
Scotland’s floating wind farm is showing how powerful offshore wind can be - AndrewDucker
https://arstechnica.com/information-technology/2018/03/first-floating-wind-farm-has-performed-better-than-expected/
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truculation
The EarthWindMap gives one a sense of how much stronger (in general) the wind
is over the sea than it is over the land:

[https://earth.nullschool.net/#current/wind/surface/level/ort...](https://earth.nullschool.net/#current/wind/surface/level/orthographic=-13.97,33.58,606)

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andrewem
Very cool site, and it makes your point quite well. I panned over to the east
coast of North America, and what's that? Oh yes, it's the Nor'easter that just
hit that area, a big rotating storm with a very clear center.

[https://earth.nullschool.net/#current/wind/surface/level/ort...](https://earth.nullschool.net/#current/wind/surface/level/orthographic=-65.16,30.81,606)

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JBlue42
You might list windy as well:

[https://www.windy.com/](https://www.windy.com/)

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swsieber
I find windy cool. However, it's not useful when looking at things like
hurricanes or other things with large wind differences because the color scale
warps around every 70mph or so.

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JBlue42
True. Just offering something else similar and cool for the person in the
previous comment to check out.

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alva
If Elon Musk (or any suitable ambitious and rich person) fancies an exciting
challenge, there is a very large and ancient body of land in relatively
shallow waters (15m) between the UK and the Continent called Doggerland [0].

Many years ago some people were looking into reclaiming the island and making
it the worlds biggest wind farm. It is in a perfect location. Plus you never
know, might be able to make it an independent nation ;). Possibly a good
launch site?

[https://en.wikipedia.org/wiki/Doggerland](https://en.wikipedia.org/wiki/Doggerland)

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jimrandomh
Not a usable launch site; it's too far from the equator to reach the most
common orbits, and for polar orbits, it'd be dropping boosters either in
Europe (unsafe) or the arctic (hard to recover).

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bthornbury
> sending 30MW of power to the grid every minute of every day

One of those little inconsistencies that stood out to me...

 _Scratches head_ MW = 1000J / s

What happens when you send 30MW per minute..

30MW per minute = 1000J / s / m

Hmmm

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epistasis
No head scratcher there.

They didn't write it in the sense of "30MW per minute", it was "30MW _every_
minute" meaning a constant power rating of 30MW, instead of a variable rating
where one minute it's 30MW and the next minute it's at 20MW, or whatever.

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bthornbury
From the language of the article it's somewhat ambiguous.

"A capacity factor of 100 percent means the wind farm would be sending 30MW of
power to the grid every minute of every day since it's been in operation."

The "sending" portion makes me interpret this in the sense of 30MW per minute.

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cbcoutinho
Most renewable energy sources are variable, meaning they have a capacity/load
factor that is less than 100% - you would never mention the load factor of a
natural gas power plant because it's essentially a turnkey solution that
doesn't fluctuate. Renewable energy is different, and it's good that this
issue is mentioned in articles so that it's acknowledged as being a challenge.
I don't think it's ambiguous in any way

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ChuckMcM
> _... you would never mention the load factor of a natural gas power plant
> because it 's essentially a turnkey solution that doesn't fluctuate._

As I understood the term the capacity factor is the percentage of time the
plant is generating power. All plants have periods of maintenance and other
"down times" which means they don't achieve 100% capacity. I would expect to
use that number like this:

Given a 30MW plant with a 50% capacity factor measured for the year, I would
consider it to provide 30MW x 180 x 24 or 129,600 MWh of generating capacity.
Two plants with a 50% capacity factor would give you coverage at their rated
power all year only if they never overlapped in their down time. So if I was
working the issue operationally I'd put in three plants to insure I had 100%
coverage of 30MW all year long.

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cbcoutinho
Maintenance does incur planned downtime on a power plant, but those things can
be planned for when there isn't much energy usage throughout the year. In
colder climates that's usually in the spring/summer. If a plant goes out for
two weeks every year for maintenance, that's not a big problem. A wind farm on
the other hand has a much lower load factor (UK offshore is around 30% [0]),
and that load capacity isn't planned at all. You might get 30% on average per
year, but that daily capacity fluctuates throughout the year - that's what I
mean about fluctuating capacity.

[0] [https://www.gov.uk/government/statistics/renewable-
sources-o...](https://www.gov.uk/government/statistics/renewable-sources-of-
energy-chapter-6-digest-of-united-kingdom-energy-statistics-dukes)

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hliyan
A different article puts the energy costs at: "140 pounds ($185) per megawatt-
hour on top of the current wholesale power price in the UK, which is about 49
pounds ($65) per megawatt-hour"

Some way to go before it becomes competitive...

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lumisota
Those aren't the costs of generating the energy. They receive ~£140/MWh in
government subsidies, and ~£49/MWh for wholesale supply.

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vuln
So the consumer is paying twice? Through taxes and then again when they
actually purchase the power? Wow...

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pjc50
If we kept going with coal, the government might have to pay the costs of
dealing with Somerset, Norfolk etc being underwater instead ...

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tonyedgecombe
The shift away from coal to gas started a long time ago and was driven by
costs more than anything else.

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sohkamyung
Just a note that research into the effects of offshore wind farms on seabirds
is still needed to minimise their environmental impact. Here's an article that
looks at it[1].

[1] "As Offshore Wind Power Picks Up, Do Seabirds Need to Suffer?"
[https://www.hakaimagazine.com/news/as-offshore-wind-power-
pi...](https://www.hakaimagazine.com/news/as-offshore-wind-power-picks-up-do-
seabirds-have-to-suffer/)

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cm2187
How steady is the electricity production of a windfarm? I would assume that it
would be subject to bursts, with the production being quite volatile over an
hour. If that's the case isn't it a problem for the grid given that the demand
isn't bursty?

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shaki-dora
Yes and no...

Having many producers, connected by the grid, smooths out any fluctuations on
the “minute” timescale. There’s also some smoothing because solar and wind
tend to peak at different times of the day.

Batteries have also improved dramatically, and there are “smart grid” efforts
that could help, such as running some consumers during times of peak
production (refrigerator compressors, aluminum smelters), or using grid-
connected batteries, such as charging cars.

The storage problem is imminently solvable and, with the improvements in solar
efficiency, renewables are certain to become cost leaders rather soon. In fact
they may already have.

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touristtam
[https://www.youtube.com/watch?time_continue=12&v=PUlfvXaISvc](https://www.youtube.com/watch?time_continue=12&v=PUlfvXaISvc)

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beefman
The material inputs for the lifetime of the project are roughly 27 t/GWh, 1/3
of which is metal. It shows how terribly poor wind energy systems are.

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trhway
what happens to that metal afterwards? wouldn't it continue to be metal which
can scrapped and reused? the reuse/remelt is much more energy efficient then
original production you seem to allude to.

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beefman
Yes, metal can be recycled. It's still more energy-intensive than concrete.
Materials intensity is a pretty good figure of merit for energy systems, and
energy intensity is an ideal one.

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azernik
Concrete's CO2 emissions are, however, doubled by the chemical processes used
to make cement.

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oldandtired
Which is relevant in what way? The amount of concrete is small in relative
terms, so doubling a small quantity is still a small quantity. A forest fire
will put out significantly more CO2 and they occur quite frequently around the
globe.

If you want us to take your comment seriously, you will need to show that the
CO2 emissions would be on some significant level.

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azernik
Concrete (specifically, the cement used to produce it) accounts for 5% of
global CO2 emissions:

[http://blogs.ei.columbia.edu/2012/05/09/emissions-from-
the-c...](http://blogs.ei.columbia.edu/2012/05/09/emissions-from-the-cement-
industry/)

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anovikov
Solar 27% capacity factor is BS, that isn't possible. Theoretical maximum for
100% perfect weather on equator is 29%. I doubt it crosses 22-23% anywhere in
the world and definitely no more than 15-16% U.S. average.

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danmaz74
A couple of actual numbers:

* For example, Agua Caliente Solar Project, located in Arizona near the 33rd parallel and awarded for its excellence in renewable energy has a nameplate capacity of 290 MW and an actual average annual production of 740 GWh/year. Its capacity factor is thus: 29%

* A significantly lower capacity factor is achieved by Lauingen Energy Park located in Bavaria, near the 49th parallel. With a nameplate capacity of 25.7 MW and an actual average annual production of 26.98 GWh/year it has a capacity factor of 12.0%.

[https://en.wikipedia.org/wiki/Capacity_factor#Photovoltaic_p...](https://en.wikipedia.org/wiki/Capacity_factor#Photovoltaic_power_station)

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gaius
Norway’s, no? It just happens to be located near Scotland.

The SNP’s plans for tidal barriers came to naught (as did their dreams of oil
at $100/barrel)

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lumisota
While it is owned by Norway's state oil company, it supplies the UK National
Grid and receives UK government subsidies.

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gaius
So England pays, Norway gets the profit and Scotland gets the credit. Hmmm.

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pjc50
This is like all other power stations in a privatised economy. For example the
Hinkley Point C power station is subsidised by the UK but constructed,
operated and will send profit (if any) to the French state-owned EDF.

Energy is a reserved area and not within the remit of the Scottish Parliament.

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gaius
Yes it's ironic that all our utilities ended up as state owned after all!

