Ok, let's review all yer comments above since I authored that hydraulic page.
First, the best one:
'The only thing 2 engineers will agree upon is that the 3rd one is an idiot.'
And I think that sums it up. I read 'snake oil' in those comments - no, it is a discussion of the benefits of using hydraulics after speaking with a GE megawatt tower engineer. There is nothing in there that says it is the best, super-duper, Neato-Nando's-Happy rig. It simply takes advantage of the durability and light weight of hydraulic motors and pumps and yes, UPS is using a regenerative braking system that is supposed to save them $38 mil a year - so all the name hurling is just a sideshow.
I remember when Paul Gipe found Andy Kruse Air X to produce only 200 watts in protection mode, vs the 400 in his literature and the bashing that ensued at another forum which drove visitors nuts. During that roast I read over and over 'Andy is giving a black eye to the industry' and a litany of other insults. Now old Andy has sold a lot of gear, most of it well liked and almost ALL GENS use a protection mode circuit.
Really guys - what gives the industry a black eye isn't a discussion on the advantages of hydraulics (there are many) compared to gear boxes and it isn't Andy's gens, which have sold more than any other unit on Earth, going into protection mode and it isn't a nut and bolt comparison of hydraulic vs. gear vs. direct drive or AC vs DC gens or even the vertical axis turbines claiming a ka-zillion watts...all that is expected.
What gives the industry a black eye is bashing from one end of the spectrum to the other, just so you can say 'Gee, I am right, they are wrong, I am protecting consumers, they are ripping them off, come to my website, listen to my advice, I am the one who knows...and that 'third engineer' is an idiot, a scammer etc.
Lemme tell ya, our blades sell, they don't come back, zero returns to date and the prices on the gens, some new, some surplus, some refurbished, all described on the site (if you can read), are all set by dealers, not us.
We make blades and in fact, nobody on Earth makes a better airfoil...period...hands down and flat out gorgeous to boot. Any questions there? Find my competition and let me know when they want to run a side by side test.
As for hydraulic rigs compared to gear boxes, you bet - much more reliable and yes, there are some losses that niether gear boxes or direct drive encounter, but all systems have some losses. Use fat pipe/lines, not too many turns and hydraulics can run with a 10-20% loss and that's acceptable, certainly when you consider losses converting DC to AC or cable runs, which are eliminated using hydraulics that can direct drive an AC gen at the right RPM - something direct drive cannot do.
And as for lines and rotation, if you READ the pages on the subject, it states the top gen has a stop point on it's rotation so it never goes all the way around. If you study winds as I do, in most locations, there is a dead spot that rarely if ever gets wind. It usually blasts/storms from one direction and there is a predominant wind from another with occassional winds from other directions and there is almost always one direction the wind rarely blows. This is especially true for canyon and ridge locations.
And Nando, as for calculations, you run em...let me know how they work out...hey post them here. I have seen you bash people in forum after forum and 'give the industry a huge black eye' for all your mouth and honestly, I don't care if you ever set up a rig like that nor do I believe you have either the inclination or perhaps the know how to do it and make it work. I do know you love to tell other folks what they can or can't do or should or shouldn't do and often you are dead wrong.
Frankly, you appear to be a knowledgable jerk from what I have read from you in other forums and apparently are out bashing things you have really never tried here as well. All mouth, a bit of brain, and zero manners. Industry black eye cometh everytime you pipe up.
Fact: the Danes have hydraulic motors that have very low losses. Expensive, yes. But when we are talking 10kw-100kw and up, not really that expensive.
Fact: UPS is using it to store and transmit energy.
Fact: Hydraulics are reliable, much more so than gens and brushes 50-100 feet up or gear boxes.
Fact: I use a direct drive on my 3kw rig.
Fact: If I had a 10-50kw rig here I'd use hydraulics.
The loads on the tower for a single blade at 50mph at the top vs. 2 or 3 blades (did you read the entire post?) on one tower, when only one is active in a storm is well within tolerance - IF - you build the tower right.
Fact: we have links to structural engineers and folks with tower construction experience. One guy at our site built the famous and huge Radio Tower in San Francisco - he does calcs. They charge for advice. Nando - want formulas? Go pay them and they'll give you answers.
Does that page say 'DO IT?' - I believe it says 'Try it.'
I have a guy right now dying to set one up and I have told him LEARN FIRST (after all, we are teachers here at KCK) and learm with a simple direct drive rig. We don't just tell people 'go buy the expensive stuff' in fact, we prefer that they start off with a small 4 ft. cheap blade and gen, learn the circuits, carve their own prop if they can and learn how for a price they CAN afford - about $35 bucks.
So when you wag your fingers (and tongues) calling me, Andy or anyone in this industry 'a scam' really, you may want to get to know the operation first or your just being a jerk. When someone approaches us and wants to build a 12 or 20 or 50 ft diamter rig, we find out if they have the wiring background, the tower experience, wood carving if they want to go that route, and usually suggest they start small, learn at a cheap price and then start buying based on educated decisions.
But hey, I guess to some folks that is a 'snake oil' approach.
To me and the customers and students KCK and the WindGenZen site serve, it is an approach that one customer said 'Change Craig's name to Mr. Support'...posted or 'More support than my therapist'...posted and a few other comments from our customers that indicate we teach, we care, we like to see people learning to unplug and use both data and their imagination to analalyze their home, their usage and figure out exactly what it will take.
All that 'finger and tongue wagging' is a side show - the real show are the people actually DOING IT for next to nothing and folks modifying the systems they learn here or at our site or at Hugh's site to suit their location and skillset. Sriannie in the South American Jungle learned from us - is that a 'scam' too? He is flying 12 foot blades up in the canopy so the miners in the region aren't burning fossil fuels...
Call it a scam - I call it thinking green.
Call it snake oil - I call it wonderful and quite real.
Now - if you want to 'drill me' get lost. Get in line. I have students who like answers that work and ours usually do. Not always, but usually. Nobody is perfect.
Now - if you want to have a constructive, positive, team-like conversation regarding hydraulics vs gear boxes vs direct drive, that would certainly help heal that black eye mouthing off gives the industry and hey, it just might cause someone to unplug a week sooner with a rig they trust, no matter what drive method is employed.
And THAT event, another home unplugging, is what it is all about...anyone disagree with that?
