Error alert:
"The maximum you can get into the grid is about 25 percent from solar," including photovoltaics, Mills says. But "once you have storage, it changes from this niche thing to something that could be the big gorilla on the grid equivalent to coal."
Note this 25% is not the same thing as 25% efficiency. This 25% if, the maximum contribution of solar to the grid, due to intermittency. For wind, it's 20 - 30% depending on whose figures you are looking at. So we can reasonably assume that solar plus wind = about 50% of grid capacity. The remaining 50% has to come from somewhere, and it needs to be firm & dispatchable power: power that can be varied as the inverse of the contributions from solar and wind. The best two sources for this are hydro and nuclear.
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THE Solar Thermal Energy Thread (merged)
Re: SciAm Article: Solar Thermal Efficiency Only ~25%
by gg3 » Tue 02 Oct 2007, 22:37:42
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Re: SciAm Article: Solar Thermal Efficiency Only ~25%
by davep » Wed 03 Oct 2007, 05:43:15
$this->bbcode_second_pass_quote('gg3', 'E')rror alert:
"The maximum you can get into the grid is about 25 percent from solar," including photovoltaics, Mills says. But "once you have storage, it changes from this niche thing to something that could be the big gorilla on the grid equivalent to coal."
Note this 25% is not the same thing as 25% efficiency. This 25% if, the maximum contribution of solar to the grid, due to intermittency. For wind, it's 20 - 30% depending on whose figures you are looking at. So we can reasonably assume that solar plus wind = about 50% of grid capacity. The remaining 50% has to come from somewhere, and it needs to be firm & dispatchable power: power that can be varied as the inverse of the contributions from solar and wind. The best two sources for this are hydro and nuclear.
"The maximum you can get into the grid is about 25 percent from solar," including photovoltaics, Mills says. But "once you have storage, it changes from this niche thing to something that could be the big gorilla on the grid equivalent to coal."
Note this 25% is not the same thing as 25% efficiency. This 25% if, the maximum contribution of solar to the grid, due to intermittency. For wind, it's 20 - 30% depending on whose figures you are looking at. So we can reasonably assume that solar plus wind = about 50% of grid capacity. The remaining 50% has to come from somewhere, and it needs to be firm & dispatchable power: power that can be varied as the inverse of the contributions from solar and wind. The best two sources for this are hydro and nuclear.
I'm not sure that you are correct. 25% due to intermittency would still be <25% with storage (due to losses). The 25% and the intermittency may be separate things.
BTW, there is storage technology available, such as Vanadium Redux which gives back roughly 80% without the progressive reduction in capacity inherent in most battery systems. It's currently being implemented for an Irish wind farm.
With storage, I don't see why there would be some 25% total capacity limit, as there is the generating capacity coupled with on-demand availability.
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Re: SciAm Article: Solar Thermal Efficiency Only ~25%
by aahala » Wed 03 Oct 2007, 11:42:15
HydroLuver
I generally agree with the numbers you gave concerning alternative
energy, subsidies and mandates. I would not described them
as you have however. I think the efforts are somewhere between
diddily squat and far less than enough.
The numbers in insolation may seem incredible, stunning or
massive, but relative to the situation they aren't, in my opinion.
Some examples relative yours:
The $22B investment for 10,000 MW wind and 300 MW solar
over 7 years is about 60% of the profit(not income or funds
invested, but profit) by Exxon in a single recent year. The
amount of energy from this alternative investment would not
likely cover even half the average annual increase in the US electrical power consumed.
The subsidies you believe are so stunning or massive for wind
and solar are rather puny when compared to the indirect
subsidies for oil included the annual military defense budget.
The generally accepted range for this annual figure -- before
the Iraq war -- is between 20 and 100 billion dollars a year.
(The total annual federal subsidy for wind and solar combined
is probably less than $2 billion).
The RPS that you described are definitely a good thing but
how good are they really? One or two of the states that have
the increasing renewable energy standards state the growing
requirement, but provide no penaly whatsoever if a utility fails
to comply. Some of the other states which have RPS, the
requirements are pretty small in the required increase, with
all kinds of loopholes the utilities will surely take advantage
of if the going gets tough.
I generally agree with the numbers you gave concerning alternative
energy, subsidies and mandates. I would not described them
as you have however. I think the efforts are somewhere between
diddily squat and far less than enough.
The numbers in insolation may seem incredible, stunning or
massive, but relative to the situation they aren't, in my opinion.
Some examples relative yours:
The $22B investment for 10,000 MW wind and 300 MW solar
over 7 years is about 60% of the profit(not income or funds
invested, but profit) by Exxon in a single recent year. The
amount of energy from this alternative investment would not
likely cover even half the average annual increase in the US electrical power consumed.
The subsidies you believe are so stunning or massive for wind
and solar are rather puny when compared to the indirect
subsidies for oil included the annual military defense budget.
The generally accepted range for this annual figure -- before
the Iraq war -- is between 20 and 100 billion dollars a year.
(The total annual federal subsidy for wind and solar combined
is probably less than $2 billion).
The RPS that you described are definitely a good thing but
how good are they really? One or two of the states that have
the increasing renewable energy standards state the growing
requirement, but provide no penaly whatsoever if a utility fails
to comply. Some of the other states which have RPS, the
requirements are pretty small in the required increase, with
all kinds of loopholes the utilities will surely take advantage
of if the going gets tough.
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aahala - Tar Sands
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Re: SciAm Article: Solar Thermal Efficiency Only ~25%
by yesplease » Thu 04 Oct 2007, 03:39:44
$this->bbcode_second_pass_quote('HydroLuver', 'T')he amount of subsidies and mandates being passed into law in favor of alternatives is incredible. Numerous states now require a percentage (often 20%) of renewable energy from their utilities by a certain date. The level of tax credits for solar (almost 50% of cost) and wind (1.9 cents kwh) are massive.
It's increasing on a regional level, but I wouldn't go as far as saying it's incredible. There are some who wish to encourage and mitigate any problems we may have with resource prices and externalities, but AFAIK, we have not slowed down significantly WRT FF emissions and/or use. Budgeting a few billion is great for both those who care about it, and those who care about how it'll make them look if ya follow. Hell, El Casa Blanca has acknowledged climate change, but I don't see 'em doing much about it... And, provided free or extremely cheap gubberment land leases could make solar thermal economically competitive w/o taxing FF externalities, I don't see how we wouldn't see something similar to prop 87 in CA, w/ the FF lobby spending hundreds of millions to protect billions, or trillions over the long haul, in profits.$this->bbcode_second_pass_quote('Professor Membrane', ' ')Not now son, I'm making ... TOAST!
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Club of Rome whitebook - Power from the desserts
by cephalotus » Sun 02 Dec 2007, 16:04:56
http://www.solarmillennium.de/pdf/TRECwhite_paper.pdf
you may also have a look at the first big European projects with solar thermal power plants in Spain on the main page:
http://www.solarmillennium.de
you may also have a look at the first big European projects with solar thermal power plants in Spain on the main page:
http://www.solarmillennium.de
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Feasibility of the DESERTEC Concept : Power from the Deserts
by thor » Thu 07 Feb 2008, 15:44:19
http://www.trecers.net/index.html :$this->bbcode_second_pass_quote('', '[')b]Feasibility of the DESERTEC Concept
The technologies that are needed to realise the DESERTEC concept are already developed and some of them have been in use for decades. HVDC transmission lines up toto 3 GW capacity have been deployed over long distances by ABB and Siemens for many years. In July 2007 Siemens accepted a bid to build a 5 GW HVDC System in China. At the World Energy Dialogue 2006 in Hanover speakers from both the companies just mentioned have confirmed that the implementation of a Euro-Supergrid and a EU-MENA-Connection is, technically, entirely feasible.
Solar thermal power plants have been in use commercially at Kramer Junction in California since 1985. New solar thermal power plants with a total capacity of more than 2000 MW are either planned, under construction, or already in operation. The Spanish government guarantees a feed-in tariff of about 26 EuroCent/kWh for 25 years and this has established favourable business conditions for CSP. Because of the higher solar radiation at good sites in the USA or MENA it is now possible to use lower rates in feed-in tariffs. The DLR has calculated that, if solar thermal power plants were to be constructed in large numbers in the coming decades, the estimated cost would come down to about 4-5 EuroCent/kWh.
In order to establish, by 2050, a capacity of 100 GW of exportable solar power in MENA, over and above the domestic needs of sun-belt countries, only a few governmental supporting measures would be sufficient to make the construction of the power plants and the necessary transmission grid more attractive to investors, both private and public. An approximate investment forecast for the TRANS-CSP scenario has been researched by the DLR (graphic on the right).
The technologies that are needed to realise the DESERTEC concept are already developed and some of them have been in use for decades. HVDC transmission lines up toto 3 GW capacity have been deployed over long distances by ABB and Siemens for many years. In July 2007 Siemens accepted a bid to build a 5 GW HVDC System in China. At the World Energy Dialogue 2006 in Hanover speakers from both the companies just mentioned have confirmed that the implementation of a Euro-Supergrid and a EU-MENA-Connection is, technically, entirely feasible.
Solar thermal power plants have been in use commercially at Kramer Junction in California since 1985. New solar thermal power plants with a total capacity of more than 2000 MW are either planned, under construction, or already in operation. The Spanish government guarantees a feed-in tariff of about 26 EuroCent/kWh for 25 years and this has established favourable business conditions for CSP. Because of the higher solar radiation at good sites in the USA or MENA it is now possible to use lower rates in feed-in tariffs. The DLR has calculated that, if solar thermal power plants were to be constructed in large numbers in the coming decades, the estimated cost would come down to about 4-5 EuroCent/kWh.
In order to establish, by 2050, a capacity of 100 GW of exportable solar power in MENA, over and above the domestic needs of sun-belt countries, only a few governmental supporting measures would be sufficient to make the construction of the power plants and the necessary transmission grid more attractive to investors, both private and public. An approximate investment forecast for the TRANS-CSP scenario has been researched by the DLR (graphic on the right).
http://www.leonardo-energy.org/drupal/node/1485 : $this->bbcode_second_pass_quote('', 'T')hey have calculated that it would be feasible to build a total of fifty square kilometres of facilities in the desert capable of generating 100 GW
Nuclear power plants can't keep up. There's not enough uranium to make this happen. Last time I checked, the sun isn't going to run out of heat anytime soon.
Last edited by Ferretlover on Sat 01 Aug 2009, 14:51:12, edited 1 time in total.
Reason: Title clarified.
Reason: Title clarified.
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