 6,290 admin
    Re: What do I buy next ???

    Thanks BB, some good info there. So if I wanted to run my small TV, radio and a couple of small CFL lights with an inverter should I get more batteries first then an inverter, panels etc... I'm thinking maybe an inverter first so I can at least power a few things with my one battery for now and then add on from there. I should mention I don't have a whole lot of cash. This may take a while, lol !
  • BB.BB. Super Moderators, Administrators Posts: 32,609 admin
    Re: What do I buy next ???

    Well.... You have to add up all the loads (in watts), multiply by approximate inverter efficiency of 1/80% (1.25), then divide that into the 50% capacity of your storage battery... Say this is a 100 amp*hour 12 vdc battery, your TV is 100 watts, and your three CFL's are 60 watt equivalent (about 3 x 13 watts):

    Load = 100 Watt + 3x13 Watts * 1.25 (inverter losses) = 174 Watts

    12 volt battery * 100 amp*hours * 50% (discharge) = 600 Watt*hours

    600 Watt*hours / 174 Watts = 3.4 hours of normal operation before recharging

    So, you decide the load and the time--that sizes the batteries. If 3+ hours of emergency power is enough--then this setup will nicely handle it. If not--then you have the choice of more storage and/or alternative power to meet your planned emergency needs.

    If you want solar charging, you can back calculate the amount of sun and other losses.

    Or, plan on a generator or utility power to recharge your battery bank.

    Turns out, that Lead Acid Storage Batteries are pretty big and heavy for the amount of energy they store--versus what people are used to using in their normal lives.

    For an emergency system, if you want 5-10 days of independence (in moderately sunny weather), then you have to cut down your loads or increase the size of the system.

    And you have to weigh that against an emergency where you will need that power... In areas that have hurricanes, ice/snow storms, tornadoes, and such--a good size system sized to provide a couple weeks of emergency power (and a good food/water supply too) using batteries and solar is a good thing.

    Here, where I live, it has been 50+ years since the last multi-day power outage--and earthquakes (the biggest fear) come only once every 100 years or so (last "major" one in our area--1906).

    I chose Grid Tie solar (for power, no back emergency power) and a small 2kW inverter/generator plus siphon hose (gas from my couple of cars will provide several weeks of power for my fridge and a few lights).

    Your choice(s) may be different.

    -Bill

    PS: MSW inverters are much cheaper than true sine wave inverters--but are probably NOT worth the cash for an emergency--possibly blowing out your CLF's and/or TV/Radio in an extended emergency with a MSW is probably not part of your plans.

    PPS: forgot the "NOT" in the previous PS...
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: What do I buy next ???

    what you could do is get more items that can run from the 12vdc as this is more efficient. you will basically have a battery or batteries that need charged and don't care of the voltage source be it utility, solar, or wind so buy a good 2 or more stage 120vac charger and do this from the utility power first so that you can get the other items up and running with as little cost as you can. once you have the batteries, charger, and inverter you want(note some inverters have builtin chargers, but are more costly initially) then you can save for the pvs and controller you wish to have.
  • System2System2 Posts: 6,290 admin
    Re: What do I buy next ???

    Good info again, thanks. So you're saying that I would be better off getting a "true sine wave inverter", is that correct ? What size should I get to start out with ?
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: What do I buy next ???

    i wasn't saying that, but i will say it. get a sinewave inverter. as to the size, well that depends on you and your needs, but go higher than your calculated needs to allow for some future expansions of your needs. you have to start adding up your wattage and factor in the time of use in hours to get your watthours or simply wh. once you know that you can figure out what you need in the way of batteries, but remember that you don't want to drain them below 50% so this will double the battery size.
    what i said was to start a system without the pvs and controller. use the utility power to charge the batteries with a good multistage charger rated at at least 5% of the ah of the batteries. as i already said, some of the better sinewave inverters have a charger builtin so if you can swing it costwise this will be a good start for you as you won't have to upgrade to a better inverter later and you get a charger along with it. then add pvs and controller later as monies allow.
  • System2System2 Posts: 6,290 admin
    Re: What do I buy next ???

    Our local "Canadian Tire" store has a 1000 W inverter for $150 Canadian ( something I might be able to afford, lol, ). Will this be good enough to power a TV and a couple of small lights. I assume this wouldn't be a sine wave inverter because of the price. I also assume it's probably junk, lol !
  • VicVic Solar Expert Posts: 3,145 ✭✭✭✭
    Re: What do I buy next ???

    Mad..

    Just to stir the pot. You might consider BUYing one of the smaller inverter output generators. Like the Honda EU-1000i or the simalar Yamaha models. They are small, quiet, light and can run many things well, especially for emergencies. Not too cheap, but very versitle, AND the inverter output means that at light loads, they use very little fuel, but have the capability of running a 120 VAC refer, a real TV set, radio, some power tools, water pump etc. All of this can be in a 35 or Lb package. Neat. During several winter storms, here, when the grid went down for about 50 hours, a Honda 1000 powered everything in my house that was essential, with power to spare, and used only a few gallons of fuel.

    If you are compelled to BUY something, perhaps this should be it. These small generators are even useful in recharging any batteries that might be in your future.

    Personally, before you BUY very much in the RE arena, you would be well served by slowing down to discover what it is that you will need to do with the RE items. They are very specific to the job needing to be done. And each part of an RE system can be expensive.

    If you feel comeplled to make a purchase, perhaps a book on RE systems. I cannot recommend which book, but bet that folks here will have some good suggestions.

    Good Luck, Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH [email protected], 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
  • BB.BB. Super Moderators, Administrators Posts: 32,609 admin
    Re: What do I buy next ???

    Mad,

    Well, the bigger issue is what are you going connect the input of that 1kW inverter too? Loaded up, imagine how long your car battery would crank (5-10 minutes?)--roughly the same load as that inverter (roughly 100 amps).

    For an emergency, the Honda inverter series is hard to beat. I got the eu2000i for around $900 shipped. Runs for ~4 hours on 1.1 gallons of gas at 1,600 watts--but what I liked, runs about 15 hours on 1/4 load (400 watts). more than enough for my fridge/freezer plus a few lights and such. 20 gallons of fuel (couple of car fuel tanks) and you are good to go for several weeks.

    The normal 2kW generators for $200 really suck the fuel down and are noisy as sin... Good for a short outage (hours/day?)--but not really friendly to use for outages that will last a week or more...

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • SolarJohnSolarJohn Solar Expert Posts: 202 ✭✭✭✭✭
    Re: What do I buy next ???

    Mad, IF you buy a MSW inverter you'll probably have:

    Noise in the sound of your radio.
    Streaks in the picture of your tv.
    Motors that will overheat and not run at the right speed.
    Damage to some of the other stuff you try to run with it.

    And you may end up with a piece of junk that will just fail completely after a short time. Do you really want to deal with that?

    You'll be better off saving up for a good True Sine Wave inverter. I love my Exeltech 1100 watt inverter, and I paid less than $600 for it (on sale). You can go higher or lower (cost and watts), depending upon your needs and budget.

    John
  • nigtomdawnigtomdaw Solar Expert Posts: 705 ✭✭
    Re: What do I buy next ???

    I agree with Vic start with some good reading material and I would reccomend a online subscription to Home Power magazine and purchase there complete back issue on DVD. This is what I did. This will give you plenty of hours/weeks/months of reading material on just about every aspect of renewable energy and NA products. During this intense study time you can save to buy your new bit of gear ! I started off with a small 300ah battery bank and a DR2424E modfied sine wave inverter/charger when I first started converting my home in Spain, again as per Vics line I purchase a small Kipor 1.6 kw inverter genset with smart throttle which only just sipped juice on no load and was able to charge my batteries to get me through the night powering my lights fridge freezer and tv and water pump. long before I purchased my first set of solar panels. I still have the little genset as backup plus portable power around my orange groves. The online PDF mag allows you instant acces to many manufacturers websites on a click of your mouse. Vics comments are spot on, Ive just nominated the reading material !

    2 years of subscription to Home Power and being a member of forums like this
    and www.Xantrex.com and www.Solarguppy.com have given me a very expandable system designed and installed by myself which already supplies all my energy on an average sunny day please view my set up at

    http://energistar.com/phpBB2/album_personal.php?user_id=8

    I say designed by myself more accurately should be copied good practice and listened to good advice and examples and help from the above mentioned bullitin boards and HomePower. HTH Nigel;)
  • System2System2 Posts: 6,290 admin
    Re: What do I buy next ???

    Man, there's alot of good info on here, thanks. I prefer to stay away from anything that is fuel powered like a generator, although they can be very handy. Would that cheap inverter from Canadian Tire be good to power anything ????
  • BB.BB. Super Moderators, Administrators Posts: 32,609 admin
    Re: What do I buy next ???

    Probably 80% of your day to day appliances will run OK on the inverter... Items with motors will tend to run hot (because of the square wave). TV's and Radios may run OK, or have background noise, or a few may overheat and die (no way of really knowing without trying).

    Overall, the inverter will probably be OK for emergency/fun use. For long term off-grid living, it is questionable how long the inverter and appliances connected will last, plus there will be a loss in efficiency due to wasted power as heat (I forgot, but it may be something like 20% lost energy).

    One of the guys here does use a large MSW inverter to run a water pump for an off-grid cabin (large inverter is not expensive, water pump does not often, so wasted power much less of an issue).

    Again, the biggest issue will be the batteries/source of power to run the inverter.

    You really should size the inverter also on the size of your batteries too (besides the load you are going to drive). A large inverter running a small amount of load can be inefficient (need to know the inverter's idle power).

    Certainly, at $150 for 1kW, the inverter will work for you--but there are issues which can limit its usefulness. And without knowing how much load you have, how long you need to run them, and how much battery bank supports the inverter--have no idea if it will meet your requirements.

    But most people really don't have a good feeling for how little power a "car sized" 100 AH storage battery contains... For example, you can run a typical TV for about 2 hours before you need to recharge the battery... It will run the TV for 3-4 hours, but if you run the battery flat, the battery will have a very short useful life because of the damages sustained from over discharging.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • VicVic Solar Expert Posts: 3,145 ✭✭✭✭
    Re: What do I buy next ???

    Hi Mad,

    Guess you have a compelling need to jump into this RE/backup power arena. My sense is that you must do SOMETHING now. SSoooo, while there have been a number of teriffic posts about analyzing studying what exactly it is that you NEED to do with such a system, I think that you feel you must do something now.

    If buying that MSW 1 KW inverter will really make you happy, and it meets your price target, then jump in, and do it. Perhaps retrospectively that purchase will help you determine what you really NEED to do.

    The inverter-output generators are great, universal tools to have, but they are a bit expensive.

    The one caution that I might toss out regarding that 1 KW inverter is that some of the inexpensive electronic stuff around is also very cheap ... ie poorly made, perhaps made with cost of manufacture being almost the only thing considered. Such a unit might not be too relaible, efficient, or effective for what ever it is that you might decide to do with it.

    Enuf for me. YMMV. All The Best, and Good Luck. Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH [email protected], 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
  • crewzercrewzer Registered Users, Solar Expert Posts: 1,832 ✭✭✭✭
    Re: What do I buy next ???

    What do I buy next?
    Madman,

    Interesting question. Since you asked, please allow to offer a few perspectives.

    One answer might be to buy some energy efficient products and or appliances for your home. For example, a small investment in compact fluorescent lamps (CFL’s) will result in a reduction of your monthly electricity bill. A larger investment might be to buy a new high-efficiency washing machine or refrigerator. These types of purchase will also reduce your monthly electricity bill, and it’s often cheaper to invest in energy conservation that it is to invest in energy generation.

    On a related note, the Canadian EnerGuide may provide some helpful hints. See: http://oee.nrcan.gc.ca/energuide/index.cfm

    Another answer might to buy an inverter to power some AC loads from your battery. Personally, I don’t think this makes a whole lot of sense except for educational purposes. Specifically, if the wall charger’s efficiency is ~90%, the battery recharge efficiency is ~80%, and the inverter’s efficiency is ~90%, the system efficiency will be ~90% x ~80% x ~90% = ~65%. In other words, it’ll cost ~50% more to buy utility electricity to power the loads from this system. Plus, the “cheap” inverter will likely die and/or kill some other applicance(s)

    I’m not in your shoes. However, I suspect I would consider buying a small PV module, perhaps ~50 W to 85 W, and a small, inexpensive (but not cheap) controller like this one or this one. An application of a system consisting of the PV module, the latter controller, and your battery might be a 12 VDC CFL or two in the evening, or perhaps a string of LED lights for a footpath, a patio, or nightime guide lights in your home.

    I’ve been using a 40 W module, a SunLight controller, and a single 12 V x 105 Ah battery for many years to power my outdoor path-, deck-, and shed LED lights. These PV components will never be part of a whole-house system. But, I suspect I’ll be using them as I am now for many, many, years to come as a small, independent system that not only does something useful but is also a practical example of “starting small”.

    HTH,
    Jim / crewzer
  • System2System2 Posts: 6,290 admin
    Re: What do I buy next ???

    I think that answers most of my questions for now but I'm sure I'll soon have more, lol. I would love to be able to afford all these things ( appliances, etc...) that everyone keeps mentioning but right now we can barely afford $100, lol. I want to get a small set up like a few batteries and an inverter by this coming winter to use as back up power during some of those snow storms we get around here in Canada. I have wood heat, a good size food/water stash, am an avid hunter, fisherman and a licensed trapper and have a couple of
    "ham" radios that I run off of a deep cycle marine battery.Can never be too prepared, haha. We've had a few power outages over the years where it would have been very nice to have "just a little bit" of power. I have 2 batteries now and I'll keep growing from there. Hopefully someday I'll be able to afford some panels, lol. Thanks for all the advice, be back soon !
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