Green, ethical, energy issues in the news

JKenH

Martyn1981 wrote: »

Duke Energy Spreads FUD About Renewables In North Carolina

There may actually be some science behind Duke Energy’s argument.
Link to full paper below the extract.

Review of the operational flexibility and emissions of gas- and coal-
fired power plants in a future with growing renewables.

Specific emission factors for the different technologies at full load are compared to those at minimum complaint load in Fig. 12. In gas-fired power plants, emissions at minimum complaint load are on average 1.5–15 times higher than those at full load. While the increase in emissions at MCL vs full load are on average 50–100% for NOx and CO2, they are 15 times higher for CO. At MCL, gas turbines produce lower or equal absolute NOx and CO2 emissions (e.g. ppm or kg/s) than at full load due to lower combustion temperatures and volumes of fuel burned. However, simultaneously they also produce lower power at a lower efficiency. Since the reduction in power and efficiency is stronger than the reduction in absolute emissions, the NOx and CO2 specific emission factors at MCL are higher than at full load. On the other hand, the significant increase in CO emissions is attributed to the incomplete combustion of the natural gas (e.g. inadequate burning, mixing or quenching of the air before complete combustion) occurring at part load in gas turbines [79]. For coal-fired power plants, NOx, SOx and CO specific emission factors reduce at MCL compared to the full load and according to literature are to a large extent proportional to the load [80], [82]. In contrary, CO2 emissions in coal plants are higher at MCL than at full load in similarly how it occurs in gas plants. On average, it was found that at MCL gas turbines produced more NOx and CO emissions than coal plants, but less CO2 and SOx emissions.

(Download high-res image (223KB)Download full-size image - sorry this hasn’t copied across)
Fig. 12. Comparison of specific emission factors for the different technologies at full load and MCL. Light thicker bars represent emission factors at full load, dark narrower bars represent emission factors at MCL. (For interpretation of the references to color in this figure, the reader is referred to the web version of this article).
The specific emission factor at hot and cold starts for the different technologies is shown in Fig. 13. On average, emissions in cold starts for all technologies are found to be 2 to 16 times higher than in hot starts. Increase in emissions between cold and hot starts is particularly large for NOx and CO emissions in gas plants (viz. 16- and 6-fold, respectively) as well as for SOx emissions in coal plants (viz. 8-fold). The increase in NOx, SOx and CO emissions during cold starts vs hot starts is attributed to the longer time during startup that emission control technologies need to properly operate, particularly below the minimum complaint load [89].

https://reader.elsevier.com/reader/sd/pii/S1364032117309206?token=2AE954BBB012469249422FA28AF48B989080BF1F02AB753A3119057547D86329979EDE93E09C5E2263DD51338A9694E3

Here is a post from Duke Enegy on the discussion in the media on this subject

https://news.duke-energy.com/our-perspective/solar-power-causes-air-pollution-wait-a-minute

JKenH

Martyn1981 wrote: »

Talking of national policies and pushing back against FF interests, this article goes well beyond its title:

UK should cut vehicle use to hit zero-carbon target, say MPs

I did note in reading the full Guardian article there was a call for a move away from personal vehicles which was exactly what GA was suggesting with his robotised vehicle fleet. I feel that may be difficult to achieve given how attached we are to our own personal transport but perhaps we should look at how we reduce the number of journeys we make or more importantly our total mileage.

While I suspect some of you get fed up with me harping back to the good old days it was a fact that the business trips we made were much shorter. People worked out of local offices and engaged more with other local businesses. In the 70s my business trips rarely took me more than 30 miles from base and I lived about 15 miles from the office. By the 90s companies were centralising and covering larger distances from regional offices. People were living further away from the office (50 miles in my case) and travelling further to meet clients or make deliveries. Materials were no longer sourced locally. In the last 20 years we have seen a move to working from home but for me that actually meant travelling over a much wider area for work (from the south coast to Edinburgh) and still in the same line of work. The same changes have affected all aspects of business and our social lives. We just all travel a lot more than 50 years ago to achieve the same objectives.

It is impossible to turn the clock back but if we/businesses all still had similar working patterns and social lives as we did 50 years ago our emissions would be a fraction of what they are now and the transition to EVs much easier as journeys would be much shorter. Centralisation and globalisation have been major factors in the growth of emissions and yet that is something that is rarely addressed.

Martyn1981

JKenH wrote: »

There may actually be some science behind Duke Energy’s argument.

I didn't realise the science was being questioned?

A similar argument was that RE generation was being built with energy from FF generation, making it dirty! :rotfl:

The issue is Duke Energy trying to avoid a switch to RE on the grounds that the FF generation will need to be reduced and any necessary compensation (grid balancing, storage, etc) rolled out to support the change. If 'the kit' isn't suitable for the RE future, then you need to change the kit, not argue to keep it ....... as that's green?

The last thing we should be doing is trying to defend these industries if they are trying their hardest to resist the necessary shift to a low carbon future. I for one won't apologise for them.

And as the article went on:

Cook’s organization labels Duke Energy “Public Enemy #1” because of its persistent embrace of century old technology as it seeks to protect against stranded assets. He says “Duke is bent on keeping its grip on dangerous and dirty sources of fuel while fighting state initiatives to promote solar and wind, because big, centralized, polluting power plants are central to the company’s business model.

“This ludicrous attempt to blame air pollution on solar energy is another example of Duke’s history of doing nearly anything to keep its captive customers reliant on fossil fuels, ensuring excessive profits and pollution, while forward-thinking utilities are moving toward cleaner, safer and cheaper renewable sources.”

He notes that Duke’s claim doesn’t mention that emissions reductions from solar and wind would be much greater if the natural gas plants were shut down for good, eliminating the need for increased cycling.

zeupater

JKenH wrote: »

There may actually be some science behind Duke Energy’s argument.
Link to full paper below the extract.

Review of the operational flexibility and emissions of gas- and coal-
fired power plants in a future with growing renewables.

Specific emission factors for the different technologies at full load are compared to those at minimum complaint load in Fig. 12. In gas-fired power plants, emissions at minimum complaint load are on average 1.5–15 times higher than those at full load. While the increase in emissions at MCL vs full load are on average 50–100% for NOx and CO2, they are 15 times higher for CO. At MCL, gas turbines produce lower or equal absolute NOx and CO2 emissions (e.g. ppm or kg/s) than at full load due to lower combustion temperatures and volumes of fuel burned. However, simultaneously they also produce lower power at a lower efficiency. Since the reduction in power and efficiency is stronger than the reduction in absolute emissions, the NOx and CO2 specific emission factors at MCL are higher than at full load. On the other hand, the significant increase in CO emissions is attributed to the incomplete combustion of the natural gas (e.g. inadequate burning, mixing or quenching of the air before complete combustion) occurring at part load in gas turbines [79]. For coal-fired power plants, NOx, SOx and CO specific emission factors reduce at MCL compared to the full load and according to literature are to a large extent proportional to the load [80], [82]. In contrary, CO2 emissions in coal plants are higher at MCL than at full load in similarly how it occurs in gas plants. On average, it was found that at MCL gas turbines produced more NOx and CO emissions than coal plants, but less CO2 and SOx emissions.

(Download high-res image (223KB)Download full-size image - sorry this hasn’t copied across)
Fig. 12. Comparison of specific emission factors for the different technologies at full load and MCL. Light thicker bars represent emission factors at full load, dark narrower bars represent emission factors at MCL. (For interpretation of the references to color in this figure, the reader is referred to the web version of this article).
The specific emission factor at hot and cold starts for the different technologies is shown in Fig. 13. On average, emissions in cold starts for all technologies are found to be 2 to 16 times higher than in hot starts. Increase in emissions between cold and hot starts is particularly large for NOx and CO emissions in gas plants (viz. 16- and 6-fold, respectively) as well as for SOx emissions in coal plants (viz. 8-fold). The increase in NOx, SOx and CO emissions during cold starts vs hot starts is attributed to the longer time during startup that emission control technologies need to properly operate, particularly below the minimum complaint load [89].

https://reader.elsevier.com/reader/sd/pii/S1364032117309206?token=2AE954BBB012469249422FA28AF48B989080BF1F02AB753A3119057547D86329979EDE93E09C5E2263DD51338A9694E3

Here is a post from Duke Enegy on the discussion in the media on this subject

https://news.duke-energy.com/our-perspective/solar-power-causes-air-pollution-wait-a-minute

Hi

Read the report, looked at the detail and there's some pretty interesting disconnects between the data presented & both the narrative & summary that should make anyone used to taking an analytical approach sit back and ponder for a while .... :think: ....

Interesting, I wonder why that's the case!? .... anyway, lots to see in the full report, and even a couple of pretty obvious ones which should raise eyebrows in the excerpt referenced above ...

HTH
Z

GreatApe

JKenH wrote: »

There may actually be some science behind Duke Energy’s argument.
Link to full paper below the extract.

Review of the operational flexibility and emissions of gas- and coal-
fired power plants in a future with growing renewables.

Specific emission factors for the different technologies at full load are compared to those at minimum complaint load in Fig. 12. In gas-fired power plants, emissions at minimum complaint load are on average 1.5–15 times higher than those at full load. While the increase in emissions at MCL vs full load are on average 50–100% for NOx and CO2, they are 15 times higher for CO. At MCL, gas turbines produce lower or equal absolute NOx and CO2 emissions (e.g. ppm or kg/s) than at full load due to lower combustion temperatures and volumes of fuel burned. However, simultaneously they also produce lower power at a lower efficiency. Since the reduction in power and efficiency is stronger than the reduction in absolute emissions, the NOx and CO2 specific emission factors at MCL are higher than at full load. On the other hand, the significant increase in CO emissions is attributed to the incomplete combustion of the natural gas (e.g. inadequate burning, mixing or quenching of the air before complete combustion) occurring at part load in gas turbines [79]. For coal-fired power plants, NOx, SOx and CO specific emission factors reduce at MCL compared to the full load and according to literature are to a large extent proportional to the load [80], [82]. In contrary, CO2 emissions in coal plants are higher at MCL than at full load in similarly how it occurs in gas plants. On average, it was found that at MCL gas turbines produced more NOx and CO emissions than coal plants, but less CO2 and SOx emissions.

(Download high-res image (223KB)Download full-size image - sorry this hasn’t copied across)
Fig. 12. Comparison of specific emission factors for the different technologies at full load and MCL. Light thicker bars represent emission factors at full load, dark narrower bars represent emission factors at MCL. (For interpretation of the references to color in this figure, the reader is referred to the web version of this article).
The specific emission factor at hot and cold starts for the different technologies is shown in Fig. 13. On average, emissions in cold starts for all technologies are found to be 2 to 16 times higher than in hot starts. Increase in emissions between cold and hot starts is particularly large for NOx and CO emissions in gas plants (viz. 16- and 6-fold, respectively) as well as for SOx emissions in coal plants (viz. 8-fold). The increase in NOx, SOx and CO emissions during cold starts vs hot starts is attributed to the longer time during startup that emission control technologies need to properly operate, particularly below the minimum complaint load [89].

https://reader.elsevier.com/reader/sd/pii/S1364032117309206?token=2AE954BBB012469249422FA28AF48B989080BF1F02AB753A3119057547D86329979EDE93E09C5E2263DD51338A9694E3

Here is a post from Duke Enegy on the discussion in the media on this subject

https://news.duke-energy.com/our-perspective/solar-power-causes-air-pollution-wait-a-minute

I recall reading an article about the Irish grid which is gas and wind heavy

They found that their gas savings were not as high as first expected and the reason was that the gas fired CCGTs are less efficient ramping up and down to fill in wind voids than they would be as baseload

CCGTs are amazing pieces of tech they really operate at the edge of possibilities
New CCGTs can get more than 63% efficiency but only at full load running constantly and much less efficient having to ramp up and down


I remember a model for a UK with just natural gas. No coal no oil no uranium
just CCGTs and mass EV deployment and natural gas for heating and LNG for ships and planes. So going from today's mix of oil gas coal uranium to just natural gas. It was a very efficient model and low carbon. About 3.3 tons per capita while Germany is about 3x that today

The reason it worked so well was it's so high efficiency.
63.1% natural gas to electricity efficiency (Vs circa 35% for coal and nuclear)
50% efficient NG to BEVs (Vs closer to 20% today for oil cars)
90% efficient condensing boilers for space heating

That would be maximum thermal efficiency model using !!!!!! as primary energy

Martyn1981

Another crucial US election is on its way. I feel the biggest lost opportunity was when Gore lost to Bush in 2000 (despite winning the popular vote, as did Hilary Clinton), so we saw an expansion of FF's rather than a reduction.

But 2020 is pitting Trump (assuming he isn't successfully priamaried for the GOP nomination) against multiple Democratic hopefuls putting forward grand plans to start tackling US emissions.

If only the US Republican hard-right would play nice like every other sizeable and respected democratic political party in the World, and stop denying AGW science whilst pocketing vast amounts of campaign monies from the FF industry.

Sanders to unveil $16tn climate plan, far more aggressive than rivals' proposals

Bernie Sanders has laid out an ambitious 10-year, $16.3tn national mobilization to avert climate catastrophe, warning that the US risks losing $34.5tn in economic productivity by the end of the century if it does not respond with the urgency the threat demands.

Sanders’ plan would reach for 100% renewable power for both electricity and transportation, the top two contributors to climate change in the US, by 2030 – aiming for complete decarbonization by 2050.

Martyn1981

GreatApe wrote: »

I remember a model for a UK with just natural gas. No coal no oil no uranium

FF methane is at best a short term option as we move from coal and oil. It is far, far, far too high in CO2 to be considered as a medium to long term solution.

Plus of course coal is all but gone, and oil consumption can and will be cut dramatically with BEV's. So it seems we have already passed the point in time when that option had any future viability.

JKenH

Martyn1981 wrote: »

Sanders to unveil $16tn climate plan, far more aggressive than rivals' proposals

“Bernie Sanders has laid out an ambitious 10-year, $16.3tn national mobilization to avert climate catastrophe, warning that the US risks losing $34.5tn in economic productivity by the end of the century if it does not respond with the urgency the threat demands.”

Interesting that one of the candidates feels confident he can make predictions on productivity 80 years ahead. I wonder if anyone in 1919 would have been able to make any realistic predictions about what the world would look like in 2020. If climate catastrophe occurs as predicted, productivity will be the least of our problems.

GreatApe

Martyn1981 wrote: »

FF methane is at best a short term option as we move from coal and oil. It is far, far, far too high in CO2 to be considered as a medium to long term solution.

Plus of course coal is all but gone, and oil consumption can and will be cut dramatically with BEV's. So it seems we have already passed the point in time when that option had any future viability.

I think the net zero target is too aggressive it will burden costs too high especially trying to move heating away from NG

The old target of -80% of 1990 figures was more realistic and likely much more economical

Something in between so a -90% on 1990 levels would have been more realistic perhaps going further if new technology or new price points are hit

Martyn1981

JKenH wrote: »

“Bernie Sanders has laid out an ambitious 10-year, $16.3tn national mobilization to avert climate catastrophe, warning that the US risks losing $34.5tn in economic productivity by the end of the century if it does not respond with the urgency the threat demands.”

Interesting that one of the candidates feels confident he can make predictions on productivity 80 years ahead. I wonder if anyone in 1919 would have been able to make any realistic predictions about what the world would look like in 2020. If climate catastrophe occurs as predicted, productivity will be the least of our problems.

I believe the AGW science is pretty solid now - but I appreciate you don't trust science, only opinions - so we may have to agree to differ.