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World’s Largest Solar Array Set to Crank Out 290 Megawatts of Sunshine Power

31 points by srikar 12y ago

mooism2 12y ago
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?
- noir_lord 12y ago
  If I had to guess. 1) Maintenance - When not cloudy you can bring them on-line to cover the maintenance on other parts of the site. 2) They've designed for a fixed output under certain conditions so in effect they don't want to push more than 290MW but the extra panels help them not drop that too far. 3) Grid operators like plants this size to be capable of consistent output - similar to why some gas plants run with either one or the other turbine on but often not both (In the old days before successive governments trashed it the UK national grid aimed for an unused capacity overhead of 25%, this would cover maintenance, accidents, natural disasters etc, we are currently running with about 4% spare)
- chrisBob 12y ago
  My only guess is that they are limited by the transmission lines. Upstate NY has a lot of hydro and wind power, and actually produces more energy than it can export on a lot of days. The obvious answer is to build more high voltage transmission lines, but people are fighting them for two reasons: No one wants to live under the transmission lines, and when they build transmission lines next to your house your electricity gets more expensive because the cheap power being exported to the rest of the state.
  - cpwright 12y ago
    I don't live quite upstate, but we already have a nuclear power plant; and our town supervisor is complaining about a plan to land a transmission line in the town not to far from it to export power from upstate to downstate (http://westpointproject.com/ http://westpointproject.com/). The HVDC converter will buzz.
- pcl 12y ago
  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.
  - sitkack 12y ago
    They are also in a better financial position if they can supply guaranteed power instead of variable power. If power fluctuates relative to the weather then energy traders get involved in your pricing and no one wants Goldman Sachs and Enron in their business.
  - Dylan16807 12y ago
    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.
- jacquesm 12y ago
  Shading can impact the power output of a string significantly. By dynamically reconfiguring the topology and effectively stringing together panels from various locations they can balance the power output in a nicer way.
mattip 12y ago
Are there any figures on ROI available for this plant?
- rwmj 12y ago
  ROI with and without subsidies would also be interesting.
- sitkack 12y ago
  You would need to calc solar insolation http://www.pveducation.org/pvcdrom/properties-of-sunlight/calculation-of-solar-insolation http://www.pveducation.org/pvcdrom/properties-of-sunlight/ca... for the site and the bulk cost of electricity over the lifetime of the plant. I don't have specifics but it looks like they have more capacity that they bring online at the beginning and the end of the day to flatten the power output. So I would use a more trapezoidal curve (or just assume a 10 hr day). 290MW * 10hrs * 42$/MWhr [1] => 120K/day With a nice fatti 0% loan and no increases in the cost of electricity payback is about 30 years. I wouldn't be surprised if costs didn't rise at least 2x to 4x in the next 20, soo I'd say they are probably going to do ok on the ROI. Even if the raw capacity of the plant was 600MW (derate panels over lifetime, more consistent output), the panel cost was less than 1/3 of the total price of acquisition and construction. And as the grid becomes smarter they can probably start to put a more variable amount of power into it. [1] http://www.powerisknowledge.com/ http://www.powerisknowledge.com/
  - masonhensley 12y ago
    Hmm, I think this wholesale pricing may be more accurate: http://www.eia.gov/electricity/monthly/update/wholesale_markets.cfm http://www.eia.gov/electricity/monthly/update/wholesale_mark... The plant will serve California which seems to be in the 130-170$/MWhr right? But, this all assumes that a plant like this would not put a downward pressure on prices.
    - sitkack 12y ago
      Wow, I had no idea it was so high. Yeah, that plant could have a 15 year payback cycle or less. http://en.wikipedia.org/wiki/List_of_countries_by_electricity_consumption http://en.wikipedia.org/wiki/List_of_countries_by_electricit... Since the US used 3800 TWhr of energy I doubt this plant would make a dent. If we got our watts/person down to the same level as Germany we would be doing pretty well in terms of excess energy capacity. We could shut down our most poorly performing power plants. With those rates you outlined if I ran the power system for a municipality I would start buying land in the desert now.
rwmj 12y ago
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 12y ago
  > 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-now-23-completed/ http://gigaom.com/2012/07/16/huge-arizona-solar-panel-farm-n... 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 12y ago
    > 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.
unwind 12y ago
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 12y ago
  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-surprising-reason-that-oil-subsidies-persist-even-liberals-love-them/ http://www.forbes.com/sites/energysource/2012/04/25/the-surp... [2] http://thinkprogress.org/climate/2012/04/13/463874/top-three-ways-that-american-taxpayers-subsidize-dirty-coal-development/ http://thinkprogress.org/climate/2012/04/13/463874/top-three...
  - protomyth 12y ago
    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 12y ago
      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 12y ago
"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 12y ago
  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...
vixin 12y ago
"Global climate change is here". I'm confused. "The RSS satellite record shows a zero trend for 210 months". 17 years, 6 months.
- phireal 12y ago
  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 12y ago
    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 12y ago
      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.
- lectrick 12y ago
  If you are going to disagree with 97% of scientists whose job it is to identify whether this is real or not, then at what point (given how crucial this is) would you actually agree with a consensus? http://climate.nasa.gov/scientific-consensus http://climate.nasa.gov/scientific-consensus
mrfusion 12y ago
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 12y ago
  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.
  - stuki 12y ago
    I like that thought. Assuming the heat exchange plumbing and attendant sensors could be made efficient and reliable enough to be relied on, the ability of panel designers to optimize their panels for operation in a tighter temperature band, should allow for improved efficiency of primary generation as well. Sounds like this mega plant is designed with a fair amount of redundant capacity; for cloudy days, maintenance etc. If so, this may facilitate "real world scale" testing of approaches like yours without unduly affecting "production."
  - jdmichal 12y ago
    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.
maerF0x0 12y ago
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 12y ago
  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 12y ago
    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 12y ago
      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.
- mhurron 12y ago
  Assuming no improvements in the technology. /and increases in power requirements but you were negative enough.
johnohara 12y ago
$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 12y ago
  I am guessing that the plant actually has double its rated capacity, so something like 600MW in panels.
ufmace 12y ago
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 12y ago
  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 12y ago
    Cool, how's the cost on them working out? Have they broken even? Any impact from subsidies/tax breaks?
    - ChuckMcM 12y ago
      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.
chiph 12y ago
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 12y ago
  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.
trothamel 12y ago
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/CleanEnergyActionProject/CS.Agua_Caliente_Solar_Project___Thin_Film_Photovoltaic_Solar_Power_Case_Studies.html http://www.cleanenergyactionproject.com/CleanEnergyActionPro...
- jdmichal 12y ago
  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)

31 points by srikar 12y ago

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?

noir_lord 12y ago
If I had to guess. 1) Maintenance - When not cloudy you can bring them on-line to cover the maintenance on other parts of the site. 2) They've designed for a fixed output under certain conditions so in effect they don't want to push more than 290MW but the extra panels help them not drop that too far. 3) Grid operators like plants this size to be capable of consistent output - similar to why some gas plants run with either one or the other turbine on but often not both (In the old days before successive governments trashed it the UK national grid aimed for an unused capacity overhead of 25%, this would cover maintenance, accidents, natural disasters etc, we are currently running with about 4% spare)
chrisBob 12y ago
My only guess is that they are limited by the transmission lines. Upstate NY has a lot of hydro and wind power, and actually produces more energy than it can export on a lot of days. The obvious answer is to build more high voltage transmission lines, but people are fighting them for two reasons: No one wants to live under the transmission lines, and when they build transmission lines next to your house your electricity gets more expensive because the cheap power being exported to the rest of the state.
- cpwright 12y ago
  I don't live quite upstate, but we already have a nuclear power plant; and our town supervisor is complaining about a plan to land a transmission line in the town not to far from it to export power from upstate to downstate (http://westpointproject.com/ http://westpointproject.com/). The HVDC converter will buzz.
pcl 12y ago
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.
- sitkack 12y ago
  They are also in a better financial position if they can supply guaranteed power instead of variable power. If power fluctuates relative to the weather then energy traders get involved in your pricing and no one wants Goldman Sachs and Enron in their business.
- Dylan16807 12y ago
  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.
jacquesm 12y ago
Shading can impact the power output of a string significantly. By dynamically reconfiguring the topology and effectively stringing together panels from various locations they can balance the power output in a nicer way.

mattip 12y ago

Are there any figures on ROI available for this plant?

rwmj 12y ago
ROI with and without subsidies would also be interesting.
sitkack 12y ago
You would need to calc solar insolation http://www.pveducation.org/pvcdrom/properties-of-sunlight/calculation-of-solar-insolation http://www.pveducation.org/pvcdrom/properties-of-sunlight/ca... for the site and the bulk cost of electricity over the lifetime of the plant. I don't have specifics but it looks like they have more capacity that they bring online at the beginning and the end of the day to flatten the power output. So I would use a more trapezoidal curve (or just assume a 10 hr day). 290MW * 10hrs * 42$/MWhr [1] => 120K/day With a nice fatti 0% loan and no increases in the cost of electricity payback is about 30 years. I wouldn't be surprised if costs didn't rise at least 2x to 4x in the next 20, soo I'd say they are probably going to do ok on the ROI. Even if the raw capacity of the plant was 600MW (derate panels over lifetime, more consistent output), the panel cost was less than 1/3 of the total price of acquisition and construction. And as the grid becomes smarter they can probably start to put a more variable amount of power into it. [1] http://www.powerisknowledge.com/ http://www.powerisknowledge.com/
- masonhensley 12y ago
  Hmm, I think this wholesale pricing may be more accurate: http://www.eia.gov/electricity/monthly/update/wholesale_markets.cfm http://www.eia.gov/electricity/monthly/update/wholesale_mark... The plant will serve California which seems to be in the 130-170$/MWhr right? But, this all assumes that a plant like this would not put a downward pressure on prices.
  - sitkack 12y ago
    Wow, I had no idea it was so high. Yeah, that plant could have a 15 year payback cycle or less. http://en.wikipedia.org/wiki/List_of_countries_by_electricity_consumption http://en.wikipedia.org/wiki/List_of_countries_by_electricit... Since the US used 3800 TWhr of energy I doubt this plant would make a dent. If we got our watts/person down to the same level as Germany we would be doing pretty well in terms of excess energy capacity. We could shut down our most poorly performing power plants. With those rates you outlined if I ran the power system for a municipality I would start buying land in the desert now.

rwmj 12y ago

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 12y ago
> 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-now-23-completed/ http://gigaom.com/2012/07/16/huge-arizona-solar-panel-farm-n... 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 12y ago
  > 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.

unwind 12y ago

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 12y ago
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-surprising-reason-that-oil-subsidies-persist-even-liberals-love-them/ http://www.forbes.com/sites/energysource/2012/04/25/the-surp... [2] http://thinkprogress.org/climate/2012/04/13/463874/top-three-ways-that-american-taxpayers-subsidize-dirty-coal-development/ http://thinkprogress.org/climate/2012/04/13/463874/top-three...
- protomyth 12y ago
  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 12y ago
    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 12y ago

"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 12y ago
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...

vixin 12y ago

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

phireal 12y ago
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 12y ago
  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 12y ago
    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.
lectrick 12y ago
If you are going to disagree with 97% of scientists whose job it is to identify whether this is real or not, then at what point (given how crucial this is) would you actually agree with a consensus? http://climate.nasa.gov/scientific-consensus http://climate.nasa.gov/scientific-consensus

mrfusion 12y ago

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 12y ago
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.
- stuki 12y ago
  I like that thought. Assuming the heat exchange plumbing and attendant sensors could be made efficient and reliable enough to be relied on, the ability of panel designers to optimize their panels for operation in a tighter temperature band, should allow for improved efficiency of primary generation as well. Sounds like this mega plant is designed with a fair amount of redundant capacity; for cloudy days, maintenance etc. If so, this may facilitate "real world scale" testing of approaches like yours without unduly affecting "production."
- jdmichal 12y ago
  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.

maerF0x0 12y ago

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 12y ago
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 12y ago
  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 12y ago
    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.
mhurron 12y ago
Assuming no improvements in the technology. /and increases in power requirements but you were negative enough.

johnohara 12y ago

$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 12y ago
I am guessing that the plant actually has double its rated capacity, so something like 600MW in panels.

ufmace 12y ago

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 12y ago
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 12y ago
  Cool, how's the cost on them working out? Have they broken even? Any impact from subsidies/tax breaks?
  - ChuckMcM 12y ago
    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.

chiph 12y ago

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 12y ago
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.

trothamel 12y ago

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/CleanEnergyActionProject/CS.Agua_Caliente_Solar_Project___Thin_Film_Photovoltaic_Solar_Power_Case_Studies.html http://www.cleanenergyactionproject.com/CleanEnergyActionPro...

jdmichal 12y ago
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)