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I would like to know why grid operators turn portions off instead of installing devices to mitigate the fire risk when a fault occurs. “Rapid Earth Fault CLeara

by amluto 3y ago

I would like to know why grid operators turn portions off instead of installing devices to mitigate the fire risk when a fault occurs. “Rapid Earth Fault CLearance” devices (REFCL), also known as ground fault neutralizers, are a newish but commercially available technology that massively reduces current, and thus heating energy, delivered into a ground fault. In testing in Australia, a REFCL-protected line was intentionally dropped into dry plants without setting them on fire. What gives? I doubt these devices are so expensive that they’re worse than the cost of “public safety power shutdowns” or of the billions of dollars that utilities are spending, and charging customers for, for undergrounding of lines and extra tree work.

mschuster91 3y ago
> I would like to know why grid operators turn portions off instead of installing devices to mitigate the fire risk when a fault occurs. The stuff you're mentioning is - at least from a quick Google, I'll admit that - only certified in Australia. Even here in Germany, introducing that onto the grid would take years for certifications. Bureaucracy moves slowly. Then, you'd need to upgrade a lot of transmission lines including the regional distribution grid (i.e. < 100 kV), a single unprotected line in a danger-prone area is enough to start a deadly fire. And there are a looooot of power lines that haven't had an inspection for decades - the hook that caused the 2018 fire was almost a century old [1]. And so, instead of inspecting, maintaining and upgrading the many thousand km's of national and regional lines, shutting them down during peak fire condition times is cheaper. IMHO it only makes sense to install REFCL devices as part of a general overhaul of an entire transmission grid area. [1] https://www.wsj.com/articles/this-old-metal-hook-could-determine-whether-pg-e-committed-a-crime-11583623059 https://www.wsj.com/articles/this-old-metal-hook-could-deter...
deleted 3y ago
[deleted]
toast0 3y ago
Because they already have the ability to turn portions off. Installing a lot of new equipment means regulatory effort to get a plan approved, and a lot of installation labor. I imagine these systems will be put in place over time, but I was just looking at Wikipedia on Reclosers and they said Sensitive Ground Fault protection reduces the risk by 80%; if the risk is high enough, that probably still warrants deenergizing risky lines at times.
- amluto 3y ago
  These aren’t quite the same thing. Sensitive ground fault protection attempts to shut down the line more quickly in the event of a ground fault. A ground fault neutralizer attempts (and apparently largely succeeds!) at reducing the fault current to near zero during a fault even before anything is shut down. These technologies can be combined.
samtho 3y ago
Electrical grids are massive, like almost unbelievably massive. Ownership is complex in that segments of it are controlled by different parties/companies with some of those segments having shared ownership. There only three grids in the USA and (I think) five total in North American with every device operating on a given grid have the capability to play by the grid’s rules and idiosyncrasies. Grid operators are constantly testing new equipment but it gets tested within sandboxes for years prior to adoption. Even if testing goes well, you still need individual buy-in from equipment operators who are allergic to risk and hate change. I am not trying to say this is the right or wrong way here, just kind of the reality of operating such a complex network.
bunabhucan 3y ago
We had a fire near Boulder CO that destroyed 1000 homes and had a few fatalities. If there are 100mph winds and dry conditions then it just takes one spark to create an unstoppable fire. The local utility closed down some (but not all) lines for a recent wind event and everyone is kvetching. Maybe this isn't obvious but domestic electric service is a marginal business. It's not profitable for every customer. That's why it's a regulated monopoly. In edge and rural areas the lines are not profitable (you can't charge more to joe farmer at the end of hundreds of poles.) New subdivisions with new poles/transformers etc. cost less Windswept lines and poles out in the middle of nowhere are the places at risk and "make no money." The utility doesn't "pay" for the shutdowns but they can get sued for a fire.

by amluto 3y ago

mschuster91 3y ago

> I would like to know why grid operators turn portions off instead of installing devices to mitigate the fire risk when a fault occurs. The stuff you're mentioning is - at least from a quick Google, I'll admit that - only certified in Australia. Even here in Germany, introducing that onto the grid would take years for certifications. Bureaucracy moves slowly. Then, you'd need to upgrade a lot of transmission lines including the regional distribution grid (i.e. < 100 kV), a single unprotected line in a danger-prone area is enough to start a deadly fire. And there are a looooot of power lines that haven't had an inspection for decades - the hook that caused the 2018 fire was almost a century old [1]. And so, instead of inspecting, maintaining and upgrading the many thousand km's of national and regional lines, shutting them down during peak fire condition times is cheaper. IMHO it only makes sense to install REFCL devices as part of a general overhaul of an entire transmission grid area. [1] https://www.wsj.com/articles/this-old-metal-hook-could-determine-whether-pg-e-committed-a-crime-11583623059 https://www.wsj.com/articles/this-old-metal-hook-could-deter...

deleted 3y ago

[deleted]

toast0 3y ago

Because they already have the ability to turn portions off. Installing a lot of new equipment means regulatory effort to get a plan approved, and a lot of installation labor. I imagine these systems will be put in place over time, but I was just looking at Wikipedia on Reclosers and they said Sensitive Ground Fault protection reduces the risk by 80%; if the risk is high enough, that probably still warrants deenergizing risky lines at times.

amluto 3y ago
These aren’t quite the same thing. Sensitive ground fault protection attempts to shut down the line more quickly in the event of a ground fault. A ground fault neutralizer attempts (and apparently largely succeeds!) at reducing the fault current to near zero during a fault even before anything is shut down. These technologies can be combined.

samtho 3y ago

Electrical grids are massive, like almost unbelievably massive. Ownership is complex in that segments of it are controlled by different parties/companies with some of those segments having shared ownership. There only three grids in the USA and (I think) five total in North American with every device operating on a given grid have the capability to play by the grid’s rules and idiosyncrasies. Grid operators are constantly testing new equipment but it gets tested within sandboxes for years prior to adoption. Even if testing goes well, you still need individual buy-in from equipment operators who are allergic to risk and hate change. I am not trying to say this is the right or wrong way here, just kind of the reality of operating such a complex network.

bunabhucan 3y ago

We had a fire near Boulder CO that destroyed 1000 homes and had a few fatalities. If there are 100mph winds and dry conditions then it just takes one spark to create an unstoppable fire. The local utility closed down some (but not all) lines for a recent wind event and everyone is kvetching. Maybe this isn't obvious but domestic electric service is a marginal business. It's not profitable for every customer. That's why it's a regulated monopoly. In edge and rural areas the lines are not profitable (you can't charge more to joe farmer at the end of hundreds of poles.) New subdivisions with new poles/transformers etc. cost less Windswept lines and poles out in the middle of nowhere are the places at risk and "make no money." The utility doesn't "pay" for the shutdowns but they can get sued for a fire.