

Apple builds massive 20 Megawatt solar farm in North Carolina - ck2
http://gigaom.com/cleantech/behold-apples-massive-solar-farm-from-the-sky-photos/

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amirmansour
As my life long pursuit of teaching people the difference between a Megawatt
and Megawatt-hour, I will link to this: [http://www.xtremepower.com/about-
energy-storage/mw-vs-mwh.ph...](http://www.xtremepower.com/about-energy-
storage/mw-vs-mwh.php). Since this article is going to attract some eyes.
DeedOfTheDay++

~~~
andrewcooke
i'm confused - the terminology in the article seems fine to me. are you
implying otherwise (am i mistaken?), or do you just intend to post this every
time power is mentioned?!

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amirmansour
I just intend to post this every time an article has something to do with
power and things of that nature. Too many people get them mixed up or simply
don't know. Even professionals get MW and MWh mixed up. Electrical engineer
here :)

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ghshephard
I work in the smart grid industry, just a lowly network engineer, but in the
last 5-7 years, I've rarely, if ever, see anyone confuse kWh/kW. I would
presume that for people who care about MWh, that there is even less likelihood
of confusion.

I think the general populace, the industry, and certainly the professionals in
Northern California have become pretty well educated on this topic, mostly as
a result of the prevalence here of energy startups, solar panel installations,
and needing to understand what that "$0.31/kWh" on their PG&E bill means.

Might be different in other places though.

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stcredzero
_> I work in the smart grid industry, just a lowly network engineer, but in
the last 5-7 years, I've rarely, if ever, see anyone confuse kWh/kW._

I suspect you're not the demographic the commenter was aiming at.

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wcoenen
For comparison, a 20 megawatt power plant that runs on diesel can fit in a
standard shipping container: [http://www.directindustry.com/prod/hyundai-
heavy-industries-...](http://www.directindustry.com/prod/hyundai-heavy-
industries-diesel-power-plant/containerized-power-plants-55206-364058.html)

~~~
hristov
No it cannot. What you are linking is a video of using multiple shipping-
container generators to form a single power plant. If you explore a bit you
will see the brochure(0) for those container based diesel generators and it
shows that each one of them produces from .6 to 1.7 MW depending on engine
choice.

So you will need around 12-30 of those depending on engine choice(1). You will
also need fuel tanks, pipes, fire suppression equipment, electrical equipment
access roads etc. Also you will need to space everything apart for fire
safety, to prevent overheating and to prevent those diesels from breathing in
each other's exhaust.

So by the time you are done I would not be surprised if you require about as
much space as the solar plant. And of course you will have a bunch diesel
exhaust and a lot of noise, so even if you do get a smaller footprint, the
land you save will be of very limited use.

Solar plants have much better footprint than it seems, because they do not
really impact the land around them. Most other types of power plants will have
very significant impact on the land around them and therefore they effectively
take up much more space than it seems.

(0)- [http://pdf.directindustry.com/pdf/hyundai-heavy-
industries-d...](http://pdf.directindustry.com/pdf/hyundai-heavy-industries-
diesel-power-plant/packaged-power-station/55206-48953-_3.html)

(1) I know the video shows around five of them only, it seems the video has
been cut off in the middle.

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wcoenen
Yes, I realized a while after posting that a 20 MW plant would produce way too
much waste heat to fit in such a small volume. My bad. I couldn't get back in
time to my comment to edit in a correction.

My gut feeling is still that something is wrong if a 20 MW plant is called
"massive". I'd expect a massive power plant to produce gigawatts, not a few
megawatts. That's the feeling I tried to convey with my bad example.

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jhaglund
100 acres is relatively "massive" compared to existing American solar
installations. But it's really not that large an area in the industrial sense.

I searched "acres refinery" to get an idea of how much land an oil refinery
takes up (required, in addition to oil fields, for your diesel generators).
Chevron's Richmond refinery took up 435 acres in 1915, expanded over the years
to to 2,900 acres in 2002.
<http://en.wikipedia.org/wiki/Chevron_Richmond_Refinery>

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teamonkey
Does anyone know _why_ they're building this?

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stephengillie
Solar is usually a good investment, especially when you can start selling your
excess back into the powergrid for a slight profit. One of the current
barriers to solar is the cost -- I think Apple have more in the bank any other
company right now.

As for "why _there_ ", maybe that was one of the sunniest parts of the US.
Maybe Apple has a datacenter nearby or will soon build one -- either for
expansion of current cloud services or for new services.

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Kronopath
> why there

The second sentence of the article:

"After the interview they kindly sent me these aerial video stills that they
took from a plane above Apple’s solar farm, _next to its data center in the
city of Maiden_."

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joubert
I'm very interested in energy generation and distribution.

In 2010 I visited South Africa and went to Jozi Power, a company that delivers
modular mobile power on demand using shipping containers to various sites
across Africa. I wrote about it here: <http://joubert.posterous.com/modular-
mobile-power>

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andrewcooke
interesting. but odd they cannot run the generators continuously. what do they
do when used in boats? i can't imagine boats turning off their engines for 6
hours each day.

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krisoft
"SunPower makes higher efficiency solar panels, which are placed on trackers
that follow the sun throughout the day." Higher efficiency than what? Or is it
a well defined term regarding solar panels, which I'm unaware of?

~~~
shimon_e
high-er- efficiency

The other commentators are missing what the OP is talking about. The grammar
is incorrect.

~~~
Dylan16807
I agree with them. It's a context issue, not a grammar issue.

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DanBC
It's great to see companies installing big solar plants.

What's 20 MW in comparison to usage for a typical company? (I'm not bashing
Apple, just for the avoidance of any doubt.)

~~~
Someone
What is a typical company?

[http://www.eia.gov/emeu/consumptionbriefs/cbecs/pbawebsite/o...](http://www.eia.gov/emeu/consumptionbriefs/cbecs/pbawebsite/office/office_howuseelec.htm)
gives 18.9kWh per square foot for office buildings. I assume that is per year
(that makes it 50Wh per square foor per day, or 2W continuous per square foot.
That seems a bit low, but it includes nights and weekends, and the 25W per
square foot I get when that 18.9 is per month seems awfully high)

Let's guess 20MW translates to 100MWh per day (probably generous). That way,
it would translate to about 5000 square-foot-years per day, or 1.8 million
square-foot-years per year. So, it would power a 1.8M square foot office
building. At (guessing) 200 square feet per office worker, that would be about
9000 office workers.

I guess this will mainly power a server park, though. As such, it would power
a 4MW server park. At (guessing) 500W/server, that would be 8k machines.

(with lots of handwaiving, possibly some miscalculations, so corrections are
welcome)

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manaskarekar
Why are those panels spaced out so much? Is there some physical attribute(s)
that prevents them from being placed too close to each other?

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plorkyeran
Inter-module shading can be a pretty significant problem with trackers. It's
surprisingly easy to hit the point where adding more panels has no benefit
outside of a few hours in the very middle of the day, and for a data center
Apple would probably prefer more consistent and cost-efficient power rather
than higher peak power.

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just2n
Wouldn't making them capable of elevating solve that problem somewhat?

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molmalo
When the sun is down, you need that space between the panels them to let the
light hit all of them. If you elevate some of them, they will cast a shadow
over the ones on the floor behind them.

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hristov
This is very good news. It is especially interesting coming from apple,
because apple are incredibly ... shall we say frugal. If they opted for a
solar plant they must have calculated that it is in their financial interest.
Which means that solar plants are becoming price competitive.

This is not surprising considering the plummeting cost of solar panels.

~~~
onetimeuse001
Not necessarily, it _could_ very well be a PR trick. Going solar is trendy so
they may have done it to get some press. It pays off but maybe in extra iPhone
sales /brand building

~~~
polshaw
I have absolutely no doubt there is some PR behind the decision, but it should
also be cost-effective in the long term.

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alid
I like to think PR and costs weren't the only drivers of this...Steve Jobs was
quite the hippie capitalist, so I like to think he instigated a move into this
space :)

~~~
onetimeuse001
Dude, if Apple is liked and their brand loved even more, that $xxx million
spent on solar there is nothing, even if it's declared a total loss. So, in
theory, you can be a total capitalist and "waste money."

My point was not to assume that this makes sense economically _just because_
Apple did it. They have other ways of getting their money back and if they
lose, it's just a rounding error
[http://finance.yahoo.com/q/cf?s=AAPL&annual](http://finance.yahoo.com/q/cf?s=AAPL&annual)

You sure have seen the Beyond Petroleum ads, haven't you?
[http://www.environmentalleader.com/2008/01/15/beyond-
petrole...](http://www.environmentalleader.com/2008/01/15/beyond-petroleum-
pays-off-for-bp/)

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tsieling
Why is this being discussed. It's not like Apple invented solar panels. Ugh
fanboys!

;)

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baklava
Apple picked the wrong time to invest in NC. The citizens in NC can use the
jobs, but are tired of politicians lining corporations' pockets with cash in
the form of tax incentives, etc. So, it is going to get expensive to be
stationed here. It isn't the new Florida; NC just had a few governors that
thought they would be more popular if they threw away tax dollars on
corporations that brought very few jobs in, because they knew the local papers
and media would spin it in a favorable way.

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Roelven
Why does everyone keep on investing in solar panels while this technology will
surely be redundant in 5 years?

