Green Energy, and the German Grid, from: Kiev Is Burning

[Huba]

Oh, I meant the public transport in general. On the efficiency/ quality of DB I have no opinion. In Poland, the state monopoly in railways was broken 2 decades ago. Now there's one main operator of rail infrastructure, another of passenger stations. There are "main" operators of passenger and cargo connections, but there is also multitude of smaller local/ regional operators, some private, some owned by local governments etc.

My point was that direct subsidies to public transport operators is nothing unusual in general, and in the end it is often an investment, not a cost.

Edited July 31, 2022 by Huba

[sunday]

There is the example of the de facto monopoly of the Central Europe skies by Lufthansa

https://simpleflying.com/ryanair-lufthansa-state-aid/

https://www.reuters.com/article/us-air-berlin-lufthansa-niki-idUSKBN1CI0SF

https://qz.com/1139446/lufthansas-monopoly-on-german-skies-sent-domestic-german-flight-prices-soaring/

https://www.tripadvisor.com/ShowUserReviews-g1-d8729113-r651107483-Lufthansa-World.html

Edited July 31, 2022 by sunday

[lucklucky]

Quote

 

France has temporarily waived environmental rules to keep five nuclear power plants running as the country grapples with a deepening energy crisis.

The country’s nuclear regulator has approved a request to keep the power stations in operation even if the water they emit exceeds the authorised limit.

Under French rules, energy giant EDF must reduce or even halt nuclear output when river temperatures reach certain levels to ensure the water used to cool the plants won’t harm the environment when put back into the waterways.

The move will grant some relief to the European power market as the continent braces for another wave of high temperatures.

 

https://www.telegraph.co.uk/business/2022/08/08/ftse-100-markets-live-news-inflation-interest-cost-living/

[rmgill]

And our Democrats in the US are going full steam ahead on green energy policy. With a glaring example right over in Europe for why that might be a mistake. 

[jmsaari]

The news clips i saw from couple of outlets mentioned only tax breaks for wind and solar. Wondering are those the only clean power generation methods getting something, specifically there was positive talk about nuclear power from the biden administraion earlier, wondering if that was now skipped in the bill or just not mentioned in the news... and if only wind/solar, is there anything for storage, P2x etc?

[rmgill]

And that's likely solar/wind that you PAY some company to do the install on which means it's a $$$ shift to the contractors. I'm sure they're donating to the correct party. 

Storage? Are you kidding? We don't build storage for power for multi-million dollar data centers for more than 30 minutes. Stored power is in the form of diesel to run generators. 2 days worth of storage to handle wind and sun being low/dim is absolutely bonkers for cost. 

[rmgill]

Battery to AC power costs..

$150 for a 500 VA UPS unit. If you get 2 hours of run time on that for 1 amp of draw I'd be surprised. I figure maybe an hour and 15 minutes. 8 hours to recharge. And that's a modified sine wave, not a true sine wave. 

A more expensive 2200  VA UPS will give you 30 minutes of run time for a 600 watt load. Say like a refrigerator of modest size. 

[DB]

15 hours ago, jmsaari said:

The news clips i saw from couple of outlets mentioned only tax breaks for wind and solar. Wondering are those the only clean power generation methods getting something, specifically there was positive talk about nuclear power from the biden administraion earlier, wondering if that was now skipped in the bill or just not mentioned in the news... and if only wind/solar, is there anything for storage, P2x etc?

The paper that was posted (by JWB?) a few days ago covers the state of play for subsidies (with certain selection criteria that it acknowledges are subject to some debate). Nuclear gets a significant subsidy but it's significantly smaller than solar and wind when costed per kWh generated. Nuclear of course gets military funding.

Thing is, though, the data stops in 2018 and both solar and wind have increased their share of production since then and the numbers may be shifting, although I doubt that it's changed the numbers by the order of magnitude needed to make them comparable using that paper's metric.

[Detonable]

If you have a large enough grid, for example 3 time zones as in the US, does that smooth out the duck curve. 

[sunday]

6 minutes ago, Detonable said:

If you have a large enough grid, for example 3 time zones as in the US, does that smooth out the duck curve. 

Only if they are connected in a common system. CONUS has three "islands" of power grids.

https://www.electricrate.com/data-center/us-power-grid/

[rmgill]

21 minutes ago, Detonable said:

If you have a large enough grid, for example 3 time zones as in the US, does that smooth out the duck curve. 

The demand rises as the sun sets in California. How does the green energy take up the slack as 6PM PST rolls around?  

[Colin]

Canada also connects to US Grids and sells electricity there and we used to buy some back when the costs were low. Not sure if we still do. BC Hydro in Canada got burned by ENRON as well.

Edited August 9, 2022 by Colin

[MiloMorai]

7 minutes ago, Colin said:

Canada also connects to US Grids and sells electricity there and we used to buy some back when the costs were low. Not sure if we still do. BC Hydro in Canada got burned by ENRON as well.

Export sales accounted for nearly 30 per cent of Hydro-Québec's net profits of $3.2 billion last year. (2019)

Hydro-Québec poised to profit from U.S. thirst for green energy | Montreal Gazette

[Ivanhoe]

A lot of Canadian hydro is synergistically located near large blue USian cities full of nimbys. A marriage made in legislatures.

20 hours ago, sunday said:

Only if they are connected in a common system. CONUS has three "islands" of power grids.

https://www.electricrate.com/data-center/us-power-grid/

That article is not entirely accurate. Everyone thinks Texas is not connected to the other grids, but there are multiple DC-DC interconnects. Not as efficient as AC-AC, but DC-DC interconnects isolate Texas from sweeping blackouts due to voltage/frequency/phase booboos.

 

[DB]

See the fourth answer here for why DC interconnects (and long range transmission in general) is better conducted (ahem) using DC.

https://engineering.stackexchange.com/questions/19758/transmitting-power-over-long-distances-what-is-better-ac-or-dc

[sunday]

40 minutes ago, DB said:

See the fourth answer here for why DC interconnects (and long range transmission in general) is better conducted (ahem) using DC.

https://engineering.stackexchange.com/questions/19758/transmitting-power-over-long-distances-what-is-better-ac-or-dc

I do not how did you order the answers, but the one I like more begins thus:

Quote

It is more efficient to transmit DC using about the same infrastructure. This is because of several effects:

Skin effect experienced with AC. There is no skin effect with DC.

Higher voltage allowed with DC for the same transmission lines. The lines have to withstand the peak voltage. With AC, that is 1.4 times higher than the RMS. With DC, the RMS and peak voltages are the same. However, the power transmitted is the current times the RMS, not peak, voltage.

No radiation loss with DC. Long transmission lines act as antennas and do radiate some power. That can only happen with AC.

No induction losses. The changing magnetic field around a wire carrying AC current causes induced voltage and current in nearby conductors. In effect, the transmission line is the primary of a transformer, and conductors near it are secondaries. With DC current, the magnetic field doesn't change and therefore doesn't transfer power.

(...)

Note that no answer mentions reduction of Corona discharge among the advantages of a HVDC transport over a HVAC transport with the same RMS voltage.

[sunday]

57 minutes ago, Ivanhoe said:

A lot of Canadian hydro is synergistically located near large blue USian cities full of nimbys. A marriage made in legislatures.

That article is not entirely accurate. Everyone thinks Texas is not connected to the other grids, but there are multiple DC-DC interconnects. Not as efficient as AC-AC, but DC-DC interconnects isolate Texas from sweeping blackouts due to voltage/frequency/phase booboos.

 

The article does mention the interconnections among the US islands, but it also mentions that their transport capacity is not very large.

[DB]

2 minutes ago, sunday said:

I do not how did you order the answers, but the one I like more begins thus:

Note that no answer mentions reduction of Corona discharge among the advantages of a HVDC transport over a HVAC transport with the same RMS voltage.

That was the answer I meant, I mistook "4 answers" for "Answer number 4".

I did see Corona discharge mentioned in other answers. The key, I think, is that there is no longer a massive efficiency loss when performing DC voltage conversion - previously AC transformers were just more efficient. Traditionally that overcame the benefits of DC for the actual transmission.

[sunday]

3 minutes ago, DB said:

That was the answer I meant, I mistook "4 answers" for "Answer number 4".

I did see Corona discharge mentioned in other answers. The key, I think, is that there is no longer a massive efficiency loss when performing DC voltage conversion - previously AC transformers were just more efficient. Traditionally that overcame the benefits of DC for the actual transmission.

Or the losses of the DC conversion are enough to compensate for other things, like the maximum length of a AC transport, need of compensation of reactive energy, and advantages in the regulation of the system. High voltage inverter technology has advanced a lot (I think they are using GTOs [Gate Turn-Off, nothing to do with those Ferraris] in newer projects instead of the old thyristors) but still it is not at the level of medium voltage ones, like railways' use of IGBTs.

[rmgill]

2 hours ago, Ivanhoe said:

A lot of Canadian hydro is synergistically located near large blue USian cities full of nimbys. A marriage made in legislatures.

It's almost like they locate cities near places where there's elevation changes in water course that lend themselves to logistics location of cities AND enables hydro power to be easily obtained. 

[jmsaari]

On 8/8/2022 at 9:23 PM, rmgill said:

And that's likely solar/wind that you PAY some company to do the install on which means it's a $$$ shift to the contractors. I'm sure they're donating to the correct party. 

Storage? Are you kidding? We don't build storage for power for multi-million dollar data centers for more than 30 minutes. Stored power is in the form of diesel to run generators. 2 days worth of storage to handle wind and sun being low/dim is absolutely bonkers for cost. 

Back-up power for electricity users that expect to have grid supply 99.99% of the time but need backup for that 0.01% is completely different set of requirements than storage for variable renewable energy. Re:VRE storage, you also have different sets of problems, from keeping frequency stable which needs rapid response but not much in the amount of energy, vs some of the daily hour-level mismatch of generation/load, and finally the longer-term mismatches, where some form of power-to-x  is looking the way to go eventually.

The main issue though is that if the idea is to reduce CO2 emissions and VRE is to be the key part of the solution, the storage part will need to be solved, and at this point, that still means R&D needs more than investment subsidies to off-the-shelf. Or if the requirement of VRE as the key solution is dropped and instead just focus were just cost-effective reduction of CO2 emissions in energy sector, then nuclear, CCS (incl.BECCS) should be on the list.

(And as a side note, i can't squint my eyes to make the duck curve look much like a duck, pregnant pterosaur somehow comes first to me...)

[rmgill]

Storage is going to increase power costs. I'm not sure if it's quadratic or logarithmic, but it's not linear. 

[DB]

So far large scale storage, such as the South Australia system installed by Tesla, has actually been used to prevent high peaks in price through peak shaving.

I'm not saying that the current solutions solve the overall problem discussed here, only that certain applications definitely save money.

I do expect to see a significant increase in available battery storage coming online, not least through intelligent charge management of connected EVs and increases in home storage systems as competitors to the Powerwall are beginning to bring prices down. For the grid to make use of those requires the control of in-home equipment that poses significant challenges as users will be suspicious that their equipment may be misused by the utility, so that's going to be interesting.

I do see a lot of dubious-seeming energy storage systems being developed. How much snake oil is present in this area remains to be seen, though.

[rmgill]

You can sell a LOT of snake oil if the tax payers are footing the bill in the form of subsidies. 

[Colin]

On 8/10/2022 at 9:34 AM, DB said:

So far large scale storage, such as the South Australia system installed by Tesla, has actually been used to prevent high peaks in price through peak shaving.

I'm not saying that the current solutions solve the overall problem discussed here, only that certain applications definitely save money.

I do expect to see a significant increase in available battery storage coming online, not least through intelligent charge management of connected EVs and increases in home storage systems as competitors to the Powerwall are beginning to bring prices down. For the grid to make use of those requires the control of in-home equipment that poses significant challenges as users will be suspicious that their equipment may be misused by the utility, so that's going to be interesting.

I do see a lot of dubious-seeming energy storage systems being developed. How much snake oil is present in this area remains to be seen, though.

I was wondering how safe those grids will be when you have all those homes feeding into the grid and then an emergency happens and there is no way to ensure everyone is taken offline so the crews can re-string the lines? Also heard that in a YT video that one area has so many people feeding into the grip, that the utilities banned further inputs as the voltage of the grid became to high and also reduced the money they pay for the power provided.