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So how much NG would you need to store onsite to supply a 1GW NG generator for 7 days? Maybe Turb can answer?

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3 hours ago, surrept33 said:

Certain families of aromatic hydrocarbons (among many other families of compounds) are very well studied:

https://en.wikipedia.org/wiki/Polycyclic_aromatic_hydrocarbon#Human_health

"Clean burning" processes, for example, the substitution of certain types of biomass, coal or oil with natural gas result in a lot less PAH. There are of course many ways to reduce the detrimental effects. 

Compared to Europe, we have a lot less regulations with other (most likely cancer or other side effect causing) organic chemicals, except for the economic heft (and Clean Air Act provisions) of some states like California. 

Sometimes the science runs ahead of politics because of the distortion caused by the effect of special interest groups on public policy. 

The list of potential or possible or conceivable cancer risks would fill several volumes of telephone books. Wake me up when they show that low level fumes of any type will cause cancer. So far, nothing.

BUT, here is a risk to our economy, oil refineries shut down due to the Texas fiasco, huge problems in oil-derived products.

When crunch time comes, we need oil.

https://oilprice.com/Energy/Energy-General/Global-Petroplastic-Markets-Set-To-Explode-This-Year.html

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On 3/23/2021 at 3:03 PM, Ecocharger said:

Here is a California (YES! California!) research team and some further evidence of climate change related to solar variables. This is the new frontier for climate change research.

Published in November 2020, recent material indeed.

https://www.mdpi.com/2225-1154/8/11/130/htm

Consistent with the work of the Russian scientist cited earlier, this study anticipates an imminent cooling phase, which will settle the argument conclusively against the Anthropogenic hypothesis of global warming, and in favor of natural climate cycles related to solar variables.

Time to call off the panic attack, buy some good mittens and ear-muffs, and break out those new model SUV's with thick rubber tires (over 60% carbon sourced).

Just noticed the publication history of this ground-shaking research which demythologizes conventional climate change science and will soon potentially overturn anthropogenic climate change.

Fascinating. Submitted July 27, 2020---Revised for two months---Resubmitted September 25---Accepted September 25---Published November 10, 2020. 

The necessary delays from submission to publication apparently prevented this ground-breaking, earth-shattering study from entering into public debate preceding the November 3, 2020 election. I recall that Trump made some unidentified reference to this research, but without specifics. I guess it arrived on the scene just a little too late to enter the debates. Unfortunate.

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2 hours ago, Refman said:

So how much NG would you need to store onsite to supply a 1GW NG generator for 7 days? Maybe Turb can answer?

0.13 kWh/cf.   This is net after accounting for generator inefficiency, but I think it is a national average which includes CCGT, so Buffet's peakers will not get this high. Counterbalancing this, we do not know if the contract would be for 100% utilization during the entire 7 days.

https://www.eia.gov/tools/faqs/faq.php?id=667&t=8

7 days*24 hours*1GW= 168GWh

168 GWh/.13 kWh= 1292.3 million cf = about 1.3 Bcf.

At 5 atm (about 70 PSI) this would occupy about 250 million cf, which is a cube 630 foot cube.

CNG is stored at 3600 PSI, or about 255 atm, so 1.3 Bcf is about 5 million cu. ft. of CNG: 500x100x100 feet. I have no idea if CNG is feasible.

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5 hours ago, turbguy said:

7 day supply locally stored?  Is that practical?  Can those in the industry comment?  

That's a lot of nat gas, and a lot of up-front investment in stored fuel.  I guess you could "buy-low" during certain periods. Or store distillate...

From my previous calculations (see above), storage is on the order of 1.3 Bcf. Ships called CNG carriers appear to be in this order of magnitude. The CNG is stored at 3600 PSI in lots and lots of 6" diameter pipes. I would GUESS that these same pipes could be placed in a ship-sized building.  For this application (rarely-used emergency reserve) efficiency is not interesting: you are already being paid for doing nothing for 99.9% of the time. However, "uncompressors" use turbo-expanders to generate some electricity at the destination terminl for ships, and I suppose you could add a turbo-expander to generate electricity to cold-start the peaker.

https://en.wikipedia.org/wiki/CNG_carrier

 

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2 hours ago, Dan Clemmensen said:

From my previous calculations (see above), storage is on the order of 1.3 Bcf. Ships called CNG carriers appear to be in this order of magnitude. The CNG is stored at 3600 PSI in lots and lots of 6" diameter pipes. I would GUESS that these same pipes could be placed in a ship-sized building.  For this application (rarely-used emergency reserve) efficiency is not interesting: you are already being paid for doing nothing for 99.9% of the time. However, "uncompressors" use turbo-expanders to generate some electricity at the destination terminl for ships, and I suppose you could add a turbo-expander to generate electricity to cold-start the peaker.

https://en.wikipedia.org/wiki/CNG_carrier

 

Let's see.  Back of envelope...

1 KWH = 3412.142 BTU's

10 GWH = 34,121,420,000 BTU's

at 1015 BTU's per cf (stp), that's 33,617,160 cf.  (at 100% conversion efficiency, 50% is more practical).

x 24 hrs x 7 days = 5,647,682,880 cf

Twice that for conversion loss = 11,295,365,760, or about 11 Bcf.

That's a lotta gas!

...or is my envelope wrong?

BTW, you just expand the gas itself to start the peaker.  You just need to remember to have enough resultant pressure on hand to shove it into the GT (compressor discharge pressures are about 200 psi +/-)

 

 

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10 minutes ago, turbguy said:

Let's see.  Back of envelope...

1 KWH = 3412.142 BTU's

10 GWH = 34,121,420,000 BTU's

at 1015 BTU's per cf (stp), that's 33,617,160 cf.  (at 100% conversion efficiency, 50% is more practical).

x 24 hrs x 7 days = 5,647,682,880 cf

Twice that for conversion loss = 11,295,365,760, or about 11 Bcf.

That's a lotta gas!

...or is my envelope wrong?

BTW, you just expand the gas itself to start the peaker.  You just need to remember to have enough resultant pressure on hand to shove it into the GT (compressor discharge pressures are about 200 psi +/-)

 

 

Your envelope matches mine: on the back of an envelope, 1.1 is the same as 1.3 😀. You were computing for all 10 of the 1 GW generators, which will be on 10 different sites scattered around the state. I was computing for only one of them.  I got 1.3 Bcf per site, which is higher than yours because I started from the EIA's pre-computed national average observed kWh/cf number.  So the storage at each site is about the same as the storage in three smallish CNG carriers.

Since these machines are idle 99.9% of the time, if a less efficient generator is cheaper, then it will be used, and you need even more storage.

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16 minutes ago, Dan Clemmensen said:

Your envelope matches mine: on the back of an envelope, 1.1 is the same as 1.3 😀. You were computing for all 10 of the 1 GW generators, which will be on 10 different sites scattered around the state. I was computing for only one of them.  I got 1.3 Bcf per site, which is higher than yours because I started from the EIA's pre-computed national average observed kWh/cf number.  So the storage at each site is about the same as the storage in three smallish CNG carriers.

Since these machines are idle 99.9% of the time, if a less efficient generator is cheaper, then it will be used, and you need even more storage.

Gotcha!  Thanx!

Who pays the carrying costs of the unused inventory of equipment and fuel storage?

Distillate fuel would take up less space and complication.

Edited by turbguy

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4 minutes ago, turbguy said:

Gotcha!  Thanx!

Who pays the carrying costs of the unused inventory of equipment and fuel storage?

Distillate fuel would take up less space and complication.

Buffet's proposal is calls for a fixed monthly fee paid by all ratepayers that returns a specified percentage on his initial investment. From a top-level accounting perspective there is no difference between the capital cost of the generator and the cost of initially filling the storage. Please note that I have no information that is not in the original newspaper article that I linked, which does not go into details.

 

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24 minutes ago, turbguy said:

Gotcha!  Thanx!

Who pays the carrying costs of the unused inventory of equipment and fuel storage?

Distillate fuel would take up less space and complication.

OK, we need ten sites at 1.3 Bcf each. A cf is about 1000 BTU, and gas costs $2.50/million BTU = $2.50/ kcf = $2.5 million/Bcf, so each site has an initial inventory cost of $3.25 million. But I don't think they will need to pay Henry Hub prices. This $3.5 million is a small percentage of the total capital cost, which is more than $800 million per site. I suspect the storage system is more expensive than the stored NG. Remember: these system will probably never run for a total of 7 days (168 hours) during their entire lifetimes and will probably never run 24 hours continuously.

As I said originally, I doubt that this is the best technical solution for reliable power in Texas. I see it as a a stake in the ground: a challenge to the Texas power providers to propose a better solution. This solution has the overwhelming advantage of simplicity: specified price, specified performance, specified payment method, specified implementation timeline. Unless an alternative can be nailed down with all four of these attributes, Texas will remain vulnerable until the politicians and regulators can get their act together.

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3 hours ago, turbguy said:

Oh, how quickly legislators abandon their fine principles. They are trying to mandate reliability instead of creating a market pay to for it. This is why Buffet's proposal is superior. If the legislature would simply tell ERCOT to add a fixed monthly surcharge to each ratepayer's bill, it would create a reliability pool. Anyone willing to commit to providing reliable power could then bid for a part of that pool. The most easily winterizable assets would bid less per GWh. Hard-to-winterize assets would not bid at all if new assets like Buffet's are cheaper.

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11 hours ago, Dan Clemmensen said:

Oh, how quickly legislators abandon their fine principles. They are trying to mandate reliability instead of creating a market pay to for it. This is why Buffet's proposal is superior. If the legislature would simply tell ERCOT to add a fixed monthly surcharge to each ratepayer's bill, it would create a reliability pool. Anyone willing to commit to providing reliable power could then bid for a part of that pool. The most easily winterizable assets would bid less per GWh. Hard-to-winterize assets would not bid at all if new assets like Buffet's are cheaper.

Politics, the art of both the possible, and the impossible...

They don't even know what the root causes are yet (if they do, they are keeping tight-lipped).

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On 3/28/2021 at 9:49 PM, Dan Clemmensen said:

Buffet's proposal is calls for a fixed monthly fee paid by all ratepayers that returns a specified percentage on his initial investment. From a top-level accounting perspective there is no difference between the capital cost of the generator and the cost of initially filling the storage. Please note that I have no information that is not in the original newspaper article that I linked, which does not go into details.

 

Given that Buffet is Demanding a 9.5% ROI, this deal is crap on its face. Right now investors are plowing $100's of billions into investment vehicles that only return 1% or even less. Buffet demands zero risk and a reward 10 times higher than others with capital are able to get. He's out for himself, and his shareholders. BTW I am a shareholder but I still thinks he's a crook. I inherited the shares. 

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3 minutes ago, Ward Smith said:

Given that Buffet is Demanding a 9.5% ROI, this deal is crap on its face. Right now investors are plowing $100's of billions into investment vehicles that only return 1% or even less. Buffet demands zero risk and a reward 10 times higher than others with capital are able to get. He's out for himself, and his shareholders. BTW I am a shareholder but I still thinks he's a crook. I inherited the shares. 

I more or less agree with you. Texas needs to quickly come up with a way to ensure reliable electricity. Buffet's proposal (if structured correctly) is one way, but as you say, and I as I have said repeatedly in  my posts on this subject,  it's almost certainly not the most cost-effective way. I don't think the legislature's approach of requiring generators to be reliable without specifying how to pay for it is the most cost-effective way either.

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1 hour ago, Ward Smith said:

Back to the topic at hand. Practical Engineering review of Texas power outage. Should be helpful to some

Not a bad summary.  Root causes still to be determined, but reasonably accurate.

He might have wanted to include the fact that about 60% of Texans heat with electricity, frequently central AC/heat pumps. Central AC/Heat pumps don't heat well in those cold conditions, and fall back to electrical resistance heaters (or less frequently, nat gas furnaces). That drives up electric demand considerably, exacerbating the crisis.

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10 hours ago, turbguy said:

Not a bad summary.  Root causes still to be determined, but reasonably accurate.

He might have wanted to include the fact that about 60% of Texans heat with electricity, frequently central AC/heat pumps. Central AC/Heat pumps don't heat well in those cold conditions, and fall back to electrical resistance heaters (or less frequently, nat gas furnaces). That drives up electric demand considerably, exacerbating the crisis.

I'm subscribed to his channel, this "journalism" stuff is new to him but he is an engineer, therefore he's thorough. I suspect he didn't mention the heat pumps because he's unsure of their exact number. Let's face it, most so called heat pumps are glorified air conditioners. 

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44 minutes ago, Ward Smith said:

I'm subscribed to his channel, this "journalism" stuff is new to him but he is an engineer, therefore he's thorough. I suspect he didn't mention the heat pumps because he's unsure of their exact number. Let's face it, most so called heat pumps are glorified air conditioners. 

Yes, those central AC/Heat Pump systems don't do well once outside temps drop below 40 degrees F or so. Recent specially designed units do perform better, but still, heat output is limited and of lower temperature than a combustion system, so they operate longer and longer in cold weather to make up for home heat loss.

And when they enter a "defrost cycle", be prepared for a volcanic eruption from the outdoor unit (which just wastes power)

Edited by turbguy
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7 hours ago, turbguy said:

Yes, those central AC/Heat Pump systems don't do well once outside temps drop below 40 degrees F or so. Recent specially designed units do perform better, but still, heat output is limited and of lower temperature than a combustion system, so they operate longer and longer in cold weather to make up for home heat loss.

And when they enter a "defrost cycle", be prepared for a volcanic eruption from the outdoor unit (which just wastes power)

I was quite surprised to discover that heat pumps have improved quite a bit over the last decade, to the point where the crossover efficiency temperature (versus resistance heat) is down below zero degrees Fahrenheit now. But this means that in addition to knowing how many heat pumps Texas has, you also need to know their age distribution. Of course, when a heat pump is "proper;y sized" for a house, it's just big enough to keep the house comfortable on a typical very cold day. It will need to kick in the auxiliary resistance heaters at a temperature higher than the crossover because the house is just too damn cold during an extreme event.

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3 hours ago, Dan Clemmensen said:

 It will need to kick in the auxiliary resistance heaters at a temperature higher than the crossover because the house is just too damn cold during an extreme event.

Yup.  That surprised me as well.  Typically those units are small (a hotel room or two).

Hopefully, the bearings in the electric meter are well designed.

I can't imagine the power bill for those power distributors (marketers) at $9/KWH.

Edited by turbguy

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On 3/29/2021 at 2:22 PM, Dan Clemmensen said:

Your envelope matches mine: on the back of an envelope, 1.1 is the same as 1.3 😀. You were computing for all 10 of the 1 GW generators, which will be on 10 different sites scattered around the state. I was computing for only one of them.  I got 1.3 Bcf per site, which is higher than yours because I started from the EIA's pre-computed national average observed kWh/cf number.  So the storage at each site is about the same as the storage in three smallish CNG carriers.

Since these machines are idle 99.9% of the time, if a less efficient generator is cheaper, then it will be used, and you need even more storage.

It would be much cheaper to just have one or two 500MW gas turbines on standby, plus a few diesel gen-sets, and about 3 GW of batteries. Looks as though that is what will happen anyway?

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24 minutes ago, Wombat said:

It would be much cheaper to just have one or two 500MW gas turbines on standby, plus a few diesel gen-sets, and about 3 GW of batteries. Looks as though that is what will happen anyway?

It would be cheaper (IMO) to assure that gas processing facilities submitted paperwork to ERCOT concerning "critical infrastructure" designations to prevemt rolling blackouts at their facility.

I have no idea about what that situation was here.

I would be highly interested, though.

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9 minutes ago, turbguy said:

It would be cheaper (IMO) to assure that gas processing facilities submitted paperwork to ERCOT concerning "critical infrastructure" designations to prevemt rolling blackouts at their facility.

I have no idea about what that situation was here.

I would be highly interested, though.

IMO paperwork is insufficient. You need at least dedicated electrical circuits, and IMO you need dedicated electrical backup generation for those circuits. Basically, power needed to maintain power is in a whole 'nother category, above "critical". According to Ward's excellent video, there were so many "critical infrastructure" circuits already that there was not enough power to "roll" the blackouts. That's cutting it way too fine. Because paperwork is easy to mess up, separate circuits and generation under control of the NG providers is a lot more reliable.

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On 4/1/2021 at 3:39 AM, Ward Smith said:

Back to the topic at hand. Practical Engineering review of Texas power outage. Should be helpful to some

Good video summarising the situation. Most of that has been discussed here but the presenters puts it into a digestible 15 minute talk. 

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