Dawn

Never count your chickens before they are hatched …

February 11th, 2011. Post by Quinta do Vale

… or your alternators before they’re run in.

I spoke too soon.

Presto Wind M-24 permanent magnet alternator installed on water wheel

We purchased this alternator from Presto Wind in the USA on the basis of its advertised power curves and a couple of videos showing no evidence of cogging, which was the problem with the first generator we tried. As soon as it was installed, it was running well over its claimed threshold for generating usable power, so it was just a matter of waiting for the bearings and rotors to run in and then the batteries would be getting some much-needed juice 24/7. Or so we thought …

After emails going back and forth for well over a month now, we (that’s me and my neighbours, who are installing a wheel on their part of the stream, and Wayne, the systems’ engineer) have a decidedly unpleasant taste in our mouths from our dealings with Presto Wind.

Our M-24 units are not producing anything approaching their advertised power curve. To begin with, when we had more water volume (it hasn’t rained in well over a month), they were producing about 50% of what they should be. Now it’s not even 30%. They’re not even producing enough power to contribute to the batteries and because of the particular way the company have responded and dealt with this, I’m taking the step of writing about our experience in some detail so others can read and judge for themselves.

At first we thought we must have got something wrong, but checking and rechecking the wiring found no errors and all connections were tight. I reported the low output to Presto Wind. The company asked was I sure the tachometer I was using to measure the rpm was accurate, but if we weren’t getting the expected output then something may be wrong. So far so good. I then, over the course of many emails, supplied full details of my system (and relevant details of my neighbours’) with photographs of all wiring plus regular updates on the rpm of the units and the power they were generating, making clear on every occasion that this was being measured open circuit with no load, which is the same conditions under which they produce their power curves. And we weren’t using a tachometer. We were counting wheel revolutions over a timed minute and multiplying that by the gear ratio, so we knew the rpm of the M-24s (+/-5% depending on whether you calculated the ratio by gear wheel diameter or number of teeth).

I frequently had to hassle them into responding after supplying them with information and getting no reply, whereupon I would be asked questions I’d already answered. After repeating myself several times and resending photographs, I was beginning to wonder if they’d paid attention to anything I’d sent, but still didn’t think more of it than that.

Eventually the company responded by saying there was nothing more they could do to help, claiming the underperformance could all be explained by water flow, wheel size, and other system components which, together with 35% efficiency, would easily explain our results. It wasn’t their PMA. It was physics. The units were installed and we couldn’t return them. I pointed out, as I had several times already, that not only was the water flow data irrelevant since we knew the rpm of the PMA (which they were obviously aware of, having asked about our means of measuring it), the rest of the system was completely irrelevant too. We were measuring the power open circuit straight off the rectifiers. And while 35% efficiency might be relevant to wind power, it was not appropriate for hydro. 60% is more the norm.

To prove beyond doubt that it was nothing to do with the rest of the system, we disconnected it all from the rectifiers, measured the power at the rectifiers in exactly the same manner as their demonstration videos (and of course got the same readings we’d been getting all along), took photos of it all, and sent that off with a request that they respond within a week. No response.

I emailed again, saying we wanted to return the units under warranty for a full refund because they were not performing as advertised. This time their explanation for the units’ underperformance was that we must have ‘damaged’ them, despite the units being installed by a qualified engineer in exact accordance with their instructions and with them having seen photographs of the installation and being able to identify no error.

During the course of the exchange, I asked them at least 3 times to confirm the basis of the relationship between rpm and power output in their permanent magnet alternators, because to do this would focus the discussion on the precise nature of the problem and clarify whether there was a fault in the units or whether they were making false claims for their performance. They ducked the question every time. When I sent an email asking just this question, they answered a different question.

We are still trying to get our money back, but it looks very much as if we’ve been had.

Since this has happened, we’ve heard reports of other people using these units in wind applications and finding the same underperformance, including units that have been re-badged for another company. And there’s posts on forums (here and here) suggesting that the company’s advertised power curves are intentionally deceptive.

So we’re back to looking for the right generator again. Intensely frustrating, particularly since Wayne hasn’t had to use a generator all winter with his wheel. Even though it’s now producing only 100W with the river being so low, his batteries are still full every morning. Unfortunately the PMG on his installation is no longer in production. Wayne is beginning to think about building one himself …

(The bottle of Portuguese cava was very good though. That I can recommend.)

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20 Responses to “Never count your chickens before they are hatched …”

  1. Anthony Jones Says:

    Maybe you need a heavier winding for amperage? Wind and Water Are not the same correct? Before you comment on other folks products you should know something about them?

  2. Quinta do Vale Says:

    Tony, our beef with Presto isn’t that the alternator wasn’t right for our situation. It was with the fact that they advertise their M-24 (the same as your Cat 5, yes? At least you publish an identical output graph for it …) as capable of producing power it didn’t deliver. The crucial point to focus on in all this is that details of our system and setup were and are completely irrelevant to our complaint. When you’re turning the PMA at a known rpm, it doesn’t matter what’s doing the turning. When you’re measuring the output straight off the rectifiers open circuit, the rest of the system that it’s not connected to is irrelevant. According to the graphs and tables, the machine is supposed to produce 72W (72V at 1A) at 200rpm. We had it running at 200-250rpm for a fortnight and the most it managed straight off the rectifiers (NOT connected to the rest of the system) was 34W.

    These published graphs and tables, together with the YouTube videos, are what decided us to buy these alternators. And thanks to Hugh Piggott, we now understand “The watts figures cannot be simply used to predict the power that you will get from the alternator at a given RPM. “All readings are based on open current voltage and shorted load” means that these are not taken at the same time (as you would do to measure power) but under two separate artificial conditions.”

    Since these figures are advertised prominently on Presto’s website with no caveat that anyone but an expert would understand the implications of (we assumed “open current voltage and shorted load” was US-speak for open circuit, no load), the impression given is that you can use them to predict the power you will get at a given rpm. This is what we (naively) did. And at no time in my correspondence with Tim Moeller did he once say those published figures could NOT be used to predict output, despite me asking pretty much that question directly. Myself and my neighbour are now $800 poorer between us for a pair of useless machines. It’s misleading to imply to potential customers, many of whom, like ourselves, are experimenting with renewable energy generation and are not experts like Hugh, that they’re going to be getting a power output from these alternators well in excess of what they’re capable of generating.

    I went into this expecting to make a goodly number of mistakes in the process of learning. I didn’t count being mislead by PMA manufacturers among them though, and $400 is not a small amount to lose.

    We now have a working alternator. It’s an axial flux alternator (Hugh Piggott’s design) which, gratifyingly, does exactly what it says on the can.

  3. Anthony Jones Says:

    Wendy my issue is this….I have a bad write up from Hugh Piggott based on your post. We sell an actual Hydro generator and which is not the same whatsoever. Apparently he is under the impression we are the same company. We are not….Hugh advised me if I understood correctly you told him that the units were the same and that I did not even understand how the units works. If this is what happened it is untrue and we do not deserve to have our business reputation attacked by an “expert” based on the premise we are someone else. I do understand your explanation of power under a load and that is all that matters we agree…I do however take issue of being lump together with a bad experience from another company that I played no role in whatsoever.

  4. Quinta do Vale Says:

    Tony I hear what you’re saying and although I can’t speak for Hugh, I think you may have possibly slightly missed the point of his post. He’s cautioning people about how they interpret the published power data for the alternators sold by both you and Presto Wind because they’re misleading.

    Clearly you’re not the same company as Presto Wind, but equally clearly you DO source your units from the same manufacturer. The designs of the units are identical in outward appearance, are advertised as being manufactured in the same locations, and are all trademarked to Moeller Engineering – would that happen to be Tim Moeller of Presto Wind? Even if some of yours have different windings to the ones sold by Presto Wind, you DO publish power curves on your website that are virtually identical to the ones Presto Wind publish. In fact, the (tiny and almost illegible) power curve graph you publish for your Cat 5 low wind generator would appear to be the very SAME graph as Presto Wind publish for their M-24 low wind generator – which is the generator I have experience with and which I’ve written about – with the amps line edited out (not too well either) and the title changed.

    Published power curve for Hurricane Wind Cat 5 low wind generator
    Published power curve for Presto Wind Wind M-24 low wind generator

    If it’s not the same unit, then one would expect different data. Therefore it has to be assumed from this that you’re making the same claims for the performance of your unit as Presto make for theirs. This is why you’ve been effectively ‘tarred with the same brush’ as Presto in Hugh’s post. I didn’t tell him you were the same company. I told him your units were effectively the same.

    I can understand your desire to distance yourself from the issues I have with Presto Wind because it didn’t involve you, but if you are (and you are) making identical claims for the performance of the units you sell which are apparently identical to the units Presto Wind sell, then Hugh’s criticisms about these performance claims DO apply to your units too.

  5. Anthony Jones Says:

    Our units are not the same and your claims are false. You do not have my unit and remarks regarding the performance of a unit you do not own are defamatory and misleading bottom line. You have a problem with another manufactuer have made assumptions that are wrong. You in you “wisdom” assume that a unit that appears similar on the outside is the same inside which is also false. Maybe I should post some reports on my many internet sites cautioning people against your resort not having been there or having a clue what its about? Fair don’t you think?

    you state
    .” Therefore it has to be assumed from this that you’re making the same claims for the performance of your unit as Presto. This is why you’ve been effectively ‘tarred with the same brush’ as Presto in Hugh’s post.”

    It does not have to be assumed moreover it is slanderous liabelous and ignorant to do so….

    We will be sure to paint you with the same subjectivity and regard for your reputation you have judged us with. Considering you one do not own the unit, two received no sales advise from me telling you that something would be good for you application and third you obviously have not researched to see that we have a unit specifically for micro hydro you haven’t a clue what you are talking about. The units are different period and you have bought something you did not do your research and now want you vengence on someone you hanen’t a clue about. Your claims about my sourcing are not correct nor do you have information regarding such. We have many Brushes to “tarr” you with as well Wendy ….

  6. Quinta do Vale Says:

    I don’t know why you keep going on about your hydro unit, or your sales advice, or anything else. It’s completely irrelevant to what I’ve been talking about and what Hugh posted about.

    Can we please focus on your Cat 5 low wind unit? This is the one that appears to be the same as the Presto Wind M-24, and it’s the Presto Wind M-24 that I have experience with. If the two units are not the same. then it would clear up some confusion if you could list the precise ways in which they differ (apart from the paint). Because if I make the assumption they are the same unit based on a comparison of what you publish on your website and what Presto Wind publish on theirs, then chances are I’m not going to be the only one to do so. As is abundantly clear from my preceding comment, my assumption was based on much more than just looks. The descriptions and published data on the two machines, including power output tables and graphs, is almost identical.

    I already posted the respective power curves. Here’s another example. This is from the detailed description of your Cat 5 alternator on your website …

    The Hurricane cat 5 wind generator starts charging your battery bank at just 40-50 RPM!  This PMA is like having 2 generators in 1 case It contains two of our specially wound high voltage stators and two N-42 high grade magnetic rotors. The Hurricane Cat 5 is the most efficient generator ever built for extracting energy from very light wind. Because the Cat 5 uses a dual output system, you have 3 options to choose from. You can charge 2 independent systems, double the output voltage with series wiring, or combine the current for maximum amps.

    100 RPM- 32 v. x .50 amp = 16 watt
    200 RPM- 72 v. x 1 amp = 72 watt
    300 RPM- 96 v. x 1.5 amp = 144 watt
    400 RPM- 110 v. x 2 amp = 220 watt
    500 RPM- 136 v. x 2.5 amp = 340 watt
    600 RPM- 156 v. x 3 amp = 468 watt
    700 RPM- 178 v. x 3.5 amp = 623 watt
    800 RPM- 194 v. x 4 amp = 776 watt
    900 RPM- 220 v. x 4.5 amp = 990 watt
    1000 RPM- 242 v. x 5 amp = 1210 watt
    1100 RPM- 268 v. x 5.5 amp = 1474 watt 
    1200 RPM- 284 v. x 6 amp = 1707 watt
    1300 RPM- 318 v. x 6.5 amp = 2067 watt
    1400 RPM- 332 v. x 7 amp = 2324 watt

    This is from the detailed description of the M-24 on Presto Wind’s website …

    The M-24 starts charging your battery bank at just 40-50 RPM!  The M-24 is like having 2 generators in 1 case. It contains two of our specially wound high voltage stators and two N-42 high grade magnetic rotors. The M-24 is the most efficient generator ever built for extracting energy from very light wind. Because the M-24 uses a dual output system, you have 3 options to choose from. You can charge 2 independent systems, double the output voltage with series wiring, or combine the current for maximum amps. The M-24 works best with 12, 24 and 48 volt systems. Other PMA’s simply don’t compare.

    50 RPM- 18 volts x 0 amp = 0 watt
    80 RPM- 24 v. x .25 amp = 6 watt
    100 RPM- 32 v. x .50 amp = 16 watt
    200 RPM- 72 v. x 1 amp = 72 watt
    300 RPM- 96 v. x 1.5 amp = 144 watt
    400 RPM- 110 v. x 2 amp = 220 watt
    500 RPM- 136 v. x 2.5 amp = 340 watt
    600 RPM- 156 v. x 3 amp = 468 watt
    700 RPM- 178 v. x 3.5 amp = 623 watt
    800 RPM- 194 v. x 4 amp = 776 watt
    900 RPM- 220 v. x 4.5 amp = 990 watt
    1000 RPM- 242 v. x 5 amp = 1210 watt
    1100 RPM- 268 v. x 5.5 amp = 1474 watt
    1200 RPM- 284 v. x 6 amp = 1707 watt
    1300 RPM- 318 v. x 6.5 amp = 2067 watt
    1400 RPM- 332 v. x 7 amp = 2324 watt
    1500 RPM- 320 v. x 6.5 amp = 2080 watt
    1600 RPM- 314 v. x 6 amp = 1884 watt
    1700 RPM- 306 v. x 5.5 amp = 1683 watt

    As well as using identical text, you’ve even used highlighting in the same places! This is your published description, not mine. All I’ve done is make the not unreasonable assumption that these units appear to be the same based on what each company has published. And please note that throughout I’ve used terms like “appear to be the same”, “effectively the same” because I don’t know they’re the same, only that they appear to be! There is nothing slanderous or libellous about making comparisons between published information and drawing attention to the instances where one source is identical to another.

    So can you please state what exactly is the difference between these two machines? If they had different windings, for instance, then there would be some differences in output, but there isn’t so much as a watt of difference between them.

    I will say this once again for the avoidance of all doubt. The issue is NOT that the alternator wasn’t suited to our site. The issue is that the unit doesn’t produce the output that the published power data leads you to believe it will. As I said above, it doesn’t matter what’s turning the alternator. It could be a power drill for all the difference it makes. If the alternator is turning at 200rpm, the published output figures suggest you should be getting 72W, and if you’re only getting 34W open circuit, then either there’s something wrong with the alternator or there’s something wrong with the published figures. When you learn from an acknowledged expert on the subject that the published output values can in no way be produced in a real world situation, then it’s reasonable to state that the published output figures are misleading.

    And as for “cautioning people against your resort”, let me go right ahead and do it for you! Don’t come to stay here folks! The facilities are appalling! This place doesn’t even deserve the faintest twinkle of a one-star rating. Half the place is a building site. The rest looks like it’s barely reclaimed from a jungle. There’s no bathrooms, no hot water, no flush toilets … there isn’t even a building for guests to stay in, let alone beds for them to sleep in. And the owner lives in a tent. What kind of a resort is this?! Well exactly …

    I’m not selling anything, Tony. I’m well past the age when my reputation had a shred of a chance of concerning me for longer than 30 seconds and what you think and say about me is your affair. The only thing I’ve been trying to achieve in publicising our experience is to prevent people making the same mistake we did in assuming the published output figures for the M-24 (and the apparently identical Cat 5) can be used to predict real world results. Hugh Piggott’s intention was, I believe, the same.

  7. Anthony Jones Says:

    You are a liar plain and simple whom is apparently to ignorant to grasp the fact that 2 companies make different products. I will advise you that not only is printing incorrect assumptions as fact is slanderous as when you print my page text it is a copyright violation….Just because a unit looks similar does not mean that the internals are the same. The magnet strength spacing air gap and stator windings are proprietary from company to company to name a few of many factors. I have no idea what you bought from Presto whether it was defective , you were to ignorant to hook it up. not do I care . You want to focus on the light wind unit yet obviously have a hydro application…..if you will also notice on the chart it clearly states volts and amps at a 12 volt cut in point. I can only assume you as the title of the post states counted you chickens without consulting with someone who had a clue what they are doing, yet for some reason author a blog about producing energy. Of course if you hook up a pma made to produce high voltage and reach low wind cut its you are not going to get a high amp output when you put the unit under a load at in a 12 volt battery bank environment.
    50 RPM- 18 volts x 0 amp = 0 watt
    Apparently you looked at an aforementioned power curve put the PMA under a load at a low cut in and wonder why you did not get high amperage. If you did not understand how a PMA works the slightest it would seem like a good idea to figure it out before you bought 800$ worth of stuff you seem to be mad about. Again no idea what the has to do with me as you are not even my customer
    Since you guys want to be critical of me consider the examples below
    1500 watt PMA from ginlong see below
    http://ginlong.com/wind-turbine-pmg-pma-permanent-magnet-generator-alternator-GL-PMG-1500.htm
    Notice voltage to amperage power curve relation… battery charging higher amperage to voltage relative
    1800 watt PMA from ginlong
    http://ginlong.com/wind-turbine-pmg-pma-permanent-magnet-generator-alternator-GL-PMG-1800.htm
    Notice voltage to amperage power curve relation High volts Vs low amps open circuit advertised. Yet I am criticized for advertising the same type of curve. No wind speed and no battery back environment posted. For Hugh’s benefit I would point out the power curve is not stated for a 12 volt battery bank at sea level i.e more density in the wind, 12.6 discharge on a 8 battery bank with x amount of amp hours. No their curve is posted just as ours. This company is considered by many to be the premium PMA building company. If you look at the examples and see our products are advertised and it is the same as “the standard”
    If you put a high voltage PMA under a load at a low cut in you will not get a high amp output period whether Hurricane, Presto , Ginlong, or the Pope made the PMA
    Both Ginlong units cost well over 1000$ plus shipping….if you hook up the 1800 watt PMA see power curve to a 12 volt battery bank guess what happens……same thing you are bitching about with Presto low amp output.
    No need to go any further of course you have a small low amp trickle charge if you loaded the low wind high volt PMA with a 12 volt battery bank. I would have advised you that but again you are not my customer and this should have nothing to do with me
    I am merely stating you have interests… Hugh apparently does as well and if you attack me for no reason expect to receive the same in kind…….what the hell are you cautioning people against? Did you purchase a product from me? no! Did I give you bad customer service? no! Did I not refund a unit for you? no! In fact you bought nothing have no knowledge of my product nor does Hugh .I offered to send Hugh a unit for him to test personally for free which he rejected. Presumably he is more interested in promoting his books and brake drum alternators and maintaining his relationship with applied magnets and then telling the truth….everyone does not want to rummage through a junk yard looking for brake drums wind coils and carve blades out of wood and glue magnets to something that looks like a birdhouse. For those who do god bless them for those who don’t we sell quality products
    If either one of you knew what you were talking about you would know that it takes 60 percent more energy to turn a pma when the battery is at 12.5 volts than if it is at say 13.6 and there are many more factors to consider. When you suggest a chart should be made at what battery environment is standard? The reason you do not see a suggestion is because the guy is simply trying to play the good guy role to promote his interests… Do I see that information from Hugh ? If we really need to go thru that book from an engineering perspective will not be difficult to find as many things to fault as he likes to with other pointing his high “stature” and “perception” towards others. I am merely stating I do not walk between the raindrops but neither does Hugh . The difference is I don’t carry myself with a pompous arrogant attitude. After this he wrote a post as if I were lucky he did not remove my link from his page and I am sure you will forward this to him…..I don’t care his is removed from my page and we have no use for the arrogant jerk. and one clown never ran the circus.

    PS I called Tim at Presto Wind last week to find out what the deal was concerning this issue and was advised of threats you made against his company based on your disagreement. My opinion based on what I know is you are a vindictive person whom wants to punish and judge others without having a scred of knowlege to back it up. What the hell does that have to do with me?
    I agree your place is a dump
    Regards

  8. Quinta do Vale Says:

    Interesting. The way this conversation is developing reminds me very much of the correspondence I had with Tim Moeller. Are you Tim Moeller?

    You’ve failed to address the point again. I wasn’t talking about the output of the PMA under load. I was talking about the open circuit output straight off the rectifiers. When you’re measuring the output straight off the rectifiers from a PMA turning at a known rpm, nothing else is relevant.

    Neither have you responded to my request to state in exactly what respects, apart from the paint, the Hurricane Wind Cat 5 low wind alternator and the Presto Wind M-24 differ. I’m focusing on the Cat 5 low wind unit because that’s the one which appears to be the same as the M-24. That’s the whole point of this conversation, is it not?! You’re upset with me for lumping Hurricane Wind and Presto Wind alternators together. Well I’m doing so because the material on your website describing the Cat 5 is, to all intents and purposes, identical to the material describing the M-24. (Quoting a couple of paragraphs of publicity material doesn’t constitute copyright violation, by the way, and comes under ‘fair use’ as defined in section 107 of US copyright law.) It’s very simple. If these units are not the same, then state where they differ!

    Your description of Hugh Piggott’s work seems to be about as well researched as your comments about my ‘resort’ here.

    And as for the ‘threat’ I made to Tim Moeller, I’ve copied below the email in its entirety so anyone who reads this is free to judge for themselves …

    From: Wendy Howard
    Subject: Re: M-24 problems
    To: “Presto Wind” Cc: (engineer) (neighbour)
    Date: Wednesday, February 2, 2011, 11:03 PM

    Dear Tim

    I’m very disappointed to have received no reply from you to my email (below) sent over a week ago.

    Finally, when we prove to you beyond all reasonable doubt that it’s nothing to do with the rest of the system, or the head and flow of the stream, or the dimensions of the water wheels, that it’s the M-24s themselves, you don’t even give us the courtesy of a response.

    These units were purchased on the basis of your advertised power curves. If they had performed as advertised, we would have been satisfied. But since neither of them appear capable of producing anywhere near the power you claim for them under the same conditions of measurement, we would like to return them for refund.

    And I would advise you against ignoring this email as well. If you enter “Presto Wind” as a search term in Google, you’ll find that my blog describing our hydro installation comes up on the first page of results. So far I haven’t written a post about the problems we’ve been having with these units, preferring to give you the benefit of the doubt until such time as it was sorted, but all it will take is a simple factual account of the performance of the M-24s and your customer service to put a significant dent in your reputation and future sales prospects. I’m not impressed with the way you’ve dealt with our problems, particularly in the light of the USA’s worldwide reputation for good customer service, but you can at the very least redeem yourself by arranging for the collection of these units at your own expense and crediting our respective PayPal accounts with a full refund.

    Please confirm that this is in order and advise me of what information the couriers will need to arrange collection.

    Wendy Howard

  9. Anthony Jones Says:

    Wendy, when you are important enough to advise how we make our PMA’s I will let you know until then enjoy your crappy “resort”…Hell why don’t I just publish a book and tell everybody our proprietary information? You bought nothing from us and do not deserve an explanation about a thing. If you could read you would have seen some of the factors that are involved in PMA building. I cannot speak to this as I do not have Tim’s proprietary information, therefore I could not speak to the difference if I wanted to. I am not Tim and you are a pathetic, we will let DCMA decide what constitutes fair use. Copy and pasting = fair use.

    Are you slow??? you fail to understand the point… you say below
    “You’ve failed to address the point again. I wasn’t talking about the output of the PMA under load. I was talking about the open circuit output straight off the rectifiers. When you’re measuring the output straight off the rectifiers from a PMA turning at a known rpm, nothing else is relevant.”

    The fact you used a high voltage low amperage PMA to charge batteries in very important and under a load does matter. So does the fact you have about enough water there to generate enough power to light a Christmas tree bulb. The criticism he made was that we use open circuit numbers….the two ginlong URL’s in the previous post was yet another example of how the largest PMA company of the planet uses the same standards. I am starting to thing you are very dense. The whole point of Hugh’s write up is that open circuit i.e. the measure you just described is misleading. So you guys were both speaking of “under a load ” being important to which I agreed..You really don’t know what this even means do you? .. You have not the first clue what you are talking about. Please stop I have no time for you or Hugh and as he would say such rubbish.

    I am very familiar with Hugh’s “work” and I will just say this…..if he were an engineer that could do math…you know the kind with the letters in it .Would you really need to make a hand written book that looks like a recipe book of trial and error? Nope! simply my opinion…..

  10. Quinta do Vale Says:

    OK. So you can’t tell me where the Cat 5 differs from the M-24 because you don’t have Tim’s proprietary information. In the light of the fact that the published descriptions and data on these two units is identical in all material respects, how then can you be so certain they’re not the same?

    High voltage is neither here nor there when you’re running it through an MPPT controller … And yes, of course under load output figures matter! But that doesn’t change the fact that this isn’t what I was talking about. To repeat myself yet again, with both the M-24s we had here turning at 200rpm, they were producing around 34W straight off the rectifiers, not 72W as advertised. That’s not even half the advertised performance under the same open circuit conditions, before the units were put under load. THAT is the basis of my complaint about this unit.

    The winter rains have failed here for the second year running now and we have less water than in summer when it was never envisaged running the hydro anyway. Nevertheless, the high voltage axial flux alternator made to Hugh’s designs which we now have installed is capable of contributing a charge (albeit negligible) to the batteries. With at least 3 times the present water volume, the M-24s under load could just about manage to produce what this alternator is producing now. I know who’s engineering competence I’d be more inclined to trust. Results speak for themselves.

    And just in case you didn’t pick up the earlier hints, this place isn’t any kind of ‘resort’. It’s a farm, a smallholding, a homestead I believe you call them in the US. It doesn’t pretend to be anything more or less than what it is.

  11. Anthony Jones Says:

    You were running PMA’s though an MPPT controller? Ever heard of a diversion load controller? I am relatively sure the “two units” are not the same because we are Hurricane Wind Power and they are Presto…..I have said all I have to say here

    You were running PMA’s though an MPPT controller? Please enlighten me where you found a MPPT controller that stated it was for a PMA? That is for solar ……and diversion load controllers are used for PMA’s. I am relatively sure they are not the same because we are Hurricane Wind Power and they are Presto..I own the company and I am not saying by any means that there was anything wrong with the unit you bought from Tim. The more you write the less it is appearant to me you know…I have said all I have to say here…..
    your write….
    Nevertheless, the high voltage axial flux alternator made to Hugh’s designs which we now have installed is capable of contributing a charge (albeit negligible) to the batteries.
    Does this mean it doesn’t work either due to your lack of water?
    I don’t think you need an engineer but perhaps a Psychologist

  12. Quinta do Vale Says:

    Yes we run the axial flux alternator’s output through an MPPT controller because it’s an efficient way to convert high voltage input to the optimum charging current for the batteries. The same charge controller also acts as the dump load controller. Perhaps you haven’t heard of all with work being done in this area? Both Outback and Midnite Solar produce controllers with MPPT algorithms for hydro applications. We didn’t use an MPPT controller with the M-24s, just a standard dump load controller … not that it was ever needed since they never even came anywhere near charging voltage under load.

    And to reiterate, there were two M-24s. Mine and my neighbour’s. Both of them performed the same. So the likelihood of the underperformance being down to a one-off fault is much slimmer. My neighbour has left his M-24 installed. He has more water than I do as another stream comes in above his property. Even so, his unit has never reached charging voltage either. This isn’t really surprising since the units aren’t capable of producing even half of their advertised open circuit output. Let me stress this once again since it really doesn’t seem to be getting through. This is NOT a case of comparing open circuit output figures to performance under load. This is comparing open circuit output figures to open circuit output. Apples and apples, not apples and oranges. Open circuit. Not under load. No load. Not even the faintest sniff of a load. Just the open circuit readings straight off the rectifiers. 34W against 72W claimed for 200rpm.

    My point about the axial flux alternator contributing a charge to the batteries was to demonstrate that it’s able to do this on a third of the water volumes we had at the time we tested the M-24s. I don’t need a psychologist, thanks, I need rain. Once (always presuming if) weather patterns return to normal, we will have the system we need in place producing the power we need to see us through the winter months when the solar panels max out at 1.3kWH.

    You’re ‘relatively sure’ the Cat 5 and the M-24 are not the same because you’re different companies? Tony, you told us that Presto build your generators when we enquired about your hydro PMA a year ago. That’s why I told Hugh that Presto make your units. Why would I do that unless I was confident in the knowledge they do? So why did you deny that and tell him you never told anyone you get your units from Presto and that you get them from a third party? I’ll give you the same advice I give my kids: no matter how difficult it is to begin with, be honest! Because otherwise you’ll end up in a far worse situation further down the road …

  13. Anthony Jones Says:

    I was aware of Midnight Solar’s controller , however there sales staff couldn’t even adequaley in my opinion describe how it works…..the outback is a new one on me..
    You switched on me and Hughes complaint was about open circuit numbers. If you stated 32 watts open circuit at a known RPM of 200 I have no explanation for you. I can advise you my knowlege of Tim is to be complete and thourough in his work and shipping out something that does not perform up to spec is not what I know of this man and having two of them is even more odd….
    I have never advised anyone where we source our generators nor have I told you we get them from Presto…..pertaining to you calling me a liar your out of bounds and you can save your speach for someone whom needs it.

  14. Quinta do Vale Says:

    The Outback’s a bit tentative. It has limited support for specific hydro generators. We hooked this one up because we knew it wasn’t going to throw anything at the controller it couldn’t handle at present water volumes. It performed just fine.

    I’ve not switched on you. I’ve said the same thing all along. Read back … everywhere I’ve stated the numbers I’ve been clear to say it was measured open circuit and every time you’ve talked about the difference between open circuit output and performance under load I’ve said that’s not what I’m talking about.

    And as for your last comment, what can I say other than here’s the email you sent us …

    From: tony@hurricanewindpower.com
    Date: Fri, Jan 21, 2011 at 4:12 AM
    Subject: Re: more info on hydro turbine
    To: nicole steijven

    Nicole Tim at Presto builds our generators…I asked for a heavier winding to make more amps as in some area of the world have higher wind and they work well in many conditions…….When you say that you are getting half of the power curve that is proabably correct….All PMA sales charts from every manufactuerer I know are done in open voltage. When you put the generator under a load the output is lower….in some situations much lower…I have seen companies advertise a 500 watt pma and under a load output 125 watts max. As dishonest as it may sound retaining half of the open voltage rating under a load is an efficient generator in my experience. Nicole it may be a typo and we are expanding to a supersite with much more to offer so I have not really gone over the site much latley…..

    In short when you build a generator the heavier wire in the stator the more amps you get but it takes higher RPM. The thinner the wire the more voltage at lower rpm but you sacrafice amps…..its all a balancing act depending on the application….in my opinion the m 24 is a great pma as the majority of the country is in a low wind zone…..while you do not get high amperage you do get a charge even in low rpm..most manufactures make a wind turbine that does nothing the majority of the time……but this is a debate withing the industry….the guys that only have car stators and can’t wind anything says its all about the amps….this is because the can only get stators that were meant for cars with heavy wire…if you have the power in the wind or water to make the rpm by direct drive or gearing and can attain higher rpms for much of the time you will gain overall by the increase in amperage

    The pma does not cog because it has a low profile stator core….it may be slightly harder to turn because of the heavier wire but this should not be by a lot….

  15. Anthony Jones Says:

    That is not from me Wendy. I don’t type books to sell PMA’s don’t have the time…if you need to be right by all means then be right….thanks for the information on the outback I wasn’t aware of that one.

  16. Anthony Jones Says:

    Wendy the below excerpt is taken from your initial post and your premise seems to be that “Hugh” enlightened you to the fact that you can’t simply rely on open circuit numbers to give you output see below” You speak of the two separate artificial conditions” I thought you were speaking of loaded values when you were speaking of 34 watts? I misinterpreted so be it but that was the source of the confusion. While I do not think I wrote the e mail you have posted from over a year ago it would seem that the author tried to enlighten you about realistic expectations and loaded output was what you needed to be concerned with in the beginning?
    You posted your were advised:
    .All PMA sales charts from every manufacturer I know are done in open voltage. When you put the generator under a load the output is lower….in some situations much lower…I have seen companies advertise a 500 watt pma and under a load output 125 watts max
    Where is the deception you guys are warning people about? if that came from someone at our company that about as straight forward as it get don’t ya think?
    you state:
    “According to the graphs and tables, the machine is supposed to produce 72W (72V at 1A) at 200rpm. We had it running at 200-250rpm for a fortnight and the most it managed straight off the rectifiers (NOT connected to the rest of the system) was 34W.

    These published graphs and tables, together with the YouTube videos, are what decided us to buy these alternators. And thanks to Hugh Piggott, we now understand “The watts figures cannot be simply used to predict the power that you will get from the alternator at a given RPM. “All readings are based on open current voltage and shorted load” means that these are not taken at the same time (as you would do to measure power) but under two separate artificial conditions.””
    My interpretation was that you were not still speaking of open circuit readings which in all fairness I misinterpreted.
    PS when Hugh can get Ginlong Hydrogen Appliances, Missouri Wind and Solar, , Windy nation, Southwest Wind Power , Wind max, Wind Blue, Sun Born Energy, ARI, Gudgraft., Hummer, SWEA Tom, Dick, and Hairy to all agree to stop advertising open circuit voltage numbers I will follow suit.

  17. Quinta do Vale Says:

    Are you insinuating this is a fabrication?!! Good grief! Well either you have a poor memory or someone else is using your email address, because this is what came from your email address in response to an enquiry about your hydro PMA. Nicole asked a lot of questions and also told you we had units from Presto which weren’t performing as expected. Your response addressed many of these points.

    Here is the email again, with the enquiry it was in response to. Perhaps this will jog your memory.

    From: tony@hurricanewindpower.com
    Date: Fri, Jan 21, 2011 at 4:12 AM
    Subject: Re: more info on hydro turbine
    To: nicole steijven

    Nicole Tim at Presto builds our generators…I asked for a heavier winding to make more amps as in some area of the world have higher wind and they work well in many conditions…….When you say that you are getting half of the power curve that is proabably correct….All PMA sales charts from every manufactuerer I know are done in open voltage. When you put the generator under a load the output is lower….in some situations much lower…I have seen companies advertise a 500 watt pma and under a load output 125 watts max. As dishonest as it may sound retaining half of the open voltage rating under a load is an efficient generator in my experience. Nicole it may be a typo and we are expanding to a supersite with much more to offer so I have not really gone over the site much latley…..

    In short when you build a generator the heavier wire in the stator the more amps you get but it takes higher RPM. The thinner the wire the more voltage at lower rpm but you sacrafice amps…..its all a balancing act depending on the application….in my opinion the m 24 is a great pma as the majority of the country is in a low wind zone…..while you do not get high amperage you do get a charge even in low rpm..most manufactures make a wind turbine that does nothing the majority of the time……but this is a debate withing the industry….the guys that only have car stators and can’t wind anything says its all about the amps….this is because the can only get stators that were meant for cars with heavy wire…if you have the power in the wind or water to make the rpm by direct drive or gearing and can attain higher rpms for much of the time you will gain overall by the increase in amperage

    The pma does not cog because it has a low profile stator core….it may be slightly harder to turn because of the heavier wire but this should not be by a lot….

    On Thu, 20 Jan 2011 13:25:05 +0000, nicole steijven wrote:
    > Dear Tony,
    >
    > I am currently looking at your web site and would like to know a bit more
    > about your Hydro Turbine.
    > At the moment we are using 2 PrestoWind M24’s at our two hydro setups, but
    > after breaking in both, they both only seems to do half of what their power
    > curve has promised us. We are disappointed since we had high hopes for
    > them.
    > The M24 turbines are virtually zero cogging and we like this.
    > I am sure that you are familiar with the PrestoWind M24 ( your turbines look
    > identical, your website wording is the same), and since your hydro turbine
    > does more Amps to RPM, can you tell me if your turbine has considerable
    > more cogging?
    > Looking at the two (parallel and series) power curves on your website, I
    > want to point out they both say parallel wiring. This must be a typo error
    > (prstoWind seems to have the same typo error on their M24 description?!?
    > Are we interpretting something wrong here, this can’t just be a coincidence?).
    > The second power curve on your site must be the series wiring since the
    > volts are higher than the amps. So am I reading it right that in series at
    > 300RPM it will give me 24volts and 18amps?
    > Looking forward to your reply.
    >
    > Kind regrds,
    > Nicole Steijven

    The style of the writing in the email, particularly the series of dots punctuating the sentences, appears to be your own from the evidence on display on this page.

  18. Quinta do Vale Says:

    Yes. That’s what I wrote and I can see where the confusion arose. I think this may be a case of confusion compounding confusion. As I stated in my first response to you above, we assumed “open current voltage and shorted load” was US-speak for open circuit, no load. When I read Hugh’s post, it seemed to me that he was saying something different because he writes “these [measurements] are not taken at the same time (as you would do to measure power) but under two separate artificial conditions“, and it didn’t seem to me to be a particularly artificial condition to attach a voltmeter to the rectifiers.

    But I can see from the ensuing correspondence between you on his blog that we were correct in our assumption to begin with. Hugh wrote that post after I told him about our experience, so I assumed he was addressing some subtlety in the power data I wasn’t aware of, and one that might explain why we had two PMAs that only produced around half their expected open circuit output. But it now seems likely he made the same assumption you did – that we were comparing performance under load to open circuit power data, probably because it’s an all-to-common complaint (custom and practice notwithstanding).

    So, in summary, the basis of our complaint about these units doesn’t lie in us confusing open circuit data with performance under load. It lies in the straightforward failure of the units to reach advertised power output.

  19. John Rider Says:

    I spoke with the people at Presto before seeing this post and was not impressed at all. The guy went on for an hour about Paypal screwing him and trying to get us to mail checks in the went on to advise us he only makes the generator like you bought once a month and there was a waiting list ect. and how great his “hand crank generator was bla bla bla.long story short is my perception of the guys was he is an ass and an arrogant jerk…..reading more online I am seeing complaints where he took money from people and never even bothered to send out a product or refund.Looks like you have a chicken even if it didn’t hatch. The guys at hurricane spoke with me and advised that the 2 generators are entirely different his vs presto and refereed me to the demos on you tube where he shows the unit outputting as advertised with tachometers. It is a bit confusing because the guy has not apparently even had an opportunity to completely update his website and told me point blank he is having to rebuild a lot of the generators like you bought from presto that were not built correctly when he was their dealer and that Presto stole money from him as well. He explained that they sell axial generators as well and were not stuck on any one design. I think you just got ripped off by an ass at Presto from what I am observing….thanks for the heads up it kept me looking and from making a mistake buying a piece of @#$%

  20. Quinta do Vale Says:

    Glad the post helped. I’ve one or two things I could say to you privately about my impressions and my reasons for feeling this way but it appears the email address you’ve registered this comment with doesn’t exist. It’s interesting, ‘John’, (or could it be Tony?) … the recurrent theme with this whole saga seems to be that all is not quite what it seems …

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