Why SpaceX isn’t YET synthesizing methane in Boca Chica but IS using solar

[Robotbeat]

To make 1 Joule of methane synthetically requires about 2 Joules of solar/wind electricity. But if you took that 2 Joules of solar/wind electricity & exported it to the grid, you’d be displacing about 4 Joules of natural gas from being burned plus you saved the capital cost of electrolysis & Sabatier reactors & CO2 capture and some of the maintenance on the natural gas plants. So even from a climate perspective it’s way better to use that gas directly as propellant and exporting (to the grid) the electricity you WOULD have used to synthesize it.

Once the grid becomes clean enough, then adding more solar and wind electricity tends to just lead to solar and wind curtailment (even with storage), but not quite enough to change that equation until almost all fossil fuels are removed from the grid. So let’s say once the grid is 75-90% clean or better (currently 40% in the US), then it may make sense to synthesize methane versus just using fossil methane and exporting (to the grid) the electricity you would’ve used to make Sabatier methane.

Similar math (but in the other direction) is partly why it may make sense to liquefy the methane and oxygen with solar and wind. Flare gas generators aren’t cheap, require about 1.5¢/kWh of maintenance and require about 3 Joules of gas (HHV) to make 1 Joule of electricity, so if you want to maximize the gas in the field for propellant usage, you’ll use solar and wind to run the liquefaction instead of burning gas in a generator (although they may still do that sometimes).

The gas in that field in Boca Chica is worth more to SpaceX than gas other places (or than exporting that gas to the pipeline infrastructure) because of lower logistics costs. So it makes sense for them to use plentiful solar and wind electricity instead of burning that limited gas supply inefficiently in an on-site generator.

[Robotbeat]

Just to do a bit more quantitative math, industrial gas in Texas has an average cost over the last decade (which has been very low by historical standards but seems reasonable for our purposes) of about $3/MMBTU, or 1¢/kWh-thermal. But that’s thermal energy. To convert that to electricity using a generator at 33% HHV efficiency (that’s for a big generator. Smaller ones are less efficient) means 3¢/kWh-electric worth of gas and another 1.5¢/kWh-electric in marginal maintenance costs (not counting the capital cost of the generator as you might want that for backup, potentially) for a total of 4.5¢/kWh-electric.

SpaceX has a gas well on-site which makes it potentially more valuable (once cleaned) than industrial gas due to logistics costs but it is small, and therefore finite. So its value to SpaceX is at least the industrial gas price and perhaps even higher.

Wind costs 2.5¢/kWh in Texas, perhaps even lower. https://nawindpower.com/innergexs-griffin-trail-wind-project-achieves-financial-close

Solar in similar climates in the US can even be lower than 2¢/kWh, even with some storage: https://www.utilitydive.com/news/los-angeles-solicits-record-solar-storage-deal-at-199713-cents-kwh/558018/

So I think it is reasonable that SpaceX has decided to use solar/wind/storage primarily for electricity requirements as the price for that is about half the cost as it would be if you valued their gas price as the same as industrial gas in Texas. And it’s practice for what they’ll need on Mars eventually and it’s better for the climate.

[Nomadd]

 Wind production is already going surplus on certain days because the transmission network can't handle all of it all the time. It would be pretty inefficient storage, but anything that could use that surplus, including CH4 synthesis, wouldn't cause more fossil juice usage.
 But batteries or other storage schemes would no doubt be a lot cheaper and way more efficient.
 Most jobs touting a "Green power source" would be much more efficient in preventing or removing carbon from the air if they used the money needed to build the source to replace generation in areas where it would reduce fossil fuel usage the most and claim the credit where they're using grid power for their project.

[Robotbeat]

Wind production is already going surplus on certain days because the transmission network can't handle all of it all the time. It would be pretty inefficient storage, but anything that could use that surplus, including CH4 synthesis, wouldn't cause more fossil juice usage.
 But batteries or other storage schemes would no doubt be a lot cheaper and way more efficient.

Yeah, the problem of relying on excess wind electricity is it’s only available like 5-10% of the time. If a new wind turbine has 33% capacity factor and costs $1.3/watt, whereas the electrolysis equipment has a capital cost of $2/Watt, then the useful average cost for using “free extra” electricity is ($2/Watt)/(10%) = $20/Watt while the directly wind coupled electrolysis is ($1.3/W+$2/W)/(.33) = $10/Watt average, or half the price. And you can do even better if you mix in a little solar and storage, too, perhaps bringing the average capacity factor up to 67% or so. (Could get to 100% capacity factor by over sizing the wind, solar, and battery, but that’s not usually worth it until your grid is totally clean.)

If electrolysis capital costs get low enough, though, then maybe it’d be worth it (like 10¢/Watt).

[Robotbeat]

SpaceX’s installation in Boca is getting big enough that they could have enough scale to use utility-scale solar and storage and cut down on transmission costs.

[Nomadd]

  What ever happened to Pons and Fleischmann?

 There is always the possibility that CH4 synthesis is for ISRU research. I'd think the air on Mars for that will be compressed to more than 1 Earth atm, so it should be easy to reproduce Martian conditions.

[Robotbeat]

As far as I know, SpaceX has no CH4 synthesis going on at Boca Chica, just liquefaction equipment like used to produce liquid oxygen, nitrogen, and methane (from the air and their well). This is still a kind of ISRU and would be needed as part of any ISRU plant on Mars as well. It also makes sense economically and climate-wise to do this liquefaction using solar (and maybe wind) with a little bit of storage.

I actually think it’d be cool if they did CH4 synthesis demonstration there anyway, but from what I can tell, they’re not doing it yet. Correct me if I’m wrong, Nomadd.

CH4 synthesis is extremely energy intensive. Need hydrogen (produced typically at 50-67% HHV plant-level efficiency), plus about 1/3rd of the hydrogen’s energy is thrown away when making CH4 using the Sabatier reaction, and you typically need about 8.8MJ per kg of CO2 captured from the air (although you could get down to half that).

CO2 + 4*H2 = CH4 + 2*H2O

44kg CO2 + 8kg H2 = 16kg CH4 + 36kg H2O.

8.8MJ/kgCO2
213MJ/kgH2
55.6MJ/kgCH4

387MJ for CO2 + 1704 MJ for H2 = 890 MJ of CH4 and 246MJ of waste heat from Sabatier and another 955 MJ of waste heat from hydrogen electrolysis.

But some of that CO2 energy could actually be provided from the waste heat from Sabatier, and so if you improve CO2 capture efficiency enough (below 246MJ) it may not add to the extra cost. Also, could improve hydrogen electrolysis hydrogen efficiency to like 75-80% HHV. So roughly 50% overall efficiency of electricity to CH4 if you try.

[DreamyPickle]

Methane production on Mars needs to work for years at a time without any hands-on maintenance or even live monitoring. A good step towards this is to build a couple of methane plants on earth and run them non-stop in order to stress-test the equipment.

It doesn't matter if the resulting methane is more expensive, they need to prove the technology.

[spacenut]

I have said before that I was an engineer for 40 years with a natural gas company.  Here are some of the problems with alternative natural gas production:

1) We tried feed stall gas by collecting cow manure from feed stalls.  This was put into a covered pond to retrieve the natural gas (95% methane) and it cost about 3 times what drilling/fracking cost, but it was doable. 

2) We tried seaweed in holding areas offshore that grew 6' a day.  It too cost over 2-3 times what drilling/fracking costs.

3) We drilled into the old Birmingham land fill and got 5 psi pressure of gas from a 1950's landfill.  Cost was cheap, but gas ran out after a couple of years. 

4) Algae has been tried by Exxon.  It is also 3-4 time more expensive than drilling/fracking. 

5) Sewer gas was tried, but humans do not generate enough methane for any real use. 

All of the above were considered "carbon neutral" by taking CO2 out of the air, making natural gas, then putting it back into the air. 

The number 1 producer of CO2 is China right now with a huge amount of cheap coal burning.

We in America are slowly switching to natural gas from coal.  This cuts over 50% of CO2 from a power plant. 

The next biggest CO2 producer is automobiles.  This is being reduced by hybrids and electrics.  Eventually electrics will take over. 

It is also more efficient (80%) to burn natural gas for heating, water heating, cooking, and clothes drying in the home vs burning the gas to produce electricity and send it to the home (33%).  So using natural gas in homes in America (50% of homes) reduces the need and of transmission of power to the home thus less CO2 in the end. 

Back in the 1970's a study was done to switch the natural gas distribution system in the US to hydrogen gas.  This would require almost all the electricity to be produced using nuclear power to make hydrogen gas during the electric off peek periods.  This could take years.  Also all of the existing natural gas appliances would have to have steel wool pads placed over to burners to glow red as hydrogen invisible when burning.  This would have to be done starting in Maine and working all the way back to the original natural gas sources.  This would take years and billions of dollars. 

Again, all of the above is carbon neutral, but costs far far more than people are willing to pay for.  Why should their $50 natural gas bill or cheap electric bill more than triple to pay for this. 

The number one thing that actually could be done quicker is to install some of these new nuclear power plants around the country to replace the coal and even the natural gas burners.  Fully one third or more of natural gas is being used to make electricity, while 1/3 goes to homes, and the other 1/3 goes to business and industry. 

The second is using more solar and wind in areas where wind is high and or there is far more sunny days.  Storage here is the problem. 

The third best thing is to get a hybrid or electric vehicle when you buy a new vehicle. 

I say all this to say using natural gas to extract the methane for the rocket fuel is the least expensive most way to go for now.  These rockets aren't going to use produce enough CO2 to change anything drastically.  One Superheavy/Starship launch is the equivalent gas that a small town would use in about a week.  Now a lot of launches would be a lot of CO2.  However, this can be offset by SpaceX selling solar or wind electric production. 

Nuclear power plants, especially the smaller ones could be installed quickly around the country, IF tax incentives were given to the power companies.  This would release a lot of natural gas for rocket use.  More than a rocket and hour.  There is also about a 200 year supply of natural gas already drilled and tapped in the US. 

[cdebuhr]

While they'll clearly want to set up pilot plants on Earth to produce CH4 and O2 from CO2 and water, it makes no sense whatsoever to attempt this using captured atmospheric CO2 (beyond the obvious eco brownie points), as it would have no real relevance to CO2 capture on Mars (which  is really mostly just a matter of compression).  Its not to say Terran CO2 scrubbers wont be needed at some point (and at the rate were going, we'll need 'em), but right now, you'd be MUCH better off using the (presumably) renewable power that would be needed to extract atmospheric CO2 to displace fossil fuel generation, and just buy liquid CO2 delivered by truck.

[Robotbeat]

Spacenut:

you’re assuming electrical heating would be resistive. But in the parts of the US that use natural gas for heating, heat pumps would be competitive. They offer a 3-4 times increase in heat output for electricity input, meaning even if you’re using natural gas fired combined cycle power plants, that is Still more efficient than burning the natural gas for heat directly. It seems like you’re cheating the laws of thermodynamics but you aren’t. (Combined cycle plants achieve a combustion temperature far higher than room temperature so there’s a lot of useful work that can be done).

Secondly, all your examples are different types of biogas, not actual Electrolysis and synthesis.

I agree nuclear is good (& also benefits a lot from storage, BTW), but solar and wind and storage are now so cheap and nuclear has become so expensive due to being locked in the courts for so long and also the inexperience of contractors that now you’re better off in the US just using solar, wind, and a bit of storage. Even with the curtailment necessary to get to a 100% capacity factor, still cheaper than nuclear has become (unfortunately). Even so, I’ll defend any nuclear power plant in the US. We should keep them all running until we stop using hydrocarbons.

[born01930]

Cold fusion fell by the wayside when Fleischmann's yeast business took off.

33% efficiency is for a steam plant, gas turbines with HRSG are well north of 60%

[Robotbeat]

Cold fusion fell by the wayside when Fleischmann's yeast business took off.

33% efficiency is for a steam plant, gas turbines with HRSG are well north of 60%

I don't think so. Combined cycle plants are above 60% LOW heating value (I believe 62.something is the record, and not a long-term number... 63% may be a newer record), which is cheating (whenever folks are going for efficiency records, they always use a denominator that makes their numbers look the best). The High heating value efficiency even for the best combined cycle plants is only 50-55% (and those are large, over 100MW with a fairly high capital cost). 33% HHV efficiency is typical for ~500-1000kW natural gas generators.

SpaceX isn’t going to build a 400MW advanced combined cycle plant with a $1.1/Watt capital cost just for refrigeration needs, so we’re comparing solar and wind and storage with 33% HHV efficiency natural gas generators.

[CameronD]

I say all this to say using natural gas to extract the methane for the rocket fuel is the least expensive most way to go for now.  These rockets aren't going to use produce enough CO2 to change anything drastically.  One Superheavy/Starship launch is the equivalent gas that a small town would use in about a week.  Now a lot of launches would be a lot of CO2.  However, this can be offset by SpaceX selling solar or wind electric production. 

Nuclear power plants, especially the smaller ones could be installed quickly around the country, IF tax incentives were given to the power companies.  This would release a lot of natural gas for rocket use.  More than a rocket and hour.  There is also about a 200 year supply of natural gas already drilled and tapped in the US.

ISTM, when most rocket folks today speak of using "methane" for rocket fuel, a goodly percentage of the time they're launching with liquified natural gas (LNG).. so, you're right, it's not only the least expensive way to "extract" methane - it's actually the same thing. 

For the folks fussy enough to insist on pure methane because they like to use their engines more than once (eg. SpX), it's not a huge ask to separate out the liquid CO2 fraction (for sale to the nearest soft drink manufacturer) and the rest of the nasties (like H2S and the occasional acid) once you've compressed your natural gas stream enough to fill your fuel tank.
   

[ZChris13]

I say all this to say using natural gas to extract the methane for the rocket fuel is the least expensive most way to go for now.  These rockets aren't going to use produce enough CO2 to change anything drastically.  One Superheavy/Starship launch is the equivalent gas that a small town would use in about a week.  Now a lot of launches would be a lot of CO2.  However, this can be offset by SpaceX selling solar or wind electric production. 

Nuclear power plants, especially the smaller ones could be installed quickly around the country, IF tax incentives were given to the power companies.  This would release a lot of natural gas for rocket use.  More than a rocket and hour.  There is also about a 200 year supply of natural gas already drilled and tapped in the US.

ISTM, when most rocket folks today speak of using "methane" for rocket fuel, a goodly percentage of the time they're launching with liquified natural gas (LNG).. so, you're right, it's not only the least expensive way to "extract" methane - it's actually the same thing. 

For the folks fussy enough to insist on pure methane because they like to use their engines more than once (eg. SpX), it's not a huge ask to separate out the liquid CO2 fraction (for sale to the nearest soft drink manufacturer) and the rest of the nasties (like H2S and the occasional acid) once you've compressed your natural gas stream enough to fill your fuel tank.
 

Vulcan, New Glenn, and Starship all use the same stuff, which is cryogenic purified NG, which is almost entirely pure methane. ULA call it LNG because of marketing or something.
Is there anybody else using it?

[spacenut]

Spacenut:

you’re assuming electrical heating would be resistive. But in the parts of the US that use natural gas for heating, heat pumps would be competitive. They offer a 3-4 times increase in heat output for electricity input, meaning even if you’re using natural gas fired combined cycle power plants, that is Still more efficient than burning the natural gas for heat directly. It seems like you’re cheating the laws of thermodynamics but you aren’t. (Combined cycle plants achieve a combustion temperature far higher than room temperature so there’s a lot of useful work that can be done).

Secondly, all your examples are different types of biogas, not actual Electrolysis and synthesis.

I agree nuclear is good (& also benefits a lot from storage, BTW), but solar and wind and storage are now so cheap and nuclear has become so expensive due to being locked in the courts for so long and also the inexperience of contractors that now you’re better off in the US just using solar, wind, and a bit of storage. Even with the curtailment necessary to get to a 100% capacity factor, still cheaper than nuclear has become (unfortunately). Even so, I’ll defend any nuclear power plant in the US. We should keep them all running until we stop using hydrocarbons.

I live in the Deep South.  I have a fairly large house with gas heat/electric air on one side, and a heat pump/strip heat on the other side.  The gas is hot faster and the strip heat comes on when the temperature drops below 35-40 degrees which it does quite often between December and February.  Gas cooks better and faster, especially if you are canning or need more precise heat.  Gas heats water faster and cheaper over the life of the water heater than solar.  Our local housing project put in solar water heaters with gas back up.  They determined the solar wasn't worth it after about 5 years.  They had constant problems keeping enough hot water without the gas.  It didn't save the housing project any money and actually cost more in the long run.  So they took out the solar and used gas water heaters only.  Even clothes drying in cheaper.  I changed out my old gas heating and air conditioning units.  The heating was still working, but the air conditioning side compressors burned up after about 25 years.  New air is cheaper on bills, but the heat pump in it's second year is giving trouble, but still in warranty.  Heat pumps sound good on paper and the power company gives kickback money for HVAC people to install them.  However, they are more troublesome and the life expectancy on them is about 1/3 less than a standard air condition/gas heat system. 

I have kept up with my bills.  Gas is much less expensive.  2/3rds of electricity is lost in the transmission from the generator to the power meter at your house.  This is the main reason electricity cost's more than natural gas.  Only 20% of the cost of gas at your home is lost in the pumping and transmission via pipeline to your house.  You see the problem.  You loose efficiency in burning gas to produce power, then in the transforming up and down to get to your house, and the resistance in the powerlines.  It is more efficient to take the gas directly and use it at your house.  It doesn't matter how efficient the electrical appliances are, you still loose 2/3rds of the power in the transmission to your home. 

As far as nuclear.  The small tractor trailer size completely self contained nuclear power plants are what should be installed around the country.  They do not melt down and are designed to last about 20 years without human hands touching them.  They can be controlled remotely to adjust power as demands change.

Wind is about the same cost as natural gas, if you live in the plains states where you have a constant wind, for producing power.  Solar is only competitive in the Southwest where you have more sun.  You also have to factor in the battery storage costs and lifetime maintenance of any type of energy.  Natural gas can be cheaply stored as LNG during summer months to be released in winter.  Solar can easily help with air conditioning bills in the Southwest during the day, while using conventional energy at night when demand is less.  One thing I don't like is the power company in Massachusetts was going to install windmills off Cape Cod a few years ago.  The people voted it down because they didn't want to look out at sea and see windmills.  They installed a fuel oil power plant.  However, most coastal areas have a constant breeze where windmills can be installed and 90% of the worlds people live within 300 miles of an ocean.   Killing birds is the biggest problem. 

From what I have experienced in life.  Homes should be built semi-underground.  In my area 3' deep is a constant 60 degrees F year round.  I personally know a man who built his house semi-underground near me.  He faced is open side north (Deep South).  He went a year without heat or AC.  He got up to 85 degrees in the summer on a 102 degree day.  He got down to 62 degrees on a 14 degree day.  Humidity was his biggest problem.  He ended up having to install a HVAC system.  He only needed a wood fire place to take the chill off on real cold days in winter.  He needed the air conditioning to take out the humidity.  He said between cooking, showers, clothes washing, the humidity built up in the house.  He did use a dehumidifier most of the time. 

Manufacturing metals uses a lot of heat from either coal or natural gas.  Natural gas is now used mostly on soft metals and glass making.  Coal on iron and steel making as it gets hotter.  Right now electricity costs way too much to smelt metals.  Recycling metals uses far less energy. 

I know this is all kind of off topic, but again, using natural gas for rocket fuel is not going to change much.  Changing the way we produce power and drive cars is going to make the biggest dent in CO2 emissions. 

[Robotbeat]

Why are people liking that post? 2/3rds of electricity is lost from generation to your meter? Nope. Try 5% according to the EIA. You’re off by LITERALLY more than an order of magnitude. With massive incorrect statements like that, I stopped reading there. Not worth responding to any of the rest, spacenut.

[CameronD]

The gas in that field in Boca Chica is worth more to SpaceX than gas other places (or than exporting that gas to the pipeline infrastructure) because of lower logistics costs. So it makes sense for them to use plentiful solar and wind electricity instead of burning that limited gas supply inefficiently in an on-site generator.

Getting back to the original question, you missed one option:  burning a little of the natural gas to compress the remaining gas stream - which, come to think of it, is what happens at most natural gas wells anyway.  http://www.solarturbines.com

The next step (which isn't a big one) is to liquify it.. although the infrastructure, permits, operating and maintenance costs to do all that are probably a lot higher than spending the money on a few solar panels and concentrating on your core business: flying rockets... and so it makes sense for them to use plentiful solar and wind electricity instead.
 

[Robotbeat]

The gas in that field in Boca Chica is worth more to SpaceX than gas other places (or than exporting that gas to the pipeline infrastructure) because of lower logistics costs. So it makes sense for them to use plentiful solar and wind electricity instead of burning that limited gas supply inefficiently in an on-site generator.

Getting back to the original question, you missed one option:  burning a little of the natural gas to compress the remaining gas stream - which, come to think of it, is what happens at most natural gas wells anyway.  http://www.solarturbines.com

The next step (which isn't a big one) is to liquify it.. although the infrastructure, permits, operating and maintenance costs to do all that are probably a lot higher than spending the money on a few solar panels and concentrating on your core business: flying rockets... and so it makes sense for them to use plentiful solar and wind electricity instead.
 

Absolutely it’s normal to use some of the gas to compress the rest. I’m saying why it doesn’t necessarily make sense for SpaceX to do that. And liquefaction is basically just compression & expansion with some heat exchangers thrown in for good measure.

[spacenut]

I was always told it was 66%.  This is the heat loss from burning coal or gas, making steam, friction turning a generator, then transmission.  Lots of transference of power from one form to another.  Heat loss, friction, etc. 

The pure product going straight to the house is a better transference.  It is only 20% directly from the well head to the house meter.  Pure natural gas only has to be filtered, go through a vertical separator to removed liquids at the bottom like ethane and butane and some water and helium at the top.  Then it is about 95% pure methane.  Most is already under pressure coming out of the ground.  One well in Mobile bay was 1,400 psi coming out of the well for several years.  It only has to be pressurized near the end of the transmission systems. 

Thus the more efficient method of transference of power.  Even nuclear power has efficiency losses making steam and turning a turbine. 

[Tommyboy]

Why are people liking that post? 2/3rds of electricity is lost from generation to your meter? Nope. Try 5% according to the EIA. You’re off by LITERALLY more than an order of magnitude. With massive incorrect statements like that, I stopped reading there. Not worth responding to any of the rest, spacenut.

I don't know which post you are referring to, but maybe you're confusing things. Indeed only 5% of electrical energy is lost between generation and your meter, but 2/3rds of the energy is lost between the well/mine/whatever and your meter.

[tbellman]

I was always told it was 66%.  This is the heat loss from burning coal or gas, making steam, friction turning a generator, then transmission.  Lots of transference of power from one form to another.  Heat loss, friction, etc. 

That's a very different thing from "2/3rds of electricity is lost in the transmission from the generator to the power meter at your house" that you wrote (my emphasis).

Yes, there are large inefficiencies in converting heat to electricity.  I believe a good power plant is almost 60% effective in turning heat to electricity, and then you have some further, but comparatively minor, losses, including about 5% transmission losses in the electrical grid.  66% inefficiency end-to-end might be a little bit high, though, but not hugely off.

Of course, no-one sane uses electrical heating.   You should use the left-over heat from electricity production to heat water in your district heating system.  That increases total efficiency of the system.  (But my understanding is that the US has very few district heating systems.  Using cleanly produced electricity to power heat pumps getting heat from the air or from the ground is often a good alternative.)

(Edit to add: By "heating" in the paragraph above, I mean general heating of living spaces.  Heating for cooking is a different case.  Producing warm water for your water taps can use district heating, unless it is a low temperature system.)

[AC in NC]

I was always told it was 66%.  This is the heat loss from burning coal or gas, making steam, friction turning a generator, then transmission.  Lots of transference of power from one form to another.  Heat loss, friction, etc. 

That's a very different thing from "2/3rds of electricity is lost in the transmission from the generator to the power meter at your house" that you wrote (my emphasis).

Yes, there are large inefficiencies in converting heat to electricity.  I believe a good power plant is almost 60% effective in turning heat to electricity, and then you have some further, but comparatively minor, losses, including about 5% transmission losses in the electrical grid.  66% inefficiency end-to-end might be a little bit high, though, but not hugely off.

56% inefficiency is the best reported here for a particular nat-gas generator cycle.  Overall the numbers (even still in 2019 -- 2nd link) look very much like the 66% inefficiency he discussed.  I agree it read like he said specifically transmission but that doesn't make sense and allowing for imprecise articulation (which happens a lot) I don't find much to criticize.


https://www.eia.gov/tools/faqs/faq.php?id=107&t=3

To express the efficiency of a generator or power plant as a percentage, divide the equivalent Btu content of a kWh of electricity (3,412 Btu) by the heat rate. For example, if the heat rate is 10,500 Btu, the efficiency is 33%. If the heat rate is 7,500 Btu, the efficiency is 45%.

Average annual heat rates for specific types of fossil-fuel generators and nuclear power plants:
 https://www.eia.gov/electricity/annual/html/epa_08_02.html


http://insideenergy.org/2015/11/06/lost-in-transmission-how-much-electricity-disappears-between-a-power-plant-and-your-plug/

Energy lost in power plants: About 65%, or 22 quadrillion Btus in the U.S. in 2013
Energy lost in transmission and distribution: About 6% – 2% in transmission and 4% in distribution – or 69 trillion Btus in the U.S. in 2013

[spacenut]

Natural gas no matter how you look at efficiencies, is still cheaper to heat anything home wise vs electricity.  It is the cost to the home owner per unit of heat.  Cheaper in cost, and longer lasting appliances.  Heat pumps are ok in Florida, but when you get below freezing, natural gas is much cheaper to operate.  Otherwise natural gas companies would be out of business because everyone has electricity, but only 50% of Americans have natural gas because they live in cities and small towns.  Most new gas furnaces have 90% efficiency. 

Also, I used a gas water heater to heat my home.  It was about 90% efficient because heat would cycle twice before the water heater had to heat the water.  It was called a hydro-heat force air system.  Now the water heater went out after about 20 years and it took both a plumber and a HVAC guy to replace it.  That is one reason they didn't sell well. 

Another reason electricity costs more per unit of heat energy.  Maintenance.  It costs more to install and maintain overhead power lines with storms and weather conditions than underground gas pipelines.  During my 40 years of work my company replaced all the old cast iron gas mains with polyethylene plastic lines.  All high pressure steel lines were coated with a plastic or vinyl coating.  90% of leaks were from someone digging and cutting a gas line.  We got rid of almost all mechanical underground connections with either plastic or welded steel.  A gas leak is money lost by not selling it.  Some companies are better than others at maintenance and replacement. 

I'm sorry I looked it up and used the wrong terms.  2/3rds of initial energy is lost from power production to the meter, not in transmission.  While 20% of initial gas energy is lost from the well head to the meter.  Some gas is tapped to run compressors to keep the pressure up and constant downstream of the well head pressure. 

We also studied using natural gas in fuel cells to produce electricity.  They are basically only 60% efficient.  Burning gas in a turbine generator is much more efficient, especially if you tap off the heat coming out if the turbine to run a downstream steam generator.  Yes only carbon dust is left out of a fuel cell and water vapor, but until they become more efficient power companies are not going to use them. 

[Robotbeat]

Modern heat pumps work just fine in below freezing temperatures. Can get remarkably high efficiency. With newer combined cycle power plants (which have increased a lot compared to even 2015) being 50-55% HHV efficient, transmission losses being only ~5%, and coefficient of performance of heat pumps being around 3 to up to 4 for new ones (meaning 300% and 400% "efficiency), it's pretty common to do even better than break even with electrical heating even if electricity is combined cycle natural gas. (And natural gas furnaces are not perfectly efficient. 80-90%, with some heat leaving in the form of flue gases and water vapor. Plus, line losses can exist in natural gas infrastructure as well. Needs to be pumped.)

Cost-wise, it's almost the same between heat pump (40% of whose electricity comes from nuclear or renewables, and rising) and gas... with natural gas having lower appliance capital cost but higher risk of indoor air pollution plus the fixed cost of having a natural gas line.

But this is all a distraction. Spacenut's long post full of errors and anecdotes got us off-topic.

[Lar]

(mod) The general economics of natural gas seem only tangentially related, so long discussions of  how the US can improve energy balances and greenhouse gas emissions are off topic. Robotbeat posted some calculations on why in this particular use case (with a finite and small amount of gas that is worth more than any other gas because it's RIGHT THERE) he feels it makes sense to not use that gas in a local generator but instead use solar/wind/grid and preserve 100% of the gas as feedstock.

Refute his numbers. But don't argue about why we need thorium reactors.

Savvy?

[waveney]

Natural gas no matter how you look at efficiencies, is still cheaper to heat anything home wise vs electricity.

No it is not.  We have an Air source heat pump this runs on Electricity.  Our Electricity bill went up (a bit) when it was installed, the Gas cost went to zero.  We have had a net gain.

[spacenut]

Depend on where you live and how cold it gets.  Natural gas companies would not be in business if heatpumps (regardless of how efficient) and the subsequent COST of electricity were lower.  Like Robotbeat said, solar power fed into the grid makes more economic sense.  Also what was the efficiency of the gas unit you replaced.  New furnaces are 90% efficient.  Hydroheat is overall even more efficient.  Another thing is what is the cost difference of the equipment + the life of the equipment + the cost of the fuel over the life of the equipment.  Heat pumps can be more expensive the higher the efficiency and the shorter lifespan of the equipment vs gas. 

Natural gas is very cheap in the US. Way cheaper than in Europe.  Therefore the reason for using it for methane rocket fuel vs making it.  We even export it to Europe, thus adding to it's cost in Europe. 

[Lee Jay]

you’re assuming electrical heating would be resistive. But in the parts of the US that use natural gas for heating, heat pumps would be competitive. They offer a 3-4 times increase in heat output for electricity input, ...

You can't say that.

Heat pump coefficient of performance is STRONGLY influenced by temperature difference.  It can be 10 or 1 (1 is the same as resistive heating).  My car has an air-source heat pump.  It reaches a COP of 1 at about 14°F when the inside temp is set to 70°F.

[Lee Jay]

Depend on where you live and how cold it gets.

Absolutely correct.

[Robotbeat]

you’re assuming electrical heating would be resistive. But in the parts of the US that use natural gas for heating, heat pumps would be competitive. They offer a 3-4 times increase in heat output for electricity input, ...

You can't say that.

Heat pump coefficient of performance is STRONGLY influenced by temperature difference.  It can be 10 or 1 (1 is the same as resistive heating).  My car has an air-source heat pump.  It reaches a COP of 1 at about 14°F when the inside temp is set to 70°F.

Yes, I can, and I am well aware of the temperature dependence. 3-4 is an average number, and stationary heat pumps exceed the effectiveness of your car's heat pump. Even good air source ones can achieve a total COP>2 even *well* below zero Fahrenheit (total COP>2 down to -13F for cutting edge air source heat pumps: https://www.energy.gov/sites/prod/files/2016/04/f30/32212_Shen_040616-1135.pdf ). To say nothing of the more complicated to install ground source ones which have much less temperature dependence.


But again, this is all completely besides the point, and y'all keep getting smacked down on it, so stop. Focus on my actual point.

[abaddon]

I was always told it was 66%.  This is the heat loss from burning coal or gas, making steam, friction turning a generator, then transmission.  Lots of transference of power from one form to another.  Heat loss, friction, etc. 

The pure product going straight to the house is a better transference.  It is only 20% directly from the well head to the house meter.  Pure natural gas only has to be filtered, go through a vertical separator to removed liquids at the bottom like ethane and butane and some water and helium at the top.  Then it is about 95% pure methane.  Most is already under pressure coming out of the ground.  One well in Mobile bay was 1,400 psi coming out of the well for several years.  It only has to be pressurized near the end of the transmission systems. 

Thus the more efficient method of transference of power.  Even nuclear power has efficiency losses making steam and turning a turbine.

Quoting you:

2/3rds of electricity is lost in the transmission from the generator to the power meter at your house.

You wrote that electricity (not energy) was lost "in the transmission".  What you write above, including generation, is clearly different.  Yes, conversion of matter to energy in the various ways we can do that is quite lossy, but is irrelevant to transmission of said power.

(EDIT: As usual, I am LTTP)

[Lee Jay]

you’re assuming electrical heating would be resistive. But in the parts of the US that use natural gas for heating, heat pumps would be competitive. They offer a 3-4 times increase in heat output for electricity input, ...

You can't say that.

Heat pump coefficient of performance is STRONGLY influenced by temperature difference.  It can be 10 or 1 (1 is the same as resistive heating).  My car has an air-source heat pump.  It reaches a COP of 1 at about 14°F when the inside temp is set to 70°F.

Yes, I can, and I am well aware of the temperature dependence. 3-4 is an average number,

For what climate?  Florida or Alaska?

The average can be below 1 or above 10 depending on the climate.

and stationary heat pumps exceed the effectiveness of your car's heat pump.

I don't know, my car has a pretty high-end variable-speed gas-injected heat pump.

Even good air source ones can achieve a total COP>2 even *well* below zero Fahrenheit (total COP>2 down to -13F for cutting edge air source heat pumps: https://www.energy.gov/sites/prod/files/2016/04/f30/32212_Shen_040616-1135.pdf ).

That's a research project (I work for the DOE EERE).

To say nothing of the more complicated to install ground source ones which have much less temperature dependence.

Ground source requires digging up the yard or drilling.  It's possibly practical on new construction, very impractical on retrofit.

But again, this is all completely besides the point, and y'all keep getting smacked down on it, so stop. Focus on my actual point.

Then don't bring up off-topic points!

[Lee Jay]

2/3rds of electricity is lost in the transmission from the generator to the power meter at your house.

The actual number in the US is 7% grid losses (plus/minus a percent or so).  It was 6% in October 2020:

https://www.eia.gov/electricity/


Total net generation (thousand MWh)     314,401
Retail sales (thousand MWh)       295,738               


Total net generation is what comes out of the power plants.  Retail sales is what is measured at the meters.  The above numbers are 6% apart.

[Nomadd]

 Burning methane to make electricity to synthesize methane reminds me of an army project. They put 12 volt backpack radios in Jeeps by mounting them in a 110 volt chassis that was powered by a very old tech, inefficient 110VAC inverter hooked to the Jeep battery. In the end, they were using about 5 amps of vehicle 12VDC to produce 1 amp of 12VDC for the radio, When I asked someone why they didn't just hook the radio to the 12VDC vehicle power, they said something about efficiency and jobs programs.

[Robotbeat]

you’re assuming electrical heating would be resistive. But in the parts of the US that use natural gas for heating, heat pumps would be competitive. They offer a 3-4 times increase in heat output for electricity input, ...

You can't say that.

Heat pump coefficient of performance is STRONGLY influenced by temperature difference.  It can be 10 or 1 (1 is the same as resistive heating).  My car has an air-source heat pump.  It reaches a COP of 1 at about 14°F when the inside temp is set to 70°F.

Yes, I can, and I am well aware of the temperature dependence. 3-4 is an average number,

For what climate?  Florida or Alaska?

The average can be below 1 or above 10 depending on the climate.

and stationary heat pumps exceed the effectiveness of your car's heat pump.

I don't know, my car has a pretty high-end variable-speed gas-injected heat pump.

Even good air source ones can achieve a total COP>2 even *well* below zero Fahrenheit (total COP>2 down to -13F for cutting edge air source heat pumps: https://www.energy.gov/sites/prod/files/2016/04/f30/32212_Shen_040616-1135.pdf ).

That's a research project (I work for the DOE EERE).

To say nothing of the more complicated to install ground source ones which have much less temperature dependence.

Ground source requires digging up the yard or drilling.  It's possibly practical on new construction, very impractical on retrofit.

But again, this is all completely besides the point, and y'all keep getting smacked down on it, so stop. Focus on my actual point.

Then don't bring up off-topic points!

I didn't bring it up. I smacked down spacenut's off-topic post (he lives in the Deep South, too, if you must know the climate... but better than 3 COP average in Alaska is possible as of 2016 in that paper). And your post just confirmed what I actually said (I said groundsource is more complicated, you simply expounded on that, didn't refute it. I pointed out what was possible for *cutting edge* air source heat pumps, and linked to a DOE paper, which you just reiterated that it was a DOE cutting edge heat pump, which is what I said. And yeah, even your car's heatpump--while no doubt containing impressive engineering to make it feasible for automotive applications--isn't comparable to stationary ground source ones... which is fine because it only has to significantly outcompete resistive for it to make sense for your car).

Again, focus on my actual point (which is summarized in the title) so I don't have to smack down these off-topic points any more.

[spacenut]

Natural gas and coal fired power plants are only 32-42% efficient.  Then you have the 4-7% transmission efficiency loss.  Thus only about 2/3rds of the usable energy in coal or natural gas is available at the meter.  I looked it up. 

However it is 80% usable energy delivered from the well to the meter for natural gas. 

If you still had coal delivered to your house for an old coal fired furnace it would be more efficient use of energy than through a power plant. 

Again, I challenge Robotbeat to install a heat pump with strip heat at his home in Minnesota and compare it to a natural gas heated home with standard electric air conditioner.  In my area alone, natural gas still beats a heat pump in 3 months of winter for heating that I get.

Efficiency doesn't mean squat if electricity costs more per kilowatt hour than gas costs per therm.  Electricity costs more because of heat heat and mechanical losses of energy. 

Thus natural gas is cheaper to make into methane for rocket fuel than making it from solar at this point in time.  If Joe Biden stops fracking and drilling, natural gas will skyrocket in price.  Same with gasoline.  Then electricity will skyrocket in cost, especially if natural gas goes up and coal prices go up if he stops mining of coal.  We have to look at the coal hard reality of cost per unit of heat energy delivered. 

I do however think there should be a transition to nuclear, solar, and wind over time.  This would allow the power companies to move to cleaner energy without the high costs of immediate conversion to keep the cost/kwh down to affordable levels.  This is already slowly being done by converting coal fired plants to natural gas.  This has cut a ton of CO2 from the air.  Then we should transition to nuclear and solar and wind where it is cost effective. 

For the next 10 years or so, natural gas will be the rocket fuel of choice.  The US has an estimated reserve of natural gas of about 200 years.  So if you stopped fracking and drilling, we will still be using gas for the foreseeable future.  Remember business and industry use 1/3 of the gas now.  This includes most restaurants, laundries, glass making, soft metal smelting, etc. 

I just wish people would stop worrying about whether Musk is going to make methane or use natural gas for the methane.  It doesn't really mater.  All we need to worry about is when the Starship/Superheavy becomes operational. 

[Lee Jay]

Natural gas and coal fired power plants are only 32-42% efficient.

Combined cycle gas plants can be 60% efficient.

https://en.wikipedia.org/wiki/Combined_cycle_power_plant#Efficiency_of_CCGT_plants

Then you have the 4-7% transmission efficiency loss.  Thus only about 2/3rds of the usable energy in coal or natural gas is available at the meter.

That's true.

I looked it up. 

However it is 80% usable energy delivered from the well to the meter for natural gas. 

But your furnace or water heater may be only 80% thermally efficient.  80% of 80% is 64%.  If you use a heat pump of COP=3 run by a CCNG plant running at 60%, well, 0.6*0.94*3 = 169.2% (versus 64%).  Yes, there are 95% efficient condensing furnaces and such but using the numbers above, you can afford electricity to be more expensive at the meter than gas is, by about 3.75x (3/0..  Electricity at my house is about 5x more expensive than gas, so it's not a net win, but not by much.  And if you can get COP above 4, you're close to a tie - with less primary energy used.

If you still had coal delivered to your house for an old coal fired furnace it would be more efficient use of energy than through a power plant. 

Again, I challenge Robotbeat to install a heat pump with strip heat at his home in Minnesota and compare it to a natural gas heated home with standard electric air conditioner.  In my area alone, natural gas still beats a heat pump in 3 months of winter for heating that I get.

Efficiency doesn't mean squat if electricity costs more per kilowatt hour than gas costs per therm.  Electricity costs more because of heat heat and mechanical losses of energy. 

But the combined efficiency depends on local climate.  And the real cost of each source depends on many things.

[docmordrid]

>
But your furnace or water heater may be only 80% thermally efficient. 
>

Our furnace has an AFUE rating of 95%. In MI we seriously need it.

[Robotbeat]

>
But your furnace or water heater may be only 80% thermally efficient. 
>

Our furnace has an AFUE rating of 95%. In MI we seriously need it.

I assume that's efficiency based on LHV. That's just 86% efficient by HHV.... So you CAN in principle get a 105% (theoretical limit is 111% but that requires like an infinitely long heat exchanger) efficient furnace (LHV) if you have a condenser. In fact, you might have a condenser already to get to 95% LHV.

Of course, that also applies to natural gas combined cycle plants. Their record efficiencies tend to be record in terms of LHV. The ratio is 1.11. So the 63% efficiency is actually 57%. But Lee Jay's overall point stands...



...and this is all off-topic except to point out that you should use HHV (which include the heat of water vapor in the exhaust) when doing calculations of fundamental energy content, which is relevant for synthesizing methane vs burning it. Otherwise you end up mixing LHV and HHV all over the place. Methane has a HHV of 55.6MJ/kg which is ALL the energy you get from burning it.

(And THAT'S my attempt to yank us back on topic.)

[Lee Jay]

>
But your furnace or water heater may be only 80% thermally efficient. 
>

Our furnace has an AFUE rating of 95%. In MI we seriously need it.

Was there something unclear about the sentence a few sentences later, "Yes, there are 95% efficient condensing furnaces..."?

[watermod]

Go to the energy god page for the US:
https://flowcharts.llnl.gov/
End the argument

[Robotbeat]

Old gas wells are frequently used to store gas for future use.  Like store in summer for use in winter.  The wells already had gas in them until they ran out of gas due to low pressure at the well head.  SpaceX might use the old gas wells as storage of methane for future liquification.  Thousands of cubic feet (how gas is measured in the US), can be stored in these abandoned wells in gas form under pressure.  Then release the gas to be liquified for liquid methane for rocket us. 

Even natural gas can be bought cheaply on the spot market in bulk and stored in these wells.  Or, gas could be made synthetically and stored.  If good records were kept on these wells as the gas was extracted, they know home many cubic feet of gas they can store in them.  It avoids the construction of large pressurized or liquified above ground tankage.  Makes perfect sense, especially if a lot of rockets are going to be launched from Boca Chica.

This is from another thread, and it's a *really* good point that I hadn't even thought of.

They could just use that old well for storage as well. Or, maybe start by tapping a bit of the methane that's left, and then keep all their infrastructure in place for liquefaction at that field and when they're ready to start synthesizing, they can just pump it into that field for super cheap long-term storage (allowing them to totally decouple their methane synthesis from methane demand, in terms of seasonal energy availability).

[spacenut]

Also, whenever they decide to make methane, these wells could store it.  Solar is only good during the day when they can make the methane and store it for night launches.  These wells are a win-win situation.  Store cheap available natural gas now and whenever they begin to make methane, use these storage wells which are on site.  No need for large storage domes. 

[Robotbeat]

Also, whenever they decide to make methane, these wells could store it.  Solar is only good during the day when they can make the methane and store it for night launches.  These wells are a win-win situation.  Store cheap available natural gas now and whenever they begin to make methane, use these storage wells which are on site.  No need for large storage domes.

Yeah, and I suspect the well is large enough for seasonal variations, not just daily.

[spacenut]

They would not have drilled a well initially if there wasn't a good payback source of natural gas.  Just a few days worth would not be worth the cost.  A few years worth would recoup the cost of drilling and make a profit.  If they played out, they only have air in them, unless water got in them, and the natural gas or methane can be pumped in and the air out.  Methane is lighter than sea level air and will rise, so a pipe can be inserted near the bottom while natural gas or methane is pumped in.  This would allow for the air to be released and when methane starts to come out, valve off and continue pumping to the maximum the pumps can produce and monitor pressure to make sure there is no leaching into the surrounding rock.  They can do this with air first to see how much pressure the well will take before it begins to leach out. 

From what I understand there are about 5 (+/-) wells at Boca Chica.  This may be able to store thousands of ft^3 of gas for future use.  Why bring it by truck, when you can pipe it in on a continuous bases over time.  Just a small 2" (50mm) pipeline can store a lot of gas over a 24/7 time when not launching.  It can be ran along the roadside like utility via Brownsville to Boca Chica if there is not already one there when the wells were producing.  If it has been abandoned it would have to be tested for leaks before activating.  This is done with air and peppermint or gas odorant.  Lots of cheap simple things can be done now. 
 

[CuddlyRocket]

Solar is only good during the day ...

Boca Chica seems a reasonable place for a wind turbine (or two)!

[Lar]

They would not have drilled a well initially if there wasn't a good payback source of natural gas. 

As I understand it, the well was there already. I didn't think SpaceX drilled any new gas wells.

[Okie_Steve]

Except for the water well that they drilled, SpaceX bought the land with the wells extant. There is one nominally producing  horizontal gas well and a vertical injection/disposal well in the yellow pipe grassy patches near the front center of the site. Nearer to the entrance beside the huge pipe elbows is another yellow pipe grassy patch with two more horizontal wells. One used to be a producing gas well and was plugged and then redrilled a different direction from the same surface location, resulting in a dry hole that has not been plugged.

The nominally producing gas well has a diagonal surface pipe running over to the suspected generator pad.

For gas storage it might be possible to drill out the plugged gas well and use it or maybe even the dry hole formations.

[spacenut]

They would not have drilled a well initially if there wasn't a good payback source of natural gas. 

As I understand it, the well was there already. I didn't think SpaceX drilled any new gas wells.

I was referring to the initial drilling of the well maybe 20-30 years ago or more, whoever drilled it would not have if it didn't have a good payback.  So, it is there, and SpaceX can reuse it to store gas.   Don't know how big the underground hollow cavity is but maybe ground penetrating radar could determine that.  Also, if the original owners knew how much gas was extracted and how much pressure it had.  That can give you an idea of how much methane can be stored. 

[edzieba]

The gas well was drilled, tapped, and not-technically-but-in-practice abandoned once continued operation was beyond economic value. The only reason it was not capped at that time as required by law is that capping is expensive, and technically 'operating' a few grams per year is cheaper. It is safe to assume that any gas remining is either too low in volume to make extraction worthwhile, too poor quality to make extraction worthwhile, or both.

From the other discussion:

It's an interesting idea for bulk storage, but it would almost certainly require reprocessing of the extracted gas before it can be used as propellant (regardless of how pure the methane you pump in is, it's going to pick up contaminants before you pump it back out) in addition to re-chilling and re-compressing back to a liquid, as well as road transport to the launch site tanks. That seems like a lot of work in order to have the fleet of tankers drive a short distance to your LCH4 reprocessing site rather than drive a slightly longer distance to existing LCH4 reprocessing and storage sites near Brownsville already owned and operated by someone else. Given that you'd need to purchase and transport LCH4 from those facilities to fill the gas reservoir in the first place, as well as needing an on-site tank farm to collect the re-extracted and post-filtered post-liquified gas again before it can be unloaded to tankers to move to the launch site, it seems like a lot of hassle to go to for little benefit.

[Robotbeat]

It makes more sense for storing on-site synthesis than trucked in LNG. There are byproducts in synthesis anyway.

[Okie_Steve]

The gas well was drilled, tapped, and not-technically-but-in-practice abandoned once continued operation was beyond economic value. The only reason it was not capped at that time as required by law is that capping is expensive, and technically 'operating' a few grams per year is cheaper. It is safe to assume that any gas remining is either too low in volume to make extraction worthwhile, too poor quality to make extraction worthwhile, or both.

From the other discussion:

It's an interesting idea for bulk storage, but it would almost certainly require reprocessing of the extracted gas before it can be used as propellant (regardless of how pure the methane you pump in is, it's going to pick up contaminants before you pump it back out) in addition to re-chilling and re-compressing back to a liquid, as well as road transport to the launch site tanks. That seems like a lot of work in order to have the fleet of tankers drive a short distance to your LCH4 reprocessing site rather than drive a slightly longer distance to existing LCH4 reprocessing and storage sites near Brownsville already owned and operated by someone else. Given that you'd need to purchase and transport LCH4 from those facilities to fill the gas reservoir in the first place, as well as needing an on-site tank farm to collect the re-extracted and post-filtered post-liquified gas again before it can be unloaded to tankers to move to the launch site, it seems like a lot of hassle to go to for little benefit.

Yes and no. Given the extreme glut of natural gas in the US market due to shale gas fracking there could still be considerable reserves available that are not economically viable to produce *AND TRANSPORT TO MARKET* but which could make sense to produce for local consumption. What that potential local use might be is still unclear. Generator, hydrogen source for insitu practice, propellant, liquification/purification  practice pending a pipeline etc,.

[Lar]

If you want to store gas, is it safe to put gas into a dry hole? I would think you would want to find a formation you knew was gas tight, or was when you stopped pumping out, anyway.

The dry hole might have reached an area where fractures led to the surface and let gas leak out, no? I have no idea if that's geologically correct though.

[Nomadd]

 It's not likely that well is going to be good for that much. For the cost of servicing that well and putting it back into production they could probably run a 12" pipeline to the Annova facility 5 miles away. It's also not known if the disposal well is still usable.

[CameronD]

If you want to store gas, is it safe to put gas into a dry hole? I would think you would want to find a formation you knew was gas tight, or was when you stopped pumping out, anyway.

The dry hole might have reached an area where fractures led to the surface and let gas leak out, no? I have no idea if that's geologically correct though.

It's certainly amusing to think that your wonderful store of gas might be being sucked out by the next guy down the road - hey if it's in the ground it's free, right??

A far more common practice (over this way anyways) that is probably not that much more expensive in the long run is to compress it for storage (as CNG) in tanks on site and/or road transport to someplace else by the highest bidder.

[spacenut]

The gas well was drilled, tapped, and not-technically-but-in-practice abandoned once continued operation was beyond economic value. The only reason it was not capped at that time as required by law is that capping is expensive, and technically 'operating' a few grams per year is cheaper. It is safe to assume that any gas remining is either too low in volume to make extraction worthwhile, too poor quality to make extraction worthwhile, or both.

From the other discussion:

It's an interesting idea for bulk storage, but it would almost certainly require reprocessing of the extracted gas before it can be used as propellant (regardless of how pure the methane you pump in is, it's going to pick up contaminants before you pump it back out) in addition to re-chilling and re-compressing back to a liquid, as well as road transport to the launch site tanks. That seems like a lot of work in order to have the fleet of tankers drive a short distance to your LCH4 reprocessing site rather than drive a slightly longer distance to existing LCH4 reprocessing and storage sites near Brownsville already owned and operated by someone else. Given that you'd need to purchase and transport LCH4 from those facilities to fill the gas reservoir in the first place, as well as needing an on-site tank farm to collect the re-extracted and post-filtered post-liquified gas again before it can be unloaded to tankers to move to the launch site, it seems like a lot of hassle to go to for little benefit.

Capping a well, oil or gas that is above ground is easy compared to deep sea wells which are much harder.  They usually have a valve on the drill pipe they can just close.  If the pressure is real high it is harder to close.  If the well plays out, it has very little pressure.  I believe these wells at Boca Chica are valved off and capped if they are not producing. 

The deeper the well, usually the higher the pressure.  The BP well was deep offshore.  You not only had the pressure of the earth against the well below the water level, but the water pressure alone was hard to work against to cap the well.  My company had a well in Mobile bay that produced over 1,400 psi for several years and never lost pressure.  It is expected to last many years.  It produced so much gas they ran a large pipeline from Mobile bay all the way to Bimingham.  This line also fed into the cross country pipeline going to Florida, middle Alabama and Georgia and one going across the northern part of Alabama feeding Atlanta.  Other gas was also coming from Texas and Louisiana. 

[Nomadd]

 You don't get to just cap a well and forget about it. It needs to be plugged at the end of it's life, which isn't a small operation when it's almost 2 miles deep. If you wait too long and the casing starts to deteriorate, you have a problem.

[FutureSpaceTourist]

twitter.com/thesheetztweetz/status/1352735219766464512

SpaceX  — through subsidiary "Lone Star Mineral Development"  — intends to drill natural gas wells near the company's Starship facility in Texas, likely for the methane that fuels its Raptor rocket engines, reports Bloomberg's @SergioChapa:

https://www.bloomberg.com/news/articles/2021-01-22/spacex-plans-to-drill-for-natural-gas-next-to-texas-launchpad

https://twitter.com/thesheetztweetz/status/1352735971297665024

Lone Star is in a legal dispute with Dallas Petroleum Group before Texas' energy regulator, over ownership claims inactive wells on an 806-acre plot of land.

[Okie_Steve]

The Bloomberg article has this tidbit about fracking equipment at the site.

"During Friday’s hearing, Dallas Petroleum CEO Matt Williams shared aerial photos that he said showed company equipment near the wells had been disconnected, while drilling and hydraulic-fracturing gear it doesn’t own had been moved onto the property."

Interesting. Not that I could identify or tell oil field equipment apart even if my life depended on it mind you.

[su27k]

https://twitter.com/elonmusk/status/1470519292651352070

SpaceX is starting a program to take CO2 out of atmosphere & turn it into rocket fuel. Please join if interested.


Will also be important for Mars

[Vultur]

Well, they will need the technology for Starship's Mars ISRU anyway since the Martian atmosphere is CO2, so why not get ecological/PR points for developing it?

Seriously doubt it will be a significant source for "Earthside" operations though, due to cost.

And Earths atmosphere actually has less CO2 than Mars's... 410-420 ppm out of ~100kPa is about 41-42 Pa, vs 95% of Mars's atmosphere... nominal datum 610 Pa, but probably more at likely landing sites, so 600-800 Pa maybe?

Partial pressure of CO2 maybe 15-20 times greater on Mars?

And Mars is a lot colder than South Texas, so if you are using cooling to separate it, it's lower energy too.

[meekGee]

Well, they will need the technology for Starship's Mars ISRU anyway since the Martian atmosphere is CO2, so why not get ecological/PR points for developing it?

Seriously doubt it will be a significant source for "Earthside" operations though, due to cost.

And Earths atmosphere actually has less CO2 than Mars's... 410-420 ppm out of ~100kPa is about 41-42 Pa, vs 95% of Mars's atmosphere... nominal datum 610 Pa, but probably more at likely landing sites, so 600-800 Pa maybe?

Partial pressure of CO2 maybe 15-20 times greater on Mars?

And Mars is a lot colder than South Texas, so if you are using cooling to separate it, it's lower energy too.

Unless they find a convenient industrial source of CO2 exhaust.

[john57sharp]

  What ever happened to Pons and Fleischmann?

There is a glimmer of hope still, UK entrepreneur Richard Dinan is hoping to produce small fusion reactors once the world wakes up to the possibility, all hopes pinned on the giant ITER working in the next 5 or so years (NB not 30!) He’s also looking at HETs and recycled plastic fuel motors, all very relevant. More here https://ukspacebulletin.wordpress.com/2021/12/08/richard-dinan-making-nuclear-fusion-reality/


Cheers
John

[CS88]

Well, they will need the technology for Starship's Mars ISRU anyway since the Martian atmosphere is CO2, so why not get ecological/PR points for developing it?

Seriously doubt it will be a significant source for "Earthside" operations though, due to cost.

And Earths atmosphere actually has less CO2 than Mars's... 410-420 ppm out of ~100kPa is about 41-42 Pa, vs 95% of Mars's atmosphere... nominal datum 610 Pa, but probably more at likely landing sites, so 600-800 Pa maybe?

Partial pressure of CO2 maybe 15-20 times greater on Mars?

And Mars is a lot colder than South Texas, so if you are using cooling to separate it, it's lower energy too.

Unless they find a convenient industrial source of CO2 exhaust.

Put it on the back end of any ethanol plant. They spew out CO2 (to the atmosphere) from fermenting the corn into ethanol, which is then used as an additive for gasoline.

[Twark_Main]

Well, they will need the technology for Starship's Mars ISRU anyway since the Martian atmosphere is CO2, so why not get ecological/PR points for developing it?

Based on the prior discussion here....   shouldn't the answer be obvious?

Because that would be dishonest and greenwashing.

R&D is good. Dishonesty is bad.

[Vultur]

I don't think it is really dishonest though.

It wouldn't make environmental sense to use as an on-Earth fuel source *today*. But if one expects the electric grid to be very low carbon & have lots of excess capacity at some times of the year, then it will make sense.

Musk is very optimistic on solar as the primary energy source for civilization, and so I think he expects that situation to arrive sooner than most would expect.

EDIT: Also, there may be a secondary goal here: as a demonstration of how you can have things that require liquid fuel, and can't work off batteries, still work in an "all-electric" future. This is arguably a "PR" goal (as I don't think anyone really believes that synthetic fuels are impossible) but not, I think, a dishonest one. It's arguable that demonstrating that might actually speed up the transition.

[Twark_Main]

I don't think it is really dishonest though.

It wouldn't make environmental sense to use as an on-Earth fuel source *today*. But if one expects the electric grid to be very low carbon & have lots of excess capacity at some times of the year, then it will make sense.

As long as that is made clear, then yes I agree it's not dishonest.

If we're giving a simplistic taking carbon out of the air = good narrative (which I've already seen examples of "in the wild"), then it's dishonest.

[DistantTemple]

Well, they will need the technology for Starship's Mars ISRU anyway since the Martian atmosphere is CO2, so why not get ecological/PR points for developing it?

Seriously doubt it will be a significant source for "Earthside" operations though, due to cost.

And Earths atmosphere actually has less CO2 than Mars's... 410-420 ppm out of ~100kPa is about 41-42 Pa, vs 95% of Mars's atmosphere... nominal datum 610 Pa, but probably more at likely landing sites, so 600-800 Pa maybe?

Partial pressure of CO2 maybe 15-20 times greater on Mars?

And Mars is a lot colder than South Texas, so if you are using cooling to separate it, it's lower energy too.

Unless they find a convenient industrial source of CO2 exhaust.

Put it on the back end of any ethanol plant. They spew out CO2 (to the atmosphere) from fermenting the corn into ethanol, which is then used as an additive for gasoline.

And/or from cement kilns. Since its from the chemical process, maybe a high % of CO2. Co2 from Cement is a difficult nut to crack, Musk making use of this would be interesting.

[Robotbeat]

True, hooking it up to a cement factory would be kind of low hanging fruit.

[DistantTemple]

True, hooking it up to a cement factory would be kind of low hanging fruit.

That's exactly the point.
Also CO2 from cement production is a big issue, as there is little that can be done to reduce it. Therefore capture and storage or reuse is an "common good". 7% of global CO2 emissions (phys.org https://phys.org/news/2021-10-concrete-world-3rd-largest-co2.html) is from cement production.
If you can get it fairly concentrated, it appears easier than scavenging it at 410ppm!

[Robotbeat]

Hey that’s 418ppm now! Gets easier every year!
*nervous laughter*

[AndyH]

Since Elon's in Texas, he can skip all the intermediate steps and go straight to methane capture.

https://www2.tceq.texas.gov/oce/eer/index.cfm?fuseaction=main.getDetails&target=373798

EMISSIONS EVENT

Venting of field gas is occurring at Ratliff Booster Station due to the shut down of compression units from the below freezing weather conditions. The shut down resulted in rising pipeline pressures that caused the safety vent valve to open.

25 tons of methane free for the taking.

[MP99]

For the folks fussy enough to insist on pure methane because they like to use their engines more than once (eg. SpX), it's not a huge ask to separate out the liquid CO2 fraction (for sale to the nearest soft drink manufacturer) and the rest of the nasties (like H2S and the occasional acid) once you've compressed your natural gas stream enough to fill your fuel tank.

If that CO2 is pure enough to go for food use, then it would be an ideal feedstock to a Sabatier plant.

Cheers, Martin