The Remarkable Progress of Renewable Energy

[TV and credit cards]

Continuous Swing Adsorption Reactor (CSAR)

New technology makes carbon capture easier - SINTEF

A recent innovation has the potential to accelerate the introduction of essential carbon capture processes in a range of industries. The technology has recently been demonstrated at a waste combustion plant in Bergen, with excellent results.

www.sintef.no

 

[ZiprHead]

By installing several gigawatt-hours of battery capacity.

...which requires several giga-tonnes of carbon dioxide emissions to manufacture, and which extends solar electricity availability "into the evening", which is not quite "until the next morning".

Not an attack, just a question.

How many giga-tons of carbon dioxide emissions to build a nuclear power plant?

 

[bilby]

By installing several gigawatt-hours of battery capacity.

...which requires several giga-tonnes of carbon dioxide emissions to manufacture, and which extends solar electricity availability "into the evening", which is not quite "until the next morning".

Not an attack, just a question.

How many giga-tons of carbon dioxide emissions to build a nuclear power plant?

According to this paper:

The results show that the total emissions resulting from vegetation loss, equipment manufacturing and labor input during construction and operation are 1232.91 Gg CO2 with a carbon intensity of 1.31 g CO2/kWh
...
The average carbon emissions at the front end, construction and operation and the back end were 11.45, 7.82 and 3.07 g CO2/kWh, respectively.

1232.91 Giga-grams (Gg) is 0.00123291 Giga-Tonnes; If that's equivalent to 1.31g.CO₂/kWh, and construction of the plant contributes 11.45g.CO₂/kWh, then that gives a construction emissions total of about 0.0107 Giga-Tonnes.

The important measure for comparing power systems is the g.CO₂/kWh. How much carbon dioxide is produced per unit of energy supplied to end users? For the Nuclear plant in the study quoted above, that figure is 11.45+7.82+3.07=22.34g.CO₂/kWh.

This figure must, to be useful, include all emmissions, from the whole system; If you are looking at Solar power, for example, you need to include emissions from panel manufacturing and eventual disposal; From transporting the panels from factory to installation site; From manufacturing of any inverters and transformers required; And from whatever system you use to obtain power when it is needed but the sun isn't shining - in this case, the batteries.

It's that last one that often gets ignored (and it applies to any generation technology - even nuclear plants don't have a 100% availability, so we must include emissions from whatever we use to generate electricity when the plant is not running; But it's generally only significant for intermittent generation, ie Wind and Solar); In my home state, the last one is coal fired power plants, which make the system emissions FAR higher than the solar advicates want to admit. Batteries might be less awful, but that's very difficult to determine, not least because batteries practically don't exist at the scale of national power grids - they are an utterly minuscule contributor to generation balancing, almost all of which is still done by pumped-storage Hydro.

A hundred nuclear plants produce about a Giga-Tonne of carbon dioxide in their construction; But it makes in the order of a million kWh (1GWh) for every hour of operation, and can operate for sixty years at 90-95% availability. A million kWh of battery storage is an astonishingly large amount of batteries; And they will need replacing several times in sixty years.

Lithium ion batteries generate about 2 tonnes of CO₂ per kWh in their manufacture; A gigatonne of carbon dioxide would "buy" you about 500GWh of storage (you still need generation!), and maybe last ten years; 100 nuclear plants get you about 500GWh of electricity every five hours for sixty years, from the same tonnage of emissions.

At the end of the day (or more importantly, the year), all that matters is the total systemwide g.CO₂/kWh. We need to cut that, sharply and rapidly.

Here's Europe in 2023:



We need to all do what the countries mostly showing in green (like Sweden, Norway and France) are doing, and to avoid doing what the countries mostly showing in brown (like Poland, Germany, and Italy) are doing.

Based on the goal of reducing carbon emissions overall and system wide, two conclusions are obvious:

What we need to do more of is Hydro, Geothermal, and Nuclear.

What we need to do less of is Coal, Gas, and Intermittent Renewables.

But that's only if we care more about actual outcomes, and not so much about feeling as though we are "in touch with nature".

 

[ZiprHead]

Thanks, Bilby.

 

[Loren Pechtel]

A hundred nuclear plants produce about a Giga-Tonne of carbon dioxide in their construction; But it makes in the order of a million kWh (1GWh) for every hour of operation, and can operate for sixty years at 90-95% availability. A million kWh of battery storage is an astonishingly large amount of batteries; And they will need replacing several times in sixty years.

That high????

What we need to do more of is Hydro, Geothermal, and Nuclear.

Hydro has the effect of messing up the river ecology. It's nowhere near as benign as people think.

 

[bilby]

A hundred nuclear plants produce about a Giga-Tonne of carbon dioxide in their construction; But it makes in the order of a million kWh (1GWh) for every hour of operation, and can operate for sixty years at 90-95% availability. A million kWh of battery storage is an astonishingly large amount of batteries; And they will need replacing several times in sixty years.

That high????

For a hundred plants? Sure. There's a lot of concrete in 100 nuclear power plants.

What we need to do more of is Hydro, Geothermal, and Nuclear.

Hydro has the effect of messing up the river ecology. It's nowhere near as benign as people think.

Indeed; And the number of suitable sites not already in use is small. But I am only talking about catbon dioxide emissions, and am ignoring other environmental issues.

Nuclear is excellent on those, because of its relatively tiny land-use footprint.

 

[Loren Pechtel]

A hundred nuclear plants produce about a Giga-Tonne of carbon dioxide in their construction; But it makes in the order of a million kWh (1GWh) for every hour of operation, and can operate for sixty years at 90-95% availability. A million kWh of battery storage is an astonishingly large amount of batteries; And they will need replacing several times in sixty years.

That high????

For a hundred plants? Sure. There's a lot of concrete in 100 nuclear power plants.

What I was questioning was the up time. Unless they build a reactor that can do fuel changes while in operation I can't see that kind of uptime. AFIAK nobody has built such a reactor. I see how one could be made, though: Adjoining the reactor you build an airlock big enough that fuel rods can be pulled from the reactor to the airlock. Flood the airlock, the rods to be changed out are pulled into the airlock, the hatches closed and the coolant pumped out. Extract the rods, replace them with fresh rods. Flood, insert the new rods and pull out others. The system can be slow, it only needs to be able to cycle fast enough to change out all the rods in whatever interval the reactor requires. Everything has to be robotic anyway, the difference in this case is that the robotics need to be able to operate while bathed in whatever the reactor uses in it's primary loop.

 

[bilby]

A hundred nuclear plants produce about a Giga-Tonne of carbon dioxide in their construction; But it makes in the order of a million kWh (1GWh) for every hour of operation, and can operate for sixty years at 90-95% availability. A million kWh of battery storage is an astonishingly large amount of batteries; And they will need replacing several times in sixty years.

That high????

For a hundred plants? Sure. There's a lot of concrete in 100 nuclear power plants.

What I was questioning was the up time. Unless they build a reactor that can do fuel changes while in operation I can't see that kind of uptime. AFIAK nobody has built such a reactor. I see how one could be made, though: Adjoining the reactor you build an airlock big enough that fuel rods can be pulled from the reactor to the airlock. Flood the airlock, the rods to be changed out are pulled into the airlock, the hatches closed and the coolant pumped out. Extract the rods, replace them with fresh rods. Flood, insert the new rods and pull out others. The system can be slow, it only needs to be able to cycle fast enough to change out all the rods in whatever interval the reactor requires. Everything has to be robotic anyway, the difference in this case is that the robotics need to be able to operate while bathed in whatever the reactor uses in it's primary loop.

The average capacity factor for existing nuclear power plants in the US is around 92%. (2021 data from: https://www.energy.gov/ne/articles/what-generation-capacity). Over the longer run from 2006-2012, US nuclear plants averaged 88.7% capacity factor. There have been continuous improvements in fuelling times and reductions in maintenance shutdowns between 2012 and the present; Plant owners have a significant financial incentive to reduce the shutdown times as far as possible.

Many plants routinely exceed 100% of their rated summer capacity, due to the larger temperature gradient available in cold weather leading to electricity output above the nameplate power rating of the facility.

The Kaiga Nuclear Plant in India holds the world record of 962 days of continuous operation between shutdowns.

When your reactor only needs fuelling every two years, you can get a 99% capacity factor even if fuelling requires a whole week - and with sensible planning, a week is a very long time, for pulling a few fuel bundles out and putting new ones in their place.

Capacity factors of 90-95% are now routine in the nuclear industry.

 

[Tharmas]

The right-wing governor of the state of Texas, Greg Abbott, announced yesterday that he intends to introduce a bill to the legislature creating a state atomic commission, with the goal of making Texas the leader in U.S. atomic power.

 

[bilby]

The right-wing governor of the state of Texas, Greg Abbott, announced yesterday that he intends to introduce a bill to the legislature creating a state atomic commission, with the goal of making Texas the leader in U.S. atomic power.

Yeah, the thing the nuclear power industry is crying out for is more government regulation and interference.

Or is this a precursor to Texan seccession from the Union, taking their nuclear industry out of the jurisdiction of the NRC? I gan see lots of positives there, not least that Texas provides the GOP with a big chunk of their power in both Federal executive and legislature. But I doubt that any Republicans would agree that these would be positives.

 

[Jimmy Higgins]

The right-wing governor of the state of Texas, Greg Abbott, announced yesterday that he intends to introduce a bill to the legislature creating a state atomic commission, with the goal of making Texas the leader in U.S. atomic power.

Odd... I thought becoming a leader in atomic power would imply building out nuclear power plants and getting lots of your energy, to most of your energy from nuclear power.

I suppose this is better than him announcing fourteen new coal power plants. Until we find out the head of the Commission runs Massey Coal.

Of course, the other issue is what good is being a leader of atomic power, if you are cut off from the remainder of the US power grid?

 

[Loren Pechtel]

The right-wing governor of the state of Texas, Greg Abbott, announced yesterday that he intends to introduce a bill to the legislature creating a state atomic commission, with the goal of making Texas the leader in U.S. atomic power.

The reactors need to be in blue states.

 

[Swammerdami]

On today's news feed I see a report from Bloomberg that renewable energy has gotten so cheap in Germany that the price has gone *negative*! (I suppose it only goes negative during daylight, and perhaps when wind is predicted. And so far the negative price is just once, I guess, and for just 4 hours.)

I don't understand this. If I was selling electricity and the customer insisted on a price BELOW zero, I'd just say "F**k You" and turn off a circuit breaker or such. Perhaps Bloomberg explains this, but they ask for credit card info after a paragraph or two. Are the electricity suppliers bound by some contract, to sell at a "market" price?

- - - - - - - - - - - -

I do remember the price of West Texas Sweet Crude futures going negative 4+ years ago, but at least that made sense: "Uh, here we are in Cushing, Oklahoma with your 1000 barrels of crude. Where the F**k are you?" // "Uh, I changed my mind; just dump it in a garbage can or something." // "You're gonna need a whole lot of garbage cans AND a place to put them. Dumping it out in the prairie and hoping nobody notices is against federal law."

 

[bilby]

On today's news feed I see a report from Bloomberg that renewable energy has gotten so cheap in Germany that the price has gone *negative*! (I suppose it only goes negative during daylight, and perhaps when wind is predicted. And so far the negative price is just once, I guess, and for just 4 hours.)

I don't understand this. If I was selling electricity and the customer insisted on a price BELOW zero, I'd just say "F**k You" and turn off a circuit breaker or such. Perhaps Bloomberg explains this, but they ask for credit card info after a paragraph or two. Are the electricity suppliers bound by some contract, to sell at a "market" price?

- - - - - - - - - - - -

I do remember the price of West Texas Sweet Crude futures going negative 4+ years ago, but at least that made sense: "Uh, here we are in Cushing, Oklahoma with your 1000 barrels of crude. Where the F**k are you?" // "Uh, I changed my mind; just dump it in a garbage can or something." // "You're gonna need a whole lot of garbage cans AND a place to put them. Dumping it out in the prairie and hoping nobody notices is against federal law."

Negative wholesale electricity prices are not particularly new, and are due to the difficulty in shutting down some types of generation.

Loss of load can destroy a power plant; Simply "turning off a circuit breaker" is not an option.

And in Germany, many wind and solar suppliers are guaranteed minimum prices to the grid, regardless of how low the general wholesale market falls.

Negative prices are a sign of a very badly managed system, or as the Germans call it, "Energiewende", in which politicians overrule engineers and grid operators.

 

[Swammerdami]

Can't one avoid shutting down or shedding all load by simply routing the current through an appropriate large resistor? (Or would such a resistor (heat sink) need to be very large and well-designed for safety?)

 

[bilby]

Can't one avoid shutting down or shedding all load by simply routing the current through an appropriate large resistor? (Or would such a resistor (heat sink) need to be very large and well-designed for safety?)

A tiny fraction of the output of a large powerplant is capable of operating an arc furnace that can melt large quantities of any metal you care to name.

From what would this hypothetical "large resistor" be made? No material can soak up a GW of power for very long without melting (and then vaporising if you persist in adding energy to it).

You can shed a few kW in the manner you describe; But not a few million kW.

 

[Swammerdami]

Ooops! But my unthinking suggestion wasn't COMPLETELY absurd:

(Or would such a resistor (heat sink) need to be very large and well-designed for safety?)

should have been

(Or would such a resistor (heat sink) need to be very large and very expensive as well as very well-designed for safety?)

OTOH, this seems to be an argument in favor of wind and solar. They have little or no problem when load is reduced, right?
And anyway why don't the best-when-cheapest applications (pumping, excavation(?), hydrogen production, EV charging, bitcoin mining ha ha ha) show up when the wholesale electricity price is near zero?

And of course this discussion just reinforces the importance of batteries and other energy storage methods.

 

[bilby]

OTOH, this seems to be an argument in favor of wind and solar. They have little or no problem when load is reduced, right?

They are the sole reason why there's a problem in the first place.

That they are less affected by the problems they themselves cause is not a point in their favour; They are bad neighbours on the grid, which would be less problematic if they were not also incapable of 24x7 operation.

If you complained that your neigbour's loud music was stopping anyone from sleeping, would you accept his claim that it's not a problem, because he doesn't play that music when he wants to sleep himself?

The easiest solution would be to make intermittent renewables eat the exact same wholesale prices everyone else gets offered. A new wind turbine or solar array isn't profitable if prices are negative whenever it is able to generate. But they get price guarantees - specifically in order to avoid their becoming unprofitable. Again, it's politicians overruling engineers, and picking winners based on feels and popularity, rather than capability to meet demand.

Negative prices are a strong indicator of too much wind and solar. Unchecked, they would drive other generators out of business, and then on calm nights, there will be no power for anyone.

 

[Swammerdami]

My question was technical. The briefest skim of the thread would suffice for anyone to know your views on intermittent renewables.

BTW, what about geothermal? Not intermittent, right?

 

[bilby]

My question was technical.

The premise of the question is false, rendering any answer to it valueless.

this seems to be an argument in favor of wind and solar.

Regardless of how it seems, it is very definitely NOT "an argument in favor of wind and solar".

For the technical reasons I have given, the whole system issues that lead to negative prices cannot be resolved by local measures to curtail wind or solar, no matter how easy such measures might be.

The grid is a hugely complex machine. Every part influences all the others. Trying to understand it piecemeal is futile; Trying to manage it piecemeal is disastrous. Engineers know this; Politicians don't want to know it, because voters don't care to know it.

Until the power goes out.