4 ms·

So, does it take 6 hours to heat up in the morning?

phorese 13y ago
If the goal is to heat up the reserve tanks as quickly as possible, I would think so, else I guess the plant can simply divert some of the heated oil from the water boiler to the tanks and slowly heat them while the sun is shining. I don't think the plant needs to warm up that long before it can produce energy, since only the oil between the collectors and steam generators has to be heated.
phaemon 13y ago
No. To be honest, I was a bit baffled by your question: why would you think that it would take the same time to heat as to cool? It will heat depending on how quickly you can get energy to it, and it will cool depending on how quickly you can remove energy from it. Have you never seen an electric heater or oven and noticed they heat quickly and take a while to cool down? Or rapidly cooled something by putting it in iced water or a freezer?
- mpyne 13y ago
  > I was a bit baffled by your question: There's nothing to be baffled about, it's a fair question. You even provided the answer: "It will heat depending on how quickly you can get energy to it, and it will cool depending on how quickly you can remove energy from it." On the other hand, there's no "electric heater" here to use to heat up the liquid used to absorb solar heat (not to mention ice or freezers...); it's the sun or nothing. Given that the sun doesn't give us peak solar flux until the midday it's entirely possible that solar energy production in the first few hours of the day would only keep up with instantaneous energy needs instead of having enough of an excess to reheat the heat storage fluid for energy production later that night. Whether this is actually an issue or not depends on the numbers, but it's not a baffling question at all and there's no reason to be so condescending about it.
  - phaemon 13y ago
    It's baffling to me because it makes no sense based on everyday experience to think that things have a set amount of time that they heat up or cool down. Why would anyone think that? If you think my comment was condescending, stop reading it in a condescending tone.
ndonnellan 13y ago
You can size your solar field to collect much more over the day than the tanks can store. So if your field were 100MW and tanks were 200MWh, it would only take 2 hours to fill them (assuming no electricity production). But after those two hours, you better have turbine capacity to take up the excess heat. Baseload CSP designs usually have storage in the range of 6-10 hours (real storage hours vary based on the solar input).
JoeAltmaier 13y ago
Very good question. It depends on thermal mass. I believe they must be 'charging' a thermal mass all day and using it to taper off at night. It probably can start instantly once the sun is up, but their 'thermal capacitor' may indeed take 6 hours to recharge.
bnegreve 13y ago
Availability is a big issue when it comes to solar energy. As you can guess, producing solar energy during the day ins't that much of a problem, but supplying the demand in the evening or at night with solar energy is a much bigger challenge. So, even if takes 6 hours to heat up in the morning, it still expand the usability of solar energy for electricity production.

If the goal is to heat up the reserve tanks as quickly as possible, I would think so, else I guess the plant can simply divert some of the heated oil from the water boiler to the tanks and slowly heat them while the sun is shining. I don't think the plant needs to warm up that long before it can produce energy, since only the oil between the collectors and steam generators has to be heated.

phaemon 13y ago

No. To be honest, I was a bit baffled by your question: why would you think that it would take the same time to heat as to cool? It will heat depending on how quickly you can get energy to it, and it will cool depending on how quickly you can remove energy from it. Have you never seen an electric heater or oven and noticed they heat quickly and take a while to cool down? Or rapidly cooled something by putting it in iced water or a freezer?

mpyne 13y ago
> I was a bit baffled by your question: There's nothing to be baffled about, it's a fair question. You even provided the answer: "It will heat depending on how quickly you can get energy to it, and it will cool depending on how quickly you can remove energy from it." On the other hand, there's no "electric heater" here to use to heat up the liquid used to absorb solar heat (not to mention ice or freezers...); it's the sun or nothing. Given that the sun doesn't give us peak solar flux until the midday it's entirely possible that solar energy production in the first few hours of the day would only keep up with instantaneous energy needs instead of having enough of an excess to reheat the heat storage fluid for energy production later that night. Whether this is actually an issue or not depends on the numbers, but it's not a baffling question at all and there's no reason to be so condescending about it.
- phaemon 13y ago
  It's baffling to me because it makes no sense based on everyday experience to think that things have a set amount of time that they heat up or cool down. Why would anyone think that? If you think my comment was condescending, stop reading it in a condescending tone.

ndonnellan 13y ago

You can size your solar field to collect much more over the day than the tanks can store. So if your field were 100MW and tanks were 200MWh, it would only take 2 hours to fill them (assuming no electricity production). But after those two hours, you better have turbine capacity to take up the excess heat. Baseload CSP designs usually have storage in the range of 6-10 hours (real storage hours vary based on the solar input).

JoeAltmaier 13y ago

Very good question. It depends on thermal mass. I believe they must be 'charging' a thermal mass all day and using it to taper off at night. It probably can start instantly once the sun is up, but their 'thermal capacitor' may indeed take 6 hours to recharge.

bnegreve 13y ago

Availability is a big issue when it comes to solar energy. As you can guess, producing solar energy during the day ins't that much of a problem, but supplying the demand in the evening or at night with solar energy is a much bigger challenge. So, even if takes 6 hours to heat up in the morning, it still expand the usability of solar energy for electricity production.