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Some of the nonsense . . . sorry that is too harsh . . . some of the misconceptions -- in this thread . . .
First -- Solar PV tends to work fine on Cloudy Days. Really. They do perform better in Bright Sunlight, but even that can be overcome with some concentration methods.
Second -- Solar PV actually produces MORE during the Winter, as the cooler temps reduce the internal resistance in the Silicon. Really, no kidding -- when we do the power production designs, we have to consider a Cold, Sunny, Winter day for the highest output. So that tends to help balance out the shorter day light time in the North and (below the Equator) South.
The is no present need for Storage, Storage, Storage. That is about like selling Ice Cubes to Eskimos. Electricity Production overnight is already So Surplus that in some areas Over Night use is Free. The Coal and Nuke generators just need somewhere to dump their production, as they cannot shut down overnight. And things are getting more-so. The overnight Energy Efficiency of small tube fluorescent, and LED lighting is starting to add up. If things were heading towards All or Mostly Solar (btw, thing already are), the old Tech Dinosaur Plants that do the overnight base load can just be mothballed at the end of their service life. (already doing that, too).
And going further, if overnight were really such a need, folks are already way ahead on that, too. Low Earth Orbit space PV (yeah, it already exists, too -- powers many satellites, and the Space Station) can beam power down, as the Sun does not go out over the horizon, and the Sun is always shining above the clouds.
But as Mack sort of almost headed in to . . . . the issue is not (and never has been) about "Energy." The only problem is the ICE (Internal Combustion Engine). It tends to run best on Carbon (and some Hydrogen) fuels. Replace the ICEs with Electric Motors, and the (now) decades long Energy Drama Problem(s) go away.
ps, who needs Transcontinental Aircraft when we can have these (faster, cheaper, safer, cleaner . . . . and all Electric. ) >>>
Some of the nonsense . . . sorry that is too harsh . . . some of the misconceptions -- in this thread . . .
First -- Solar PV tends to work fine on Cloudy Days. Really. They do perform better in Bright Sunlight, but even that can be overcome with some concentration methods.
Second -- Solar PV actually produces MORE during the Winter, as the cooler temps reduce the internal resistance in the Silicon. Really, no kidding -- when we do the power production designs, we have to consider a Cold, Sunny, Winter day for the highest output. So that tends to help balance out the shorter day light time in the North and (below the Equator) South.
Some clarifications are needed.
Solar panels do not produce anything, they harvest. An analogy would be the person who doesn't plant the crops but shows up when they are ready to gather them. In this case, the planter is the sun. This is important because unless one understands that, it becomes easy to believe that solar panels harvest more in Winter because the temps are cooler.
It is true that in cooler temperatures, the panels harvest increases but this is only short term. As soon as the panels heat up, the differences between the harvest on a day with cooler temps and one with higher temps is inconsequential for practical purposes.
The more important factors are the length of the harvest and the quality of the harvest. In the Winter, there is less sun exposure because the sun sets much sooner. The angle of the sun relative to the panels also decreases so that the quality of the harvest is lower.
These factors make the harvest in Winters much less than in summer.
It is also important to understand that the harvest of the panels must be measured not at a point in time but in total per day. The reason for that is that most people live according to time. With shorter daylight hours in Winter, it is true that most people will use more electricity.
So, at the critical time when electricity needs are highest, the solar harvest is lowest. If solar harvest were greater in total during the Winter when temps are cooler, it would be a very good selling point for solar but the facts are the opposite.
But this thread is about the entire world being 100% solar. This would also require that the harvest be transmitted globally because if we include the premise of not needing storage, one of two things would have to happen:
1. Either the use of electricity would have to be regulated to the amount of harvest that could be obtained without transmitting the electricity past the area it is being harvested or;
2. Harvest would have to be transmitted globally so that areas of need when there is no sunlight would be able to use harvest from areas that are sunlit.
Both have their own significant consequences including the social and economic (and that brings in governments and cultures) issues of how does it get paid for and how is it regulated? Unlike oil and coal which can be stored or in the case of the owner, retained, solar harvest without storage disappears.
Many people think solar panels are like batteries, they are not. They are point if use things, you use it or lose it unless you store it. If you don't store it, it doesn't matter how much harvest you can get because you start the next day at zero.
If you could transmit the harvest across the globe so that areas not sunlit can use the harvest from those that are, the costs to do that would likely exceed creating storage. In any case, it isn't practical in even the most basic terms.
Another reason the world can't go 100% solar is the reality of wars. As I said before, unless the many social, cultural, economic and other problems are first solved 100% solar is achievable. While certain entities can disrupt grids or even take down entire power generation plants, imagine what happens when someone decides to disrupt the transmission lines from a solar harvesting country to one that doesn't have that capacity. The entire country goes dark, instantly. Not some of the cities, all of them.
Not every country will or does have the capacity to go 100% solar. That means they have to get their electricity from some other country. Oil and coal are easily shipped. Electricity must be transmitted and is far more easily disrupted because it would not be as widely distributed by source. Oil and coal can be bought from many sources. It requires only transportation and that transport can take many forms and many routes during many different times, day or night.
Solar harvest without storage would have to transmit only during daylight. Even with storage, it isn't practical to create the storage needed to allow the entire planet to use only solar harvest for electricity.
In essence, the 100% solar idea (which was envisioned long before anyone here thought about it) isn't practical. it is so impractical to say it won't happen without a single world government and that fellow readers, it really what global solar is all about. Considering that, it isn't really green at all, it is more about single world government than anything else. Think about it, the various governments of the world can't stop fighting wars, kills people on genocidal scales and yet all of them will get together to use only solar harvest for electricity?
Like I said, the planet going 100% solar also assumes (because it must) a single world government. There are in fact, agendas at work in the 100% solar vision. There must be.
Some of the nonsense . . . sorry that is too harsh . . . some of the misconceptions -- in this thread . . .
First -- Solar PV tends to work fine on Cloudy Days. Really. They do perform better in Bright Sunlight, but even that can be overcome with some concentration methods.
Second -- Solar PV actually produces MORE during the Winter, as the cooler temps reduce the internal resistance in the Silicon. Really, no kidding -- when we do the power production designs, we have to consider a Cold, Sunny, Winter day for the highest output. So that tends to help balance out the shorter day light time in the North and (below the Equator) South.
The is no present need for Storage, Storage, Storage. That is about like selling Ice Cubes to Eskimos. Electricity Production overnight is already So Surplus that in some areas Over Night use is Free. The Coal and Nuke generators just need somewhere to dump their production, as they cannot shut down overnight. And things are getting more-so. The overnight Energy Efficiency of small tube fluorescent, and LED lighting is starting to add up. If things were heading towards All or Mostly Solar (btw, thing already are), the old Tech Dinosaur Plants that do the overnight base load can just be mothballed at the end of their service life. (already doing that, too).
And going further, if overnight were really such a need, folks are already way ahead on that, too. Low Earth Orbit space PV (yeah, it already exists, too -- powers many satellites, and the Space Station) can beam power down, as the Sun does not go out over the horizon, and the Sun is always shining above the clouds.
But as Mack sort of almost headed in to . . . . the issue is not (and never has been) about "Energy." The only problem is the ICE (Internal Combustion Engine). It tends to run best on Carbon (and some Hydrogen) fuels. Replace the ICEs with Electric Motors, and the (now) decades long Energy Drama Problem(s) go away.
ps, who needs Transcontinental Aircraft when we can have these (faster, cheaper, safer, cleaner . . . . and all Electric. ) >>>
PV does not work well on cloudy day. You get 20-30% of a clear sunny day. The upside is that load is usually lower on cloudy days.
PV does not produce as much energy in the winter. Production in Nov-Dec is about 1/2 production in June- July.
Wind is a good complement to pv since the wind resource is strongest at night, but we will still need some dispatchable generation like natural gas fire turbine or hydro.
PV does not work well on cloudy day. You get 20-30% of a clear sunny day. The upside is that load is usually lower on cloudy days.
Which was why I was mentioning optional concentrators. Add very little to the cost, but much to the production.
But as you mentioned -- lower loads on Cloudy Days. It is worth understanding why that is. Air Conditioning for the buildings.
But one must question if it even makes sense to use Solar PV (an Electrical Source) for Air Conditioning (a Heat Load) when Solar can make and directly cancel a Heat Load with Heat Source.
PV does not produce as much energy in the winter. Production in Nov-Dec is about 1/2 production in June- July.
Let's define things a bit? Power (Volts x Amps) can go higher in the Winter, due to the Cold Weather keeping internal resistance of the cells low. Really, Winter Temps with Normal Winter Insolation is the Peak Current design.
ENERGY on the other hand may go lower due shorter days -- (Energy being Power x Time) -- depending on how far North or South one goes. But even that can be improved with East-West trackers.
Our numbers tend to be higher (in Texas) without tracking, and just tilt matching (normal to the Sun) stays above half. But if tracking is added (for customers where this matters) the overall day is extended.
Most are between 30 degrees North and 30 degrees South Latitude
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Wind is a good complement to pv since the wind resource is strongest at night, but we will still need some dispatchable generation like natural gas fire turbine or hydro.
Agree on that. Not a purist nor perfectionist at all on my side of things. We have even looked at Hydrogen Production here (Texas) just to have something to do with all the Over Night surplus Wind, Nuke and Coal Generation.
It is true that in cooler temperatures, the panels harvest increases but this is only short term. As soon as the panels heat up, the differences between the harvest on a day with cooler temps and one with higher temps is inconsequential for practical purposes.
Ummm. The panels do not "heat up" -- the internal current in a panel is too low to produce much internal heat, and when it is 0 degrees out -- the panel is pretty near the same. Even in the Sun. It just sits there, only about an 1/8 inch thick -- cold and exposed on both sides to the cold and wind.
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The more important factors are the length of the harvest and the quality of the harvest. In the Winter, there is less sun exposure because the sun sets much sooner. The angle of the sun relative to the panels also decreases so that the quality of the harvest is lower.
We tend to put "trackers" on the installations where this matters. That tends to give them Dawn to Dusk optimization whether Winter or Summer.
The economics of this became skewed by the Grants and Rebates programs. In the US -- Grant and Rebates tend to be awarded based on Maximum (Watts) Production Rating under the PV Watts Calculator System -- NOT Overall Energy Production. If they used an Energy Model which considered daily run time, and gave the awards with consideration for tilting (North and South for Winter/Summer) AND tracking (East to West) for the Daily Sun Crossing -- Overall Energy Production from the installed base of Solar would be MUCH higher, already.
These factors make the harvest in Winters much less than in summer.
As noted above, this was driven by an apparent flaw in the Grants and Rebates modeling.
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It is also important to understand that the harvest of the panels must be measured not at a point in time but in total per day. The reason for that is that most people live according to time. With shorter daylight hours in Winter, it is true that most people will use more electricity.
I think I follow you are intuiting that -- but there is a flaw in your reasoning.
Heating and Cooling is the primary load for most people. Not lighting. Lighting is a Very Small Load and is shrinking.
Heaviest US Electrical Use is the Afternoon in the Heat of Summer -- which is a perfect match for Solar Thermal / Concentrators. If these were used directly as Heat and Cooling sources, much of the US Demand for Electricity Generation would be destroyed.
Going a little deeper, the logic you are surmising for Time of Use being secondary to Total Daily Energy Production is backwards, as well. Time of Use is EVERYTHING, it turns out. That is why there are daily Peak Demands in most every resource -- from Electricity, to the Internet, to even Local Traffic -- e.g., "Rush Hour(s)." Having a source that hits those Peaks well is the Premium.
That is why Baseload Coal and Nukes plants are Very Undesirable -- they are not flexible to hit the Peak(s). Gas Turbines and Hydro on the other hand are very Desirable, as they can be spun up quickly and pulled off when things go surplus. Solar, just by happy coincidence hits our Human behaviors and Time of Use Demands rather well, and as noted above Solar Thermal hits Air Conditioning Peak Load perfectly.
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So, at the critical time when electricity needs are highest, the solar harvest is lowest. If solar harvest were greater in total during the Winter when temps are cooler, it would be a very good selling point for solar but the facts are the opposite.
Again, you have this information backwards.
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But this thread is about the entire world being 100% solar. This would also require that the harvest be transmitted globally because if we include the premise of not needing storage, one of two things would have to happen:
1. Either the use of electricity would have to be regulated to the amount of harvest that could be obtained without transmitting the electricity past the area it is being harvested or;
2. Harvest would have to be transmitted globally so that areas of need when there is no sunlight would be able to use harvest from areas that are sunlit.
Both have their own significant consequences including the social and economic (and that brings in governments and cultures) issues of how does it get paid for and how is it regulated? Unlike oil and coal which can be stored or in the case of the owner, retained, solar harvest without storage disappears.
Many people think solar panels are like batteries, they are not. They are point if use things, you use it or lose it unless you store it. If you don't store it, it doesn't matter how much harvest you can get because you start the next day at zero.
If you could transmit the harvest across the globe so that areas not sunlit can use the harvest from those that are, the costs to do that would likely exceed creating storage. In any case, it isn't practical in even the most basic terms.
Maybe take a look at the map link above for World Population Distribution?
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Another reason the world can't go 100% solar is the reality of wars. As I said before, unless the many social, cultural, economic and other problems are first solved 100% solar is achievable. While certain entities can disrupt grids or even take down entire power generation plants, imagine what happens when someone decides to disrupt the transmission lines from a solar harvesting country to one that doesn't have that capacity. The entire country goes dark, instantly. Not some of the cities, all of them.
See the CFR note, below.
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Not every country will or does have the capacity to go 100% solar. That means they have to get their electricity from some other country. Oil and coal are easily shipped. Electricity must be transmitted and is far more easily disrupted because it would not be as widely distributed by source. Oil and coal can be bought from many sources. It requires only transportation and that transport can take many forms and many routes during many different times, day or night.
Solar harvest without storage would have to transmit only during daylight. Even with storage, it isn't practical to create the storage needed to allow the entire planet to use only solar harvest for electricity.
You may be a bit (quite a bit) stuck on the Central Plant Model.
Dunno if you track the difference between Central Plant v. Distributed Generation?
The Energy Corporations have and are not amused.
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In essence, the 100% solar idea (which was envisioned long before anyone here thought about it) isn't practical. it is so impractical to say it won't happen without a single world government and that fellow readers, it really what global solar is all about. Considering that, it isn't really green at all, it is more about single world government than anything else. Think about it, the various governments of the world can't stop fighting wars, kills people on genocidal scales and yet all of them will get together to use only solar harvest for electricity?
Like I said, the planet going 100% solar also assumes (because it must) a single world government. There are in fact, agendas at work in the 100% solar vision. There must be.
Dunno if you have tracked the Genesis and underlying Purpose of the Council on Foreign Relations (CFR) -- but that is a Whole Other Topic.
The premise of the thread is 100% solar, if you were going to do 100% solar you need both a lot of capacity and storage.
Not so much as you may think?
First let's do Production -- Turns out in practice you never even need 100% at any given time. If you add up the loads, Everything is Never ALL turned on at the same time.
Fancier term we use is "Load Diversity" or its inverse "Demand Factor." About the Highest things get even under Heavy Industry is around 80%.
As far as Storage -- again, one needs to do the Diagnosis BEFORE you write the Prescription.
If you look at the typical Overnight Loads -- just about the only real consistent ones are SOME lighting -- but even then, MOST lighting is off. There is very little overnight demand. And IF one pulled the overnight Heating and Cooling loads off -- even far less.
And as was mentioned above -- it makes little sense to do Solar PV remotely sourced (or even local) sourced Heat and Cooling, if you can do Local Source Solar Thermal. And for most of the World -- Local Sourced Solar Thermal Heat and Cooling would work fine.
Did a Large Greenhouse a few years ago. Relatively small Solar Thermal Collectors were used to heat water, which circulated through the Concrete Slab. Had an 80 gallon conventional Water Heater as back up. In the middle of Winter, with a single short Sunny Afternoon, the Greenhouse warmed up to 80 degrees F. (20 degrees outside) We shut the system off for three days, to see what would happen. Building temps stayed at 80 F, while a winter storm came through.
Solar Thermal A/C works the same, but in reverse. The hotter the Sun, the better it works. It just makes more sense to Use what nature gives us -- rather than always fight and struggle against it.
The problem on current building heat and cooling is NOT an Electricity Production or Storage Problem, but rather a problem with the buildings and methods, themselves.
Apparently you've never taken temp readings on solar panels.
Let me help you understand. If a solar panel converts (harvests, not produces) at a rate of say 20% (being generous here) what happens to the remaining 80% of the solar radiation reaching the panel? Hint - quite a bit of it is converted to heat and as a result, the temperature of the solar panel increases.
Saying that solar panels do not heat up means you have no idea what you're talking about. Absolutely, they heat up from the solar radiation striking them. Perhaps you are confusing something and that would be saying that the harvest process itself doesn't heat the panels. That however is not what was being discussed.
To say in any way that a solar panel is the same temperature at 32 degrees as it is at 110 degrees is astounding.
Now, if you want to argue that a solar panel somehow does not increase or decrease in temperature , please, enlighten me because it should prove very interesting.
On the subject of trackers, again there is a flaw in your ideas. A tracker does not increase the time it is possible to expose a solar panel to the sun. Once the sun sets and before it rises, a tacker has no effect on harvest.
A tracker will allow for greater harvest regardless of the time of year so once again, you're taking an exception and trying to apply it to all conditions. This is a common theme in your descriptions, one off examples that bear no relation to the OP about the world going 100% solar.
Measure the total harvest for a tracked array throughout the year and you'll find that there is less harvest in the Winter months. If you say that isn't the case, the rest of your ideas fall apart just as quickly.
A day in the time doesn't mean anything other than what happened that day nor can it be used as an example of what will always be.
One-off point in time examples are nice to talk about but that is pretty much it.
Last edited by Mack Knife; 12-27-2014 at 05:20 PM..
Which was why I was mentioning optional concentrators. Add very little to the cost, but much to the production.
But as you mentioned -- lower loads on Cloudy Days. It is worth understanding why that is. Air Conditioning for the buildings.
But one must question if it even makes sense to use Solar PV (an Electrical Source) for Air Conditioning (a Heat Load) when Solar can make and directly cancel a Heat Load with Heat Source.
Let's define things a bit? Power (Volts x Amps) can go higher in the Winter, due to the Cold Weather keeping internal resistance of the cells low. Really, Winter Temps with Normal Winter Insolation is the Peak Current design.
ENERGY on the other hand may go lower due shorter days -- (Energy being Power x Time) -- depending on how far North or South one goes. But even that can be improved with East-West trackers.
Our numbers tend to be higher (in Texas) without tracking, and just tilt matching (normal to the Sun) stays above half. But if tracking is added (for customers where this matters) the overall day is extended.
Most are between 30 degrees North and 30 degrees South Latitude
Agree on that. Not a purist nor perfectionist at all on my side of things. We have even looked at Hydrogen Production here (Texas) just to have something to do with all the Over Night surplus Wind, Nuke and Coal Generation.
Phil I'm opining based upon actual kWh meter readings of operating systems.
Cloudy days = less energy
Winter month = less energy.
I'm a great fan of pv, but people like you who make baseless claims don't help.
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