I'm continually amazed at how little I know (despite my batchlor's degree in physics, including courses on electricity and magnetism) and how much I'm learning just from following guys like you on substack.
Synchronous wind generators were originally touted as a source of employment since they require more maintenance than DC machines. Now someone realized that the cost savings from wind power will be reduced by labor cost, so we now need neodymium for permanent magnets in those machines.
Thank you for this article. The grid is so complex, and this article adds clarity!
FWIW, I wrote about Phase Loop Lock in a post in June 24. I think the post is still interesting. (My post should be read in conjunction with your post, if possible.)
Just discovered your stack and had no idea that maintaining the grid was so complex — thanks.
A question - if we were setting up the grid from scratch today, given DC green energy sources, greater efficiency of HVDC lines and increasingly DC loads, would we skip a/c altogether, incorporating dc to ac inverters where needed (induction cooktops, e.g.)?
Another way to ask: should Africa develop a DC grid as it energizes?
I don't think we are ready yet Bob. In 50 years we might be. AC is just easy, that is why it won, and it still is. Right now we are figuring out we don't know the things we didn't even know we didn't know, and that is huge progress
Known knowns: These are facts or variables that we're aware of and understand. They form the basis of our knowledge and provide a solid foundation for decision making.
Known unknowns: These are factors we know exist, but don't fully understand. They represent gaps in our knowledge that we must address through research, investigation, or consultation with experts.
Unknown knowns: These are elements that we don't realize we know. They're typically buried in our subconscious, overlooked, or dismissed as irrelevant. Uncovering these insights can lead to surprising breakthroughs in decision making.
Unknown unknowns: These are factors that we're not aware of and can't predict. They represent the most significant source of uncertainty and risk, as they can catch us off guard and derail our plans.
That works Al, or a computer UPS system. I think Bob meant our end user devices like our air conditioners and fan motors being DC also. We aren't ready for that, but if you have a variable speed AC compressor you are close.
Good article. But I don’t understand why a GFM inverter should be hardly any more expensive than a GFL. Seems like the vast majority of the costs would be in the high power switches. Sophisticated control with a 32 bit microprocessor and associated peripherals should cost only a few dollars. Maybe R&D increases the cost of early designs but that should decrease with volume.
This is where I would have to to defer to the experts. I do know the GFM inverters have more sophisticated switching and more filtering to make a cleaner sine wave. But I am by no means an expert in what drives what cost.
Great article - thanks!
I'm continually amazed at how little I know (despite my batchlor's degree in physics, including courses on electricity and magnetism) and how much I'm learning just from following guys like you on substack.
Synchronous wind generators were originally touted as a source of employment since they require more maintenance than DC machines. Now someone realized that the cost savings from wind power will be reduced by labor cost, so we now need neodymium for permanent magnets in those machines.
Thank you for this article. The grid is so complex, and this article adds clarity!
FWIW, I wrote about Phase Loop Lock in a post in June 24. I think the post is still interesting. (My post should be read in conjunction with your post, if possible.)
https://meredithangwin.substack.com/p/ibrs-with-planning
Thank you Meredith
Just discovered your stack and had no idea that maintaining the grid was so complex — thanks.
A question - if we were setting up the grid from scratch today, given DC green energy sources, greater efficiency of HVDC lines and increasingly DC loads, would we skip a/c altogether, incorporating dc to ac inverters where needed (induction cooktops, e.g.)?
Another way to ask: should Africa develop a DC grid as it energizes?
-Bob
I don't think we are ready yet Bob. In 50 years we might be. AC is just easy, that is why it won, and it still is. Right now we are figuring out we don't know the things we didn't even know we didn't know, and that is huge progress
The four quadrants of the Rumsfeld Matrix
Known knowns: These are facts or variables that we're aware of and understand. They form the basis of our knowledge and provide a solid foundation for decision making.
Known unknowns: These are factors we know exist, but don't fully understand. They represent gaps in our knowledge that we must address through research, investigation, or consultation with experts.
Unknown knowns: These are elements that we don't realize we know. They're typically buried in our subconscious, overlooked, or dismissed as irrelevant. Uncovering these insights can lead to surprising breakthroughs in decision making.
Unknown unknowns: These are factors that we're not aware of and can't predict. They represent the most significant source of uncertainty and risk, as they can catch us off guard and derail our plans.
Perfect
An example of direct use of DC from batteries is the 12 volt system in RVs, but I'm not sure it would be practical in other situations.
That works Al, or a computer UPS system. I think Bob meant our end user devices like our air conditioners and fan motors being DC also. We aren't ready for that, but if you have a variable speed AC compressor you are close.
Good article. But I don’t understand why a GFM inverter should be hardly any more expensive than a GFL. Seems like the vast majority of the costs would be in the high power switches. Sophisticated control with a 32 bit microprocessor and associated peripherals should cost only a few dollars. Maybe R&D increases the cost of early designs but that should decrease with volume.
This is where I would have to to defer to the experts. I do know the GFM inverters have more sophisticated switching and more filtering to make a cleaner sine wave. But I am by no means an expert in what drives what cost.