Measuring Natural Gas

[gmerkt]

I was thinking about this after making another post. When we moved here years ago, there was no natural gas service. So we were "all electric" by default. Except for wood burning, of course. In the meantime, quite a few years ago, a new development was built off to the east and they were plumbed with nat. gas. As a back-up, they brought a gas main through my area and we were encouraged to sign up and install. Well, I thought about it seriously a couple of times but never made the move. The break-even payoff time was about 15 or 16 years for the gas line from the main to the house, meter, and plumbing the house. But no appliances. So I finally decided to forget it. By now, it would be paid off a couple of times, but that's another story. BUT: Now I'm on the cutting edge of Green-ness, all electric, no polluting carbon emissions. Except for wood burning.

Anyway, in our old 1928 house that we lived in before our present place, the city owned the nat. gas utility. It was very inexpensive service, and the volume of natural gas used was measured in cubic feet. What I've noticed in this area (Puget Sound Energy) is that nat. gas is measured and billed in therms. Which is a measurement of heat value. One therm is equal to 100,000 BTU's. Yes but: Don't they have to know how many cubic feet are used up to calculate a therm? I feel like a cubic foot is easier for the consumer to measure, a more honest number. I've read that the reason therms are used now is because the heat value of nat. gas varies. So you might get cubic feet that contain more energy than others, depending on chemical blends of the gas. Well, in that case, we just have to trust the utility company that they are being honest and are adjusting the heat value of the gas that results in honest therms. I guess. My gut feeling is that the use of therms is a way for utility companies to confuse and bamboozle consumers. It surely wouldn't be above some companies to do this. Remember ENRON?

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[jackrv]

I'll have to look at my bill, but I have NW Natural and I believe they still calculate by cubic feet.

Oops, guess I was wrong. Therms

 

[dangerranger60]

Your gas meter can only measure in volume. [ cubic feet, cubic meters , etc...] the conversion to therms is a calculation done at the utility office.
Therms per cubic foot should be very stable if they are using a single provider of gas. But if they are buying from multiple suppliers that number may change daily. One plant I worked in used to blend Propane or air to keep a stable number. DR

 

[gmerkt]

the conversion to therms is a calculation done at the utility office.

My point exactly. It doesn't seem (using today's vernacular) "transparent" and therefore is beyond consumer scrutiny.

 

[jbett98]

If you happen to cut a NW Natural Gas line without calling for a locate, they will charge you for all of the natural gas released into the atmosphere.
The charges start when you call them for an emergency line repair and stop when they clamp off the broken line.

 

[Flopsweat]

My point exactly. It doesn't seem (using today's vernacular) "transparent" and therefore is beyond consumer scrutiny.

I'm sure they changed the billing for what seemed to them a good reason. Your wellbeing was likely not a major factor.

 

[Foreverlost]

Ok.........the short version of how it works! First the short list of analyzers that were on the resume: ABB Questor IV (mass spectrometer), ABB Vista 3100 (gas chromatograph) and little stuff down to a Hach CL-17.

Yes, not unusual for natural gas to be sold to a home residence in therms. On the main pipelines I believe one way or the other it is BTUs. From natural gas well head to well head the BTU can and does vary. What to do.......what to do? Somewhere between the well heads and main transmission lines, a blending station is located, put in place. This blending station adds nitrogen gas to control the BTU content of the natural gas flowing down stream to customers. Been there and done that here in the States & Western Europe. Used a very simple and easy to calibrate, calorimeter. In some of the company's hydrogen plants, steam methane reformers, we used a calorimeter to control the carbon to steam ratio. These were small SMR's in oil refineries and at times could use butane which is a byproduct of those refineries instead of natural gas (methane).

My fields were cryogenic air separation & hydrogen production (gas & liquid).

Foreverlost,

 

[thorborg]

Might consider propane if you have enough property to meet the distance requirement from property lines and structures (roughly 12 feet to here or there) and reasonable or available delivery service.,. tanks only fill about 80% so include that when sizing.
Propane cost a little more than natural gas by volume, But it puts out more BTU's (British thermal units) (burns hotter) than natural gas so things are able to use less gas, (Generators run better).
I don't know the cost of turnkey install between the two, so that might be a factor when considering payback. I'd also add to the cost comparison, tank life, tank inspections / maintenance/ certification fees etc.

Propane gives off less pollutants when burned so is also more environmentally friendly than natural gas.
At least was what I was lead to believe.

 

[Joe13]

NW Natural is a shlte company and if I had been home when one of their techs threaten my wife 12 years ago then I'd have a felony assault charge for kicking his arse 2 miles down the road.

Turned off my service and went electric and will never go back.


No it wasn't the first issue with the but the worst and the last.

 

[MikeInOr]

Cubic feet isn't really a proper measurement for any kind of gas. It has to be cubic feet at a particular temperature and pressure. You could consume 100 cubic feet of natural gas at 5 psi and only get half the BTU's of someone consuming 100 cubic of natural gas at 10 psi. This is why they express natural gas measurements in therms, it is independent of both pressure and volume.

 

[64MercurysRule]

Only as a side note ...... my grandfather said you measure natural gas by the amount of people that leave the room..... but I digress . Back to your regular programming .

 

[jbett98]

Always call for a free locate when digging in your yard. My friend had a locate done last year for a new city water line install.
The locate guy only marked the area where the city water line was going to be excavated, not his whole street frontage.
A couple of weeks ago on a Saturday, he decided to bootleg a new 4" sewer line out towards the street and when he got close to the curb, he nicked a NW Natural gas line.
4 -1/2 hours later, the crew involving 6 guys, 1 supervisor, 4 trucks, along with a flat bed trailer pulling a track hoe, repaired the plastic line.
The emergency repair bill could be over $3,000 bucks.

 

[Flopsweat]

Always call for a free locate when digging in your yard. My friend had a locate done last year for a new city water line install.
The locate guy only marked the area where the city water line was going to be excavated, not his whole street frontage.
A couple of weeks ago on a Saturday, he decided to bootleg a new 4" sewer line out towards the street and when he got close to the curb, he nicked a NW Natural gas line.
4 -1/2 hours later, the crew involving 6 guys, 1 supervisor, 4 trucks, along with a flat bed trailer pulling a track hoe, repaired the plastic line.
The emergency repair bill could be over $3,000 bucks.

I would think the flatbed and trackhoe would be over $100 hour just by themselves.

 

[Foreverlost]

Cubic feet isn't really a proper measurement for any kind of gas. It has to be cubic feet at a particular pressure. You could consume 100 cubic feet of natural gas at 5 psi and only get half the BTU's of someone consuming 100 cubic of natural gas at 10 psi. This is why they measure natural gas in therms, it is independent of both pressure and volume.

Careful now............

You are getting into some deep stuff. Gasses in one way or the other, delivered via pipeline, etc., have pressure, temperature, flow compensation all factored in, period. Then the AGA will toss in a calculation for gas flow compensation. This gets really deep when you are the poor sucker that has to decipher the legal contract between the seller & purchaser. Are you, the poor sucker, to verify the paymeter or calibrate?

Keeping things easy to understand for us poor mortals; pressure, temperature, flow compensation will produce a number for us mere mortals, a number of "stuff" at a standard temperature, and standard barometric pressure. All clearly defined in the contract.

When the gas meter at your house was manufactured, it most likely met all specs. Like any meter used for billing, it should be checked/calibrated or replaced at specified intervals. Us mere mortals don't have the equipment in our garage to work on a gas meter.

Spend your time at the BBQ, smoke some ribs tonight.

Foreverlost.

 

[Flopsweat]

Careful now............

You are getting into some deep stuff. Gasses in one way or the other, delivered via pipeline, etc., have pressure, temperature, flow compensation all factored in, period. Then the AGA will toss in a calculation for gas flow compensation. This gets really deep when you are the poor sucker that has to decipher the legal contract between the seller & purchaser. Are you, the poor sucker, to verify the paymeter or calibrate?

Keeping things easy to understand for us poor mortals; pressure, temperature, flow compensation will produce a number for us mere mortals, a number of "stuff" at a standard temperature, and standard barometric pressure. All clearly defined in the contract.

When the gas meter at your house was manufactured, it most likely met all specs. Like any meter used for billing, it should be checked/calibrated or replaced at specified intervals. Us mere mortals don't have the equipment in our garage to work on a gas meter.

Spend your time at the BBQ, smoke some ribs tonight.

Foreverlost.

Well, this has been a gas, but I'm gonna go get lit now. Don't worry, I don't hit the pipe or do lines. I burn clean.

 

[Certaindeaf]

300 therms is equal to 500,000 persians. pretty sure

 

[gmerkt]

Yes, not unusual for natural gas to be sold to a home residence in therms. On the main pipelines I believe one way or the other it is BTUs. From natural gas well head to well head the BTU can and does vary. What to do.......what to do? Somewhere between the well heads and main transmission lines, a blending station is located, put in place. This blending station adds nitrogen gas to control the BTU content of the natural gas flowing down stream to customers. Been there and done that here in the States & Western Europe. Used a very simple and easy to calibrate, calorimeter. In some of the company's hydrogen plants, steam methane reformers, we used a calorimeter to control the carbon to steam ratio. These were small SMR's in oil refineries and at times could use butane which is a byproduct of those refineries instead of natural gas (methane).

Yes but. Is this precision reflected in honest billing?

Cubic feet isn't really a proper measurement for any kind of gas. It has to be cubic feet at a particular pressure. You could consume 100 cubic feet of natural gas at 5 psi and only get half the BTU's of someone consuming 100 cubic of natural gas at 10 psi. This is why they measure natural gas in therms, it is independent of both pressure and volume.

What Foreverlost said, there is a pressure regulator right at the meter into the house. There has to be some way to control and measure natural gas flow, no matter whether it's measured in cu. ft. or therms. Otherwise they wouldn't know how much to bill, whichever system was used

Which gets back to my original premise. In order to bill using therms, they still have to know some kind of volume, don't they? Regardless of what the energy content is. Because they don't give you a blank check amount of therms. Volume still has a place in there somewhere. Which is why I am suspicious of the added step of recalculating in therms. As a consumer, as long as my range gets gas, I don't care about the variations in the chemical content of the gas. It's more important to me that I see a solid number in consumption that I can reference backward and forward in time.

 

[gmerkt]

Might consider propane

I'm too far along in life to do this. BUT: I think this is a solid recommendation for natural disaster preparedness and other emergencies. Because you can have a standby generator calibrated to run off propane. When you've got that big propane tank out there, it could last quite some time until the PUD gets power restored.

 

[Foreverlost]

Yes but. Is this precision reflected in honest billing?


What Foreverlost said, there is a pressure regulator right at the meter into the house. There has to be some way to control and measure natural gas flow, no matter whether it's measured in cu. ft. or therms. Otherwise they wouldn't know how much to bill, whichever system was used

Which gets back to my original premise. In order to bill using therms, they still have to know some kind of volume, don't they? Regardless of what the energy content is. Because they don't give you a blank check amount of therms. Volume still has a place in there somewhere. Which is why I am suspicious of the added step of recalculating in therms. As a consumer, as long as my range gets gas, I don't care about the variations in the chemical content of the gas. It's more important to me that I see a solid number in consumption that I can reference backward and forward in time.

You answered your own question, sort of. The gas meter measures volume. The gas company know the BTU content (therms). One way or the other gas companies have to purchase natural gas from the companies which own the main transmission line. With out a doubt the BTU content (therms) are factored into the cost and passed on to the customers. The blending stations once again control the BTU content (therms). This is not an unknown number. Just think of the volume the main lines move from wells to the customers. A 1% error in billing equals millions of dollars. This is not a guessing game! Close is not good enough. The pressure regulator mentioned is to make the appliances in our home happy and not burn the house down to ground level.

I could make site managers sweat bullets when I was a witness for work on a paymeter. Most of the time they didn't have a clue as to the difference between verify or calibrate. We spent hours pouring over the contract as to requirements for both.

There are utilities which are on my list of bottom feeders. Like or dislike at times doesn't work. They mostly have a monopoly in their area, get used to it.

Foreverlost,

 

[Stomper]

I was thinking about this after making another post. When we moved here years ago, there was no natural gas service. So we were "all electric" by default. Except for wood burning, of course. In the meantime, quite a few years ago, a new development was built off to the east and they were plumbed with nat. gas. As a back-up, they brought a gas main through my area and we were encouraged to sign up and install. Well, I thought about it seriously a couple of times but never made the move. The break-even payoff time was about 15 or 16 years for the gas line from the main to the house, meter, and plumbing the house. But no appliances. So I finally decided to forget it. By now, it would be paid off a couple of times, but that's another story. BUT: Now I'm on the cutting edge of Green-ness, all electric, no polluting carbon emissions. Except for wood burning.

Anyway, in our old 1928 house that we lived in before our present place, the city owned the nat. gas utility. It was very inexpensive service, and the volume of natural gas used was measured in cubic feet. What I've noticed in this area (Puget Sound Energy) is that nat. gas is measured and billed in therms. Which is a measurement of heat value. One therm is equal to 100,000 BTU's. Yes but: Don't they have to know how many cubic feet are used up to calculate a therm? I feel like a cubic foot is easier for the consumer to measure, a more honest number. I've read that the reason therms are used now is because the heat value of nat. gas varies. So you might get cubic feet that contain more energy than others, depending on chemical blends of the gas. Well, in that case, we just have to trust the utility company that they are being honest and are adjusting the heat value of the gas that results in honest therms. I guess. My gut feeling is that the use of therms is a way for utility companies to confuse and bamboozle consumers. It surely wouldn't be above some companies to do this. Remember ENRON?

FYI-

There are 1,000-btu/scf of natural gas.

100-scf of NG = 1 therm



also…


LP (propane) has 2,500-btu/scf


SCF=Standard Cubic Foot