

How Many Solar Panels To Power The World? - Freebytes
http://gizmodo.com/5350191/how-many-solar-panels-would-it-take-to-power-the-entire-world

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electromagnetic
Is covering 500,000 sq KM of desert (which has a relatively high albedo for a
non-frozen surface) with dark solar panels really going to help with global
warming? Especially considering that as our power needs expand, we will
decrease the surface albedo even more. However my biggest concern is the
effects on the local regions, it's been shown that when rainforest is cut
down, the change in surface albedo and evaporation can increase temperatures
by 3C.

Covering 1/18th of the Sahara with solar panels (a number that will
drastically increase as African economies grow and as the large majority of
Europe is still growing quickly) will not only raise the temperature in one of
the hottest places on the planet, but it will cause significant changes to the
climate of Eurasia and Africa. The weather in most of Europe is heavily
influenced by Saharan winds, and I don't think it's especially wise to screw
with the one thing that keeps the region temperate and capable of widespread
food production.

Their predictions don't appear to include the fact that solar power isn't 100%
guaranteed, you need extra production if you're planning on powering a region.
Most wind and solar production has to be turned off after meeting a quota,
because they have to supply customers with the same amount, you can't go
producing 500MW one day and then produce only 50MW the next because it's
cloudy.

Perhaps I'm just a doomsayer, but all the gung-ho environmentalism that gets
proposed seriously disturbs me. Farmers get paid to have wind turbines on
their land, not only does this cause demineralization of their fields, which
increase fertilizer use, which no matter what causes nitrates to get into the
water, but it also decreases bird and bat populations that act as natural
pesticides. Now you have to increase pesticide usage too, which gets more into
the food and more into the water. There's a solution to all this, whilst
sticking with wind turbines, but I've yet to see a company deploying helical
wind turbines (which significantly reduce demineralization and bird strikes).

I like good old green nuclear, it produces guaranteed amounts of power on a
daily basis rain or shine, windy or calm. Modern reactors produce
significantly less waste than old reactors, produce medical isotopes. Reactors
also often cause a benefit to the environment as the majority of their land is
a buffer zone, which goes untended and becomes a natural habitat.

I'm sorry but when nuclear frequently increases biodiversity and 'green'
frequently reduces it, you've got some serious shit going wrong with your
plans to save the planet.

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brazzy
Um... _how_ exactly do wind turbines cause demineralization?

How do modern reactors produce less waste? The underlying nuclear reactions
can't really be influenced by technology.

Not to mention that your "green" reactors' fuel is

A) produced in strip mines that devastate entire landscapes

B) running out about as soon as oil is, unless you start using breeder
reactors, which are a much less tested technology and pose a massive
proliferation risk.

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patio11
That shows you how powerfully a good visualization can deceive you.

Here's the same statistic, shown in another light:

[http://www.bingocardcreator.com/blog-images/lying-with-
numbe...](http://www.bingocardcreator.com/blog-images/lying-with-numbers.png)

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brazzy
"solar panels, distributed across deserts and areas with almost 24/7 sun"

Um... I don't think so...

~~~
smanek
I think (hope?) the implication is that the sun is always shining on some of
this world-wide network of panels - so we don't need huge batteries to store
power for nights/cloudy-days.

Kind of like the old saying that "the sun never sets on the British Empire."

~~~
brazzy
The only thing that the phrase "with almost 24/7 sun" can logically apply to
is the word "areas", because otherwise that word makes no sense.

But it's a silly oversight that is irrelevant to the practicability (or lack
thereof) of this proposal.

In any case, you'd probably still need some sort of power storage, not because
of night and cloudy days, but because of demand variation and peaks. The big
problem would be around midnight GMT: lots of demand for power in Europe and
North America, but most of the sunlight shines on the Pacific, with its
distinct lack of desert areas (or dry land in general).

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psadauskas
How much energy would it take to produce and ship that many solar panels?

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jerf
Now, supposing that our solar panel capacity increases by something reasonable
every year, like 25%, how many decades would that take to cover square miles
upon square miles upon square miles with collectors, and, given that power
demands will rise in those decades, how much longer will it take to catch up
to that again? How expensive will it be, in light of an effectively infinite
demand during those periods where it hasn't been completed yet?

Some people see these charts and see possibility. I see the sheer scale of the
operation and boggle; it's absurd.

~~~
brazzy
Think about cost and scale the _already_ existing power infrastructure of oil
fields, coal mines, pipelines, refineries, supertankers, gas stations and
power plants.

That's mind-boggling too, you just don't think about it because it's already
there.

~~~
jerf
Yes, that's right. The project being proposed is _merely_ several orders of
magnitude larger than all existing infrastructure created up to now.

That's exactly my point; I _do_ grasp how much that took, and then to propose
that we could solve all our problems by just doing a thousand times more work
(or more) is just silly.

~~~
brazzy
Any numbers to back up that claim?

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zokier
I have seen far smaller estimates, 300x300 km area for entire world (current
consumption) in Sahara, or 125x125 km area for Europe. Dunno about
credibility, was in a newspaper article related to some German investors
building large solar farm in Sahara.

I actually think that the 125x125km area should be doable. Its not like we
don't have space in Sahara. US is more difficult as its probably not practical
to transfer electricity as it from Africa. Maybe as hydrogen, dunno.

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darien
And thus, we could also expect a boom and bust cycle for the solar tech
industry. Boom: Let's see how fast we can make money selling solar panels.
Bust: We sold so many solar panels that we have more energy than we need.

~~~
wlievens
We'll always find a use for that excess electricity, especially if it's
renewable.

~~~
darien
It's not going to happen overnight. The value of nearly all commodities will
become suspect the instant energy/electricity approaches the cost of zero.
This means global market volatility will surge as countries/investors figure
out a new means of evaluating worth. Free is good, but not if it causes a
global panic.

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onreact-com
This has been on HN already yesterday and it's logic is flawed as I explained
last time. You don't need to cover extra space with solar panels as they are
situated on roofs etc.

See: <http://news.ycombinator.com/item?id=800264>

