4 ms·

And very inefficient as a result, funny enough.

snovv_crash 4y ago
You can get multiband sonlar panels with efficiency in the low 40% range. This is similar to coal, nuclear etc.
waynesonfire 4y ago
was curious about mirrors, which are used to boil water, "most concentrated solar power technologies will have an efficiency somewhere between 7 and 25 percent." "Though most commercial panels have efficiencies from 15% to 20%, researchers have developed PV cells with efficiencies approaching 50%." "Both nuclear and coal plants show a range of efficiencies. Nuclear plants currently being built have about 34-36% thermal efficiency, while one of the new reactor designs boasts 39%. In comparison, new coal-fired plants approach 40% and CCGT plants reach 60%."
- kadoban 4y ago
  These comparisons seem basically meaningless though. What does it tell us that coal is "40%" vs solar being "20%"? Why does that number matter?
  - tuatoru 4y ago
    Coal is "40%", less the energy used in mining and transporting the coal, less the energy used in coping disposing of the ash and coping with the environmental and health harms arising from burning coal. For PV, a higher "efficiency" means less land is used for a given nameplate power output. Desert land is not in noticeably short supply, though. Or it might mean that PV is economically feasible in high-latitude or chronically cloudy areas.
ncmncm 4y ago
In kWh per dollar invested, solar panels are the most efficient generation technology ever fielded.
- addaon 4y ago
  I'd have to think that any water mill over a couple hundred years old would give a circa 2000 solar panel a run for its money; they weren't particularly expensive, and amortization adds up.
  - ncmncm 4y ago
    The amount of power your traditional water mill extracts would be exceeded by solar panels on its roof, which would be cheaper than the building under them, not even counting the cost of the water wheel and weir. The mill might last centuries, but only with continuous maintenance. A weir way uphill with a penstock and Pelton wheel could do better than the old mill, but both depend on landform features with limited distribution. If you needed twice the power, you would be stuck. But you can put out more panels.
  - bacon_waffle 4y ago
    It's not clear to me why the reference points need to be a couple hundred years ago, and a couple decades ago. Was the intent to point out that the dollars are a one-off, where the kWh's keep on coming as long as the equipment works? Even in my relatively wet and grey corner of the world, I'm confident that if I spent $X on PV vs hydro, the PV would produce more electricity and require less maintenance.
dpierce9 4y ago
I don’t want to be rude but to say solar is ‘inefficient’ without qualification is essentially baseless ignorance or lying. PV/wind turbine efficiency and Rankine cycle efficiency are basically entirely different concepts physically and economically. Highly efficient rankine plants might turn 35% of the potential energy of expensive nuclear/coal fuel (which costs money) into electricity. In the process they produce waste heat and waste (dealing with those things is typically kicked down the road). Solar turns 20% of something that is free (being pointed at the sun modulo land use) into electricity with zero waste and zero additional waste heat. How is that inefficient (even if it were half that)? You can and should say lots of things about scale or nighttime but none of those have to do with prime mover efficiency. Now consider economic efficiency. The denominator of economic efficiency for solar/wind is financing charges and the numerator is multiplied by a lower capacity factor whereas for everything else the denominator is financing charges plus fuel costs. Fuel costs are expensive and boom/bust volatile creating huge economic uncertainties. These uncertainties increase financing charges further reducing economic efficiency. This is before you get to waste or waste heat. I don’t think 100% solar is a realistic option but neither are baseless claims of inefficiency.
- jsjohnst 4y ago
  > into electricity with zero waste > I don’t mean to be rude, but to say this without qualification is essentially baseless ignorance or lying. Your own words can be used back at you. (Not agreeing with GP, but your zeal in rebuttal falls victim to your own accusation)

You can get multiband sonlar panels with efficiency in the low 40% range. This is similar to coal, nuclear etc.

was curious about mirrors, which are used to boil water, "most concentrated solar power technologies will have an efficiency somewhere between 7 and 25 percent." "Though most commercial panels have efficiencies from 15% to 20%, researchers have developed PV cells with efficiencies approaching 50%." "Both nuclear and coal plants show a range of efficiencies. Nuclear plants currently being built have about 34-36% thermal efficiency, while one of the new reactor designs boasts 39%. In comparison, new coal-fired plants approach 40% and CCGT plants reach 60%."

kadoban 4y ago
These comparisons seem basically meaningless though. What does it tell us that coal is "40%" vs solar being "20%"? Why does that number matter?
- tuatoru 4y ago
  Coal is "40%", less the energy used in mining and transporting the coal, less the energy used in coping disposing of the ash and coping with the environmental and health harms arising from burning coal. For PV, a higher "efficiency" means less land is used for a given nameplate power output. Desert land is not in noticeably short supply, though. Or it might mean that PV is economically feasible in high-latitude or chronically cloudy areas.

ncmncm 4y ago

In kWh per dollar invested, solar panels are the most efficient generation technology ever fielded.

addaon 4y ago
I'd have to think that any water mill over a couple hundred years old would give a circa 2000 solar panel a run for its money; they weren't particularly expensive, and amortization adds up.
- ncmncm 4y ago
  The amount of power your traditional water mill extracts would be exceeded by solar panels on its roof, which would be cheaper than the building under them, not even counting the cost of the water wheel and weir. The mill might last centuries, but only with continuous maintenance. A weir way uphill with a penstock and Pelton wheel could do better than the old mill, but both depend on landform features with limited distribution. If you needed twice the power, you would be stuck. But you can put out more panels.
- bacon_waffle 4y ago
  It's not clear to me why the reference points need to be a couple hundred years ago, and a couple decades ago. Was the intent to point out that the dollars are a one-off, where the kWh's keep on coming as long as the equipment works? Even in my relatively wet and grey corner of the world, I'm confident that if I spent $X on PV vs hydro, the PV would produce more electricity and require less maintenance.

dpierce9 4y ago

I don’t want to be rude but to say solar is ‘inefficient’ without qualification is essentially baseless ignorance or lying. PV/wind turbine efficiency and Rankine cycle efficiency are basically entirely different concepts physically and economically. Highly efficient rankine plants might turn 35% of the potential energy of expensive nuclear/coal fuel (which costs money) into electricity. In the process they produce waste heat and waste (dealing with those things is typically kicked down the road). Solar turns 20% of something that is free (being pointed at the sun modulo land use) into electricity with zero waste and zero additional waste heat. How is that inefficient (even if it were half that)? You can and should say lots of things about scale or nighttime but none of those have to do with prime mover efficiency. Now consider economic efficiency. The denominator of economic efficiency for solar/wind is financing charges and the numerator is multiplied by a lower capacity factor whereas for everything else the denominator is financing charges plus fuel costs. Fuel costs are expensive and boom/bust volatile creating huge economic uncertainties. These uncertainties increase financing charges further reducing economic efficiency. This is before you get to waste or waste heat. I don’t think 100% solar is a realistic option but neither are baseless claims of inefficiency.

jsjohnst 4y ago
> into electricity with zero waste > I don’t mean to be rude, but to say this without qualification is essentially baseless ignorance or lying. Your own words can be used back at you. (Not agreeing with GP, but your zeal in rebuttal falls victim to your own accusation)