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> Pakistan's big deployment is one example .. A valid example of what can go wrong when you pick the wrong technology, don't do small scale trials first, and r

by Jedd 6y ago

> Pakistan's big deployment is one example .. A valid example of what can go wrong when you pick the wrong technology, don't do small scale trials first, and rely on government oversight. (Refer the Background & Operation section of the wikipedia article -- toe-curlingly alarming, yet ultimately unsurprising.) They almost definitely should have pursued concentrated solar thermal. It partly solves the 'storage problem', provides power well into the evening, doesn't need more water than they have to clean it, and improves magnificently with high temperatures (the wikipedia article cites the problem of regular 45C days, which are above the 25C optimum temperature for PV panels). Given all this was known and understood before they broke ground, this sounds like a traditional government project problem -- susceptibility to corruption, vanity, hubris etc.

CydeWeys 6y ago
Is solar thermal still a going concern? Are new plants still being built?
- Jedd 6y ago
  It seems to be in a lull, but the technology is still maturing. I suspect as the generation + storage costs continue to shift, it'll be adopted more eagerly. PVCs cost reduction has been a boon for that industry, but that tech, of course, ignores the storage problem. Reading about some of the missteps of CSP, much like the above, they seem to be share similar traits of government mishandling, bureaucracy, dodgy dealings, etc. EDIT: In any case, a naive interpretation of the Pakistan project cited -- if it truly is getting ~20% of anticipated power, cost per unit is 5x forecast, at which point a CSP would have been better value for money.
  - CydeWeys 6y ago
    Why wouldn't solar thermal have the exact same issue with mirrors getting dusty though? I suspect that solar thermal is in more than a lull; I suspect that it's been obsoleted by PV and we aren't going to be seeing many new installations at all.
    - Jedd 6y ago
      I suspect there's several answers to your first question. For example, the mechanical factor of parabolic mirrors that are typically used for CSP's - they can provide more shelter in terms of wind-deposited dust than flat panels all angled in the same direction (a la PV panels). I also suspect that mirrors are less sensitive to dust than PV cells. And that it's cheaper to just install more mirrors (flat reflective surfaces) to compensate for anticipated dust build-up, than photovoltaic panels (per unit of area or per unit of power generated). But, really, I expect there's a fair bit of research on this subject already out there. As I intimated, it's probably not so much an obsolescence issue, as one of pushing the storage question aside. CSPs address generation, with some ephemeral (cloud, evening, etc) storage capabilities. As per the standard observation - it's going to be a blend of power generation and storage technologies that sees us through.
      - CydeWeys 6y ago
        Good points. I still think that, overall, money talks, and the vast majority of solar installations are not managed nearly as incompetently as this one was (i.e. not forgetting to take into account sand in a desert). So the fact that close to 100% if not 100% of new solar installations are PV over solar thermal really does mean that once you take all these factors into account, PV is still more cost-effective. The storage issue is interesting, but doesn't matter so much to most plants since they tie into a larger balanced grid, and battery storage is coming down in cost at the same exponential rate as PV. These same advantages are not accruing to solar thermal. So I do think we are seeing the death knell for solar thermal, even when energy storage is desired alongside peak production.
        Jedd 6y ago
        Agree up to a point. Storage can't be ignored - and the 'balanced grid' that we're all part of relies heavily on burning fossil fuels for both baseload coping with peaks (sun goes behind a cloud or the horizon, or the wind stops for a while). As we decom more of the fossil fuel systems, a more robust & scalable storage system, even a relatively ephemeral one, will become more compelling. (my prediction : )
sho 6y ago
> what can go wrong when you [..] rely on government oversight > this sounds like a traditional government project problem I don't know why you're trying to turn this into an "obviously govt can't do anything" point. There are plenty of very well-run governments who would have ably foreseen and solved these problems. And no doubt there's any number of private companies who would have screwed up just as badly. Trying to tar the entire idea of government with Pakistan's performance is pretty bad faith IMO.
- igravious 6y ago
  Amen. Not just bad faith; ignorant, myopic and ahistorical. > this sounds like a traditional government project problem -- susceptibility to corruption, vanity, hubris etc. said the person on a web forum (the web comes from CERN, a gov project) over the internet (the internet comes from DARPA, a gov project) on a computer (ever heard of the ENIAC? a gov project) Tech bros mouthing off off-topicly about the government is the most tedious and boring thing ever. https://techpinions.com/its-not-just-the-internet-how-government-built-the-computer-industry/8104 https://techpinions.com/its-not-just-the-internet-how-govern...
  - Jedd 6y ago
    > Amen. Not just bad faith; ignorant, myopic and ahistorical. Referring to GP's wikipedia reference, can you explain the two 'for unknown reasons' on a) why the original (Canadian) contract was not engaged, and b) the Turkish project was not engaged. What precisely was ashistorical about any of my post? > > this sounds like a traditional government project problem -- susceptibility to corruption, vanity, hubris etc. > said the person on a web forum (the web comes from CERN, a gov project) over the internet (the internet comes from DARPA, a gov project) on a computer (ever heard of the ENIAC? a gov project) I really am bewildered. Are you claiming that because I'm using the Internet I am not authorised to claim that any government project in any country at any time is beyond questioning? > Tech bros mouthing off off-topicly about the government is the most tedious and boring thing ever. Goodness. I'm sorry you're bored, I'm not a tech bro, claims of poorly run projects within the land of the pure isn't off-topic to the claims made.
labawi 6y ago
> doesn't need more water >improves magnificently with high temperatures Thermal solar is a solar heat energy source + classic steam turbine. The efficiency of a thermal->electric converter (turbine) is largely governed by the difference between the hot and cold side. Increasing both the hot and cold side temperatures equally would not increase efficiency, AFAIK it would actually decrease efficiency, and without lots of water, they can't use evaporative cooling either.
- Jedd 6y ago
  > Increasing both the hot and cold side temperatures equally would not increase efficiency ... Hence the C in CSP. Contemporary molten salt CSPs operate at ~700C, so the difference between the concentrator and ambient air temperature would be 3% (at 25C) and 6% (at 45C). In other words, a 3% difference. Perhaps measurable at the output, but certainly not significant. New CSP designs are coming along that are working around 1000C, which would render that delta even more negligible. In contrast, while PV cells vary, I believe max power temperature coefficients of around 0.4% / 1C is a standard figure. That means at 25C your panels are losing 10% of max capacity, but at 45C that number goes up to 25%. A massive reduction in capability.
  - labawi 6y ago
    I was merely pointing out that CSP efficiency likely doesn't increase with increasing ambient temperature, it's just inherently more tolerant. As an aside, your calculations are improper, even though results are close enough. 0℃ is merely 273.15K and the temperature at which water tends to freeze. E.g. PV efficiency is usually quoted at 25℃ (or 300K), so at -20℃ they could generate cca 120% of "max" (rated) capacity.

by Jedd 6y ago

CydeWeys 6y ago

Is solar thermal still a going concern? Are new plants still being built?

Jedd 6y ago
It seems to be in a lull, but the technology is still maturing. I suspect as the generation + storage costs continue to shift, it'll be adopted more eagerly. PVCs cost reduction has been a boon for that industry, but that tech, of course, ignores the storage problem. Reading about some of the missteps of CSP, much like the above, they seem to be share similar traits of government mishandling, bureaucracy, dodgy dealings, etc. EDIT: In any case, a naive interpretation of the Pakistan project cited -- if it truly is getting ~20% of anticipated power, cost per unit is 5x forecast, at which point a CSP would have been better value for money.
- CydeWeys 6y ago
  Why wouldn't solar thermal have the exact same issue with mirrors getting dusty though? I suspect that solar thermal is in more than a lull; I suspect that it's been obsoleted by PV and we aren't going to be seeing many new installations at all.
  - Jedd 6y ago
    I suspect there's several answers to your first question. For example, the mechanical factor of parabolic mirrors that are typically used for CSP's - they can provide more shelter in terms of wind-deposited dust than flat panels all angled in the same direction (a la PV panels). I also suspect that mirrors are less sensitive to dust than PV cells. And that it's cheaper to just install more mirrors (flat reflective surfaces) to compensate for anticipated dust build-up, than photovoltaic panels (per unit of area or per unit of power generated). But, really, I expect there's a fair bit of research on this subject already out there. As I intimated, it's probably not so much an obsolescence issue, as one of pushing the storage question aside. CSPs address generation, with some ephemeral (cloud, evening, etc) storage capabilities. As per the standard observation - it's going to be a blend of power generation and storage technologies that sees us through.
    - CydeWeys 6y ago
      Good points. I still think that, overall, money talks, and the vast majority of solar installations are not managed nearly as incompetently as this one was (i.e. not forgetting to take into account sand in a desert). So the fact that close to 100% if not 100% of new solar installations are PV over solar thermal really does mean that once you take all these factors into account, PV is still more cost-effective. The storage issue is interesting, but doesn't matter so much to most plants since they tie into a larger balanced grid, and battery storage is coming down in cost at the same exponential rate as PV. These same advantages are not accruing to solar thermal. So I do think we are seeing the death knell for solar thermal, even when energy storage is desired alongside peak production.
      - Jedd 6y ago
        Agree up to a point. Storage can't be ignored - and the 'balanced grid' that we're all part of relies heavily on burning fossil fuels for both baseload coping with peaks (sun goes behind a cloud or the horizon, or the wind stops for a while). As we decom more of the fossil fuel systems, a more robust & scalable storage system, even a relatively ephemeral one, will become more compelling. (my prediction : )

sho 6y ago

> what can go wrong when you [..] rely on government oversight > this sounds like a traditional government project problem I don't know why you're trying to turn this into an "obviously govt can't do anything" point. There are plenty of very well-run governments who would have ably foreseen and solved these problems. And no doubt there's any number of private companies who would have screwed up just as badly. Trying to tar the entire idea of government with Pakistan's performance is pretty bad faith IMO.

igravious 6y ago
Amen. Not just bad faith; ignorant, myopic and ahistorical. > this sounds like a traditional government project problem -- susceptibility to corruption, vanity, hubris etc. said the person on a web forum (the web comes from CERN, a gov project) over the internet (the internet comes from DARPA, a gov project) on a computer (ever heard of the ENIAC? a gov project) Tech bros mouthing off off-topicly about the government is the most tedious and boring thing ever. https://techpinions.com/its-not-just-the-internet-how-government-built-the-computer-industry/8104 https://techpinions.com/its-not-just-the-internet-how-govern...
- Jedd 6y ago
  > Amen. Not just bad faith; ignorant, myopic and ahistorical. Referring to GP's wikipedia reference, can you explain the two 'for unknown reasons' on a) why the original (Canadian) contract was not engaged, and b) the Turkish project was not engaged. What precisely was ashistorical about any of my post? > > this sounds like a traditional government project problem -- susceptibility to corruption, vanity, hubris etc. > said the person on a web forum (the web comes from CERN, a gov project) over the internet (the internet comes from DARPA, a gov project) on a computer (ever heard of the ENIAC? a gov project) I really am bewildered. Are you claiming that because I'm using the Internet I am not authorised to claim that any government project in any country at any time is beyond questioning? > Tech bros mouthing off off-topicly about the government is the most tedious and boring thing ever. Goodness. I'm sorry you're bored, I'm not a tech bro, claims of poorly run projects within the land of the pure isn't off-topic to the claims made.

labawi 6y ago

> doesn't need more water >improves magnificently with high temperatures Thermal solar is a solar heat energy source + classic steam turbine. The efficiency of a thermal->electric converter (turbine) is largely governed by the difference between the hot and cold side. Increasing both the hot and cold side temperatures equally would not increase efficiency, AFAIK it would actually decrease efficiency, and without lots of water, they can't use evaporative cooling either.

Jedd 6y ago
> Increasing both the hot and cold side temperatures equally would not increase efficiency ... Hence the C in CSP. Contemporary molten salt CSPs operate at ~700C, so the difference between the concentrator and ambient air temperature would be 3% (at 25C) and 6% (at 45C). In other words, a 3% difference. Perhaps measurable at the output, but certainly not significant. New CSP designs are coming along that are working around 1000C, which would render that delta even more negligible. In contrast, while PV cells vary, I believe max power temperature coefficients of around 0.4% / 1C is a standard figure. That means at 25C your panels are losing 10% of max capacity, but at 45C that number goes up to 25%. A massive reduction in capability.
- labawi 6y ago
  I was merely pointing out that CSP efficiency likely doesn't increase with increasing ambient temperature, it's just inherently more tolerant. As an aside, your calculations are improper, even though results are close enough. 0℃ is merely 273.15K and the temperature at which water tends to freeze. E.g. PV efficiency is usually quoted at 25℃ (or 300K), so at -20℃ they could generate cca 120% of "max" (rated) capacity.