Wind/solar hybrid systems


My objective is to get some of the new folks enthused about what is possible with a system like ours. Many of you have larger systems. A handful of you could probably offer me advice regarding my system. We've been off grid for 5 years, certainly there have been mistakes along the way. We have had an anemometer above our place for over 2 years. We have an 11.5 mph wind resource--certainly very average. As far as solar isolation--30 miles from Pocatello, Idaho. Let me make this clear, I am no expert. Our hybrid system is not perfect. There is much to accomplish. More panels will be in our future, probably one more wind machine as well. That said, I have not run our gasoline generator in 2 years.

My immediate objective has been to cut our propane use to where we use it for cooking, at our discretion. We currently utilize a kenmore clothes dryer that is propane fired. We do have a back-up Bosch Aquastar (propane) for times when we have guests. We utilize a wood stove for heating in winter. We use compact flourescent bulbs for all of our lighting. Here are our daily/weekly loads....

15 gal. Marathon electric water heater 120v set for 130 degrees--2 baths daily. (2000 watt).
Frigidaire Commercial 20.6 upright freezer. Kenmore 6.0 compact refrigerator (w/ no freezer). Sony 27" T.V. , DirecTV box, Small Sharp Microwave, Reg Coffee maker. Our weekly loads include a Speed Queen Heavy Duty clothes washer. The electric portion of our Kenmore dryer. A big Dirt Devil, portable, booster pump 1/2 h.p. for watering. Various power tools, portable swamp coolers (60 watt), and of course this p.c.!

We do want to get a 120 volt clothes dryer. We would like to get a larger, energy star refrigerator. We are, however at our power consumption threshold. More loads will require more panels--and turbine. There are days where the system would certainly power the extra loads---but we do try to make it through absorption cycle every day with those batteries. That, in itself can be challenging with the loads we already run.

We try to add to our system a little each year. As you power more loads, there always seem to be more loads that you would like to power. This keeps me coming back to NAWS.




  • BB.BB. Super Moderators, Administrators Posts: 32,004 admin
    Re: Wind/solar hybrid systems

    You probably have done this--but just to cover all of your bases... You need average kWhrs per device plus how much (and what month) power you are generating from solar and wind. Depending on equipment age and usage, you can get quite a wide difference in electrical power required.

    My humble suggestion would be to first install solar hot water heating for your bath water. This would probably be more cost effective than purchasing more panels/inverters/storage to run the hot water. And you can use the electricity saved for other uses without installing more capacity. You could also use solar hot water or solar hot air to help heat your home and cut down on wood usage too...

    I am pretty impressed that you are able to run your current electrical loads without the generator.

    Providing some basic numbers about power generated and consumed should also help others in their quest for solar power too.

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • RoderickRoderick Solar Expert Posts: 253 ✭✭
    Re: Wind/solar hybrid systems

    Now that's an inspiring system!

    Do you use a computer much, and if so, how much power does that take?
  • System2System2 Posts: 6,290 admin
    Re: Wind/solar hybrid systems
    BB wrote:
    My humble suggestion would be to first install solar hot water heating for your bath water. -Bill

    That is one very excellent suggestion!! There is just NO comparison in the efficiency regarding the heating of water. This would give you much more hot water than you now have and free up a lot of electricity for other uses. Another thing, have a serious look at your upright freezer consumption, generally, they use a lot more power than chest types, especially the newer ones with 3 inches of insulation. Finally, have a serious look at your fridge consumption, the new energy star units can save you tons of power. It's far easier and far cheaper to conserve through efficient use, than to produce and store more power. And, what about a natural, outdoor clothes dryer? It costs nothing to operate a clothes line.
    Good luck and thanks for your informative post. You've got an awesome setup.
  • System2System2 Posts: 6,290 admin
    Re: Wind/solar hybrid systems

    Bill, Roderick, Wayne,

    Thanks so much for your input. I need to take a second look at solar water heating. The reason I have overlooked it in the past is because the water from our spring bubbles through limestone--among other things--and I have always thought our water was too hard. Visions of crusted deposits plugging everything up have steered me away from that option.

    I also believe it is sound to utilize something like a Trimetric. I have one, and played around with it for a couple of years. When the new batteries arrived and the new charging sources--I simply need to re-engineer my negative bus to accept that shunt. I do agree that the unit gives you some idea of what goes into the bucket and what comes out. I will say that the MX60 average between the 2 units is 15-16 kwh (summer). They control 2 separate, fixed arrays set at winter angle. Keep in mind that the MX60 numbers are often reduced by wind turbine contributions, sometimes dramatically. The nice thing about wind assets is that they are your charging source at night, which often gives you a higher system voltage come morning. Also, the combination of wind/solar charging sources is simply necessary if you want to run the larger loads regardless of weather conditions-- and refuse to start the gasoline generator. One of the reasons I mentioned the acquisition of another solar array and another turbine was to have the ability to run some electric heat--even at night. I had done this in the past, but the water heater has been a major draw. By the way, the reason I chose the Marathon unit was due to its efficiency.

    Roderick, We run the P.C. 2-3 hrs in the day/night. I need to get back in there and see what it draws. It can't be more than a drop in the bucket.


  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Wind/solar hybrid systems

    there isn't a requirement that your drinking water from your (limestone) well water should pass through the solar collector and you're right it shouldn't. the solar collector system can and should be seperate from it. an easy example would be having the collectors heated water go into a 55 gallon drum where the copper pipe is coiled to release its heat to the water in the drum. the drum water could be your limestone drinking water, but if you run antifreeze through the solar collector your drinking water has to be doubly protected, which means just dipping the coil into the drum with your drinking water is out of the question as that is only 1 barrier. there is a solution and it would depressurize the drum too is by putting in another coil of copper pipe carrying your drinking water through it in the drum water where the coil for the solar collector is also to go off as heated pottable water with 2 barriers of protection afforded. granted the heat transfer has another step, but the law states 2 barriers when antifreeze is involved. this example isn't the only way either, but shows you it can be done and if you're worried about the deposits then your whole place's plumbing is subjected now to these deposits. you may wish to look into filtering to reduce the future damage to your plumbing system.
  • System2System2 Posts: 6,290 admin
    Re: Wind/solar hybrid systems


    Thanks for your explanation. Sometimes I think too mechanically. I perused our Energy Conservation thread regarding the same subject.......

    Can we switch gears and approach the problem from a different angle? Has anyone come up with a way to make a 5 h.p. industrial engine run on straight hydrogen? If so, it follows that you could get a generator to run on the stuff. You could then utilize your electric water heater, electric heating and charge your batteries. (I'm sure fuel cells are very sexy, but way too spendy for me). I wouldn't be all that concerned about the efficiency of such a unit, just that the motor would run. Once you began making and storing your own hydrogen, you'd be done. If you could cheaply distill your own water, you'd really be done.

    Maybe I will switch to decaf!

  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Wind/solar hybrid systems

    you'd have a bigger problem of making and storing it. you could make it with electricity, but in any conversion there are losses. all this if the appliances are able to utilize the hydrogen at all, let alone with any kind of efficiency as they weren't originally designed for hydrogen. i know of one person(richsas) who told me he was experimenting in the area of hydrogen and i haven't heard from him for many months now so i have no idea what progress if any he's gotten in it.
  • TelcoTelco Solar Expert Posts: 201 ✭✭✭✭✭
    Re: Wind/solar hybrid systems

    An idea - A solar water heating shed.

    Found this while researching a new build, and decided that barring a better method this is how I'll be going. You can use a closed loop with distilled water and antifreeze, and transfer water with a heat exchanger. Radiantech shows some different configs for open, indirect and closed systems, and one site I looked at (don't have the link handy) showed a heat exchanger the size of your head that was rated for a huge amount of heat transfer. If the heat exchanger itself isn't double isolated, then using two of them as a chain link between the house water and the solar water would work fine. Might need a tiny pump to keep water circulating within the loop, and you'd need a way to remove the exchangers for cleaning and repair (mainly an issue with the limestone side).

    If you build the system large enough, you could also incorporate it into a central heat and air system. It doesn't matter how the air gets heated, just so it gets hot. Would not need a fancy heat exchanger either, although I'd consider one just in case of leakage. Depending on the antifreeze used a pinhole leak would make the whole house stink and might be dangerous to boot.

    For emergency heat, a wood fired boiler could be used to heat the water tank in the shed. One fire would heat everything, and the fire would not be in the house.

    Hope this suggestion helps. The only thing I see a real problem with is getting it all installed into an existing house, might require some major work. I'm wanting to incorporate all this into a new build, so the issues won't be a problem for me. Just planning on a large room dedicated to household utilities.
  • mike95490mike95490 Solar Expert Posts: 9,358 ✭✭✭✭✭
    Re: Wind/solar hybrid systems
    deepcreek wrote: »
    Maybe I will switch to decaf!

    I'm already including plans for my remote system, to be able to run from what's called, Cold Start, low speed diesel. Lister in England made these in the 20's, and there are some clone mfgrs around, but it looks like the right step for me. These are in the single cyl 6 - 12 HP range, and even some twin configurations - up to 24 hp, but for me, 6hp, spinning a 5KW generator should do me nicely for a couple hours a week. Once broken in, they can start and run on home grown veggie oil, which is way easier than trying to crack Hydrogen out of water. As for running hydrogen in an existing engine, I think it detonates too easily, and modifications need to be made to the piston/head area, mayeb lowering compression ratio.
    Slow speed diesel info:
    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

    gen: ,

Sign In or Register to comment.