Need a little advice.

bill and rosa
bill and rosa Solar Expert Posts: 26
http://cabininok.blogspot.com/ is our blog and plans for our retirement cabin.

We will be using gas (natural or propane) to heat and cook with. Good backup water heat also.

Will have to tie into the electrical grid and county water to start with until well is dug and the electrical system (wind and solar) are complete.

On our blog we have listed a few items we are looking at to power our system (12 volt) and links to batteries and all items.

We would like sound advise on the system. We are over the road truckers so over the next 5 to 10 years want be there much, so should we build the system grid tie with a small battery backup system to maintain the fridge and freezer. The electrical company does install the old meters than can be ran backwards. While we are still working we thought to buy a few batteries every month and store them in a NON hooked up state until we get the amount of amp hours we think we will require. I have installed a small grid tie system on my children's home just to see how it works. I liked the outcome of lowering the power bill.

OR

Should we just build the full battery system and then grid tie off of it while we are on the road.

We would like good sound advice and response to our situation.
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Comments

  • petertearai
    petertearai Solar Expert Posts: 471 ✭✭✭✭
    Re: Need a little advice.

    Hi Sounds exciting.
    If you have grid to start with then stick with that. Grid tie wold be easier as no battery's to maintain while away. Forget the wind, too much trouble with the solar prices as they are.Should you really have a desire to be completely of grid then a 24 or 48 volt system is a better choice. Also work out your loads first, then design around them.
    2225 wattts pv . Outback 2kw  fxr pure sine inverter . fm80 charge controller . Mate 3. victron battery monitor . 24 volts  in 2 volt Shoto lead carbon extreme batterys. off grid  holiday home 
  • Himins
    Himins Solar Expert Posts: 54 ✭✭✭✭
    Re: Need a little advice.

    Where is this place, northern climate? I've been off grid only 6 months, depending how long you are away, consider buying your groceries when you get back. I wouldn't buy batt. untill you are ready to install them. Sounds like the batt purchase may strain your budget. What I'm suggesting is build an expandable system and start by not including the cost of the grid tie, spend a little more on your panels, wire, inverter, and charge controller all grid tie compatible. You didn't mention where your budget limits are for the project. Everyone will ask the same question so here goes....do you know how much demand your system will require? You will have to budget your electrical demand. if you have a northern climate...your freezer cost is minimal several months a year...just do like i did and toss the thing outside. Expensive, but a fridge can also run on propane and they are cheap to own. I stripped one out of an old motor home for nothing. Removed some of the wire too as the batt leads were handy and long. The folks offered the generator, but I didn't want to feed the beast and purchased a much smaller 2500 watt. that sipps the fuel. Also i made the mistake of buying a very large inverter...dumb for me. A smaller inverter tru sine wave made a lot more since after i watched the big one gobble up batt. I made a few mistakes along the way but i couldn't afford a system that would meet my needs out of the shoot, so I put together a modest system and curbed my budget on what was available. I burn wood to heat the home and water heater, I have a flowing well so I can pressure my farmhouse with a 12v water pump(works fantastic) salvaged from same motor home.
    Well, in summary, look around for things that our ancestors did, My farm didn't have ele pole until 1956, neither did the dairy farm a mile away, so with some thought and a few concessions here and there, your new place can be pretty comfortable without messing with the grid right away. If a grid tie system is in the future...just add the components that are compatible untill the day you are ready to hook in.
    I am still using salvaged batteries, I don't reccomend them but as this is all new to me, I have been murdering a few and get them all free. Now the system is half done, my battery life has improved considerably and can feel more certian about proper batt maintance when i can spring for the new set.
    Cosmetics are not high on my list of priorities, and won't be for another three years do to an injury, so I have to hobble together the best I can until my health, then money is back in this operation.
    I'll gladly help all I can, there are some wonderful tech's on this forum and you will be in very good hands..I'm better at telling you the mistakes I've made, hope this helps you avoid a few pit falls. Good luck on your project, I'll bet you will have fun with it.
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Need a little advice.

    these guys are giving you some good advice. if you have already purchased batteries then they must be kept on a charge through a good 3 stage charger or they will go bad. you must also maintain them with proper water levels. you may be jumping the gun in buying stuff until it is determined how and when things will be done. a backups is a good idea for while you are on the road, but it won't back up everything long term making himins' suggestion of buying the food when you get back a viable one.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Need a little advice.

    Do not buy batteries in advance; they will go bad just sitting there.
    Save your money up, plan/buy/install when you can afford to. Over time available equipment changes and sometimes becomes incompatible with what you already bought.
    Grid is cheaper than off-grid. You want battery back-up to maintain the refrigeration while gone? Unfortunately that equipment has big demands for start-up and running. You may need 2kW hours worth of power per day per 'frige/freezer to keep them going. How often/long does the power go out? Most refrigerators can stay cold for a day with the door shut. Freezers for two or three days. In other words, have you found that such back-up is necessary? Otherwise it's big money for something that will return you nothing most of the time.

    Check with your utility about grid-tie. It's less expensive, can include battery back-up, and will at least reduce the cost a bit by selling surplus back to the grid when possible.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Need a little advice.

    On your blog--You are also looking at small wind turbines.

    I would recommend that you not start with small wind--Get your solar PV system up and running well, with a backup generator of some sort.

    Once you get everything working well--You can look at small wind--But do a lot of research on any brand/model you are thinking of buying. For the most part, wind turbines do not output any useful amount of energy until you have ~12 MPH or more wind (starting to turn blades at 5 MPH is meaningless).

    Also--You should be looking at towers that are, at a minimum, of 60' or more, 500' and >30' taller than any nearby obstructions.

    Small wind, usually, needs a lot of maintenance, so some way of accessing the turbine without having to rent a bucket truck or crane will save you money. And do not install near home/place where people live/play--They do shed blades and fall from towers on occasion. Also, if you have lightning in your area--A 60+ foot metal tower topped with a turbine and electrical wiring is going to be an issue too.

    As you can tell, I am not a fan of small wind (or big wind either). There are a few people here that have installed wind turbines are are very happy with them--But they are few and usually do their own work (or even build their own).

    In the end--You say that there will be utility power connected to the property. Generally, off grid power costs around 10x utility power when all costs are added up (hardware, batteries, maintenance, battery replacement every ~5-10 years, electronics replacement every 10+ years, etc.).

    If you start with conservation in mind during construction (lots of insulation, double pane windows, energy start appliances, designing to take advantage of sun in winter/shade in summer, etc...)--It is usually a better investment of your time and money. It is almost always less expensive to conserve power than to generate it.

    You might look at solar/generators as backup power instead... And for backup power a smaller/correctly sized generator supplying enough power for short term use can be a much less expensive solution vs solar.

    A very low power/conservation minded off grid home/cabin can use as little as ~100 kWH per month (no A/C, using fuel for heating, electricity for fridge/lighting/washer/well pump/laptop computer/radio/etc.)... That is only a $10-$20 per month power bill (unless you have high power chargers for connection feeds, remote power, etc.).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • bill and rosa
    bill and rosa Solar Expert Posts: 26
    Re: Need a little advice.

    Thank you for your responses. Our budget is pretty much open as we plan on building the system roughly 1000 to 1500 a month. The land payment is very cheap and the portable building was less than 8500 dollars. The cost to finish the inside is less than 2000, (not including the appliances).
    This land is 10 miles south of I-40 in okema, ok (ofuskee county). The wind there has a yearly daily average of 5 to 7 mph. The sun for solar is 4.5 to 5.5 hours ( i plan off the 4.5 hours.
    From the electrical side the fridge and freezer will be the biggest draw of wattage roughly 400 watts. The lighting will all be 12 volt (45 watts), I already have two 1500 by 3000 watt inverters that I used in the trucks. one is a true sine and the other is modified. Will only use the true sine for my Mac Book and the 15 inch flat screen DVD/TV less than 150 watts.. For the first few years we will only be there 2 to 4 days a month since we are always on the road building our retirement.
    Will use either propane or natural gas for heat, cooking, and water heating to start with until I get the dump load system (hot water element ) mastered.
    This land has never had electrical power brought to it. It will cost me roughly 5200 dollars to have the power lines brought in. The county water will cost roughly $1000 to have meter put in and for us to run 1 1/4 inch line to the property. I havent gotten a quote on the natural gas installation since they seem to be pretty slow to come out and do there survey. I research natural gas verse propane and the CNG is cheaper overal.
    Eventually we will have a out door wood burner for heat. but this plan is for our retirement which is 5 to 10 years away.

    We have the land and building. Just want to do it right so upon retirement we are dept free and utility bill free. We plan on living on 1000 to 1500 a month for total expense.

    Thank you for the information on the batteries. We will keep them charge as the are being stored. If I am thinking right a small 15 amp charge controller and small 150 to 300 watt solar setup would do fine since the batteries will no be getting used. Might hook up a few 12 volt lights on a timer just to have a little security lighting on the cabin.

    As you can see we are only setting up a 1000 watt basic startup system. It of course will be growable. Have we started off on a good basic plan. The grid tie to reduce our electrical cost is in the plan but I am curious should I take the $5200 dollars that it would cost to get electrical power brought to the property and invest it toward the OFF Grid. We have several gas generators that can be used the 2 to 4 days a month we are there. You guys KNOW allot more than we do. We have been researching solar and wind power for a little over a year. We have built a few DIY panels and bought a few grid tie inverters and use them on our kids home in GA. No wind there to test wind power.
    Please, if you think we need adjustment in our plans or thinking, we welcome good sound advice. The batteries (type, amh, voltage) are our biggest concern and worry as we know the WHOLE system is based off this voltage. I can get the wind turbine in 12, 24, 48 with no added cost. The panels I know I would have to wire different for the 12 to 24 volt and might have to purchase a bigger setup. The seller I am looking at will work with me on the wattage required and try to keep cost to .78 cents a watt.

    Again thank you for your responses so far. We thank you for helping steer us straight and hopefully keep us from wasting our money on to many mistakes.

    P.S. The utility company allows for grid tie and will pay for excess electricity they still use the old meters.
  • vtmaps
    vtmaps Solar Expert Posts: 3,741 ✭✭✭✭
    Re: Need a little advice.
    Thank you for the information on the batteries. We will keep them charge as the are being stored. If I am thinking right a small 15 amp charge controller and small 150 to 300 watt solar setup would do fine since the batteries will no be getting used.

    No No No! Don't store batteries. They go bad whether you use them or not. (see Cariboocoot's post). Also, it is bad to mix batteries of different ages in a single bank.

    I suppose that if you had to store batteries, the best thing to do would be charge them up and put them in the freezer.

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Need a little advice.

    Save your money!!!!!!

    Get a genset to run those few days a week you are at home... If you can use a Honda eu2000i (1,600 watt max)--Do it. You probably will only use 2-3 gallons of fuel per day maximum. Keep the oil changed and you can get 2,000-6,000+ hours out of the generator.

    At this point, it is not worth keeping a fridge running (fresh food will only last 4-7 days or so), and a freezer+power to for long term storage vs just buying enough for those few days a month (canned foods, dried/sealed foods, root cellar, etc. for sure).

    And--if you want "quiet time"--Build a small system out of two to four 6 volts @ ~220 AH (golf cart) batteries, a MorningStar 300 watt TSW 12 volt inverter, and a solar array (note: 5% to 13% rate recommend rate of charge, 10% is a good sized array):
    • 14.5 volts charging * 220 AH * 0.10 rate of charge * 1/0.77 panel+charger derating = 414 Watt "good sized array" for 220 AH bank
    • 14.5 volts charging * 440 AH * 0.10 rate of charge * 1/0.77 panel+charger derating = 828 Watt "good sized array" for 440 AH bank

    And get a backup 20-40 amp @ 12 volt AC Battery charger to run off your eu2000i (40 amp) or even eu1000i (900watt can run a typical 20 amp @ 12 volt charger).

    Assuming the above system and 4.5 hours of sun nominal per day:
    • 414 Watt array * 0.52 system efficiency * 4.5 hours of sun = 969 Watt*Hours per day (assuming AC inverter)
    • 828 Watt array * 0.52 system efficiency * 4.5 hours of sun = 1,938 Watt*Hours per day

    You can run your fridge/freezer from the generator (run genset at least 12 hours per day to keep stuff cold). And run the battery system at night/quiet time.

    The MorningStar will not run a refrigerator or freezer (typically), but the 828 watt sized system is very close to being large enough to run a fridge or freezer -- So you could use a larger 1,500+ watt inverter on that system (assuming around 1kWH per day or 365 kWH per year rated appliance). There are people who use a converted chest freezer to fridge that uses around 0.25 kWH per day -- Which may be "good enough" for your needs at this time. Finding a good 12 volt inverter to power the fridge (efficiently) is a bit of a pane (just turning on an inverter can use 0.24 to 0.48 kWH per day which is a significant power usage for small off grid systems).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Need a little advice.

    A little inserted advice from a guy who lives both on and off grid.
    Thank you for your responses. Our budget is pretty much open as we plan on building the system roughly 1000 to 1500 a month. The land payment is very cheap and the portable building was less than 8500 dollars. The cost to finish the inside is less than 2000, (not including the appliances).

    My cabin system cost $8,000 four years ago, self installed. It is capable of 2.5 kW hours per day. You would likely spend as much on an off-grid solar power system as the whole project has cost to date. Buying it piecemeal will be a mistake.
    This land is 10 miles south of I-40 in okema, ok (ofuskee county). The wind there has a yearly daily average of 5 to 7 mph. The sun for solar is 4.5 to 5.5 hours ( i plan off the 4.5 hours.

    That wind will do you no good. If it was 10 mph faster you'd have something to work with. Wind power requires good turbines (not cheap) and good installation (even more expensive) so if you don't have good wind it is money down the drain. The sun availability is good.
    From the electrical side the fridge and freezer will be the biggest draw of wattage roughly 400 watts.

    No, it will draw 400 Watts while running perhaps. The start-up surge will exceed 1kW and the total Watt hours per day is likely closer to 2kW hours each. Get a Kill-A-Watt meter and measure the power consumption of stuff you use. You'll be surprised. Best investment you can make, no matter what.
    The lighting will all be 12 volt (45 watts)

    This is a mistake. Low Voltage lighting requires some pretty big wires to get the power any distance without large losses. If you are already going to need an inverter for running a 'frige, it's easiest and most efficient to go with all 120 VAC stuff.
    I already have two 1500 by 3000 watt inverters that I used in the trucks. one is a true sine and the other is modified. Will only use the true sine for my Mac Book and the 15 inch flat screen DVD/TV less than 150 watts.

    The Mac will run off the MSW; it does not care about the quality of waveform. Contrary to popular belief, computers have really good power supplies that can take lousy input power without flinching. Laptops even more so as they have built-in batteries; essentially their own UPS systems.
    For the first few years we will only be there 2 to 4 days a month since we are always on the road building our retirement.
    Will use either propane or natural gas for heat, cooking, and water heating to start with until I get the dump load system (hot water element ) mastered.

    Good. Save up money. Save up every dime you can. You never know what may happen. One accident and all the plans change. Trust me; I know this too well.
    Use of gas for heating is smart. Heating with electric is dumb. Your "dump load" may not be an applicable function once you get the system details worked out. Direct solar heating (of water or air) can be very viable. It is quite efficient in most cases and can be used even if you don't go off grid.
    This land has never had electrical power brought to it. It will cost me roughly 5200 dollars to have the power lines brought in. The county water will cost roughly $1000 to have meter put in and for us to run 1 1/4 inch line to the property. I havent gotten a quote on the natural gas installation since they seem to be pretty slow to come out and do there survey. I research natural gas verse propane and the CNG is cheaper overal.
    Eventually we will have a out door wood burner for heat. but this plan is for our retirement which is 5 to 10 years away.

    $5,200 to bring in utility power is cheap. Even with on-going expenses it is likely cheaper than buying an off-grid system capable of meeting your needs. Burning wood for heat is cheap, providing you have control of the source. I've got acres of standing tree and heat both places with wood. That's why our utility bills for gas & electric combined are <$60 a month.
    We have the land and building. Just want to do it right so upon retirement we are dept free and utility bill free. We plan on living on 1000 to 1500 a month for total expense.

    You may be utility bill free by going off grid, but you will not be utility expense free; it comes with a price. Over the lifetime of the equipment with full power potential utilization the off-grid power will cost you are $1 per kW hour if you're lucky. Our cabin production costs over $4 per, but it is only used 1/2 the year and I haven't realized full amortization on it yet. I expect it will drop to about $2 per over all. The reason we have it is because getting utility power there is impossible; it would require miles of high Voltage lines across public and private land to service five places. That just isn't in the realm of reality.
    Thank you for the information on the batteries. We will keep them charge as the are being stored. If I am thinking right a small 15 amp charge controller and small 150 to 300 watt solar setup would do fine since the batteries will no be getting used. Might hook up a few 12 volt lights on a timer just to have a little security lighting on the cabin.

    Regrettably, even if kept charged the batteries will deteriorate over time. There is no way to store a battery and have it not decline. You can slow the rate, but you can not stop it.
    As you can see we are only setting up a 1000 watt basic startup system. It of course will be growable. Have we started off on a good basic plan.

    Nope. Nope. Nope.
    A system provides Watt hours per day. Sizing it by the array Wattage or inverter capacity doesn't mean anything. You need to think in terms of the quantitative power: Watt hours.

    Expanding a system over time is extremely difficult. The only way it can be done is to plan "both ends" and then adjust the plans so that what you get now will still be viable later. This is because as system power requirements go up it is necessary to increase system Voltage; simply adding more Amp hour capacity to the battery bank runs in to trouble. Also what you get now and what you get later may not be compatible. Too often expanding a system is an exercise in frustration that results in replacing the whole thing or adding a completely new system on. Can be done, but it's a lot of headache.
    As for the third item, see remarks above. The best thing you've done is come on here and ask before tossing any more of your hard earned $ at the plan. We don't mean to sound cruel; we're just trying to save you money and frustration.
    The grid tie to reduce our electrical cost is in the plan but I am curious should I take the $5200 dollars that it would cost to get electrical power brought to the property and invest it toward the OFF Grid. We have several gas generators that can be used the 2 to 4 days a month we are there. You guys KNOW allot more than we do. We have been researching solar and wind power for a little over a year. We have built a few DIY panels and bought a few grid tie inverters and use them on our kids home in GA. No wind there to test wind power.
    Please, if you think we need adjustment in our plans or thinking, we welcome good sound advice. The batteries (type, amh, voltage) are our biggest concern and worry as we know the WHOLE system is based off this voltage. I can get the wind turbine in 12, 24, 48 with no added cost. The panels I know I would have to wire different for the 12 to 24 volt and might have to purchase a bigger setup. The seller I am looking at will work with me on the wattage required and try to keep cost to .78 cents a watt.

    I think you better think it out again. :D
    Start by measuring the actual amount of power you use now. Work up an estimate to supply that power via off-grid solar. Compare that cost to installing and paying for grid. Do not forget that solar has on-going costs too (batteries must be replaced, anything that breaks down is your responsibility to repair).
    Again thank you for your responses so far. We thank you for helping steer us straight and hopefully keep us from wasting our money on to many mistakes.

    P.S. The utility company allows for grid tie and will pay for excess electricity they still use the old meters.

    That's what we're here for. :D We don't like to see people jump in to solar and get short-changed or ripped-off. We do see it, of course. All too often.
  • bill and rosa
    bill and rosa Solar Expert Posts: 26
    Re: Need a little advice.

    Thank you for the advise. It has been very helpful. I reached out to a professional to survey the wind and solar capabilities were my land is. They have done 85% of all installs in the region. This will get me better wind and solar information so I will have that data to help us narrow down the system I will use. Dont want to be walking into the dark fire pit with our eyes closed.
    You may be utility bill free by going off grid, but you will not be utility expense free; it comes with a price. Over the lifetime of the equipment with full power potential utilization the off-grid power will cost you are $1 per kW hour if you're lucky. Our cabin production costs over $4 per, but it is only used 1/2 the year and I haven't realized full amortization on it yet. I expect it will drop to about $2 per over all. The reason we have it is because getting utility power there is impossible; it would require miles of high Voltage lines across public and private land to service five places. That just isn't in the realm of reality.
    Can you explain this a little simpler, I cant seem to get it clear in my head.

    We will start off using our generators that we already have to power the cabin while we build the power system. We have found a supplier for our Trojan batteries that will let us pay for the batteries a couple a month (lay-a-way plan sort of) and when we get the number of batteries we required paid for then he will ship the whole lot at once. (we may go pick them up to save on shipping since they are less than 300 miles away. Thanks again for the advise on the batteries.

    Still have a lot of research to do but NOW we have a better plan in place due to this forum helping us out. Once I get my full power system design together I will post what we are doing so I can get your opinion on the system before I spend the money.

    So you can all get a laugh I will use a 225 watt panel, 2 12volt batteries, my small 15 amp Charge controller and a 1000 watt inverter for my night time lighting. Can always put this test system in the barn to light the way for the cows later own.

    Again thanks for all your help.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Need a little advice.

    Okay, off-grid power costs:

    Initial capital investment of $X buys equipment that will only last "so long". The panels are warranted for 20 years, inverters aren't but can easily last 10, batteries are a definite "will need to be replaced" item. Often sooner than we would like.

    During the time the original equipment is in place and producing power it will produce up to "so many" kW hours. The more you can make use of this potential the better the costs.

    Therefore the total capital cost (plus any maintenance/repairs) divided by the total kW hours produced over the lifetime of the equipment = cost per kW hour.

    My own example: over $4 per so far. This is because the equipment is only at half its lifespan so far, therefor I can expect it to drop to over $2 per kW hour before major replacement is needed. The other thing that makes it so expensive for me is that it is at a cabin and only gets used 6 months of the year. Were it used year-round the cost per kW hour would again be halved. So from over $4 per kW hour we get down around $1 per if used full time over the expected lifespan of the equipment.

    You pay for off-grid power, and you pay most of it up front.
    Here is an example of a pre-designed off-grid system: http://www.solar-electric.com/1waofsoposyw.html
    That's about $8,000 and has a 1890 Watt array which should produce (minimally) 4 kW hours per day, 1460 kW hours per year, or 14,600 kW hours in 10 years.
    8,000 / 14,600 = $0.56 per kW hour, but there are no installation costs or taxes in that price nor any allotment for maintenance/repairs. On the other hand, add in a new battery set (or two) over time and it may give you 20 years of service. You could also, depending on your particular site, realize more kW hours than that from it.
  • bill and rosa
    bill and rosa Solar Expert Posts: 26
    Re: Need a little advice.

    thanks Cariboocoot , that helped me understand (bow).
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Need a little advice.

    Also, remember that an Off Grid system--You either use the power or it is "lost".

    Marc only can use ~1/2 of the power generated (2-3 day storage)--So, that doubles the "cost of power", because the amount of "power used" is only 1/2 the year (summer vs winter matters too in costs--You may generate 3/4 of the power or more during the summer, and 1/4 of that during winter--again, the numbers can be adjusted to better represent your living situation).

    Also, you can only, on average, use about ~66 to 75% of your daily power... You cannot, for an off grid system, use 100% of your power every day--Unless you are really careful about your optional loads (water pumping is good example--Pump when the batteries are full). But, in the end, electricity keeps about as long as fresh food in the fridge.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Need a little advice.

    Actually you can never realize 100% of the power potential because batteries require more power to recharge than they are capable of supplying.

    As Bill said, taking advantage of "opportunity loads" once they are charged can go a long ways towards improving the over-all efficiency and thus reducing cost per kW hour.
  • bill and rosa
    bill and rosa Solar Expert Posts: 26
    Re: Need a little advice.

    My professional wind and solar technician has surveyed my property. He had a cool setup that he left on the property for 36 hours to get some data plus he had all sorts of maps and charts of the area. Well worth the $100 dollar fee in my eyes. Since this is the early winter time the reading for sun are a bit lower than what will be in the spring and summer. Here are some stats:

    He had 2 full sun rises and 1 1/2 sunsets

    Sun 4.75 hours of true direct sun (best solar power generation time) He stated to me that in the summer I should see 5 to 5.25 hours.
    Wind 23 hours of wind over 10 mph at 20 ft off the ground during the 36 hours. Told me if I go higher I will get more wind and speed.

    The maps show the average wind for my property area for the year is 9 to 11 mph. The spring and fall averages are slightly higher at 10 to 13 mph average. Winter and summer fell in the 9 to 11 mph. I dont know the height they took the wind speeds at.

    After I got this information I went back to the company I am talking to about supplying everything I want and reworked my plans and got a quote.

    I want to know what you think of this quote. I already have a 30 ft tower and a 60 foot tower to hold my Wind turbine.

    1600 Watt Missouri Raider Wind Turbine 24 Volt qty 1 $599.98
    MW Combo 440 Amp Charge Controller w/ Divert Load (2 Resistor), 24 Volt qty 1 $184.00
    3000w solar inverter charger 24v split phase 120v Inverters Battery DC to AC qty 1 $1199.00
    KD 220 Watt Solar Panel qty 3 1047.00
    battery, 225 Ah qty 12 $1775.40 (T105 Batteries which gives you 675 amp hours)
    Total Cost 4805.38
    Out-of-state sale, exempt from sales tax

    Again we will only be using this cabin 2 to 4 days a month until we are ready to retire. We already have several gasoline generators to help us power the cabin to start with and when we have low wind or sunlight. We have propane for cooking, heat and hot water. (hope to eliminate the hot water and heat from propane later)

    Got the specs from the energy star fridge/freezer it uses 394 kwh per year. (normal family use)
    The stove is gas, water heater is gas, heat is gas with blower that runs off thermostat. Low 12 watts to high 85 watts. this I know will be hard to judge depending on how much its used. Thought of eliminating the blower and use the ceiling fan to move the air.

    from all the standard energy efficient items we plan on using i have calculated a 800 to 1000 watt usage. I rounded everything up.

    the floor plan of the cabin has 288 sq loft area and 480 sq ft floor area. If I have to cool it will use a generator and the small 110 window unit I have that is energy star. Until I find a better way to cool the cabin.

    cabininok.blogspot.com is my blog were I am putting logging what we are doing. I need to update it also.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Need a little advice.

    I think you got really good value out of your site survey! :D

    Can't say the same about the system quote.
    Batteries: the heart of the system. Three parallel strings is a bad idea. 675 Amp hours of battery wants 67 Amps charging. That's an Outback FM80 or MidNite Classic, and I don't see a solar charge controller on the list. It also means 2kW of array, not 660 watts. From that wind survey I would not rely on that to make up the difference.

    I can't think of any good quality 3kW 24 Volt inverter-charger for $1,200. There is absolutely no point in buying no-name stuff if you're in it for the long haul. That may apply to that wind turbine as well; someone here probably knows about Missouri Wind products.

    You've calculated 1000 Watt hour (very important) usage? That is quite low. 675 Amp hours of battery would supply up to about 7kW hours, so why buy that much battery if you need less than 1/3 its capacity?

    Use two parallel strings of four T105's: 450 Amp hours @ 24 Volt, capable of about 4.8 kW hours AC. Gives you two days worth of power at 50% DOD given up to 2.4 kW hours per day. Needs one charge controller capable of at least 45 Amps and a 1400 Watt array. More dependable than wind power. If you want to add wind later as a supplementary charging source you can.

    Do you need 240 VAC split phase? If not, just buy a 120 Volt inverter-charger. Magnum (also available as 240) or Outback will serve well. About $2,000 and worth the extra $.

    Just my thoughts. No one has to agree. :D
  • bill and rosa
    bill and rosa Solar Expert Posts: 26
    Re: Need a little advice.
    and I don't see a solar charge controller on the list.
    MW Combo 440 Amp Charge Controller w/ Divert Load (2 Resistor), 24 Volt. It is a hybrid wind and solar charge controller. I am looking at the MPPT Outback but its 599.00 for 60 amps 2400 watts at 24 volts. Compared to $184.00 for 440 amps and 10,000 watts. (lots of room for growth)

    inverter that I am looking at but 3000 watt not the 6000 watt. the 240 is for future growth.

    I can add more solar panels at 349.00 each so i need at least 3 more to get to 1320 watts. Would that do the trick. We have looked at our finances and are willing to spend $6,000 on the system since my quote from the power company to bring power to the land was $6500 complete.

    I will ask him for a quote on the
    Use two parallel strings of four T105's: 450 Amp hours @ 24 Volt, capable of about 4.8 kW hours AC
    to see his price. I got this back in a fast email also.
    I listed (12) T105 Batteries which gives you 675 amp hours.
    You could also go with (8 ) L16 batteries which would give you a 740 amp hour bank.
    (8 ) L16's would cost you $1,960.00 and the (12) T105's would cost you $1,775.40.
    I was just trying to give myself some room for growth and if any of my calculations were off. I also learned that if I dont pull below 30% i could perhaps get 20 years out of the batteries. I would hope for 15 years.

    You have been very helpful I am learning and understanding much better now. I salute your knowledge.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Need a little advice.

    I know nothing about Missouri Wind and Solar products, but a look at the link throws up phrases like "24 Volt Split Phase" which makes no sense (240 VAC split phase does) and "low frequency inverter charger" also makes no sense. It has a built-in MPPT charge controller. Oh goody. A 6kW 24 VDC inverter is something to avoid in my opinion: that's 250 Amps at the rated power. Also its surge rating to 18kW is psychotic. This sounds like the sort of thing AIMS builds, which I also try to avoid. "Optional 25 Watt power-save mode". Oh yeah? An Outback uses 20 Watts running full-out, and about 6 when in stand-by.

    You can buy what you like but I wouldn't touch this thing with a 40 foot utility pole. :roll:

    I'm not keen on all-in-one charge controllers either, because if it fails you lose wind and sun. You can buy a MidNite Classic 150 Lite for $510; 80 Amp capacity and the best controller going right now (you can add the meter later if you want).

    The L16's would give you more Amp hours. Then you'd need more charge capacity. The question is: how many Amp hours do you really need?
    Example: I use 232 @ 24 Volts on 700 Watts of panel and can get 2.4 kW hours per day in good weather no problem. I would like to double the battery bank and array to give me plenty of extra capacity. Haven't won the lottery yet, though. As it is the system cost $8,000 self-installed back in 2008. Today you could get more capacity for slightly less money, especially in the U.S.

    It is extremely doubtful you will get 20 years out of any set of batteries even if you limit the DOD to 10%. Batteries start to go bad the moment they are made, whether they are used or not.

    What can you get out of 1320 Watts of panel? About 2.7 kW hours AC per day. It would charge 423 Amp hours (450 would work) @ 24 Volts. With 25% max DOD you'd have that 2.7 kW hours too. It's a nice match. You can run a lot on that much power. I know because I run a lot on that much power, and I squeeze it out of half as much panel & battery (lots of load shifting).
  • inetdog
    inetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: Need a little advice.
    My professional wind and solar technician has surveyed my property. He had a cool setup that he left on the property for 36 hours to get some data plus he had all sorts of maps and charts of the area. Well worth the $100 dollar fee in my eyes.

    Wind 23 hours of wind over 10 mph at 20 ft off the ground during the 36 hours. Told me if I go higher I will get more wind and speed.

    The maps show the average wind for my property area for the year is 9 to 11 mph. The spring and fall averages are slightly higher at 10 to 13 mph average. Winter and summer fell in the 9 to 11 mph. I dont know the height they took the wind speeds at.

    That is a lot more information than most people start with. (And with that wind, I expect everything in the area to be leaning. :-) )
    But you also need some information about the higher end of the speed distribution. Since turbines are rated at about 25mph, and available power goes as the cube of the wind speed, the 10 mph times will be giving you some power, but not very much.

    Quick pair of examples:
    A: Wind speed is constant at 10mph. Average is 10mph. Turbine is (honestly?) rated at 1600 watts. Result is 100 watts output for 24 hours, or 2.4KwH per day.
    B: Wind speed is 0 for 12 hours and 20 Mph for 12 hours. Average is 10 mph. Result is 820 watts for 12 hours or 9.84 KwH per day.

    Since the tech measured 23 hours of winds above 10 mph during the 36, the peak wind speeds could theoretically still be not much higher than 10 mph and still match the 9-11 average speed values from the charts. (Do the charts you looked at show wind speed at the ground, in which case you are right that the wind at 60 feet could be much higher?)

    My recommendation: Since you already have the towers, put your own recording anemometer at the top and let it run for a few months to a year before spending the money on a wind turbine. That will also allow you to estimate what peak wind speeds the turbine will have to withstand.

    Second recommendation: Do an extensive Google search on Missouri Wind and Solar (including with a "site:www.wind-sun.com" qualifier for this Forum) before spending your money with them.
    SMA SB 3000, old BP panels.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Need a little advice.

    Dump controllers are not "optimum" for charging battery banks--But for systems that need constant battery load (horizontal axis wind turbines, hydro turbines, etc.)--It is something that you have to live with.

    However, for Solar PV Systems you can use a "series" charge controller (rather than a shunt/dump type charge controller).

    There a dozens (if not more) of various solar charge controllers that will meet your needs. From "simple/low cost" PWM controllers ($100-$200) to, very nice (some with data gathering, networking) MPPT charge controllers that can help if your solar array is located a fair distance from your home/battery shed (you can use Vmp~100 VDC from the array, and use an MPPT controller to efficiently "down convert" voltage to your 12/24/48 volt battery bank) for $500-$600+).

    My two cents--Design the system based on 1) loads, 2) battery bank, and 3) Solar PV panels. Then review/pick the hardware to support your loads (probably a backup genset).

    Once you get your system working well, then look into adding wind to your system (basically to give you more power during poor weather and saving fuel costs).

    At this point, no solar/wind system is really going to be "cost effective" for 2-4 day a month use...

    My suggestions, a minimum battery bank to support "quiet time/instant power" for lights/water pump/radio/TV/ and laptop computer/cell phone charging. And enough solar panels to keep the bank floating (minimum) or enough panels to keep up with daily loads over 9+ Months of the year... Use a genset for extra power needs (tools, fridge, etc.).

    Later make a larger battery system+solar array (and your eventual wind turbine(s)) to support heavier loads/full time living/poor weather power requirements. Your batteries will still die in 5-8 years or so--whether you use them or not. They will still need a minimum amount of solar/generator/wind power to properly charge--If you install a 2-4x larger battery bank (for eventual full time living)--Your panels/wind/generator will have to be 2-4x larger now (hardware costs, fuel costs, etc.) to keep the batteries "happy".

    A $1,100 or so Honda eu2000i genset plus 3 gallons of fuel for 24x7 power usage--A few days a month... Not the end of the world. That would be ~100 hours per month. Generator should last around 2,000-6,000 hours. Around a 2-5 year generator service life (all things being equal--which they rarely are).

    And if your "smaller" system can supply lights/computer/cell phone energy for 16 hours a day (and generator for 8 hours of "high power" usage)--Even less fuel and longer generator life.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • bill and rosa
    bill and rosa Solar Expert Posts: 26
    Re: Need a little advice.

    can I ask you too look at these solar panels and tell me what you think.
    Shipping & Handling: $198.76 to my local ace hardware (cheaper to ship to him) 318.00 to my property
    I was trying to get the full package from one place but I might have to buy a few items else were.

    Thank you
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Need a little advice.

    While the panels look like a good deal (check shipping/insurance costs to your door--Those can be very significant), I would suggest you do a paper design first.

    Buying equipment then trying to fit it all together in a "balanced" system design can be frustrating and expensive.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • bill and rosa
    bill and rosa Solar Expert Posts: 26
    Re: Need a little advice.

    Need a little more of your time. I know you guys are getting tired of me (hope not).
    think batteries.
    i need 1000 watts to run my basic needs
    24v batt =1000 / 20 = 50 amps
    then
    24v batt 50amps x hours I need = AH required from battery bank.

    If this is correct I will need a 1200 amh in my bank for 24 hour coverage.

    my panels will be 220watt x6 24v. 1320 watts. was thinking of 24 volt battery bank with eight of the T105’s (225 amh) total amp hours is 900. (if my math is right) this want work then.
    Or did I miss something.

    Not even adding the wind power until I get more data from my own weather station $145.00 from walley world, with wind attachment. Will run it for 6 months to get a good average.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Need a little advice.

    Do you mean you need 1000 Watt hours?
    That's 1000 / 24 Volts = 42 Amp hours, or 84 Amp hour battery minimum.
    You have to use the right units in the right order. You also have to remember that 1000 Watt hours AC is higher on DC because of conversion loss (the exact amount varies with the particular inverter but is usually 10%). And you have to include the amount of power the inverter uses (which also varies with the particular inverter).

    So 1000 Watt hours AC becomes 1100 Watt hours DC. If the inverter uses 20 Watts and runs all the time that's an additional 480 Watt hours. The total is now 1580 Watt hours.

    1580 / 24 Volts = 66 Amp hours. At 50% DOD that's 132 Amp hours. At 25% DOD (better) 264 Amp hours.

    If the 1000 Watts is maximum draw that will size the inverter, but it has little bearing on the battery capacity needed. For that you need to have some idea of the Watt hours.
    You seem to have derived this from an odd formula of averaging the maximum draw over 24 hours?

    Your 1320 Watt array on an MPPT controller would support 423 Amp hours +/- a bit. If you went with the 220 Amp hour batteries you could have two parallel strings for 440 Amp hours @ 24 Volts. In basic math terms that would be around 2kW hours @ 25% DOD and a peak charge current around 9% so it would work fine. The panel to AC Watt hours would be 2.7 kW hours (based on 4 hours equivalent good sun and 52% over-all system efficiency). Again that works.
  • Eric L
    Eric L Solar Expert Posts: 262 ✭✭
    Re: Need a little advice.
    i need 1000 watts to run my basic needs

    Bill, I know Cariboocoot asked you this twice above and I'm sorry if I missed your answer, but it's unclear whether you mean 1000 watts per hour (for each of 24 hours), or 1000 watt-hours per day.

    The difference is, obviously, huge; it's the difference between 24 kilowatt hours per day, or 1 kilowatt hour per day.

    One other thought here. As you know, OK is incredibly hot in the summer. Last summer it broke a record with an average temperature of 86.9 degrees. At night, it barely cools off. This means you and your batteries are going to be subjected to high heat in the summer. Even if you can take it, batteries don't like that - it shortens their life -- so you'll need to think about a way to keep them cool.

    Needless to say, 1000 watt hours per day is not nearly enough to run an air-conditioner, even a small one, if that's what you had in mind.
  • bill and rosa
    bill and rosa Solar Expert Posts: 26
    Re: Need a little advice.

    Im sorry I should have been more specific
    the 1000 watts would be my daily normal usage, frig, lights, fan, tv. Everything else runs off gas (propane) This wattage is giving myself a extra 100 watts. I know thats tight but if I can achieve this then I know adding a couple batteries to my purchase would probably be good. Looking at the t105 450 but havent gotten a good price yet.

    Sorry for the confusion.
  • bill and rosa
    bill and rosa Solar Expert Posts: 26
    Re: Need a little advice.
    Your 1320 Watt array on an MPPT controller would support 423 Amp hours +/- a bit. If you went with the 220 Amp hour batteries you could have two parallel strings for 440 Amp hours @ 24 Volts. In basic math terms that would be around 2kW hours @ 25% DOD and a peak charge current around 9% so it would work fine. The panel to AC Watt hours would be 2.7 kW hours (based on 4 hours equivalent good sun and 52% over-all system efficiency). Again that works.

    Can you help me understand the basic math terms for the conversion of 2.7 kw and 2kw hours Im a bit confussed.
  • bill and rosa
    bill and rosa Solar Expert Posts: 26
    Re: Need a little advice.
    Eric L wrote: »
    One other thought here. As you know, OK is incredibly hot in the summer. Last summer it broke a record with an average temperature of 86.9 degrees. At night, it barely cools off. This means you and your batteries are going to be subjected to high heat in the summer. Even if you can take it, batteries don't like that - it shortens their life -- so you'll need to think about a way to keep them cool.

    Needless to say, 1000 watt hours per day is not nearly enough to run an air-conditioner, even a small one, if that's what you had in mind.

    Will be running a propane generator to power 2 small 110 Air condition units. one in the solar control room and one for the cabin. Until I get a better way to cool. The cooling has been a pain in my back side other than the constant wind we have there. Hot air is better than no air I have been told.

    Hoping my artesian well is a blower (cold air that is) and will feed that into the solar control room,
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Need a little advice.
    Im sorry I should have been more specific
    the 1000 watts would be my daily normal usage, frig, lights, fan, tv. Everything else runs off gas (propane) This wattage is giving myself a extra 100 watts. I know thats tight but if I can achieve this then I know adding a couple batteries to my purchase would probably be good. Looking at the t105 450 but havent gotten a good price yet.

    Sorry for the confusion.

    This is still confused because Watts does not include the very necessary time factor. If you use one Watt for one hour that is one Watt hour; a quantity of electric power.
    A refrigerator, for example, may only use 120 Watts running but over the course of a day it could use 1200 Watt hours. Something that uses even less Watts running but is on all the time can end up using more Watt hours per day. The total Watts used at any given time is needed to make sure the inverter is large enough to handle that maximum load. The total Watt hours used in a day is vital to making sure the battery bank is large enough to supply the power needed.
    Can you help me understand the basic math terms for the conversion of 2.7 kw and 2kw hours Im a bit confussed.

    Two different source references.
    1320 Watts of panel * 4 hours equivalent good sun * 0.52 over-all efficiency rating = 2.7 kW hours 'harvest' per day from the panels.
    440 Amp hours of 24 Volt battery @ 25% DOD is (110 Amp hours * 24 Volts) = 2640 DC Watt hours. Subtract allowance for powering inverter and factor in conversion to AC and you get a number pretty close to 2 kW hours potential from the batteries.

    If you can make use of the power available from the panels after the batteries are fully charged (which would otherwise go unrealized) you can squeeze more Watt hours out of the system. This is 'load shifting' and/or 'opportunity loads'; turning things on at the full charge mark so make use of that panel power potential that would otherwise be lost.
  • bill and rosa
    bill and rosa Solar Expert Posts: 26
    Re: Need a little advice.

    i used this site to plug in my kill-a- watt information to get my daily wattages. hours of use of tv, lights etc. (basic tutorials)

    system size

    battery bank designer i have wore out