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You are so very smart. It is a pleasure to meet you on this forum. Spain at one time was a solar leader, the grid instability and high cost of electricity impoverished the country, a solution recently enacted was to tax solar producers. It is possible for the government to tax any type of energy, including solar or wind. Infrastructure costs are not insignificant for net metering. Take a look here - http://www.usu.edu/ipe/wp-content/up...ull-Report.pdf
Let me know where they went wrong, your expertise likely far exceeds that of the academics who wrote the piece. A summary from the linked document, regarding solar reliability concludes:
Not wanting to copy too much of the report, please check and comment on how the poor are affected. It turns out they bear the brunt of the cost. We further impoverish our poor with solar subsidies. Check also the lifetime cost per megawatt for various types of power, solar is at the top, and is many times more expensive than natural gas.
It is wonderful to have an expert such as yourself to help me understand where all these folks have gone wrong. Today staring out my New England landscape, every roof has close to a foot of snow on it, and has for a day or so, and will likely be mostly covered for a week or two as more snow is coming Sunday to Monday night. Does solar produce power under a foot of snow? Does heavy snow, ever affect the structure of a solar power system? Tell me, what level of decrease in power production should one expect over a 20 year solar panel lifespan?
Some panels have a drop of 20% in energy output after 11 years, the best seem to have a 16% drop after 25. How can an average consumer evaluate the type of solar cell they are purchasing, there is so much variation in type of panel. Is there any maker that legitimately guarantees output of solar panels over time? If so what is the guarantee? Will they replace with a newer better panel? Will they cover depreciated value lost over a 20 to 25 year lifespan? Consumers have no guarantee they can rely upon. For a large power company, with engineers such as yourself, this isn't a problem. For mom and dad who don't understand how PV works, this is a problem.
Too much to deal with. Try to shorten things down to bite sized question. Right off the bat I see some issues I find troubling with your reference. Let me repeat the statement.
Quote:
Because solar power is intermittent and inefficient, it increases the need for backup power plants. Solar power is also commonly generated in remote locations, far from high electricity demand. Making solar power reliable would require expensive investments in grid-level energy storage and transmission infrastructure. The current costs of making solar power physically reliable outweigh its limited benefits.
1. I don't understand the relevance of efficiency in this reference. Since solar radiation is free, efficiency doesn't seem to have much relevance. The solar array will have an output capacity that takes into account it's efficiency. The need for redundancy is a grid level determination driven principally by the size of the largest unit on the system. Solar is a long way from forcing additional spinning reserves.
2. "Solar power is also commonly generated in remote locations" Spain must be doing it differently from how we do it in the US. Much of our solar is located on roofs. It actually reduces the need for grid investments.
Keep trying and reflect on Sam Goldwyn's advice "If you can't fit your idea on the back of a business card, you don't have a clear idea." Keep it short and one question at a time.
Too much to deal with. Try to shorten things down to bite sized question. Right off the bat I see some issues I find troubling with your reference. Let me repeat the statement.
1. I don't understand the relevance of efficiency in this reference. Since solar radiation is free, efficiency doesn't seem to have much relevance. The solar array will have an output capacity that takes into account it's efficiency. The need for redundancy is a grid level determination driven principally by the size of the largest unit on the system. Solar is a long way from forcing additional spinning reserves.
2. "Solar power is also commonly generated in remote locations" Spain must be doing it differently from how we do it in the US. Much of our solar is located on roofs. It actually reduces the need for grid investments.
Keep trying and reflect on Sam Goldwyn's advice "If you can't fit your idea on the back of a business card, you don't have a clear idea." Keep it short and one question at a time.
My suspicion is solar is inefficient as it is produced in 12-24 volt direct current, then goes through an inverter to connect with the power grid. Inverter efficiency, and DC current loss over local copper is likely substantial. Of course they could be referring to solar panels being only 20-40% efficient at converting sunlight to electricity, which as you state wouldn't seem relevant.
The output any home may make is limited. Assuming most homes are connected to transformers, the energy they produce has to be converted to a higher than home voltage. Through the DC wire into the inverter than up to the local homes transformer, there are many places to lose net energy. If most substations are 3 phase, any phase with intermittent solar production can cause issues with balance across the phases which may adversely affect neutral current.
Over here Solar Angle Calculator | Solar Panel Angle Calculator the angle calculator informs me it is best to move from about 20 degrees south facing angle in winter to 76 degrees during summer. My guess is every few days to optimize my solar power generation all panels should be tilted a degree on the roof. Sort of difficult to do in rain and snow, or in compliance wish OSHA for a homeowner. What do you charge to tilt a panel a degree or two every few weeks on a northeast roof with shallow angle about 30' above the ground. Your freefall force would be stopped by grass or pavement depending on where you fell. F=MA as they say.
You combine discussion of inverters with discussion of 12-24 volt DC current, which reveals you actually have no clue as to what's going on. Grid connected solar is produced at 120 VAC. Off grid systems may well be lower voltage DC, but while interesting, isn't what we are talking about. You mix the two. The only thing in common are the PV panels. Just as you mix discussion of what happened in Spain, which is predominantly solar thermal, with what's happening in the US, which is PV.
Your snarky comment in the earlier post that I'm so smart fails. It's not that I am so smart, it's that your understanding of technology is completely inadequate. You'll serve more to confuse people on the board who lack a technical background.
You combine discussion of inverters with discussion of 12-24 volt DC current, which reveals you actually have no clue as to what's going on. Grid connected solar is produced at 120 VAC.
FunctionFx is right - Solar panels are DC devices that operate at around 20-30 volts although there is a lot of variation in that. Typical bus voltages for PV systems are 48 VDC but you also see lower, at 24 VDC. This is driven by batteries which are usually some multiple of 12 volts. Granted, a grid-connected system does not use batteries but they use the exact same equipment as off-grid systems so they usually have bus voltages that are the same. Almost all DC-AC inverters are designed to operate at an input voltage of 48 volts, or 24 volts. As FunctionFX points out, this forces the DC side to be high current. High current suffers high losses. I believe that is the point he is making.
The interesting thing is the Tesla Power Wall operates at a bus voltage of 300 volts. That is smart in a way since it lowers the DC current and allows smaller wires to be used. But it is a problem for home PV systems because they are not designed to work at such high voltages. So Tesla (actually Solar City) will sell you a special inverter that runs at 300 VDC.
PV panel inefficiency is due to the fact that not all photons are converted to electricity. Some are reflected, some is absorbed and readmitted as thermal radiation. Efficiency is less than 20% last I saw. But the exact conversion efficiency is temperature dependent.
There are inefficiencies (or losses) in all steps of a PV system. The charge-controllers have losses, the inverters have losses, wires have losses. You just budget for them. The good news is, except for the panels, most components are up in the 96% efficiency range.
Your scenario is not realistic. Reading your post, it seems you don't understand the difference between load and resource.
We have generation resources already that can quickly ramp up and down -- simple cycle gas turbines are cheap to buy, easy to site and respond well. Coal and Nuclear generally doesn't ramp at all so it's useless in this scenario.
I can't help you. Your understanding of the very basics of fiance is inadequate. BTW depreciation is not a consideration in NPV. It's a consideration in accounting.
It's a realistic scenario. For someone who claims to be so knowledgeable, have you never heard of the duck curve?
You are either not explaining your finance calculation accurately or you shouldn't give advice. Solar panels, as an asset, do depreciate over time. Feel free to clarify your meaning if it wasn't that getting your costs back after 10 years is a 7% return--which is what you said.
You combine discussion of inverters with discussion of 12-24 volt DC current, which reveals you actually have no clue as to what's going on. Grid connected solar is produced at 120 VAC. Off grid systems may well be lower voltage DC, but while interesting, isn't what we are talking about. You mix the two. The only thing in common are the PV panels. Just as you mix discussion of what happened in Spain, which is predominantly solar thermal, with what's happening in the US, which is PV.
Your snarky comment in the earlier post that I'm so smart fails. It's not that I am so smart, it's that your understanding of technology is completely inadequate. You'll serve more to confuse people on the board who lack a technical background.
No. DC is the output of all solar panels, 12-24 volt is typical. https://www.wholesalesolar.com/solar...nel-efficiency power from solar panels must be fed to an inverter if there is any desire to use most appliances in a home. Virtually all appliances are alternating current (AC) as direct current (DC) has issues with long distance transportation to to inability to amplify DC voltage efficiently via a transformer. This was settled over a century ago by the Tesla / Edison feud with a side of Westinghouse trying to deliver power from Niagara Falls.
As to Spain it was maybe still is the most solar country in the world, and went bankrupt attaining that status. It's energy prices have driven industry away, and power cost impoverishes the entire nation. Green looks great from a distance. Mentioning Spain as it is has more experience with a large percent of it's energy from solar makes sense when discussing how good or bad solar is. A Spanish Breakthrough in Harnessing Solar Power | 40th Anniversary | Smithsonian
It's a realistic scenario. For someone who claims to be so knowledgeable, have you never heard of the duck curve?
You are either not explaining your finance calculation accurately or you shouldn't give advice. Solar panels, as an asset, do depreciate over time. Feel free to clarify your meaning if it wasn't that getting your costs back after 10 years is a 7% return--which is what you said.
Any large percentage of power, going offline quickly, will strain our power grid. Somewhere after 20% or so, power grids become unstable with transient renewable power. When a large plant goes offline our grid can handle it, with renewables nearly 100 plants can go offline at any time if we exceed 20% renewable our power grid will fail. It gets tougher to cover for transient output the more power is created by solar or wind.
My suspicion is solar is inefficient as it is produced in 12-24 volt direct current, then goes through an inverter to connect with the power grid. Inverter efficiency, and DC current loss over local copper is likely substantial. Of course they could be referring to solar panels being only 20-40% efficient at converting sunlight to electricity, which as you state wouldn't seem relevant.
If your point is the preceding paragraph is irrelevant, I agree.
Quote:
Originally Posted by functionofx
The output any home may make is limited. Assuming most homes are connected to transformers, the energy they produce has to be converted to a higher than home voltage. Through the DC wire into the inverter than up to the local homes transformer, there are many places to lose net energy. If most substations are 3 phase, any phase with intermittent solar production can cause issues with balance across the phases which may adversely affect neutral current.
You are correct all electrical systems ave losses. The homeowner gets credit for the energy that passes through his/her electric meter, what happens after that is irrelevant.
Quote:
Originally Posted by functionofx
Over here Solar Angle Calculator | Solar Panel Angle Calculator the angle calculator informs me it is best to move from about 20 degrees south facing angle in winter to 76 degrees during summer. My guess is every few days to optimize my solar power generation all panels should be tilted a degree on the roof. Sort of difficult to do in rain and snow, or in compliance wish OSHA for a homeowner. What do you charge to tilt a panel a degree or two every few weeks on a northeast roof with shallow angle about 30' above the ground. Your freefall force would be stopped by grass or pavement depending on where you fell. F=MA as they say.
Rooftop solar arrays are fixed at a constant angle. No one adjusts them daily, or monthly. Again irrelevant.
It's a realistic scenario. For someone who claims to be so knowledgeable, have you never heard of the duck curve?
You are either not explaining your finance calculation accurately or you shouldn't give advice. Solar panels, as an asset, do depreciate over time. Feel free to clarify your meaning if it wasn't that getting your costs back after 10 years is a 7% return--which is what you said.
I have a Masters in Finance from a top university and have been employed as a financial adviser to electric utilities for 35+ years. Your inability to understand is not my problem. My comment was that a ten year simple payback on a pv system was approximately a 7% return on assets. I made no comment on depreciation, which is an accounting term that is rarely relevant in financial calculations. If you mean that solar systems have a finite lifetime, I agree, but that's irrelevant to the discussion since the lifetime is well longer than the 10 year period we are talking about. Warranties are as long as 25 years these days.
No. DC is the output of all solar panels, 12-24 volt is typical. https://www.wholesalesolar.com/solar...nel-efficiency power from solar panels must be fed to an inverter if there is any desire to use most appliances in a home. Virtually all appliances are alternating current (AC) as direct current (DC) has issues with long distance transportation to to inability to amplify DC voltage efficiently via a transformer. This was settled over a century ago by the Tesla / Edison feud with a side of Westinghouse trying to deliver power from Niagara Falls.
I'm left baffled by any possible relevance of what you were able to glean from Wikipedia.
Quote:
Originally Posted by functionofx
As to Spain it was maybe still is the most solar country in the world, and went bankrupt attaining that status. It's energy prices have driven industry away, and power cost impoverishes the entire nation. Green looks great from a distance. Mentioning Spain as it is has more experience with a large percent of it's energy from solar makes sense when discussing how good or bad solar is. A Spanish Breakthrough in Harnessing Solar Power | 40th Anniversary | Smithsonian
Again with respect to Spain, what's the relevance? BTW Spain is not bankrupt.
We have almost 4 times the installed solar capacity as Spain.
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