"Ed Huntress" wrote:


"Wes" wrote in message
...

Do you need something precise, with documentation, etc.? If so, there are
lots of studies, using different methods of measurement. Search on "wind
power embedded energy," wind power embodied energy," or "wind power life
cycle analysis."

I just need to get a rough idea if windmills are net energy plus and what the span is.


I did this a few years ago. At that time photovoltaic was showing a
worst-case payback of around 24 years, while wind power showed a payback in
6 months or even less.

Just grabbing one from a Google search, without checking it for accuracy,
here's something that shows how it's calculated and some specific numbers.
There are better studies that you can find, I'm su

www.rogerhelmer.com/sustainability.pdf

I googled a bit and didn't find something better yet. That one gave me a good enough idea
of inputs and how long to recover them.

Near the end where they break down financial payback was an added plus, saved me another
question. However, my googling shows estimated life of about 20 years for these
machines. About the time the project recovers the expendature it needs major renovation.

Of course getting longer life than estimates could happen and the designs are going to
improve over time as a body of experience is collected.

At least now I have something in my head to detect if someone is trying to run some bs on
me.


While googling I ran into this chart:
https://eed.llnl.gov/flow/images/LLN...y_Chart300.jpg showing energy inputs and where
they go. Notice how much waste is in electrical distribution.

https://eed.llnl.gov/flow/ The section of the site were this came from looks like it has
some interesting reading material.

I notice that there assumptions for next few decades have coal as an energy source. I
guess they didn't get the memo.

Wes