Prologue First, my background: I have degrees in computer science, applied mathematics, and system engineering. I retired from the Caltech Jet Propulsion Laboratory, after 53 years, in 2020. During evenings for seventeen years I served as an adjunct associate professor of computer science at a small university. I am an associate editor of a professional journal. Before retirement I was a member of two international committees and one U.S. committee related to computer software, and contributed to two others without being an official member; I was instrumental in founding one of them. My professional responsibilities included producing mathematical models for engineers and scientists, implementing those models in software, operating the software to convert measurements into data, and helping to interpret the data. I learned a lot, in many fields, from my clients.
Thank you for you concise explanation of material that Thunberg should have been taught in school, instead of warping the minds of the gullible. The saddest part is the bulk of humanity doesn't know how the physical world works and prefers the uninformed rabblings of celebrities. Your efforts might reach a few thousand who are already pre-declined to follow actual science. But this will hardly stem the flow of the herd who happily follow the charlatans. I think an Atlas Shrugged type of moment will be upon us at some point the way the World is going.
Thanks again for your efforts to stem the tide of ignorance.
Very good. We are in nearly complete agreement. I would add that there are two other problems with solar and wind because of its intermittency. 1st is seen in off-the grid solar homes with large batteries. Critical question: What is your coverage period and what is your recovery period? Typically, cheaper systems are sized for 3 days for both. This means that the system must be able to generate enough power during the lowest period (winter usually) to fill those batteries over 3 days, while meeting 24 hour load demands. Let's call our daily needs X. If we assume low period days are 50% (generous) of average days, then our capacity requirement is: [X+(x/3)]/0.5 = 2.66 x your average daily needs. Sounds fine?
Think about it. This means that most of the time, you will have 1.66 x your daily needs in excess. In the real world, you will have a low starvation period, and a summer high wild excess period. What do you do with that excess energy? Answer. You don't. You have to not accept it from your solar cells. Hey. That means that the energy required to make those solar cells doesn't get paid off by generating solar power for a lot longer. If that time is 2 years, now the real time to energy payback is around 5.32 years. If, that is, everything goes swimmingly.
Maybe we can do better by harvesting more of that excess energy through the year. That means expanding the battery banks tremendously. You now need to save energy in those batteries for 3-6 months. Batteries don't do that very well. The cost is astronomical. And, most batteries don't do well with severe deep cycling. That's why when you drive that Tesla, you leave 30 miles or more in the battery so you don't "brick" your car. It's around 12% or more that you want to keep. So, the longer the time period of coverage and storage, the more margin you need, and that costs.
Alternatively, you build solar + wind capacity so that you will almost always have excess. But to do that, if you take a look at a wind energy graph, you have to expand your capacity to 5-15 times your normal load on the grid. Then you can turn some of it off when you don't need it, which will be most of the time.
The basic problem here is that solar and wind generates energy when it wants to---not when you need it. So the process for control to meet demand is to cut off energy, not generate it. This is why Scottish windmills have made more money to not deliver power than to deliver it.
Thank you for you concise explanation of material that Thunberg should have been taught in school, instead of warping the minds of the gullible. The saddest part is the bulk of humanity doesn't know how the physical world works and prefers the uninformed rabblings of celebrities. Your efforts might reach a few thousand who are already pre-declined to follow actual science. But this will hardly stem the flow of the herd who happily follow the charlatans. I think an Atlas Shrugged type of moment will be upon us at some point the way the World is going.
Thanks again for your efforts to stem the tide of ignorance.
Very good. We are in nearly complete agreement. I would add that there are two other problems with solar and wind because of its intermittency. 1st is seen in off-the grid solar homes with large batteries. Critical question: What is your coverage period and what is your recovery period? Typically, cheaper systems are sized for 3 days for both. This means that the system must be able to generate enough power during the lowest period (winter usually) to fill those batteries over 3 days, while meeting 24 hour load demands. Let's call our daily needs X. If we assume low period days are 50% (generous) of average days, then our capacity requirement is: [X+(x/3)]/0.5 = 2.66 x your average daily needs. Sounds fine?
Think about it. This means that most of the time, you will have 1.66 x your daily needs in excess. In the real world, you will have a low starvation period, and a summer high wild excess period. What do you do with that excess energy? Answer. You don't. You have to not accept it from your solar cells. Hey. That means that the energy required to make those solar cells doesn't get paid off by generating solar power for a lot longer. If that time is 2 years, now the real time to energy payback is around 5.32 years. If, that is, everything goes swimmingly.
Maybe we can do better by harvesting more of that excess energy through the year. That means expanding the battery banks tremendously. You now need to save energy in those batteries for 3-6 months. Batteries don't do that very well. The cost is astronomical. And, most batteries don't do well with severe deep cycling. That's why when you drive that Tesla, you leave 30 miles or more in the battery so you don't "brick" your car. It's around 12% or more that you want to keep. So, the longer the time period of coverage and storage, the more margin you need, and that costs.
Alternatively, you build solar + wind capacity so that you will almost always have excess. But to do that, if you take a look at a wind energy graph, you have to expand your capacity to 5-15 times your normal load on the grid. Then you can turn some of it off when you don't need it, which will be most of the time.
The basic problem here is that solar and wind generates energy when it wants to---not when you need it. So the process for control to meet demand is to cut off energy, not generate it. This is why Scottish windmills have made more money to not deliver power than to deliver it.