
World’s Largest Solar Array Set to Crank Out 290 Megawatts of Sunshine Power - srikar
http://www.scientificamerican.com/article/world-s-largest-solar-array-set-to-crank-out-290-megawatts-of-sunshine-power/
======
unwind
_The project, which cost a total of $1.8 billion to construct, received a
million-dollar loan from the DoE as a part of its “SunShot” initiative (so-
named in the spirit of president John F. Kennedy’s “moon shot” program)._

That's generous, getting a loan for a massive 0.056% like that must have been
a real boost. Also: wut?

~~~
olegkikin
Meanwhile

"The summary of oil-related subsidies in the U.S. for 2010 totals $4.5
billion" [1]

"The Treasury Department estimates that eliminating just three tax preferences
for coal would save $2.6 billion between 2013-2022" [2]

[1] [http://www.forbes.com/sites/energysource/2012/04/25/the-
surp...](http://www.forbes.com/sites/energysource/2012/04/25/the-surprising-
reason-that-oil-subsidies-persist-even-liberals-love-them/)

[2] [http://thinkprogress.org/climate/2012/04/13/463874/top-
three...](http://thinkprogress.org/climate/2012/04/13/463874/top-three-ways-
that-american-taxpayers-subsidize-dirty-coal-development/)

~~~
protomyth
How about the actual subsidy data for 2010
[http://www.eia.gov/analysis/requests/subsidy/pdf/subsidy.pdf](http://www.eia.gov/analysis/requests/subsidy/pdf/subsidy.pdf)

Renewables get about 10x the subsidies (both direct and indirect) of oil.
Nuclear seems to be getting screwed in the deal. Given the crappy economy,
looking at the number of people employed by each sector is helpful.

~~~
gamerdonkey
Renewable energy sources are seeing tons of direct subsidies. However, quoting
those numbers in a discussion like this can be a little misleading because of
the disclaimer on page ix of that report titled "Not All Subsidies Impacting
the Energy Sector Are Included in this Report"

> This report only includes subsidies meeting the following criteria: they are
> provided by the federal government, they provide a financial benefit with an
> identifiable FY 2010 federal budget impact, and, they are specifically
> targeted at energy. These criteria, particularly the energy-specific
> requirement, exclude some subsidies that benefit the energy sector. Some of
> the subsidies excluded from this analysis are discussed below.

The examples that they list overwhelmingly benefit oil, gas, and nuclear
energy sectors.

~~~
protomyth
"The examples that they list overwhelmingly benefit oil, gas, and nuclear
energy sectors."

Let's look:

"For example, Section 199 of the American Jobs Creation Act of 2004"

This was not specific to oil or gas and benefited those "provides reductions
in taxable income for American manufacturers", wonder why that was more
beneficial to oil and gas then renewable in 2010? 25% of $13 billion is listed
as energy related with the remainder being other industries.

"The tax code allows a foreign tax credit for income taxes paid to foreign
countries." Benefits oil, but also a lot of other industries buying raw
materials from foreign countries to use in the USA.

"The tax code also provides special treatment for some publicly-traded
partnerships (PTP)." This one should benefit both sides equally.

"Another potential subsidy source not addressed in this report is associated
with energy-related trust funds financed by taxes and fees." These are
industry funded and "there is no direct federal budgetary impact in FY 2010"

"This report also does not attempt to quantify the potential subsidy resulting
from limits to liability in case of a nuclear accident provided by Section 170
of the Atomic Energy Act of 1954, the Price-Anderson Act." Nuclear accidents
can be bad so this is actually the most beneficial.

Oil and gas are using the same tax incentives that other companies that employ
American workers in the US and manufacture a product with local resources or
foreign bought resources are using. If solar is not using these tax breaks
then I wonder where they were getting their panels?

~~~
gamerdonkey
I meant that the examples benefit oil, gas, and nuclear overwhelmingly as
opposed to the renewable sectors in the report. I'm sorry if that wasn't
clear.

Obviously, a program that applies to all companies will see more expenditures
for the oil and gas companies because they exist in a larger and more
established industry. That is still tax-payer money being spent to encourage
growth in that sector, and much less, comparatively speaking, is being spent
in those sectors than on renewables.

Thus, I find it a little disingenuous to roll out that 10x factor which
ignores a lot of subsidization for an industry which many would argue doesn't
need much more encouragement.

~~~
protomyth
Other than the nuclear part, the taxes are not field specific and 10x is
actually an understatement of part of the table of taxes. It is a common
canard that we don't provide incentives for renewable energy when we actually
do in great amounts. I find it disingenuous to say we are not giving subsidies
and breaks to renewables when it is right there in a table (ES2). Heck, direct
expenditures were 46 million for oil and gas to 4,696 million for Renewables.

The technology failure to build an energy source / process that is cheaper
with better storage options than oil & gas is the primary problem. Lack of
taxpayer funds is not.

------
maerF0x0
Mankinds total energy consumption is on the order of 10^13 , 290 million new
power ... about 34500 more of these required. Or to be really blunt: A new
plant every day for 100 years.

~~~
anigbrowl
Not sure why you're being downvoted; this is sad, but true. Worldwide average
power consumption is estimated to be 15 terawatts
([http://en.wikipedia.org/wiki/World_energy_consumption](http://en.wikipedia.org/wiki/World_energy_consumption)
\- with sources). Now obviously there is a great deal of waste we could
engineer away, but that has to be offset against the growing demands of the
developing world and a global population that is still growing, albeit set to
level off by 2050 or so.

I love renewable energy, and I purchase carbon offsets on my power bill each
month to mitigate the fossil fuel I use. But it doesn't scale that well, and
the environmental costs of manufacturing energy capture and storage technology
need to be taken into account as well. We need to face up to this scale issue,
which is something many green people don't like to do because that brings
nuclear power into the conversation, but facts are facts.

~~~
jdmichal
Total energy consumption is also very different from total electrical
consumption, which is only at 14% of total energy consumption. I don't know of
anyone who's targeting things like direct burning of fuel for, say, a steel
foundry. Or anyone who would argue that PV can take that job over. Maybe
concentrated solar could?

~~~
anigbrowl
Sure, but it's still a useful metric. Even if we assume that 14% as an upper
bound, that's still over a decade of bringing on plants the size of this one
at the rate of one a day. I just think the economics point strongly towards
greater deployment of nuclear power.

------
mooism2
_There are extra panels built into the site, so “when the plant is partially
covered by clouds, the control system can actually call upon the portion of
the panels that is not impacted” and recruit the extras there to make up the
difference._

I don't understand. Why forego the extra power when there are no clouds?

~~~
pcl
I imagine that this is just one of a number of uses of extra capacity. When we
deploy servers, we don't like to run them at 100% for a number of reasons
(extra capacity to handle spikes and failures, unpredictable behavior of
components at full load, breathing room for planned maintenance, etc.). I bet
a large-scale solar deployment is no different.

~~~
Dylan16807
The panels themselves are getting maximum sun and converting it into voltage
no matter what. So the only thing you have to upgrade is the distribution
wires, so they can handle the full panel output without being at capacity.

But I guess nobody wants to buy the highly-variable extra power. And it leaves
them room to install storage in the future.

------
johnohara
$1.8B / 5MM = $360 per panel. That includes frames, land, infrastructure and
most importantly, connection to the grid, which itself was significantly
upgraded in late 1990's early 2000's to support the construction of gas fired
turbine facilities (which use ALOT of water for cooling).

$360 per panel is very reasonable.

With PPG is buying all of its capacity, it appears this is a solution that
works.

Is my math right tho'? 290MW is roughly 58 Watts per panel. Aren't these
things capable of 300+ watts or more?

edit: changed $1.6B to $1.8B

~~~
sitkack
I am guessing that the plant actually has double its rated capacity, so
something like 600MW in panels.

------
mrfusion
Does a large installation of panels like this have a cooling effect on the
nearby area? If so I wonder if they could put some wind turbines around the
permitter to capture wind energy?

~~~
neltnerb
I think generally the opposite, as the panels absorb much more overall light
than the ground generally does. They're by design as close to "black" as
possible since the goal is to capture light and not reflect any.

Of course, a hot spot also causes updrafts, so your thought there is still
valid.

Personally, I think combining solar PV with solar thermal is an interesting
option. When your panels are often seeing temperatures in excess of 90C (that
part I am confident is true), it seems like using a heat exchange fluid to
both cool the panels (improving efficiency and lifetime) and deliver that heat
to a heat engine or use as a preheater for a steam generation system is
interesting.

I think possibly more interesting for residential, where a 90C heat source
preheating your residential water before your water heater could significantly
increase the effective efficiency of your panels. You generate high value
electricity from as much light power as you can, and use the waste heat to
decrease your use of electricity/gas for heating. Win-win, and the cost is
just some heat exchangers and tubing.

~~~
jdmichal
90°C is not really hot enough to extract efficiently. The Carnot cycle
efficiency of such a process, even assuming it used a cold-sink at 0°C (not
likely), is only 25%.

However, using that warmed water as a preheat for another process is perfectly
valid.

~~~
neltnerb
Yeah, that's my thought. Think heat exchanger, not heat engine. If you managed
to get your input water at 10C from the ground up to 30C, you'd have very
little left to do before it's usable in a shower. Either way, the thermal mass
of the flowing cool water will definitely improve the solar PV efficiency and
lifetime.

------
trothamel
I'll just point out that according to the project's website, it has a capacity
factor of 25%, for 71 MW.(Although it's probably much higher during the day,
and obviously much lower at night.)

[http://www.cleanenergyactionproject.com/CleanEnergyActionPro...](http://www.cleanenergyactionproject.com/CleanEnergyActionProject/CS.Agua_Caliente_Solar_Project___Thin_Film_Photovoltaic_Solar_Power_Case_Studies.html)

~~~
jdmichal
That math works out pretty much perfectly with the listed "annual production"
number:

[https://www.google.com/#q=(626.219+*+1000)+%2F+(365.25+*+24)](https://www.google.com/#q=\(626.219+*+1000\)+%2F+\(365.25+*+24\))

------
protomyth
"But as solar power becomes cheaper, Davidson predicts that utilities will
pass those savings on to consumers."

I pretty sure history says this line is false.

~~~
fixermark
It depends on the utility. In Pennsylvania, the local power companies are
required to serve as distribution brokers for people who want to buy supply
from a particular company. This means that if I want to buy specifically from
the nearby wind farm, I can do so (and I can compare price between them and,
say, the big coal-fired powerplant owner in the state).

Individual homeowners may not care. I imagine if Target or Wal-Mart is
choosing their energy supplier, however...

------
ufmace
I'm curious what kind of maintenance costs and tasks are involved in running a
solar plant of this size. Do the panels need replacing much, or cleaning?

~~~
ChuckMcM
I'm going to guess cleaning, wiring repair when rodents damage it, and more
cleaning. I've had a 5.2kW of panels on my roof in Sunnyvale for 12 years now
and it is really obvious when you get water spots on them or dust. This is
being mitigated by new panel architectures (micro-inverters so loss of a
single panel doesn't affect the whole system) but its still a challenge.

~~~
ufmace
Cool, how's the cost on them working out? Have they broken even? Any impact
from subsidies/tax breaks?

~~~
ChuckMcM
I was part of the "first" California/Federal rebate/subsidy program. Depending
on how you treat depreciation they have returned either 19 or 23% annually on
their capital investment. Overall a solid investment even if they don't change
the potential sale value of the house. At during the depths of the 2009
recession it was a much better return than my 401k portfolio.

I'm considering replacing them with the latest technology. That
cost/efficiency I believe I can boost them to 7.8kW raw conversion on the same
mounts. I may also be able to boost total efficiency with some of the newer
modes (mine are connected serially into high voltage strings, vs today where
they are more commonly a set of parallel micro-inverters.

------
rwmj
A couple of questions: Do they move the panels to follow the sun? Are these
thin film panels more efficient than solar thermal collectors?

~~~
jacquesm
> Do they move the panels to follow the sun?

No, they are fixed frames.

[http://gigaom.com/2012/07/16/huge-arizona-solar-panel-
farm-n...](http://gigaom.com/2012/07/16/huge-arizona-solar-panel-farm-
now-23-completed/)

The reason why is probably that they did the same computation everybody else
has made that considers movable panels and they concluded that the extra costs
sunk in the hardware to move the panels could be spent on extra panels with a
net increase in power at reduced complexity.

I wished I had made that same computation before investing in my actuator
controlled panel setup.

> Are these thin film panels more efficient than solar thermal collectors?

You can't really do that comparison directly, you can only compare one
installation end-to-end with another using different technology. Just
substituting one part of the chain is impossible, and even if the one or the
other would show a benefit there is no point making the comparison without
adding best-of-breed versions of all the other parts in the chain so that the
resulting power generated at the systems output can be compared with the
energy input by the sun.

Even then, the systems are of such different breed that you could have a
problem comparing them at all, for instance, photovoltaics do not allow for
easy storage and thermal collectors give you the option of storing the energy
in the form of heat for a while before using it for conversion.

~~~
neltnerb
> Even then, the systems are of such different breed that you > could have a
> problem comparing them at all, for instance, > photovoltaics do not allow
> for easy storage and thermal > collectors give you the option of storing the
> energy in > the form of heat for a while before using it for > conversion.

And then there's the difference between energy efficiency, energy return on
energy invested, cost efficiency, and energy return on money invested which
are all totally different measures.

The energy efficiency of solar PV is really rather ridiculously high all
things considered, I think it's rarely acknowledged that the ~10% conversion
efficiencies common for PV are actually extremely high compared to plants with
their more typical ~1% for even organisms like algae. Really kind of puts
things in perspective.

I think solar thermal is less energy efficient generally for producing
electricity, but is obviously more efficient for generating heat. But the cost
efficiency is less clear. I've seen studies that indicate solar thermal can be
on par cost-wise even though the efficiency is lower, because it's an array of
mirrors instead of semiconductors. Not really sure what the result of that
analysis ended up being, but probably varies by site.

------
chiph
Storage for night-time or cloudy days might be the next big challenge. They
could go with molten salt, or even carbon-fiber flywheels.

~~~
stuki
With solar still a tiny fraction of the total mix, and with plenty of paid
for, weather independent capacity already existing, it's likely more efficient
to lean on those for when the sun don't shine.

In the Southwest, where counteracting the direct effect of solar radiation
(cooling/Ac) is a main consumer of power, this makes even more sense.

------
mattip
Are there any figures on ROI available for this plant?

~~~
maerF0x0
ROI on non renewables are high because the producers do not pay (all) of the
externalities such as the cost of pull the carbon out of the air after it's
been burned. I would love to see the true cost of oil and then decide if the
ROI is real, or if its just a shift of wealth from those who get to breath
polluted air to those who pumped the oil.

~~~
stuki
You'd have to put an unusually high value on air cleanliness to argue that
oil, period, and the scale economies it has enabled, has not have a net ROI in
total.

Whether the marginal added "value" to some, of commuting in a hummer vs a
Prius, is worth the cost to third parties of the incremental added pollution
is, of course, a different matter.

~~~
maerF0x0
I agree with your general feeling that Oil has had a positive ROI, but I doubt
it is very high after all the cleanup is paid for.

------
vixin
"Global climate change is here". I'm confused. "The RSS satellite record shows
a zero trend for 210 months". 17 years, 6 months.

~~~
phireal
The oceans have been absorbing the heat from the atmosphere, yielding the flat
trend in atmospheric temperatures. The total energy in the system is
increasing.

~~~
stuki
How do you even go about measuring "total energy in the system?"

Intuitively, adding greenhouse gasses to the atmosphere should, in isolation,
increase energy in the system. But what if we really were heading for a new
ice age as some feared in the 70s. And the only thing that prevented us from
freezing to death, was the concerted effort of those notoriously concerned and
altruistic SUV drivers taking one for the team, by revving up their Hummers.

~~~
phireal
Total energy in the system is radiation received from the sun minus that
emitted from the earth's surface back into space. Both of these things are
pretty well understood and fairly simple to calculate.

As for the ice age business, climate modeling from 40 years ago is an entirely
separate thing compared with today's climate modeling. The advances we've made
in model resolution and understanding the physics is quite compelling.

