"Free Whisper 200 & 50' tower"

SheldonSheldon Solar Expert Posts: 51 ✭✭✭✭
Some back ground:

We were given a Whisper 200 & 50 ft tower kit, built in '04 by the widow of a former colleague, its a long story, but the system was never unpacked.

We live South of San Jose, (near Gilroy) on the valley floor, where we get fairly predictable afternoon winds and have a very predictable "marine layer" which blocks sun till 11:00 most days.

I'm a graduate EE, and lifelong sailor, have worked with Photonics at the micro-scale as well as power conversion at the component level for > 30 yrs, so I am I think realistic about what to expect from wind energy conversion.

We would like to use this in a grid tie for reducing our power billing, we have had up to 30kWhr a day in peak summer, with pool pump and AC. Eventually I plan to add PV for additional capacity. I don't see a need for significant battery back up, we have a 3600 watt Honda Generator for any long run grid fails.

After reading the other threads, I am glad I didn't buy a SWWP product, especially one of recent vintage, though I have spent $500 for an engineered foundation plan and plan to spend another $400 for permits and $300 for tower pipe, as well as buy an inverter etc.

Having said all of that: a few questions:

Assuming that the system efficiencies at 48V are significantly better than at 24, I would go that way unless there was a significant reason not to, opinions?

Looking at inverters the only ones I am aware of with 48V inputs and 120/240 output puts me into either a Xantrex XW, or an Outback CVFX3648, any better alternatives?

Both of those have excess capacities, for the expected 1kW peak output of the turbine.
I would add up to 3kW of PV, using either an XW MPPT charge controller or similar.

What bits and pieces would I need to compete the install other than 4x 12V batteries?


  • BB.BB. Super Moderators, Administrators Posts: 30,629 admin
    Re: "Free Whisper 200 & 50' tower"

    If you are still looking at installing a wind turbine--check the output voltage. Many work better at 12 volts vs 48 volts.

    Also, if you are looking at a battery based GT system + DC Wind Turbine, then you may want to look at / wait for the Midnite Solar Classic MPPT charge controller for Wind Turbines. It may address quite a few of the weaknesses in wind turbine power generation (i.e., matching alternator I*V curve to battery I*V curve for better output).

    You can setup the PV + GT system without the wind turbine component and add it later when you have nailed down a cost effective setup.

    Otherwise--my two cents. If you have a genset + fuel to handle you grid failures and don't need battery backup--You may be a lot better off with just a simple PV+GT inverter without the battery bank. A lot cheaper (no charge controllers, no batteries, no replacement batteries every 4-10 years) and no batteries to monitor/clean/water/store/vent/etc.

    I would like the GT + Battery Backup -- but in our area (San Mateo, just south of San Francisco on the Peninsula) we have so little in the way of power failures that battery backed off-grid/hybrid just is not cost effective.

    Regarding your genset--look at matching your power needs to available fuel. You started out right with a smaller genset. If you really do not need a lot of power, can store gasoline for a year (with fuel stabilizer) you may wish to look at the Honda eu2000i -- Very fuel efficient at 1/4 load (400 watts) and quiet for powering a fridge/freezer and a few lights/radio/etc... You can still use the larger genset for well pumping/AC etc. when needed.

    Most gensets only run at 50% of rated fuel flow at 50% and less electrical output. Many of the 5+ kWatt units are very fuel inefficient at lower loads and noisy as heck.


    PS: Here is a thread with a bit more details about the Midnite Classic setup...
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: "Free Whisper 200 & 50' tower"

    morning bill and merry christmas to you and your family in addition to the op and all on the forum as well.
    i don't think he has much of a choice as to if batteries are needed as the whisper series turbines are not straight gt like the skystream. he is going to have to make a choice on which battery configuration to use, be it 24v or 48v and that is what i believe is the main focus of his post.

    can i assume all is with the turbine, including the controller? your dilemma may come down to being solved by needs and availabilities. the efficiency will be slightly better at 48v, but we could be splitting hairs on it. a large high power system may be best run at 48v, but i don't think your system may fall into that category that would nearly mandate the 48v system. 48v systems do have to add pvs or batteries such that it adds up properly so more is needed when an upgrade occurs. for example in 24v battery arrangements this can be reached with 2 12v batteries, but for 48v this has to be 4 12v batteries. the 24v battery bank will have any additional capacity added in parallel and most advise against too many paralleled strings of batteries as inequities start to arise more easily in charging and discharging and wiring needs to be much larger to pass the higher currents present in the lower voltage system. it is doable though as 2 paralleled strings of 2 12v batteries in series of very heavy capacity batteries can be configured to handle most systems with a possibility of a 3rd string of 2 12v batteries many would say may be pushing it, but we'll call it doable as well and somewhat of the limit.
    of course you don't want to drain the batteries beyond 50% and if you find the 24v battery system may be depleted to this point or beyond that this may necessitate the 48v battery system and then start paralleling strings of batteries for more capacity as needed. rather than 2, 4, or 6 batteries as in the 24v battery bank systems, the 48v battery banks will go in multiples of 4 for 4, 8, or 12 batteries.
    you mentioned the voltage availability of inverters as a possible sway point as you are right that more 24v stuff is out there so this could be a deciding factor if you can't make up your mind for those cases that will work well in either battery voltage scenarios.
    lastly, the future pvs will need to be added in higher multiples where a 48v battery system is utilized, but with an mppt controller you may want to use a higher pv voltage anyway and this could work in a straight through apples to apples manner as well depending on the voltage specs of the pvs in question.
    i guess the bottom line is you need to determine your loads first and work out various conditions and needs from there to see what fits best both now and in the future with the turbine's output as part of that equation. batteries can be reconfigured or added to as long as they are in good condition and not too much time has elapsed (within a year with less as best) since the original purchase.
    i guess you figured it out that there isn't any straight answer unless a 24v battery bank is overtaxed. the efficiency of the inverter would be about 1% better on a 48v system and wiring losses are easier to overcome at 48v.
    allot to weigh.
  • SheldonSheldon Solar Expert Posts: 51 ✭✭✭✭
    Re: "Free Whisper 200 & 50' tower"

    Thanks for the replies.

    Yes as far as I know all of the pieces are together with the whisper 200, including the charge controller. I don't feel a need for a battery back up, but as you note the whisper is not configured to run without. I am thinking I can use relatively small batteries, something along the lines of a 4D at most to effectively ballast the turbine, as compared to providing reserve capacity.

    As this is a gift, I am somewhat obliged to make use of it, and there is also a derivative value as we will be starting a winery and its a good locator beacon.

    As regards the 24 vs 48 question, clearly there is a 2:1 difference in battery costs, but since I am not looking at big Amp-hr, its not likely to be too pricey.

    I don't think that 24 vs 48 for the PV strings would be an issue, as I would need multiple panels in any case, and the wiring runs would be under 10 m so benefit of running at 2x voltage vs cable costs/losses are perhaps more significant in the long run.

    Of course one perhaps best solution is to make a small 24V GT battery system to run off the turbine, and use a high voltage 3kw PV system in parallel, with the generator
    plugged in as needed.

    with PG&E time based metering, I would expect to knock off my top tier with the Turbine, as we would be selling in peak demand, and really not using much then, but the payback is a bit hard to estimate at this point as I don't have a final system cost

    so far its looking like this

    whisper 200 and tower kit $0 (market $3500-4k)
    permits $400
    foundation design & stamp $500
    Foundation concrete etc $300
    foundation digging $0 (priceless for the exercise)
    tower pipe 60' @ $2.90 $200

    Inverter $2500 (depends on choice)
    DC breaker & box $200
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: "Free Whisper 200 & 50' tower"

    preliminarily that small 24v battery backed gt system sounds like a winner and know that i'm not a wind expert. there was a thread, that escapes me at present, that had problems interposing both a turbine and a pv system with common batteries so separate wind and solar systems could be employed to avoid interacting problems. unless power losses are frequent or long the solar portion can and should be straight gt and no batteries. also note that the turbine has to be loaded at all times or it could self destruct.
    do utilize the batteries as a backup for something you'd like power to stay on with if possible as you have to have the batteries and i say use 'em. with that i'll step back and invite comments from those more acquainted with wind and their thoughts on interposing both solar and wind.
  • halfcrazyhalfcrazy Solar Expert Posts: 720 ✭✭✭
    Re: "Free Whisper 200 & 50' tower"

    Get your self the 48 volt Xantrex XW inverter it will do all you want and offer the ability to expand later. Crewzer can fill you in on all the benefits but the XW is a real nice piece that does have all the features any one needs. I would say a minimum of 400 AH of battery for this system. Wind power is a ton of fun it can have its challenges but I would not trade it for the world it is a blast to watch and play with.

    Definitely go with 48 volt if the turbine will allow it.
  • SheldonSheldon Solar Expert Posts: 51 ✭✭✭✭
    Re: "Free Whisper 200 & 50' tower"

    I'm looking at the XW4548, as it's got all the upward compatibility I can want. The only doubt is with respect to the cost vs benefit (as I don't foresee the need for big battery backup)

    Living in CA, I'd rather avoid the local sales tax, since shipping will be less than 10%.
  • BillFBillF Solar Expert Posts: 48 ✭✭
    Re: "Free Whisper 200 & 50' tower"

    The Whisper 200 is a good turbine for off grid use. However energy output at low wind speeds is less than desirable. A company has a fix which may help you out...hmmm their web site expired. It was a canadian company called globalmicrowindturbine.com . They made a replacement board for the controller that enabled current to pass through the controller at lower wattage. If anyone bought one let us know. I was hoping to get one in the spring. :(
  • Truth SquadTruth Squad Solar Expert Posts: 126 ✭✭
    Re: "Free Whisper 200 & 50' tower"

    A Whisper 100 is more durable in the long run.
  • SheldonSheldon Solar Expert Posts: 51 ✭✭✭✭
    Re: "Free Whisper 200 & 50' tower"

    Unfortunately I was not given a Whisper 100, but a 200... so its a matter of making do and as appropriate fitting it up.
  • EhutchEhutch Registered Users Posts: 9
    Re: "Free Whisper 200 & 50' tower"

    I agree that the Whisper 200 has a problem in very light winds. I put one up about a year ago and was frustrated by the spinning in light winds with no output at all. All that bearing wear for nothing! I built a small 3"x5" circuit board with a three phase voltage doubling rectifier circuit (bridge circuits). The total parts cost about $25 (all new components from Mouser). The box to put it in and the 4 circuit breakers to protect it cost three times as much as the circuit so the total cost was over $100, then I added another $55 to put a DC Watt Hour meter in the box to measure the additional output. The circuit attaches to the terminals of the Whisper conrtroller 3 AC, 2 DC, and ground. It operates seamlessly with the Whisper controller, so when the overvoltage dump load switches in, the output drops to zero. The low impedance of the batteries and the high impedance of the input capacitors "self regulates" the circuit. Now when the blades start to turn ever so gently I start to see output. In a steady 4mph breeze it will generate about 10W or about a quarter of a kWh per day. In stronger winds most of the energy goes through the Whisper controller.

    Of course SWWP could have avoided the whole problem with a few more turns on the stator windings. At 5 mph the wind is strong enough to spin the rotor quite fast but the voltage developed is about 20V 3ph RMS. When rectified that isn't above the 48V battery charging voltage 55V more or less. It takes about 39V RMS to start the Whisper controller. The voltage doubler bumps 20V up enough to draw some current and slow the blades. About 30W goes around the Whisper controller before the green light comes on indicating a charging voltage from the Whisper.

    My tower is too short (30') and my location is not optimal. But the modification has substantially increased the output. It hasn't been in place very long but it seems to increase the output from about 1kWh/day to about 1.2kWh/day. But more significantly I get some generation on days that would produce nothing without it. It will take a long time at 3 cents a day to pay for itself (13years?), but the satisfaction of no movement without some generation is worth it. For me it isn't about saving money, it's more political. The PV system does most of the generation here, but it cost 3 times as much as the whisper 200 and tower.
  • EhutchEhutch Registered Users Posts: 9
    Re: "Free Whisper 200 & 50' tower"

    After two years of operation our Whisper 200 on a 30' mast has been marginally successful. Our system is primarily for battery backup during fairly frequent grid outages but also used for powering the "protected loads" during regular daytime hours using mostly PV energy (even when the grid is up) whenever the batteries are more than 75% of full charge. Any wind contribution is useful and nightime contribution is especially useful, when the batteries are not in use but recovering for the next day's loading, or when they are in use during a grid outage.

    In the first year May 2009 - April 2010 the Whisper controller logged 59.41 kWh for the entire year. That is about 163 watt hours per day. I was frustrated that the prop would spin all day but no production would be logged. That failure to produce output was confirmed by the PV system's battery monitoring that logs all inputs and outputs through separate sensing shunts.

    Near the end of the first year I built a three phase voltage doubling bridge with a DC Watt Hr meter that "bootstraps" around the Whisper controller.

    From May 2010 through April 2011 the Whisper controller logged 87.65 kWh for the entire year (a bit more than the prior year). The bootstrapped meter from the voltage doubler circuit logged 150.74 kWh for a total of 238.39.
    That is only about 650 Watt hours per day but four times better than without the voltage doubler. Our wind exposure at 30' is clearly not sufficient for a productive Whisper 200 but it did contribute significantly to the total energy in the system, almost 20% of the total renewable contribution to the protected loads.

    I think I can substantially increase the output by raising the Whisper controller's regulation voltage from the "float" value for my batteries closer to the "absorb" voltage. There is some risk of battery damage from over charging because the whisper controller is not programmable for multi-stage charging cycles. The 1.3kW PV system attached to the same batteries will not over charge because it is programmed to hold the absorb value for a limited time each day and return to the float value after that time. Now, as soon as the PV system goes above the float value the wind system is shunted to the resistor and does not contribute again until sunset. That in effect eliminates most day time contribution by the wind system. In reality the PV system rarely completes an absorb cycle in a day and could use help from the wind system to keep the batteries charged. I end up using grid energy to bring the batteries to full charge frequently. I routinely run, from the grid, an "equalize" cycle that holds the voltage above absorb level for about two hours. I believe the wind could safely be allowed to go up to a volt below the absorb voltage and would double its annual contribution. The PV controller will log the number of hours that absorb voltage is maintained and I can monitor it to prevent consistantly staying at that level too long from wind power. A few extra hours per month well above the "float" level after an absorb cycle is completed will probably do little harm. I predict that it will rarely happen but will keep an eye on it. I may be able to start the daily programmed time spent off the grid earlier if the batteries reach full charge too early most days.
  • keyturbocarskeyturbocars Solar Expert Posts: 375 ✭✭
    Re: "Free Whisper 200 & 50' tower"


    Good job on optimizing the output on your Whisper 200 with that circuit. I am surprised that such an expensive turbine as the Whisper 200 puts out so little power.

    I'm not trying to brag here, but only make a comparison... I've got a HY-2000 on a 36' tower (far from ideal) and last week we had a windy day averaging in the low-mid 20mph for most of a 24 hour period. I logged a little over 31 kwh during that 24 hour period. Now, that is not a typical day by any means, but this is a decent wind area, so the turbine does provide some good power at times.

    I would expect that the Whisper 200 would put out more power than that. I thought about buying a Whisper 100 or 200 in the past, but ended up with this HY-2000 wind turbine instead.

  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: "Free Whisper 200 & 50' tower"

    it seems to me that a large part of the problem is the controller in it. the midnite classic would take advantage of the voltages present without the need for doubling.
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