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How to Build a Windmill (2012) (jacquesmattheij.com)
129 points by ff_ 9 months ago | hide | past | favorite | 22 comments



Discussed at the time:

How to build a windmill - https://news.ycombinator.com/item?id=4579932 - Sept 2012 (53 comments)

also:

How to build a windmill part 2: Parts, nuts, bolts and blades (2012) - https://news.ycombinator.com/item?id=10791461 - Dec 2015 (7 comments)

How to Build a Windmill, Part 2: Parts, Nuts, Bolts and Blades - https://news.ycombinator.com/item?id=4584772 - Sept 2012 (10 comments)



Was in the Netherlands recently and toured an old windmill. Highly recommended. The way they reuse the same core equipment to perform various jobs is awesome. Plus it just sounds cool.


So, at his site, 10+ years ago, his wind produced more frequent power than PV would have, at 3x the cost of a commercial solution.

Even then, PV would have been more cost-efficient. Now with storage probably even more so.

Small wind is a mug's game except in very specific circumstances.


I sooo want a wind turbine to supplement my solar, but as you say, I just can't make the economics work.

For starters, wind is a lot more mechanical. Meaning moving parts. Meaning maintainence, storm care, and so on.

For another it's more obtrusive, large, high, creates some degree of noise etc.

It's not exactly cheap. My inverter could handle it, but between the mounting and turbine, it's some real cash.

The argument for it just falls apart when I do the math. For less money and waaay less hassle, I could just extend the solar.

So I love the -idea- of wind but the economics of it just don't work at personal-scale (yet?)

Personal Hydro also looks interesting (but alas I have neither the elevation, nor river for that). For a while I researched ocean wave (especially shore wave), but I dont live by the sea.

Ultimately we use what we can get, which for me is solar. I get plenty of wind here, which is why it seems a waste to not use it, but again, economics...


There are commercially available wind turbines, rated for 1-20kW.

My partner's parents installed such a system in Oregon, they live off-grid and use it to minimize their propane generator's use. A 3kW system was around $7k in total.

It doesn't make much sense if you have a grid connection, the payback time will likely be at least 15 years or so. But it makes sense for an off-grid system.


What is the longevity of such a wind turbine? How much maintenance goes into it, both hours and money for parts? 15 years is quite a long time.


The maintenance needs to be done about once every two years or so. It requires lowering down the mast and inspecting the bearings. Both are pretty easy to do.

It's a simple system without a gearbox, the only moving parts are the rotor and the brakes.

The turbine is supposed to last for 20 years, and it can probably exceed that.


How many kwh per day does the 3kw system cost?

2 of those could, theoretically, power all of a typical house's electricity if they got anywhere near 3kw on average.

$14k to not need the grid would be a deal.


You won't really be able to power a house consistently with wind turbines because there are long periods (many days) without enough wind. No amount of storage can compensate for that, you'll need a generator or a grid tie-in.

The average capacity factor over the last year was about 30%, and they live in a rather windy location.


If you supplement that with some solar panels and a battery, a generator wouldn't have to run that often.


Big commercial onshore turbines run at something like 20% peak on average. Your tiny system would likely be much worse.


You would need energy storage as well, not to mention spare parts.


sometimes, it's not about the money.


Indeed. It is a fascinating journey and he even notes it in the article:

  "...even though from an economical point of view this project was an absolutely terrible loss the amount of satisfaction of seeing a dream like that come true is truly amazing"
I hope he sees the post hit the front page and shares any updates on it.


Note that the original uses (pumping, grinding) of windmills were for high-torque, low-speed applications.

In principle, gearing should make the low-torque, high-speed motors that one can drive via PV their equivalent or better. I'm no MechE; what's the situation in practice?


Especially enjoyed the part where they fabricate a custom 500 watt, 54-pole (if I counted right) out-runner alternator essentially from scratch. Sheet metal was cut!


That was almost as hard as cutting the blades. The tricky part was that the sheetmetal when plasmacut deforms so much and so fast that you have to really move the plasmatorch upwards and out of the way or you'll have a material strike. This required intervention into the guts of the plasmacutter driver to pick up the voltage across the arc which is a good way to gauge proximity. Keep that voltage constant and you're going to be a relatively constant (+- .5 mm) distance away from the material you're cutting. The cutter used was a 12KW Thermal Dynamics unit, it would go through 1/2" like butter, very nice tool.


But is this actually a windmill? This is a turbine, a generator. A windmill does milling. It is connected to mechanical devices that do mechanical work such as milling flour, rather than a generator that creates electricity.

The inside of a working windmill are more complex and beautiful than any turbine.

https://d1dqs20vqfxmh2.cloudfront.net/wp-content/uploads/201...


So what does a textile mill do? Does it grind cloth into fine dust, or does it something else? Is the sawdust produced by a sawmill its primary output product?

The word mill is overloaded. In Dutch, these are two separate words: molen, a singular noun describing a machine using a rotational mechanism for powering some industrial process; and malen, a verb describing the milling of particles into flour. In this case, the article describes a mill of the first kind.


If the brits and not the yanks had taken the lead in production hw, we would still be saying "mill" instead of "ALU".


One suspects there's a certain amount of grinding in Fickmühlen.




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