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Comment by pkulak | Hacker News Reader

How hard can it be to have your own grid, but also have inputs on the edges to draw from? Or would that no longer be independent?

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Texas does have connections to other grids. But the problem is that since the grid frequencies aren't synchronized, you can't just plug one into the other.

Transferring energy between grids requires either converting it from AC to high-voltage DC and back using solid-state electronics, or converting it via mechanical energy using a variable-frequency transformer. With either approach, you need bulky and expensive equipment in proportion to how much power you want to handle. These connections are designed to smooth out (and profit from) short-term capacity fluctuations, not to power the entire state.

Currently, the Texas grid has two DC ties operating at full capacity and drawing about 800MW from the Southwest Power Pool. But that's a drop in the bucket compared to the ~45GW of current demand, or the estimated 70-80GW of demand that would be likely if it weren't for the outages.

http://www.ercot.com/content/cdr/html/real_time_system_condi...

Thank you! I didn't think about the AC synchronization.

Electricity networks are a really fascinating hole to dive in. I did software and firmware for Smart Metering solutions for a half decade and know more about that stuff than I'll ever need.

TX grid is connected via HVDC, but keep in mind that even if it was "fully" connected there is no hope in hell it would be much better. There wouldn't be enough transmission to transfer 40GW+ from the East or West coast grids to TX. It's an enormous amount of power to go offline. I don't think California for instance has more than 10GW of transmission north to south.

Basically, no amount of grid infrastructure can really help you much when you lose 50%+ of generation capacity on your highest demand days in history.

Seems like CA might has 15-20GW of spare NatGas generation capacity. Looking back at the summer peak (9/6/20) I see 25GW generated at the peak, while we are currently only needing to generate about 8-9GW from NatGas (looking over night when solar drops off).

The parent said there is not enough transmission capacity not generation capacity. Generation needs to be near loads. If not then transmission lines are required to bring current from generators to loads. Transmission lines have fixed capacities, like your internet connection can only transmit so much data/s, they can only transmit so much power.

It's likely that the transmission lines are less of a bottle neck than the frequency conversion. Power lines are pretty darned efficient, and given the cold weather, theyd be more efficient than usual too

That actually isn't true:

https://3dfs.com/articles/wasted-electricity-vs-lost-electri...

Almost 62% of electricity is lost in the grid. AC is the primary reason (matching, vibration, I2R, etc.).

HVDC is WAY better at transmitting power over any appreciable distance.

The Chinese have an amazingly ambitious plan to shift power from one part of the country to another with UHV DC. It has its own challenges, but it is definitely the way to shift massive amounts of power without grid interconnect (and the resulting frequency stability issues). Much lower loss, even with DC-AC converters.

https://spectrum.ieee.org/energy/the-smarter-grid/chinas-amb...

If America built a network of 20GW HVDC interconnects it would be far more significant infrastructure than building some highways.

The article is wildly incorrect: the 62% figure includes the losses during generation e.g. heat lost when burning coal or cooling towers for nuclear.

I recall that losses after generation due to transmission across the electricity grid are typically about 10%.

They make long distance DC innerconnects, while expensive they are resistant to particular types of problems and can connect to multiple different grids at the same time.

there has been a 3GW DC interconnect between Portland, OR and LA for 5 decades or so. https://en.wikipedia.org/wiki/Pacific_DC_Intertie

Electrical engineers wouldn't build a power line to Texas with a capacity of 5000 MW and then put intertie hardware such as phase shifters or ac-dc-ac converter with capacity of 1000 MW on the end of it. So it is likely that the transmission capacity and intertie capacity are exactly the same!

It's not the capacity of the converter, it's the efficiency of the conversion. There's some loss involved.

I thought they were saying there wasn't enough transmission capacity but it wouldn't matter anyways since the rest of the grid didn't have any to spare. Maybe I misinterpreted or responded to the wrong comment.

If your gap is 40GW, and you could get another 8GW. That's enough to give everyone an extra hour of electricity every 5 which would be game changing. The different between a 33 and 45 degree house is enormous.

From the articles I've read they do:

> Even today, ERCOT is also not completely isolated from other grids — as was evident when the state imported some power from Mexico during the rolling blackouts of 2011. ERCOT has three ties to Mexico and — as an outcome of the "Midnight Connection" battle — it also has two ties to the eastern U.S. grid, though they do not trigger federal regulation for ERCOT. All can move power commercially as well as be used in emergencies, according to ERCOT spokeswoman Dottie Roark. A possible sixth interconnection project, in Rusk County, is being studied, and another ambitious proposal, called Tres Amigas, would link the three big U.S. grids together in New Mexico, though Texas' top utility regulator has shown little enthusiasm for participating.

https://www.kvue.com/article/weather/texplainer-why-does-tex...

The latter. They do not want federal regulation.

For the pedantic TX does have connections to other grids but the capacity is so low that it wouldn't have mitigated this event and is under whatever threshold is set for federal oversight.

It would be independent from a practical point of view but from a regulatory one it would become subject to federal regulations, which is the real reason Texas keeps theirs separate.

The Tres Amigas Super Station is, ironically, being built in TX. If it was done, it could help the situation a lot. 30 GW of capacity!

https://en.wikipedia.org/wiki/Tres_Amigas_SuperStation

Nit: IF this gets built (big if), it will be in New Mexico, not Texas.

It's also very unlikely that it would be near 30GW of transmission capacity.

Regulations probably.

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