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Permalink Reply by Steve P on July 9, 2019 at 15:41

So, going back to your prior post on how solar + storage crushes NG.  As i read the news, at least here domestically, utilities are rapidly moving away from coal and building NG generators.  Those generators go into their rate base, and they are set up for 30 year amortizations.  Even if solar and batteries become more economical in the next 5 years, those utilities can't just walk away from those new NG power generating plants (at $1+B per) at 10 years of service to reduce costs by 5, 10, or even 20% from solar.  I haven't researched this, but I'm pretty sure that utilities aren't trying to shut down newly constructed coal-fired power plants because NG is cheaper.

The last article you posted, regarding the prospects of solar in undeveloped countries, poses a substantial treat to NG and LNG, because there is little existing infrastructure that is built around NG power production, and companies would need to invest huge $$ in building an LNG port to receive LNG transports.  But that's a market that isn't discussed every day in the media.  The LNG markets being discussed are existing markets that are already using NG, and maybe even LNG.

And, finally, I read an amusing clip from one of my legal newsletters I get every day.  In the midwest, a utility is trying to permit a large wind farm.  As part of the wind farm, the utility needs to build a new power line to connect the wind farm to their grid.  An environmental group is suing the utility and FERC over the power line permit, because the wind farm poses a threat to whooping cranes.  

this might go into the "no good deed goes unpunished" category for that utility.

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Permalink Reply by dbob on July 9, 2019 at 16:24

If you do a deeper dive into the documents Skip posted in the last one, you'll see that in certain area/certain projects, the levelized cost of solar or wind, with tax incentives, is cheaper than natural gas, but when weighted by actual generation, natural gas comes out ahead, and if you take out incentives, natural gas comes out ahead.  

I think the battle ground will actually be the developing countries, rather than 3rd world.  A key example would be India - there is certainly a lot of power demand there, and if more LNG infrastructure doesn't get built soon, renewables are likely to rule the market.  For 3rd world countries that won't be developing meaningful new infrastructure in the next 10 years or so, potential for fossil fuel power supply is minimal, unless the fuel is developed indigenously. 

That said, 10 years ago, if you would have told me that Monticello, Big Brown, and Martin Lake would either be closed or generating at a much reduced capacity by 2020, I would have laughed at you and talked about turning off your power in the heat of summer.  Markets are changing fast.

   

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Permalink Reply by Mister Sunday on July 11, 2019 at 6:45

The last power plant I was in looked like it burned NG with a metering valve type system that blew pulverized coal into the flame.  Maybe I'm wrong, as I didn't have anyone there to explain it to me, and I, by no means, am an engineer.

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Permalink Reply by Max on July 12, 2019 at 1:01

Mister Sunday, all the pulverizers that I've worked on basically worked the same.  The "valves" were simply a swing gate that was either open or closed.  Babcock & Wilcox pulverizers had seven of these valves on each pulverizer and if any of them hung up or didn't open, the pulverizer couldn't be put in service.  

The problem with coal is that the valve gate has to be clear of the pulverized coal flow because of abrasion.  Any gate that didn't drop down and out of that flow would wear out in a very short time.  The only way to meter the flow was by how much raw coal was fed into the pulverizer.  However, the less coal fed in resulted in more wear of the roll wheels and turn table, so the pulverizer operates best when running at full flow.  The way to limit how much fuel was going into the boiler was to either start up another pulverizer or shut one down.

Coal fired boilers have much larger firebox's than NG boilers.  It takes a lot more time to "burn" the coal and if the firebox is not big enough, a lot of the coal doesn't burn and ends up clogging up the system and wasting fuel.  NG boilers need shorter firebox's so that the heat is efficiency absorbed by the tubes and not "cooled" off before getting to the heat exchangers.

This makes the two fuels out of sink with each other.  NG burns too fast and coal burns too slow.  A coal/ng combination boiler would have to be specially designed with coal burners at lower elevations and NG burners closer to the top of the boiler firebox.  The problem with this is keeping the upper burners from "burning up".  Anything in this upper zone would have to operate at much higher temperatures and you need some type of cooling to keep the NG from igniting prematurely in the burner.

The best solution for this is to not combine the two fuels.  A coal boiler could use NG for startup and bring the boiler temperature up, but most of the time they use fuel oil/diesel fuel for that because it's a lot safer.

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Permalink Reply by Mister Sunday on July 15, 2019 at 8:10

Thanks for the explanation.

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