My understanding is that if we could turn off all the coal plants tomorrow we could actually significantly reduce greenhouse gas emissions.
Would it buy us a significant amount of time if we accelerated the conversation to natural gas?
https://www.vox.com/energy-and-environment/2019/5/30/1864381...
https://www.scientificamerican.com/article/coal-ash-is-more-...
What's more scary is the production of things like rare earth minerals - that quite heavily concentrates the uranium and thorium as part of the extraction process, producing large quantities of relatively radioactive mining waste.
Anyway, methane is a short term problem. It's CO2 that is long term.
Coal adds much more CO2 to the atmosphere. At least twice as much?
Rather than losing more time waiting for the perfect solution, a big step 10 years earlier might buy us additional time.
Leakage is a problem with straightforward extant solutions, but well operators are poorly incentivized to implement those solutions—the loss is often too small to substantially impact their profit, and the leak is invisible (natural gas being colorless) so it's easy to turn a blind eye and not implement effective monitoring.
I would expect the only credible thing we can do is design it out, e.g. by running seal vents to flare rather than safe location, improving reliability, flareless operation etc.
I imagine the majority of "leakage" must be unburnt hydrocarbon in flare and GT exhausts.
But when you say "straightforward extant solutions" what are you referring to? In the industry, nobody particularly assesses "leakage" or really designs for minimising leakage per se.
Clearly with that being the case, one needs much bigger more expensive pipes.
I am quite interested in the idea of methane leakage though. There seems to be a growing consensus online that it exists and is significant, but within industry it is really not recognised.
An interesting perspective.
You sound as if you have relevant first-hand experience. From your knowledge, what is the state of aerial/satellite detection? Those are the solutions that I've seen cross my news feeds in recent years.
To put it in perspective, we have another low-tech approach where you put tape around a potential leak point, spray a soapy mixture, then count the bubbles. The pass/fail criterion is measured in bubbles per minute. Yet inside the pipe you measure the flowrate in tens or hundreds of tonnes of gas per hour.
Possibly unburnt hydrocarbon in the flare could contribute to this "leakage" but flares are designed for complete combustion so I can't imagine it would make any difference in terms of GHG emissions compared to the already-considerable CO2.
We already have plenty of fixed gas detectors and personal gas monitors around site that are sensitive to about 0.04% methane (I think) so I can't really picture a satellite doing anything better.
The initial testing is all very well, and I have no reason to expect it's at all ineffective, but I imagine it would be more interesting to look at the consequences of wear/weathering over time.
I suppose my biggest question is the mechanism by which those (fixed and personal) detectors work. I know that the aerial solutions work via lidar, and I expect satellite similarly looks for absorption in particular wavelengths.
https://spectrum.ieee.org/tech-talk/at-work/test-and-measure...
yes. in 2018 40% of all CO2 emissions were from coal: https://ourworldindata.org/co2-and-other-greenhouse-gas-emis...
that graph is the simplest possible way to think about "dealing with climate change". Its a checklist: #1 coal. #2 oil. #3 gas.
Gas has been a "transitional" fuel in the sense that its made the last decade less bad than it would have been, but given the timeline left* its already too late to build new gas infrastructure, assuming you intend to finance it with 30 year bonds.
* per the ipcc in order to stay under 2C emissions need to hit zero somewhere between 2040 for rich/western countries and 2055 for the whole planet, and then be followed by negative emissions for the rest of the century
> Coal power plants in the US have been retiring at an average clip of 10 gigawatts per year as the clean energy transition takes hold. That may sound impressive, but it’s not nearly quick enough, considering that climate change is already buffeting the Earth. The pace has to pick up quickly in order to avoid more catastrophe. That’s where a new thing called solar-for-coal swaps comes in. The “swap” part is a bit complicated, but if the idea catches hold it could speed up coal power plant retirements and skim more than 20 gigawatts right off the top.
> In a new white paper, the clean energy group Energy Innovation has identified some low hanging coal fruit, in the form of 179 gigawatts that can’t compete on cost with solar any more. These coal units are still operating for various reasons even though solar saves money, but Energy Innovation has picked out a group of 22.5 gigawatts that could be rolled over in short order.
https://cleantechnica.com/2020/08/09/solar-for-coal-swaps-co...
This is Detroit and fuel efficiency all over again. Look how good we are doing dragging our feet! (Even though the results allow a lot of cool things).
Natural gas conversion mostly reduces particulates. The EIA data says natural gas produces more CO2/MkWh than coal:
Electricity generation CO2 emissions million kWh million metric tons million short tons pounds per kWh Coal 1,124,638 1,127 1,240 2.21 Natural gas 1,246,847 523 575 0.92 Petroleum 21,860 21 23 2.11
https://www.eia.gov/tools/faqs/faq.php?id=74&t=11
Ironically, particulates decrease insolation and actually slightly reduce warming (CO2's half life is a lot longer than particulates, so the "cooling" is short-lived and will go away when you stop burning coal, net warming, overall). Natural gas doesn't produce as many particulates, so I would expect that converting to natural gas would increase global warming in the short and long term compared to continue to burn coal.
It's far better to switch to solar/wind/geo/nuclear than natural gas in the long run, but there are health benefits to removing the coal particulates:
"Coal impacts: air pollution When coal is burned it releases a number of airborne toxins and pollutants. They include mercury, lead, sulfur dioxide, nitrogen oxides, particulates, and various other heavy metals. Health impacts can range from asthma and breathing difficulties, to brain damage, heart problems, cancer, neurological disorders, and premature death." https://www.ucsusa.org/resources/coal-power-impacts#:~:text=....
I presume that the primary driver of this conversion isn't the environment, but economics. The price of coal/kWh is more expensive than the volume of gas required to generate the same kWh. The Total system LCOE is usually the number people want to minimize. https://www.eia.gov/outlooks/aeo/pdf/electricity_generation....
tl;dr: No. Burning gas is worse from a climate perspective.
Maybe this[1] or this[2] is clearer.
[1] https://www.eia.gov/environment/emissions/co2_vol_mass.php
[2] https://www.eia.gov/electricity/annual/html/epa_a_03.html
That table says there's slightly more kWh generated from natural gas (1,246,847) than from coal (1,124,638). I assumed they read this wrongly and thought this was CO2 emissions per kWh.
The best number to read from that table is the last column, "CO2 emissions - pounds per kWh":
Natural Gas: 0.92
Coal: 2.21
So yeah, natural gas's CO2 emissions are much lower.
Countries/ regions that show dark brown are mostly relying heavily on coal. Getting on for 1 gram per watt-hour of CO2, which is ludicrous.
In a few cases they've managed to find something even less environmentally responsible to burn than coal, such as oil or the most pants-on-head crazy electrical generation method - peat†, which unless somebody starts a national project of shooting endangered animals and then burning the corpses as fuel ought to stand as the least responsible way to make power.
† In theory burning wood could be sustainable because you really could grow enough wood quickly enough to power a not insubstantial electricity plant forever. You probably shouldn't but you could. Peat does not form quickly enough for that to ever be practical.
Gas plants are much better from that point of view but still too expensive. Renewables are really killing it on the cost front and with viable energy storage solutions coming online even a role as peaker plants is not going to be a long term thing for gas plants.
Economics are also the reason nuclear is not happening. It's just too expensive and risky for operators to get involved in. When prices below 0.02$/kwh are becoming normal for new solar bids, that kind of puts the squeeze on everything else. Even gas. And there is no sign of this being a final price, this will likely dip well below 0.01$ at some point.
The only reason for investments like this is short term gains while production capacity for clean energy simply can't cover the whole market just yet. So converting coal plants makes sense to replace expensive capacity with slightly less expensive capacity while enough cheap capacity to replace it is short term just not there yet.
Solar and wind require gas plants as balance when the sun is not shining and the wind is not blowing. All other "infinite" energy sources such as coal or nuclear don't have enough dispatchability to perform solar/wind load following. Hydroelectric has a high dispatchability but is not infinite (the lake level gets too low and you have to wait for the next rain).