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The aging U.S. power grid is about to get a jolt

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121–130 of 158 posts

Re: The aging U.S. power grid is about to get a jolt

#121

Earlier quoted context omitted.

> one of its biggest hurdles is that it can't adjust up and down for demand very well This is a historic limitation. We have the technology to perform load follow with the legacy fleet. Most utilities just designed their fleets around the assumption that nuclear would be base load and therefore are less incentivized to operate their nuclear reactors this way.

No, it's an economic limitation. You can of course turn the output of a nuclear plant up and down, reasonably quickly. The problem is that nuclear power is mostly capex. If you throttle your plant to 30% output, it just means that you produce power at three times the price.

> No, it's an economic limitation.

I don't believe that I said it was not. Although, you should look at France as a special case.

> You can of course turn the output of a nuclear plant up and down, reasonably quickly.

Well, yes and no. Most contemporary reactor designs do have the physical capability to fluctuate between about 30%-100% power. But the ability to model such a core (accurately) has been a relatively recent thing, which has knock on effects for developing a core loading plan, doing a safety analysis, and performing monitoring/prediction. This was because most of these reactors were specifically built to satisfy base load requirements for their communities, there was no demand to develop the methodology initially. The whole economics reason came about much later when people started talking about actually developing said methodology. Its kind of a big deal because your AO bands are part of your licensing basis.

Re: The aging U.S. power grid is about to get a jolt

#122

> 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?

> How do you get people to only charge their cars when it's windy? Market prices and "smart" chargers

That can encourage it, but people will need to charge even when it's not windy. Having a smart charger wait for cheap electricity which may never come is a great way to end up with dead battery.

Re: The aging U.S. power grid is about to get a jolt

#123
Most power lines across the nation have If we had smarter systems to plan and route power transfers, we could get the network to move far far more power

Most of that overcapacity is in little local wiring, like the cables to your street, where there is likely nothing smart at all right now.

Re: The aging U.S. power grid is about to get a jolt

#124

Earlier quoted context omitted.

Chicago has some of the cheapest electricity in the world. Thanks comed for building all the nukes.

What? Lots of states have cheaper rates than that: https://www.electricchoice.com/electricity-prices-by-state/ And none of them are anywhere near 40-80c, so maybe that commenter is in another country.

Although your bill might only show one bundled price depending on who supplies and delivers your electricity, the cost of electricity in the US usually includes both a "supply" or "generation" charge and a "delivery" charge. Based on what I'm seeing on that page I think it's almost certainly only showing the electric supply rates, not the combined total of supply + delivery.

I don't live in California so the nuances are lost on me, but it looks like for SF county the residential delivery rate is about 19c/kWh, the supply rate ranges from roughly 12-16c/kWh, and "surcharges" are 0-1c/kWh, for a total of 31-37c/kWh. For San Diego county the delivery rate is 25-26c/kWh, the supply rate is 15-18c/kWh, and surcharges are 2-5c/kWh, with a total of 45-46c/kWh.[1]

[1] https://www.cpuc.ca.gov/RateComparison

Re: The aging U.S. power grid is about to get a jolt

#125
post #76
post #71

Earlier quoted context omitted.

These days with even off-peak being 40-80c / kWh the best way to charge EVs (which are mostly owned by homeowners) seems to be to bypass the grid and charge using rooftop solar during the middle of the day (or time shifted using battery storage). Obv. not possible for renters or condo owners or for people who can install solar.

> Obv. not possible for renters or condo owners or for people who can install solar. That can be as much as 67% or more of the households in large Metro areas. This is really why I think EV adoption is a pipe dream. It is probably a boon for the grid as well.

65-70% of all dwellings are single-family homes. So most will be eligible for EVs.

I couldn’t actually believe it but I guess the default state of the vast majority of the country is sprawl.

Re: The aging U.S. power grid is about to get a jolt

#126
post #32

Is building a long high voltage line not profitable? It seems like the potential for arbitrage should allow for sufficient profit, but maybe not? I know there's a lot of blockers, but if there's money to be made I would have thought more people would have worked around them.

It turns out homeowners with veto rights are a lot more powerful than capital in the US.

Could you buy land from existing lower voltage lines? It seems like a solvable problem.

Re: The aging U.S. power grid is about to get a jolt

#127

Earlier quoted context omitted.

> not being built though. Not at nearly the rate needed …according to “consultancy Grid Strategies and commissioned by trade group Americans for a Clean Energy Grid (ACEG).” This is like the civil-engineering society perennially failing our civil-engineering spending.

That doesn’t make them inherently incorrect, in the same way that oil companies are correct that building more pipelines is safer and more environmentally friendly than oil trains.

> doesn’t make them inherently incorrect

Did you see a claim that seems to stand on its own?

Re: The aging U.S. power grid is about to get a jolt

#128
post #98
post #80

Earlier quoted context omitted.

This just isn't true. The burden on nuclear is the extremely long construction time and massive cost overruns.

> The burden on nuclear is the extremely long construction time and massive cost overruns. Yes, and: * Risk of catastrophic failure * Long term waste which there is no technology capable of handling * Decommissioning

> Long term waste which there is no technology capable of handling

IMO too many people are dying from conventional dirty energy sources. We don't know how to handle the waste.

Re: The aging U.S. power grid is about to get a jolt

#129
post #79

Earlier quoted context omitted.

I mean this is where pumped hydro would be pretty handy actually. Pumped hydro can't charge as fast as batteries, but can have enormous energy capacity. You could almost certainly tune a pumped hydro installation to absorb the ramp of a reactor cycling up and down, but you'd lose the risk of running dry due to renewable unpredictability.

Pumped storage can absorb power faster than any built battery array. It can't switch between storing and providing as quickly.

Pumped hydro can store more energy then any battery array. You can size a battery, or pumped hydro, to any power level you like, but batteries by their nature scale differently: the faceplate capacity of a battery multiplied by 4 is also pretty much the energy storage.

Whereas pumped hydro can store far more energy (limited by upper reservoir size) then any battery array, but you pay for it in the fact that if you have a 1 MW turbine system on it, and 100 MWh of storage, you still only have 1 MW of power capacity (and about 100 hours of storage).

The problem is 100 hours of storage isn't much use if your grid needs more then that right now and it also can usually only be "charged" at about half that rate, so that 100 hours takes 200 hours to accumulate and that number is fixed - there's no surge capability - but if you're dealing with solar panels putting out on average 30% of their faceplate power, but obviously peaking at 100% frequently, you need to be able to store the peak to store it at all.

Re: The aging U.S. power grid is about to get a jolt

#130

> 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?

If you don't monitor conditions then you always have to operate as if conditions are at their very worst.

And that may only be 1% of the time.

So monitoring may increase the load you can carry the vast majority of the time.

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