We have what we need to drastically cut emissions — but we're going to need much more
Great post on the necessity of an “all of the above” approach to decarbonization. I find it very telling that in an academic context (where I currently spend most of my time) this is really a matter of settled science.
I’m absolutely guilty of having wanted to pick the technologies that fit my meet my political preferences (and deride those that fit the preferences of my political opponents) but truly we are not in a position to leave some of our tools in the shed. There is indeed a clear role for energy with high levelized costs and for energy with low levelized costs, for CCUS and DAC and nuclear, etc.
I think it’s also refreshing that regardless of the political debate, the triple threat of BIL, IRA, and the Manchin permitting reform bill clearly demonstrate that policymakers know this also.
Just to give people some hard numbers, energy generated per mole of carbon dioxide emitted for the full combustion of some fuels in oxygen: methane: 802.31kJ, n-octane: 634.32kJ, carbon: 393.52kJ.
Natural gas is mostly methane; gasoline averages out as roughly n-octane; coal is very close to being pure carbon.
This gets you a decent estimate at a 4:3:2 ratio of energy per emission for gas : oil : coal. In fact, gas and oil are marginally better than that (gas is about 3.9% better; the composition of oils varies too much to get a number at this level of precision), but both have more emissions in production and refining (gas leaks and emissions in refining), so that tends to balance out.
If you know a bit of chemistry, the explanation is that the enthalpy of formation for water (less the enthalpy of formation for the two carbon-hydrogen bonds you have to break) is almost exactly half the enthalpy of formation of carbon dioxide (-393kJ/mol for carbon dioxide, -241kJ/mol for water vapor and about -37kJ/mol for two carbon-hydrogen bonds, ie half the enthalpy of formation of methane) - which means that four hydrogens in a hydrocarbon will generate about the same energy as one carbon, so the key thing is the carbon:hydrogen ratio in the fuel, which is 1C:4H in methane, 1C:2H in long-chain hydrocarbons and 1C:0H in carbon, ie coal.
Renewables becoming such a political battlefront has made being pro or anti nuclear also another dumb culture war.
Like, progs hate nuclear because they want 100% renewables. Cons love nuclear because it's an own-the-libs form of clean energy that isn't renewable. It's so exhausting.
Investing in these long shot technologies is my day job. I agree you just have to try a bunch of stuff and you won’t really know for decades what works. But at least the money and the talent is there now and things are happening. FWIW I’m more bullish on hydrogen than nuclear but hey I might be wrong. I can see the appeal in cold cloudy countries, but even they have the option of running transmission to the nearest sunny country.
I'll be honest, I have no idea who the intended target audience for this piece is. Basically noone serious in the field of renewables disputes that you need gas as a backup for the next five to ten years! You might be able to switch to hydrogen afterwards or massively invest in biomass or something, but the necessity for a backup is absolutely not disputed. This very much seems like "making up a guy to get mad at".
The problem with CCS, on the other hand, is more of a political one. We absolutely do need CCS to work in the future, because our progress has been much too slow the last few decades and we can't reach our climate goals without sucking like five percent of CO2 out of the atmosphere. Even the IPCC acknowledges that. The problem is that as of right now, CCS is a VERY unproven technology that is 20 years away at least. (Sort of like those small nuclear reactors everyone is talking about.) So it's hard to rely on it, because we don't know when we can actually deploy it on scale.
But lazy politicans love to use the prospect of CCS in the future as a pretext for taking not enough action in the present. This happens all the time in Europe. "I know that our ten-year plan doesn't actually reduce nearly enough emissions, but that's okay, we'll just do carbon capture in the future." That's why a lot of climate and energy experts are actually rather sceptical about carbon capture, because right now, all it achieves is climate action delay.
Matt said it well on the "political will" line: it's a weasel phrase that masks what's really being asked, and that's the will to sacrifice. They really need to be forced to say upfront that we're being asked to do things like give up cars, give up meat, and give up consumption in general. If they were regularly confronted with the heavy backlash that would come with it, they should then be more willing to admit that expanding clean* technologies dramatically is the better and more feasible way forward.
*As an aside, I really despise the term "renewable" as it's often used. We don't necessarily want energy sources that repopulate themselves, what we want are energy sources that don't use fossil fuels. Renewable is an ugly four syllables and nine letters, while clean is a (heh) clean five letters and one syllable.
One point to make on the need for direct air capture is that while it's a task for later this century, it's pretty clear we'll need to go beyond Net Zero and go Net Negative for some time to bring the climate back to something closer to pre-industrial normal.
As far as seasonality goes, we haven't even considered how we could reshape demand to take advantage of the peaks and troughs of very cheap but seasonally variable renewable generation. Would it be economically viable to run aluminium smelters 9 or 10 months of the year if the electricity was super-cheap for those months? Or bake bricks? Could California desalinate seawater when their energy is at its cheapest?
Yes, all of those cost money, but so does nuclear, and SMRs will be similarly expensive for decades to come (anybody who thinks otherwise is more than welcome to take a long bet with me on the topic).
"Because massively overbuilding renewables would not only cost a lot of money but wastefully consume vast tracts of land, it seems like a better idea would be to use long-term batteries. If you had really big batteries that stored electricity for a long time, you could simply store surplus power in the high season and unleash it in the low season."
In the spirit of focusing the energy debate on numbers, not adjectives (https://bit.ly/3LJLFUZ), Iet's look at some of the literature we have on this trade-off.
Perez et. al, 2020 find that "while unconstrained, intermittent renewable generation will achieve very low [cost] targets-they are already below grid parity-transforming PV into the firm, effectively dispatchable resource needed by world economies will be very costly if done with storage alone, even when considering the most aggressive future cost projections for storage. Overbuilding renewables can reduce the storage requirements to the point where true below parity firm generation will be attainable." (https://bit.ly/3SE0YRq)
Concretely: in Minnesota, 0% overbuilding of panel requires so much storage to deal with seasonal intermittency that cost of power shoots up to 28 cents/KWh, compared to 5 cents/KWh today. By contrast, 50% overbuilding (implying you'd throw away a third of the summer surplus) drives the cost down below grid parity, 5 cents/KWh. (The mix assumed here is 55% solar / 40% wind / 5% natural gas). (https://bit.ly/3SE0YRq) They've observed the relationship between overbuilding and cost across other geographies (https://bit.ly/3ULxov9).
The reason this happens is that 1.5x overbuilding of panels allows you to use 10x less storage (https://bit.ly/3SDZ3fG). That's the tradeoff.
This is just one study. I'm it has limitations (it's not clear whether the growing marginal cost for summer-surplus panels is factored into the cost figures above), and I'd love for folks to chime in with other evidence. The key claim here that solving seasonal intermittency via storage requires such profound amounts of storage that it will never be cost-effective.
But I do think it's worth a response!
Topics this important should get a multiple post treatment. Matt’s article is basically an articulate restatement of the obvious. It avoids the interesting questions that would deepen my understanding of climate:
1). How much solar and wind must one overbuild to achieve a given reduction in fossil fuel peak generation?
2). How expensive is this overbuilding?
3). How many degrees would the planet warm if we just deployed existing technologies at scale and still used fossil fuels for shipping and aviation? How effectively could seawalls and air conditioning mitigate this?
4). How much carbon can we remove from the atmosphere by planting trees?
There are probably consensus answers to these questions. I understand it’s commercially important that Matt publish every weekday. Matt has the chops to write an excellent Atlantic style feature every week or four intriguing blog posts on different topics. I would prefer the former, especially because Matt is running out of topics and doesn’t have much new to say about housing.
One of THE main advantages of a tax on net emissions is that it is neutral between more of existing technologies and to-be-developed new technologies while being guaranteed NOT to waste a lot of money on high cost technologies. Another is that it generate fiscal resources for useful things like assistance to lower income folks to offset the income effects of higher energy prices and and making energy saving investments like in heat pumps, AND resources for the growing costs of public investments in mitigation of fires, floods, and sea level rise.
Presumably, but more speculatively, a tax on net emissions may also stimulate better regulatory change.
It is annoying how renewable proponents hype the cheap marginal cost while ignoring the need to overbuild to avoid peaking and contingency plants.
Anyway, my view is that if this is really a crisis, then every option needs to be on the table. But that’s not what’s happening - people claim there is a crisis but then will oppose anything but their own narrow preferences.
Finally, I don’t think enough is said or done about the grid. If we are going to rely on intermittent power sources (renewables), then we need robust regional and national interconnects to account for weather and to provide resiliency.
The people who would oppose this are:
1) Those that deny any need to fight climate change.
2) The anti-growth/anti-human environmentalists who really just want most of humanity to go away.
3) The environmentalists who want everyone to drop everything else and focus 100% on fighting climate change right now, and won't settle for anything else.
4) The environmentalists who are theoretically okay with the 'everything but the kitchen sink' approach, but for strategic reasons don't want to entertain CCS because they think it will slow current progress down in cutting emissions.
Between all of those group, you probably have well over 50% of the population, unfortunately.
And the first 3 groups are basically lost causes.
Based on all that, we probably just need to focus on group #4 and all the apathetic-but-not-necessarily-opposed folks.
howdy Slow Boring climate tech nerds. If you feel like reading more about innovation in clean energy -- specifically, off-shore wind turbine technology innovation -- here's a nice interview with a developer at Sandia working on a new turbine design. (Hope this link is accessible: https://www.techbriefs.com/component/content/article/tb/pub/features/qa/46629?oly_enc_id=6799H0362467F0Z). In addition to explaining the new design, he goes through the cost-effectiveness calculations, limitations in how the industry currently designs and builds off-shore wind farms, and how they are consulting with a wide range of industries to optimize this design. Nerd out!
Gift of Fire on Medium (https://medium.com/@tgof137), my favorite "blogger" that I'm not sure anyone else has heard of, has a great series of posts that implicitly make the same point about the need for both flexibility and technological innovation:
He begins with some great posts about the scale of the challenge facing renewables:
That inevitably leads to nuclear, but even here there are problems because of the limited amount of uranium and where that is likely to lead us:
Anyway, my chemistry and physics knowledge isn't remotely good enough to critically evaluate his pieces, but I wanted to point others his way because I think he does such a great job of writing clearly about these issues:
P.S. Should add that I originally discovered Gift of Fire because he wrote the most comprehensive/best written articles I found debunking the anti-vaxxers:
Anyway, really just wanted to give this guy a shout because I think he is worth reading.
I'd like to push back on the argument that the land use issues from overbuilding renewables are insurmountable. We don't need that much land all told, fractions of a percent per state, and there's a lot of land that would suffice.
For instance, there's an analysis from Conservation Gateway of available land in Virginia that meets the criteria for grid-scale solar generation (near a high voltage transmission line, inexpensive to lease, available in large tracts, not in a conservation area, etc). Virginia needs about 0.5% of the state to become solar farms to meet their targets, and nearly 20% of the state is suitable for solar farm development.
Obviously not all of that land is being sat on by people willing to lease it, and there are good questions about whether we want certain kinds of farmland turned into solar farms and whether we're okay with taking down second growth forest or not in the process. But that's a large margin for figuring that out! I'm independently working on something similar for New York with a few colleagues, which is why this is top of mind for me.
Totally agree that we need to figure out how to make the overbuilt panels economical (otherwise, nobody is going to pay to lease that land in the first place!) but I'm feeling confident that the hydrogen generation / battery technologies / molten salt pits or whatever will become viable by the time we've built enough solar to be there. It's going to take a few decades.
 http://conservationgateway.org/ConservationByGeography/NorthAmerica/UnitedStates/virginia/Pages/solar-siting-va.aspx. Some colleagues and I are independently working on something similar for New York.
If Democrats are so smart about tradeoffs, why was Diabo Canyon even considered being taken down? Why has the international left been against building nuclear? I think it's actually still up in the air how captured Democrats are by anti growth environmentalists, and it seems clear to me that Diablo Canyon is only open because of a last minute energy crisis the Democrats did not forsee because that's just not something on the top of their minds.