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>Her group is calling for the natural gas system to carry a mandated share of renewable and decarbonated gases, including biomethane, synthetic methane and hydr

>Her group is calling for the natural gas system to carry a mandated share of renewable and decarbonated gases, including biomethane, synthetic methane and hydrogen, starting at 1% in 2021 and rising to 10% by 2030. Those are most likely volume percent... methane/natural gas has 3x the energy density of hydrogen so it pretty much does not have any effect on emissions but is mostly a publicity stunt.

alex_duf 7y ago
That's an interesting point. i just assumed that having a mix 90% methane, 10% hydrogen would reduce the carbon footprint by 10%. But what you say makes perfect sense, it all depends on how much energy we generate from the mix. Is there any literature or numbers on the subjects I could read somewhere?
- aurelwu 7y ago
  Sure, energy density can be looked up pretty much everywhere but here is a paper mentioning it, which might be otherwise interesting to you as well: https://afdc.energy.gov/files/pdfs/hyd_economy_bossel_eliasson.pdf#page=6 https://afdc.energy.gov/files/pdfs/hyd_economy_bossel_eliass... (middle of the page) To show that its really by volume they usually talk about, here just 1 example: https://www.energy.gov/sites/prod/files/2014/03/f11/blending_h2_nat_gas_pipeline.pdf#page=6 https://www.energy.gov/sites/prod/files/2014/03/f11/blending... ( first paragraph). Using volume percent is not directly a dishonest way to talk about it as that is pretty common way to look at things when it comes to gas and gas distribution networks, however it conveniently gives the wrong impression to a lot of people about potential emission savings - originally myself included ;). A 50% hydrogen - 50% methane/natural gas (by volume) mix just reduces the carbon footprint by ~22% (while requiring lots of investments, for example into gas turbines which work well with such a gas mix, lots of other end users also would have trouble with that mix)

alex_duf 7y ago

That's an interesting point. i just assumed that having a mix 90% methane, 10% hydrogen would reduce the carbon footprint by 10%. But what you say makes perfect sense, it all depends on how much energy we generate from the mix. Is there any literature or numbers on the subjects I could read somewhere?

aurelwu 7y ago
Sure, energy density can be looked up pretty much everywhere but here is a paper mentioning it, which might be otherwise interesting to you as well: https://afdc.energy.gov/files/pdfs/hyd_economy_bossel_eliasson.pdf#page=6 https://afdc.energy.gov/files/pdfs/hyd_economy_bossel_eliass... (middle of the page) To show that its really by volume they usually talk about, here just 1 example: https://www.energy.gov/sites/prod/files/2014/03/f11/blending_h2_nat_gas_pipeline.pdf#page=6 https://www.energy.gov/sites/prod/files/2014/03/f11/blending... ( first paragraph). Using volume percent is not directly a dishonest way to talk about it as that is pretty common way to look at things when it comes to gas and gas distribution networks, however it conveniently gives the wrong impression to a lot of people about potential emission savings - originally myself included ;). A 50% hydrogen - 50% methane/natural gas (by volume) mix just reduces the carbon footprint by ~22% (while requiring lots of investments, for example into gas turbines which work well with such a gas mix, lots of other end users also would have trouble with that mix)