This is what gets me. Relative efficiency of stuff is pretty much nullified when the energy used is free. Total power use still matters because it will determine the total size of the array of solar panels to generate the power needed.
But this is near and dear to my heart. I like hydrogen as energy storage. If you burn it, you get water. Natural gas is just CH4, so the output of burning it is 1CO2 + 2H2O. But a lot of natural gas stuff can also use hydrogen with little modification, so we don’t have to upend entire industries to adapt. Machines can be updated to use the new fuel type with little expense and we’re not throwing out entire production lines to replace them with ones based on electricity.
Why hydrogen? Simple, hydrolysis. Using power generated for free from the sun, you can split water into its base components. Hydrogen and oxygen. With some fancy knowledge, you can capture pretty much all of the hydrogen and none of the oxygen, and store it for use.
It’s inefficient compared to some other technologies, in that it takes a lot of power compared to how much hydrogen/oxygen you get, but bluntly, if it’s coming from solar, who cares? Not like we’re paying for the power anyways.
I keep thinking about this in the form of industry. Say a factory uses natural gas in boilers to make something hot. Whatever the material, whatever the reason, that’s what they’re doing. With little modification, the system can be adapted to hydrogen, and the company can build a hydrogen hydrolysis reactor on site using either city water, rain water, lake or river water… Even an underground well. The reactor runs all day and generates hydrogen, stored in a large, high pressure tank, also on site, then pipelines run it to the machines, boilers, whatever, to run the production lines. It’s free to run, and only requires a single capital investment.
Hydrogen, also, can be stored indefinitely and not “lose charge” unlike other, battery-based storage systems (or heat, or flywheels). So hydrogen is ideal for long term energy storage. Fuel cells are still the most efficient way to convert hydrogen to electricity, and yeah, you lose a lot of potential energy in the electrolysis/fuel cell conversions, but the energy input is free in the first place, so who cares?
I’m not saying we should go all in on hydrogen. I’m just saying that it’s worth continuing to develop the technology for it. Batteries, capacitors, storage via heat or flywheels, they all have their place in the energy future. At least until fusion makes them all obsolete (once we find a way to make that self fueling or use materials that are not extremely limited. IMO, we’re making good progress but we’re decades, if not centuries away from something practical, given our currently known planetary resources).
And yes, battery EVs are a good thing. Hydrogen electric vehicles… Let’s just say “too soon”, and leave it at that. Batteries for daily charge/discharge for home use, absolutely. Larger scale heat/flywheel storage, absolutely. But longer term than days to months, hydrogen may be the better option. It’s certainly a good option for industry that currently relies almost exclusively on natural gas.
Hydrogen is troublesome as an energy storage. The roundtrip efficiency (electricity -> hydrogen -> electricity) is just… very not worthwhile compared to batteries. Then beyond efficiency there is still the question of “how do we store hydrogen safely?”
Storing energy indefinitely is not a problem for electricity storage, since we are pretty much guaranteed to use the stored energy up in a single day.
Yep. When you’re using the energy quickly, within days or weeks, then hydrogen is extremely impractical.
The merits of hydrogen are in long term storage and cycles. A well built storage tank can last a lifetime. To be fair, a poorly built one might not last a year… So it’s very dependent on the external factors involved.
Batteries have their flaws, which I think we all know by now. Weight (regardless of state of charge), volume (energy density), charging speed, cycle life, etc.
It’s all about the application. Is the energy storage method going to be efficient for the desired outcomes.
Regardless of what other outcomes are in play, one that should be constant is to preserve the environment. Lithium technologies have reached a high level of development in recycling, so, for the most part, the environmental impact of end-of-life batteries is effectively mitigated to a large extent. This is a great thing that we have developed.
We need to do the same with solar PV panels, and mitigate as much of the environmental impact as we can from that as well. I know that’s something that’s being worked on, but we’re not at the same level of efficiency as we are with batteries, probably due to the comparatively long life of PV panels, vs the comparatively short lifetime of lithium cells. We’ve simply had a lot more lithium to deal with and find ways to recycle, so far. I’m sure PV panels recycling will come along as more early adopters upgrade to something newer, and more panels get into the stage where they need to be recycled. I haven’t checked in on PV panel recycling in a while so I’m not sure how outdated my information is.
To be clear, I am not, have not, and would never suggest that we move all our efforts into any technology, including, but not limited to, lithium, solar, wind, hydrogen, or anything else that’s been discussed. IMO, we need to leverage several technologies to achieve our long-term goal of global net zero, while meeting the energy demands of everyone.
I just feel like hydrogen is treated like a dead end technology, and I can’t blame the public for thinking so. A lot of the information about it as an energy storage solution is either very old, or still in its infancy. From electrolysis, which is a very old idea, to hydrogen fuel cells, which are extremely new by comparison. IMO, there’s a lot of work that can be done here, and we need to keep looking into it. Maybe it goes nowhere, maybe it becomes so practical that other solutions seem like shit by comparison. I don’t think either of those is likely, we’ll probably land somewhere in the middle of those extremes. I don’t know, and I’m not a scientist, so I’m just hoping we, as a society of people, keep working on it.
One thing I’m particularly excited for in this field is solid state batteries. But that’s also in its infancy. I know a lot of work is being done on them, so we’ll see what happens.
My point, if I have any point at all, is that we need to keep researching varied technologies for it. While solid state might be the right answer for EVs, and cellphones and most consumer electronics, they might not be the best solution for other applications. We need answers to energy demands of all sorts and giving up on something like hydrogen when there’s still research to be done, isn’t a great idea. We don’t know what researching a technology could uncover. Maybe an air battery that’s hyper efficient and has a high energy density, better than solid state technologies could hope to achieve. Maybe a lot of things. We just don’t know.
Let’s try everything and figure out what works for what application.
I agree that H2 can have certain applications as a bridge technology in some industries, but there is a very important parameter missing in your premise.
Even if solar power seems “free” at first glance it really isn’t. It needs infrastructure, e.g. Photovoltaic Panels and lots of it. So just having H2 instead of a battery for an application means, it needs thrice the PV capacity or even more and with it the grid capacity. Now add to that, we aren’t just talking about replacing electricity from fossil fuel plants by PV, but about primary energy as a whole, which makes the endeavor even more massive. Also H2 will not magically become much more energetically efficient in its production, transport, storage and usage, because there are physical limits. (Maybe with bacteria for production) The tech could and should get better concerning longevity of the electrodes for example. Also as the smallest molecule out there, storage will never be completely without losses. And long term storage requires even more energy and/or material.
All this is to say, that efficiency is still paramount to future energy supply, since also the material is limited or just simply because of costs of infrastructure and its implications on the biosphere. Therefore such inefficient energy carriers as H2 or what people call “e-fuels” should be used only where the enormous power and/or energy density is critical. H2 cars should therefore never be a thing. H2 or e-fuel planes, construction machines or tractors on the other hand could be more appropriate uses.
There’s certainly costs involved with solar. Even the act of cleaning the panels is going to increase maintenance costs. More panels to clean, more cost. More space needed for the panels, more cost. It might not be much per panel, but it’s still a cost. The wear of the panels is more cost, they only last so long before they degrade, and replacements are not free, so if the panels degrade without doing a lot of “work” (aka the outcome of having them) vs the cost of installing and maintaining them, was it worth it? These are all economic questions that also need to be considered.
Yes, it’s not free, but it’s the closest thing to “free” power we have. Literally pennies for gigawatt hours of output. If that power isn’t consumed, then it wasn’t useful to produce. Whether that generated power goes into batteries, homes, or hydrogen production, that’s going to be something we have to solve for.
I see a hydrogen reactor + fuel cell “generator” as a secondary storage system to batteries. When production is unusually high, push the power into hydrogen. It’s not nearly as efficient, but it can be stored for much longer without losing any. It can be stored far more densely than what can be accomplished by batteries. If the batteries are full and your PV plant is still pouring out unused watts, rather then let that energy go to waste, pushing it into hydrogen storage is a better option. If you don’t need it for 6 months, a year, two years? No big deal. When production is low and your batteries are almost out, just fire up the fuel cell and recharge from the excess energy you couldn’t put in the batteries. It’s inefficient, yes, but bluntly, it’s better than letting any of the excess production go to waste.
There’s other competing technologies for the same purpose. I see hydrogen as the second stage of storage. It’s not as good as the first stage, but it’s better than turning to fossil fuels to generate power.
I don’t know if that’s the right answer to the problem. I don’t know if it’s even a good idea. All I know is that it is possible. IMO, it’s not a bad idea.
I’ve said it before and I’ll say it again: if I’m saying anything at all here, it’s that we need to keep researching everything. I don’t want anyone to drop research on another technology to dedicate to hydrogen, just as I wouldn’t want anyone to drop hydrogen to research something else. We need to keep looking into this stuff.
There’s no single solution to our energy needs, as of right now. I don’t see one emerging in our lifetimes. The only goal I want to see pursued, if not obtained, is net zero for climate change. Stop the destruction of the environment, especially, but not limited to, our energy needs. Whatever gets us there, whether hydrogen, nuclear, fusion, solid state, flywheel, heat storage, thermoelectric, geothermal, hydroelectric, or whatever… I’m game. I feel like hydrogen still has a lot of discoveries that can be made, and I really don’t want to see it abandoned because of a lack of popularity in the consumer space. It’s there, it’s green, it’s got potential, let’s keep trying to get it to a place where it can be beneficial, just like with everything else in that market segment.
It is not only economic cost though. As I’ve mentioned, materials are also limited (on the same level as: There isn’t enough copper to wire all motors needed to replace all cars today with EVs). And it needs alot of surface area compared to the concentrated power plants of the past, which means an even bigger impact on the biosphere (especially if not done on rooftops in cities but in mountain ranges or fields, etc.). Don’t get me wrong; solar energy, if done right, is the only source that doesn’t interfere with natural cycles and does not increase entropy of the planet (which makes it actually sustainable). Using it inefficiently though, means inefficient use of other resources which are limited. (Not only economic. But on that note: Public infrastructure is always built with costs in mind, because we shouldn’t waste tax money, so we can do a better and more comprehensive job with what we have.)
So if there is a more efficient way to store energy for long periods, then it should take precedence over a very inefficient one. This will get complex since it is very much dependent on the local conditions such as sunshine, water sources and precipitation, landscape, temperatures, grid infrastructure and much more. As an engineer, I would throw in though, that if you need this secondary storage, that is not much cheaper, doesn’t have some very essential advantage, or doesn’t mitigate some specific risk, but is much more inefficient over your primary storage, then the system’s design is… sub-optimal to put it mildly.
For the argument of exploring everything: We simply can’t. More precisely we could, but it would need much more time, money and resources to arrive at the goal. And since climate catastrophe is already upon us, we don’t have that time and need to prioritize. Therefore a technology that has a physical, not human-made, efficiency limit loses priority as a main solution. That doesn’t mean, that H2 should not be looked into (for specific purposes, where it is essential or the reuse of existing infrastructure is the better option), but that we have to prioritize different avenues, with which we can take faster strides towards true carbon neutrality.
P.S. it doesn’t help, that today’s H2 is almost exclusively derived from natural gas.