> When the wind blows, for example, power lines are cooler, allowing for more capacity. Okay, but what do you do when the wind isn't blowing? How do you get people to only charge their cars when it's windy?
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The aging U.S. power grid is about to get a jolt
21–30 of 158 posts
Re: The aging U.S. power grid is about to get a jolt
#22These ‘grid enhancing technologies’ look like cheap fixes that can only buy some time before real work is needed. Sure, with better monitoring and some overload management systems you may work closer to some limits, but that’s not a solution for long-term usage increases. Where I work, they are used a lot to adjust for renewables power surges, not to increase transit. The bit about automaticaly shifting power to othe…
The article says they are buying the time. New lines are slow to build, so while they are being built, it is possible to squeeze more from the existing lines.
Re: The aging U.S. power grid is about to get a jolt
#23EDIT: Where I live, there is mostly 69 kV and 138 kV, with only a few 345 kV lines. There aren't nearly enough 500 kV lines, and 765 kV aren't present in the region.
EDIT2: Here's what a 765 kV line looks like: https://maps.app.goo.gl/3fV1hFuQmpq3hVNx5
Map of US electric grid: https://www.arcgis.com/apps/mapviewer/index.html?layers=d409...
Real wiring is dominated by current, resistance of the conductor, and cooling.[0,1]
The way out is to rebuild with much high voltages and live monitoring, optionally with superconducting segments like Nexans where advantageous.
0. Ikeda, Yoshirô and Katsuhiko Yoneta. Temperature rise of a conductor due to the electric current. (1931). http://hdl.handle.net/2115/37682
PDF: https://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/3768...
1. Riba, J.-R.; Llauradó, J. A Model to Calculate the Current–Temperature Relationship of Insulated and Jacketed Cables. Materials (2022) 15,6814. https://doi.org/10.3390/ma15196814
PDF: https://mdpi-res.com/d_attachment/materials/materials-15-068...
Re: The aging U.S. power grid is about to get a jolt
#24These ‘grid enhancing technologies’ look like cheap fixes that can only buy some time before real work is needed. Sure, with better monitoring and some overload management systems you may work closer to some limits, but that’s not a solution for long-term usage increases. Where I work, they are used a lot to adjust for renewables power surges, not to increase transit. The bit about automaticaly shifting power to othe…
The article says they are buying the time. New lines are slow to build, so while they are being built, it is possible to squeeze more from the existing lines.
I get it, I'm just baffled with the hint the article gives that the stuff needed now wasn't planned 10 years ago. I guess this is yet another "US infrastructure disaster" article, but with a positive outlook.
Re: The aging U.S. power grid is about to get a jolt
#25[dead]
Re: The aging U.S. power grid is about to get a jolt
#26Summary: utilities will use dynamic rating and other tricks to squeeze a bit more performance out of existing lines. (Transmission lines have losses, these heat up the wires. If they get too hot, they droop too much. So they have a maximum power rating. Dynamic rating takes weather effects into account to vary that maximum.) Meanwhile in China: thousands of km long megavolt UHVDC transmission lines. https://www.hitac…
So basically, next time there's a heatwave and everyone cranks up their aircon, the system will still collapse.
Re: The aging U.S. power grid is about to get a jolt
#27Summary: utilities will use dynamic rating and other tricks to squeeze a bit more performance out of existing lines. (Transmission lines have losses, these heat up the wires. If they get too hot, they droop too much. So they have a maximum power rating. Dynamic rating takes weather effects into account to vary that maximum.) Meanwhile in China: thousands of km long megavolt UHVDC transmission lines. https://www.hitac…
I was intrigued by one of the other ways—"high-performance wires"—which they don't explain at all. I found one article[0] (podcast, I guess, but with a transcript) that goes into it: old wires are aluminum supported by steel. By using aluminum supported with carbon fiber, you get less weight and less thermal expansion, allowing for more aluminum and without it sagging as much.
High conductivity, less transmission loss. Potentially fewer towers (because you can space them out a little further), offsetting the cost of the wires. Neat!
[0] https://www.volts.wtf/p/one-easy-way-to-boost-the-grid-upgra...
Re: The aging U.S. power grid is about to get a jolt
#28Summary: utilities will use dynamic rating and other tricks to squeeze a bit more performance out of existing lines. (Transmission lines have losses, these heat up the wires. If they get too hot, they droop too much. So they have a maximum power rating. Dynamic rating takes weather effects into account to vary that maximum.) Meanwhile in China: thousands of km long megavolt UHVDC transmission lines. https://www.hitac…
omg the name just sounds like "precision scheduled railroading"
Re: The aging U.S. power grid is about to get a jolt
#29Summary: utilities will use dynamic rating and other tricks to squeeze a bit more performance out of existing lines. (Transmission lines have losses, these heat up the wires. If they get too hot, they droop too much. So they have a maximum power rating. Dynamic rating takes weather effects into account to vary that maximum.) Meanwhile in China: thousands of km long megavolt UHVDC transmission lines. https://www.hitac…
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Re: The aging U.S. power grid is about to get a jolt
#30These are bandaids. Fine in themselves, but not addressing the real problem.
The US really need to legalize transmission line construction!