4 ms·

I'm not an engineer but I would imagine that they're maxed out in the sense that they either rated to hold exactly what they're holding, or they designed them f

by Teever 3y ago

I'm not an engineer but I would imagine that they're maxed out in the sense that they either rated to hold exactly what they're holding, or they designed them for some sort of planned upgrading later, but they're not going to overbuild them because doing so would be a waste of resources. Why build a tower that can hold like 2 tonnes of wire when it will only ever carry 1 ton for it's entire life?

sudodudeo 3y ago
Well theoretically so that when you decide to, y'know, improve the grid in 50 years time, you can just add more wires instead of replacing everything?
- danans 3y ago
  Why would investors today put additional money into something that might be useful in 50 years? They would never see a return on the additional investment. Would you make that investment? The only entities that can make such long term investments are governments, via taxes, and not all governments at that. And such investment is usually reserved for either basic research or incentivizing production by mobilizing human capital (i.e the IRA in the US), not building excess capacity of questionable utility.
  - eru 3y ago
    To be a bit more sophisticated: Whether it's worth it depends on interest rates, not on how long your investors live. It's just that 50 years is a long time, so the savings from leaving the additional space would need to be quite big to be worth it today when discounted back. In addition, you have lots of uncertainty: overbuilding the infrastructure in this way only takes care of exactly this one contingency, but there's plenty of other reasons why you might want to replace your pylons. Eg perhaps in 50 years we will have figured out how to send power without wires, or we will move to buried lines everywhere, or we will get our power as laser beams from orbital solar satellites, or we need new pylons in new places because settlement patterns have changed, etc.
    - danans 3y ago
      > Whether it's worth it depends on interest rates, not on how long your investors live. We had near zero interest rates for years, but I didn't see any private investors making infrastructure investments that wouldn't possibly produce a return for 50 years. > In addition, you have lots of uncertainty: overbuilding the infrastructure in this way only takes care of exactly this one contingency, but there's plenty of other reasons why you might want to replace your pylons. Practically I think that's the real reason. Nobody has a crystal ball to to tell them what tech will be a good investment in 50 years. It's anyone's guess, and no interest rate will allow that kind of private investment.
      - eru 3y ago
        > We had near zero interest rates for years, but I didn't see any private investors making infrastructure investments that wouldn't possibly produce a return for 50 years. We had short term near zero interest rates (and even below zero real interest rates), but that doesn't mean that long term interest were that low. See eg https://fred.stlouisfed.org/graph/?g=1jVdN https://fred.stlouisfed.org/graph/?g=1jVdN or https://fred.stlouisfed.org/graph/?g=1jVe8 https://fred.stlouisfed.org/graph/?g=1jVe8 for the inflation adjusted one. Those are interest rates that the US government is paying on 30 year bonds. Private issuers typically pay more. (I picked 30 years, because that's the longest duration the US typically borrows at.) > It's anyone's guess, and no interest rate will allow that kind of private investment. If you can lock in a zero or negative interest rate now, it might still be a good investment.
        danans 3y ago
        > If you can lock in a zero or negative interest rate now, it might still be a good investment In the real world, what lending entity is going to offer you financing at <= 0% for 30 years? Just because 30 year Treasury yields fell below zero from 2020-2022 didn't mean I can get that kind of financing for a project.
        eru 3y ago
- pinkmuffinere 3y ago
  For a toy example this makes sense. For something produced in massive quantities and shipped around the country, all optimizations of cost and weight which still meet engineering requirements are taken. The only case that they would be strong enough and have the space is if "ability to improve grid in 50 years time by adding additional wires" was a hard requirement at the get-go.
- metaphor 3y ago
  Oh, please. Capital has a cost, and infrastructure is both a depreciating asset and operational liability. You've summarily lost your mind if you think any sane utility CFO would greenlight deploying capex to the tune of billions in gross excess of requirements for the speculative option of expansion capacity at marginal cost several decades into the future. Also, good luck convincing rate payers that increased costs realized today is to speculatively reduce the utility company's cost of doing business long after they're dead.
eru 3y ago
There's probably a margin of safety, and you could try to eat into that one. But that's only useful, if you now need less of a safety margin than you thought you needed earlier. Which is sometimes the case: when things are less well understood, properly conservative engineers add more of a safety margin. Compare how old manufactured things are often much heavier than newer designs. See also eg how over time we managed to pack broadcast channels closer together in frequency space, because we got better at dealing with interference. The 'magic ball' from the article is a good example of how more sensors (and better models) can help you be less conservative in your margin of error without sacrificing safety.
ars 3y ago
> in the sense that they either rated to hold exactly what they're holding Or maybe all of their strength is used to hold themselves up and the load they carry is an inconsequential part. From the ground they do appear that way, but I don't really know how much load the cables put on them.
rainbowzootsuit 3y ago
It's likely that every tower is not a uniquely designed one off, so whatever external forces were considered were probably for the peak loads x peak degradation in some set of towers. I'd guess there are probably some areas where the towers are overbuilt by a useful margin. How good are the records and field measurements to get that evaluated would have to be considered.
deleted 3y ago
[deleted]

by Teever 3y ago

sudodudeo 3y ago

Well theoretically so that when you decide to, y'know, improve the grid in 50 years time, you can just add more wires instead of replacing everything?

danans 3y ago
Why would investors today put additional money into something that might be useful in 50 years? They would never see a return on the additional investment. Would you make that investment? The only entities that can make such long term investments are governments, via taxes, and not all governments at that. And such investment is usually reserved for either basic research or incentivizing production by mobilizing human capital (i.e the IRA in the US), not building excess capacity of questionable utility.
- eru 3y ago
  To be a bit more sophisticated: Whether it's worth it depends on interest rates, not on how long your investors live. It's just that 50 years is a long time, so the savings from leaving the additional space would need to be quite big to be worth it today when discounted back. In addition, you have lots of uncertainty: overbuilding the infrastructure in this way only takes care of exactly this one contingency, but there's plenty of other reasons why you might want to replace your pylons. Eg perhaps in 50 years we will have figured out how to send power without wires, or we will move to buried lines everywhere, or we will get our power as laser beams from orbital solar satellites, or we need new pylons in new places because settlement patterns have changed, etc.
  - danans 3y ago
    > Whether it's worth it depends on interest rates, not on how long your investors live. We had near zero interest rates for years, but I didn't see any private investors making infrastructure investments that wouldn't possibly produce a return for 50 years. > In addition, you have lots of uncertainty: overbuilding the infrastructure in this way only takes care of exactly this one contingency, but there's plenty of other reasons why you might want to replace your pylons. Practically I think that's the real reason. Nobody has a crystal ball to to tell them what tech will be a good investment in 50 years. It's anyone's guess, and no interest rate will allow that kind of private investment.
    - eru 3y ago
      > We had near zero interest rates for years, but I didn't see any private investors making infrastructure investments that wouldn't possibly produce a return for 50 years. We had short term near zero interest rates (and even below zero real interest rates), but that doesn't mean that long term interest were that low. See eg https://fred.stlouisfed.org/graph/?g=1jVdN https://fred.stlouisfed.org/graph/?g=1jVdN or https://fred.stlouisfed.org/graph/?g=1jVe8 https://fred.stlouisfed.org/graph/?g=1jVe8 for the inflation adjusted one. Those are interest rates that the US government is paying on 30 year bonds. Private issuers typically pay more. (I picked 30 years, because that's the longest duration the US typically borrows at.) > It's anyone's guess, and no interest rate will allow that kind of private investment. If you can lock in a zero or negative interest rate now, it might still be a good investment.
      - danans 3y ago
        > If you can lock in a zero or negative interest rate now, it might still be a good investment In the real world, what lending entity is going to offer you financing at <= 0% for 30 years? Just because 30 year Treasury yields fell below zero from 2020-2022 didn't mean I can get that kind of financing for a project.
        eru 3y ago
pinkmuffinere 3y ago
For a toy example this makes sense. For something produced in massive quantities and shipped around the country, all optimizations of cost and weight which still meet engineering requirements are taken. The only case that they would be strong enough and have the space is if "ability to improve grid in 50 years time by adding additional wires" was a hard requirement at the get-go.
metaphor 3y ago
Oh, please. Capital has a cost, and infrastructure is both a depreciating asset and operational liability. You've summarily lost your mind if you think any sane utility CFO would greenlight deploying capex to the tune of billions in gross excess of requirements for the speculative option of expansion capacity at marginal cost several decades into the future. Also, good luck convincing rate payers that increased costs realized today is to speculatively reduce the utility company's cost of doing business long after they're dead.

eru 3y ago

There's probably a margin of safety, and you could try to eat into that one. But that's only useful, if you now need less of a safety margin than you thought you needed earlier. Which is sometimes the case: when things are less well understood, properly conservative engineers add more of a safety margin. Compare how old manufactured things are often much heavier than newer designs. See also eg how over time we managed to pack broadcast channels closer together in frequency space, because we got better at dealing with interference. The 'magic ball' from the article is a good example of how more sensors (and better models) can help you be less conservative in your margin of error without sacrificing safety.

ars 3y ago

> in the sense that they either rated to hold exactly what they're holding Or maybe all of their strength is used to hold themselves up and the load they carry is an inconsequential part. From the ground they do appear that way, but I don't really know how much load the cables put on them.

rainbowzootsuit 3y ago

It's likely that every tower is not a uniquely designed one off, so whatever external forces were considered were probably for the peak loads x peak degradation in some set of towers. I'd guess there are probably some areas where the towers are overbuilt by a useful margin. How good are the records and field measurements to get that evaluated would have to be considered.

deleted 3y ago

[deleted]