Nothing really is the "best bet" in this. The correct solution is to hedge your bets by betting on just about every possible solution. The local resources available dictate just too much what is the "best" solution but even then one should not put all the eggs in one basket.
But solving the electricity problem is just solving one part (~25%) of the equation. There is still a lot of greenhouse gasses being released from cars, construction (concrete), farming and various industrial processes. But the electricity seems to be the easiest problem to solve and once we have that on track to being fixed we can move more resources into the other issues.
> Nothing really is the "best bet" in this. The correct solution is to hedge your bets by betting on just about every possible solution. The local resources available dictate just too much what is the "best" solution but even then one should not put all the eggs in one basket.
It aggravates me to no end that people are fighting this pointless nuclear vs. renewables war, all the while fossil fuels are laughing all the way to the bank.
Should be invest in building nuclear? YES! Should we invest in wind and solar? YES! Should we invest in grid-scale storage? YES! Should we invest in transmission capacity? YES!
> But solving the electricity problem is just solving one part (~25%) of the equation. There is still a lot of greenhouse gasses being released from cars, construction (concrete), farming and various industrial processes. But the electricity seems to be the easiest problem to solve and once we have that on track to being fixed we can move more resources into the other issues.
Electricity is in some ways the easiest problem, yes, but also once we have clean electricity we can use that to decarbonize many other sectors. Transportation, to a large extent. Heating, yes. Many important industrial processes can use hydrogen, like steel production. Etc.
> But solving the electricity problem is just solving one part (~25%) of the equation. There is still a lot of greenhouse gasses being released from cars, construction (concrete), farming and various industrial processes. But the electricity seems to be the easiest problem to solve and once we have that on track to being fixed we can move more resources into the other issues.
With the exception of concrete and farming, the answer to the rest of these is "produce a shit load of power cheaply". A lot of industrial uses of fossil fuels are merely using them to heat something directly, like a boiler or a furnace. These kinds of work loads can be electrified, but the demand on our grid will go up massively.
Ditto with transit. We can make EVs now that are superior to ICE vehicles for 98-99% of use cases. We can make electrified rail transit a reality again if we want to. The issue is that we currently don't make enough electricity to meet current demands, industrial demands, and transit demands. We need a lot of electricity to do that, and we're currently nowhere close.
Not true: solar is the clear winner. Thus far, storage hasn't been important, but will become so soon. Very cheap iron-air batteries will roll out in 2023. Wind will remain important, as will long-distance power transmission.
Spending on other methods is not just wasted; it means not spending those dollars on solar.
But replacing Portland cement with one of the numerous carbon-neutral alternatives is urgent, as is building out all-electric ammonia and hydrogen synthesis: hydrogen for steel production, and ammonia to fuel retrofitted container ships.
Ok how do you use solar in Northern Europe during the winter? For 3 months you get less than 1% of the normal summer output (in most cases you will spend more energy just to melt the ice and snow off the panel)
Also hand waving the storage problem away with “just buy it from someone else using transmission lines” is naive. Basically that just makes you ultra reliant on those other countries that the line goes through of and whoever is on the other end of it. At least with coal and gas you can just ship it from some other party if politics block you from getting it from your current provider.
Where in Northern Europe? Norway, e.g., has lots of hydro. Iceland has geo. Different places will need different solutions. Wind is viable in many places. Tides, in some. Ships full of ammonia synthesized elsewhere will be right for some places, at times. (Norway is right now building a major industrial-scale ammonia synthesis plant.) And transmission lines will be important and unproblematic in many places (e.g. Sweden), even if not all.
The "storage problem" is solved by building out storage. Some places will need more storage than others; where you need a lot, underground or deep-water compressed air might be best. Transmission lines are a backup plan. You need to use everything. Cost matters.
Every unproven battery technology is "right around the corner." I would love cheap, scalable iron-air batteries to be available in 2023, but I am not holding my breath. We need to plan around technologies that exist, because we need to act now rather than wait 5 years before acting.
What we need to do now is build out solar panels. Until their share of generating capacity approaches a stability limit, spending on other tech is counterproductive.
Iron-air is not, in fact, unproven. Factories big enough to build what will be needed are right now under construction. We will need a lot. We will also need hundreds of ammonia and hydrogen production plants.
Just FYI, hydrogen fuel cells are hydrogen-air batteries. There's no rational reason to reinvent the wheel for what is basically an inferior version of hydrogen fuel cells.
Hydrogen fuel cells are not especially efficient, and are quite expensive. Efficient electrolysis is also expensive. Hydrogen storage is quite expensive. And, mitigating explosion risks around hydrogen is complicated. So, there are sound reasons to prefer other non-problematic storage.
If panels get cheap enough, overprovisioning to account for even a large round-trip loss may become a thing. Then, the cost of the storage and conversion equipment dominates. So, it seems like even after you have other reasons to make hydrogen anyway, a better storage medium seems worth using, too.
Nobody is quoting round-trip efficiency for the iron-air battery, so I would guess that is not very close to as good as lithium tech. Their descriptions of battery installations say they include a fraction of lithium cells; probably the lithium cells are used to smooth off the peaks, falling back to iron when the lithium cells get low. We have lots of other reasons to overprovision panels.
It is possible that, as hydrogen gets more integrated into the energy system, starting with steel production and later aviation, its use for primary storage will increase. That probably depends on developing cheap, volume production of aerogels for LH2 tankage. Cost will always be important.
The round-trip efficiency for iron-air is going to be worse or the same as hydrogen-air. They are both the same idea but iron-air is much less mature.
The other point is that hydrogen electrolysis and storage is cheap and in fact extremely so. In large facilities it is <$1/kWh and is basically unrivallable by anything else.
With iron-air, you charge by splitting rust to iron and oxygen, vent the oxygen, keep the iron in the battery; discharge by oxidizing the iron with oxygen from air. How do you get the iron to rust fast enough? How do you get the oxygen through the membrane and into the electrolyte fast enough? High pressure? Maybe you need thousands of cells in parallel to get much current flowing?
With hydrogen-air, you charge by separating water into hydrogen and oxygen, venting the oxygen, refrigerating and condensing the hydrogen into insulated tanks underground. (It slowly boils off, according as how good your tank insulation is; underground insulation can be very good.) Bank the removed heat? Discharge by boiling and then oxidizing the hydrogen to water vapor, condensing that to a tank for later, maybe using heat from condensation to help boil the LH2?
So, for iron you need to pump air to high pressure, and probably heat the iron. For hydrogen, you have to liquify it after it is hydrolysed, and move heat around a fair bit, and capture both H2 and (probably) H2O.
The Chileans are building a liquified-air (O2, N2) storage system. That charges by refrigerating and condensing air into insulated tanks, and pumping the removed heat into a heat reservoir. Discharge by boiling, using banked heat and latent atmospheric heat, venting through a turbine. The turbine needs much less maintenance than a steam turbine, because nothing gets hot.
I also heard that iron-air batteries are just another kind of metal-air batteries. The problem is that hydrogen-air batteries already exist, and are basically the same thing. Iron-air is therefore just reinventing of the wheel.
They vent the oxygen, and draw it back from the atmosphere as needed. Hydrogen would need to be stored, and probably liquified first. It is similar to the difference between a rocket and a turbojet: for efficiency, jets always win (except where you get to cruise through vacuum).
Nothing really is the "best bet" in this. The correct solution is to hedge your bets by betting on just about every possible solution.
This seems like a "fallacy of the option spectrum". Of course we don't try cold fusion or discredited options. Trying options based on how credit they seem is a reasonable approach but "try it 'cause it's a thing" isn't argument.
I agree, but would point out that "Try every option based on how credible it seems" is also an insufficient or under-specified answer, because the viability of each option depends on how much resources are invested in that option.
For example, if a trillion dollars were invested in nuclear reactors, it would probably be possible to build them fast enough and safely enough to satisfy most people, whereas spending just ten dollars on nuclear energy would not be enough to solve climate change. Similarly, over-building renewables and researching batteries with a trillion dollars might be enough to start reversing CO2 levels, but ten dollars won't make a difference.
Given limited resources, determining how to allocate them to maximise the probability of success is really the essence of the problem, rather than just identifying that there are several approaches that could be tried simultaneously.
I agree, but would point out that "Try every option based on how credible it seems" is also an insufficient or under-specified answer, because the viability of each option depends on how much resources are invested in that option.
I could say that how many resources an option has is a part of how credible it seems. But I didn't really specify an algorithm for choosing options, I just wanted to point out that "try it because it's an option" isn't argument in a world where one generally has unlimited hypothetical options.
Edit: all that said, different energy production methods have different capital intensity levels. You get zero for a ten dollar or even a ten million dollar investment in nukes today. Solar has lower capital intensity but can still can scale to meet needs.
The more money there is on offer for nukes, the bigger the corruption problem becomes. There is literally no upper limit on how much money corruption is willing to absorb.
But there is a lower limit, below which corruption will look elsewhere.
But solving the electricity problem is just solving one part (~25%) of the equation. There is still a lot of greenhouse gasses being released from cars, construction (concrete), farming and various industrial processes. But the electricity seems to be the easiest problem to solve and once we have that on track to being fixed we can move more resources into the other issues.