wind turbine recommendations

brenneisbrenneis Solar Expert Posts: 34
I have seen a lot of putting down on this site of people who want to put up small scale wind products themselves as opposed to professional installation. I am no contractor but it doesn't seem that hard to dig a 5 foot hole and insert a 1.5 inch galvanized pipe, level and pour concrete. I think cost is a consideration for all of us with professional installation.

So what wind systems do you guys recommend for small scale wind production. We use a lot of power in our house because of kids, pool pump, irrigation pump etc. I honestly don't want to change my lifestyle but I would be willing to pay to offset my use for personal power.

I live in Southeast PA and we have weeks where we get very high wind at low height because I live on a hill. This may sound silly but I was thinking about mounting 1k or so wind turbines on a 15ft 1.5 inch galvanized pipe and painting them in brown and green to match my landscape (yes I am ex army and camoflouge (sp) was drilled into us. Since we have an acre of land I could add one or two more as I can afford it on different areas of my property kind of like trees to look astheticly pleasing. My neighbors will kill me if I stick a big white fan with a 10 ft wingspan 35 feet in the air???

I too have looked at some of the models on ebay like windmax ex and have read the links stating they are bad but no real proof. Am I just p ing in the wind here no pun intended with my idea of dotting my landscape with smaller lower height generators....

Comments

  • BB.BB. Super Moderators, Administrators Posts: 29,967 admin
    Re: wind turbine recommendations

    brenneis,

    Sorry--your post was placed into the website announcements queue--which we (Niel and I) don't normally monitor (the announcement sub-forum requires us to actively approve posts here before others can see them--nowhere else is that required here--so we tend not to look for these posts as they look almost identical--to Niel and I--as every other post here that do not require moderation--so nobody else sees them).

    I will give my "standard answer" to wind turbine questions--but be aware, I do not use wind turbines or have anywhere I can install one.

    First question... Is this for an On-Grid or Off-Grid application (no batteries, or battery based system). Most Wind Turbines generate DC for battery charging and you need another conversion step to AC (inverter). Batteries tend to be expensive and a bit lossy (80-90% efficient)--so off-grid systems tend to cost more, have more loses, and require more maintenance vs Grid Tied...

    There are one (or more?) "home sized" Grid Tied Wind Turbines available--so that is one issue.

    Another is the mounting of a wind turbine. Lots of stresses from wind, vibration, and flexing. Requires lots of concrete/bracing/large mono-pole to hold them safely. Can be done by a do-it-yourselfer. However, using a civil engineer / pre-designed mounting package would not hurt (don't want pieces of wind turbines ending up damaging your or neighbor's property or people if/when they fail).

    In general--you would want to mount the wind turbine at least 30' above any obstructions within 300-500 feet of the turbine (up wind obstructions). And for best results--you would probably want to be on a minimum of a 60 foot tall pole. Wind speeds are much higher once you get out of the turbulence/drag of the ground and make for much higher average generation numbers.

    Wind looks cheap--however, most people do not have high prevaling winds (example; local trees permanently bent by prevailing winds) at their site. If your planned site is not miserably windy (for many hours/days at a time) for the average human--then you will probably not get much power.

    Also, wind turbine require maintenance--so if you mount one 60+ feet in the air--are you going to need to pay riggers once a year to inspect/lube the turbine and replace very 1-5 years (seems to be the life of the average "home turbine" from what I have read). Those will really drive costs up.

    In the end, there may be a few good turbine designs out there--However, for the most part, installing solar PV panels for most people, would generate more consistent power.

    A recent poster here put some interesting history in this thread about their wind turbine installation. I cannot say that this is an average example--but it does highlight that wind turbines should be near the bottom of Solar RE systems at this time (because of low production and high maintenance requirements).

    This thread discusses a little bit of the issues with "cheap" turbines and how much a vertical turbine can generate (not much)... Please take "Kimberly's" posts with a grain of salt--"she" was sock-puppeting here and left pretty soon thereafter.

    In the end--your best solution would be to spend your time and money on conservation first... Insulation, Engery Star appliances, measuring/documenting loads, change in energy habits (turning things off, using passive solar heating, etc.).

    Conservation is almost always a better investment for your money vs generating your own power with solar RE.

    Grid Tied systems (currently, Solar PV Panels plus GT Inverters) are usually your most cost effective means to generate AC power if you are currently on grid (and your utility supports net metering for GT/Utility Interactive Inverters)--plus you usually can get nice state and federal tax rebates.

    However GT systems, because there is no battery bank, do not provide emergency/backup power--so they may not give you what you want if you have less than reliable utility power (storms, ice storms, local outages from falling trees, etc.).

    Off-grid power systems (and hybrid GT/Off-Grid systems) can give you power whether or not the grid is up--but tend to be 2-5x or so more expensive (per kWhr) vs GT systems.

    Also, pure Off-Grid systems generally may not apply for state/federal tax rebates/credits (laws are changing).

    Anyway, not to "scare" you off of wind--but in my humble opinion, a 1 acre lot may not be large enough to safely mount a wind turbine on a 60 foot pole (keep falling parts on your property) and wind turbines are usually pretty noisy--so if you have nearby neighbors--that may be an issue too...

    Bergey has some nice Excel Spread sheets you can play with to see how much power a system can generate in your area (based on tower height, average wind, altitude, temperature, etc.).

    And you can read through this pro-wind site (link from our host's NAWS web-store) for more information (such as one state planning on removing tax credits for wind-power as the sites generate so little power--Massachusetts Small Wind Report 2008).

    Your thoughts?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: wind turbine recommendations

    actually we aren't against somebody putting in their own wind genny, but just feel there aren't any really worth installing at this point. for the record, a 1.5 inch mast is not strong enough for a wind genny unless you are talking solid all the way through rather than hollow.

    ps-curb the swearing.
  • icarusicarus Solar Expert Posts: 5,400 ✭✭✭✭
    Re: wind turbine recommendations

    I would read ALOT about small scale wind from people who have actually done it in the real world,,,, as opposed to sales brochures. I think that you will find that there are very few people who have had a favorable experience with it. Those that have have spent a lot of time getting educated and learning by the school of hard knocks.

    As I understand,,, one of the biggest issues with wind (aside from the fact that people overestimate the amount of wind they really have!) is turbulence from ground effects such as trees, buildings etc. This turbulence is what blows wind machines apart,,sudden micro shift in direction/speed/updraft/downdraft etc. That is why most wind machines start at +30 off the ground,,, even at hill top locations.

    If you think this is a matter of digging a few holes, pouring some concrete and putting some blades in the air I think you will be disappointed.

    Tony
  • HE411HE411 Registered Users Posts: 7
    Re: wind turbine recommendations

    You are on the right track brenneis but I'm not sure of your train of thought. Harvesting power from the wind is not a simple matter. As you have already learned many have spent thousands on wind a system that failed to live up to their expectations. Why did they fail? Lack of buyer knowledge. Look at the manufacturers spec sheet cautiously. If you see a wind genny advertised as producing 2kw of power in a 7 mph breeze with a 4 foot rotor then you are looking at a definite scam. It is physically impossible. As you already know, everything starts with the amount of wind available at your site. One acre of land is enough for a wind genny but if your annual average wind is low then a small turbine will be disappointing. How low is low? If you live in a class 2 wind zone then you are in a low wind zone. Take a look at http://rredc.nrel.gov/wind/pubs/atlas/maps.html#2-12 to find your zone classification.

    There is only so much power in the wind and an efficient, well built system can, at best, harvest about 40% of the total power available. That's the nature of wind energy. To generate big power you need a big machine and power comes from the size of the rotor. Useful power can be generated with an 8 foot rotor in higher winds but don't expect to make serious break away from the grid power with it. What you describe doing is fine for experimenting but don't expect too much from it. Putting a small genny a few feet off the ground will give dismal results. 30 feet up is good, 60 feet is better and 100 feet is better still because there is simply more clean wind to harvest the higher up you go. Keep in mind that height = cost. A safe, adequate tower can easily be well over half the cost of a complete system. And yes, the tower should be at least 30 feet higher than the tallest land object within 500 feet of the tower. Why? To get into clean air that is free of turbulence.

    So, to sum things up, do your homework first. Figure out exactly what it is you want to do. If you want to become grid free or just reduce you monthly power bill will determine what size system you need. Take inventory of your total home power demand. Have a look at www.AdvancePower.net and use their on line calculator to help with the inventory. Study the wind at your site to determine whether or not there is enough wind there to do what you want to do. Wind maps give you an idea of how much wind is there but a site specific study is needed to make the ultimate decision. If there is not enough wind then consider solar or a hybrid solar/wind system to achieve your goals. I highly recommend the book Wind Power by Paul Gipe as an excellent well founded basic education in wind power. Google the title and author to see a preview of the book. Lastly, try not to become discouraged. Energy independence is a big step and must be thoroughly researched and planned to get the most out of your system and to achieve your goals.

    Hank
  • icarusicarus Solar Expert Posts: 5,400 ✭✭✭✭
    Re: wind turbine recommendations

    Nicely said Hank!!

    Tony
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: wind turbine recommendations

    yes, ditto what tony said from me and the links are good too.
  • brenneisbrenneis Solar Expert Posts: 34
    Re: wind turbine recommendations

    thanks guys, I have been doing a lot more reading and figuring out just how many wind scams are actually out there. I was almost sold on a 5k wind turbine at 15 feet with 6 foot rotor...generates power at 7mph....then the common sense factor started to kick in and I got that feeling on the back of my neck that something didn't seem right....was an ebay dealer.......I still might do a small turbine just for experimentation but I have given up the idea of off the grid with my landscaped wind farm....LOL.......to really get what I would need in consultation with a professional would require a 40 foot tower and a 12 foot rotor and a 15k genny.....that just aint gonna happen.....

    PS...sorry didn't really think I was swearing with the word p_ _ _ ing in the wind...thought it was a nice play on words...
    rather than make a distraction from the subject matter i will just say here that we'd get the meaning in how it has been rewritten as we still get some kids and ladies from time to time. a few asterisks or something like it can also be substituted rather than spaces, but don't worry too much of it as long as you think who might read it.;)8)
  • icarusicarus Solar Expert Posts: 5,400 ✭✭✭✭
    Re: wind turbine recommendations

    Good on ya for ready, aim, fire,,, rather than ready, fire , aim! The idea of a small cheap wind gennie as an experiment is a fine idea. I have toyed with the idea myself for years,,, just haven't done it.

    Tony
  • WindsunWindsun Solar Expert Posts: 1,164 ✭✭
    Re: wind turbine recommendations

    Responding to wind power questions and problems is one of our big time wasters in our store. Wind has been so overhyped and there are so many scams that far too many people start believing it.

    About 80% of the questions we get are for wind generators that we did not sell, and quite often recommended against, such as the vastly over-specced VAWT's that now seem to be the rage.

    We have been de-emphasizing wind for quite some time, we just got tired of explaining to people that 400 watts or whatever is the absolute best case scenario, and 95% of the time they will not get anything close to that.

    One of the biggest problems we see with small wind is that it would be very expensive to make a well engineered and very reliable unit. For example, we probably only sell about 100 of the Air-X type a year anymore, but we sell about 250 blade sets a year.
  • EcnerwalEcnerwal Solar Expert Posts: 101 ✭✭
    Re: wind turbine recommendations

    If you want to read the trials, travails, sucesses (and some impressive failures, with gory pictures) of folks doing wind rather seriously (and generally not with commercial turbines - they build their own, and have made those more robust over time, if you go and read about the old systems as well as the more current ones) poke around

    http://www.otherpower.com

    Most of the good gory details are under "experiments" in the current organization of the website, and down at the bottom of "wind".

    For me, wind is right out - I'm in a lousy (1 or 2) wind zone, and I have 85 foot trees which I don't want to clearcut. I'd need a huge (120-150ft) tower to get up to what little wind there is, and the expense in to energy out is not there. There's a guy near me who has one (grid connect, induction type) he was given, which he's invested about $4000 in (with free tower and turbine) to play with. He's had it up a few years, and had a net output of 153 KWh over the years as of the last time I visited. It's his hobby project, so he's happy, but it's clearly not an economic winner - I think the cut-in speed is 13 mph. Being in a lousy wind zone means there just isn't much power available, even if you feel like the wind blows sometimes.

    Still, it can be a fun thing to play with, even if it's more or less whirly-gigs and ornaments to put on the well-house (at least where I grew up, the miniature Dutch windmill was one of the more common things to be sitting on top of your well in the yard.)
  • System2System2 Posts: 6,290 admin
    Re: wind turbine recommendations

    I understand the Math and wind dynamics. But I just don't understand this Half Acre to One Acre requirement. The three wind generators in San Francisco are on top of Flats and Apartment Buildings in Residential neighborhoods. The American Wind Energy Associations Labeling of "There" recomendations has put limitations on us all. It has caused uneducated people to write zoneing and other laws for an Industry that is only in its very beginnings. You and I both know that right now there are hundreds of back yard tinkerers answering the very questions you and I ask. Accept one.... What do you mean I can't put this up in my back yard to test it? The Answer My Friend Is Blowin In The Wind!!
  • BB.BB. Super Moderators, Administrators Posts: 29,967 admin
    Re: wind turbine recommendations

    In general--Wind turbine blades and structures can fail. And having a large enough lot such that the tower only falls on the owner's property (and/or shedding blades which can travel pretty far) would limit liability problems.

    The other issue is noise... That seems to be a wild card for at one manufacturer. Some turbines/installations seem to be pretty quite... Others keep the neighbors awake.

    Of course, where the turbine is installed (city, country), expectations, and NIMBYism (Not in My Back Yard).

    And there is the practical side of wind--the turbine should be at least 30' taller than any structure within 500' (zoning issues--30'+ higher--add blade radius to that--than any other nearby structure)... And to really have any chance at generating significant power; 60-120 foot towers are much more desirable.

    In the end--typical horizontal axis wind turbines of any size tend not to be very neighborhood friendly. And Vertical Axis Wind Turbines tend not to generate much power (but the smaller "Urban HAWT" don't generate much power either).

    Lastly, for example a Skystream 3.7 meter diameter turbine on a 30-60 foot tower, in a windy location, generates ~$20-$60 worth of electricity per month. And in an urban setting maybe a fraction that.

    Who would risk $10,000+, or fight city hall, risk angry neighbors, etc. for a hand full of dollars worth of power per month.

    Here is one Skystream buried among apartments on a 45' tower among three story blocks in the San Francisco Mission District. Which is interesting, in San Francisoo the oldest districts had the best weather (good sun, less wind)--that is why they were settled first. According to wind 30 meter maps (like this one), The entire city is less than 10.1 MPH. Video of it running here.

    I would be very interested to find out how much power the turbine has generated (per month). I am always ready to learn new things.

    The Skystream owner has setup a company to install wind turbines (zero energy home). So, perhaps we will see more of them.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
Sign In or Register to comment.