# Solving the flaws with wind and solar, i.e. energy storage systems. Why not hydrogen? **URL:** \ **Category:** Great Debates\ **Created:** [June 5, 2019, 3:24pm UTC](https://boards.straightdope.com/t/solving-the-flaws-with-wind-and-solar-i-e-energy-storage-systems-why-not-hydrogen/835076 "2019-06-05T15:24:57Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [June 5, 2019, 8:22pm UTC](https://boards.straightdope.com/t/solving-the-flaws-with-wind-and-solar-i-e-energy-storage-systems-why-not-hydrogen/835076/21 "2019-06-05T20:22:11Z")
> [@XT](#): > > Yep, definitely. Of course, on the other side, hydrogen can be stored for much longer periods, while lithium-ion batteries don’t store energy well. Lithium-ion batteries are actually very good for long term storage, only 2-3% loss per month. But that’s irrelevant for this thread, isn’t it? Aren’t we talking about “demand response” (responding to rapid changes in electricity usage)? > [@](#): > > Also, they degrade over time and are very expensive in the scales we are talking about. Fuel cells also degrade over time. > [@](#): > > It’s not all about energy efficiency when you are talking about engineering solutions. On the flip side, hydrogen storage and transport is expensive as it’s corrosive and needs to be cooled, compressed and liquefied for transport either via pipeline or truck/train. Well, if it’s a pipeline, it probably doesn’t need to be liquefied or even compressed. But it would need to be sealed much better than a natural gas pipeline. > [@](#): > > What we need is a system that can ramp up fairly quickly to fill in the gaps in the spiking parts of our energy requirements and can do this for potentially days or even weeks if needed. If there is a nasty storm, say, or a hurricane or something else that is disrupting sunlight or wind but when things are optimal can basically take in all the excess and currently dumped energy and store it. Every one of the solutions I’ve seen for this has issues. I don’t think energy efficiency is really all that critical considering we are currently just dumping that excess energy that isn’t being used, and I think the fact that it can (in theory, if the engineering challenges can be overcome) be used for much longer term and scaled storage seems to mean it has potential, to me at least. Why would this need a “long term” storage? Those “gaps in the spiking parts of our energy requirements” are on the timescale of seconds to hours, not weeks or months. ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [June 5, 2019, 8:32pm UTC](https://boards.straightdope.com/t/solving-the-flaws-with-wind-and-solar-i-e-energy-storage-systems-why-not-hydrogen/835076/22 "2019-06-05T20:32:28Z")
> [@XT](#): > > The needs, requirements and usages for storage systems in vehicles, IMHO, are very different than the types of loads and requirements for what we are talking about in this thread. OK, then how do you suggest we store the hydrogen, if not in compressed tanks? Cryogenic liquid hydrogen tanks? Uncompressed rubber balloons? [The Tesla battery farm in Australia](https://electrek.co/2018/09/24/tesla-powerpack-battery-australia-cost-revenue/) stores 129 MWh of energy. Hydrogen gas at STP has an energy density of 3.3 Wh/L, so assuming a 70% efficient fuel cell, an equivalent hydrogen energy storage station would need to store 190 million liters of hydrogen at 1 atmosphere. ---
**Author:** ![XT](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/xt/32/456_2.png) [@XT](https://boards.straightdope.com/u/XT)\ **Post date:** [June 5, 2019, 8:32pm UTC](https://boards.straightdope.com/t/solving-the-flaws-with-wind-and-solar-i-e-energy-storage-systems-why-not-hydrogen/835076/23 "2019-06-05T20:32:53Z")
> [@scr4](#): > > Lithium-ion batteries are actually very good for long term storage, only 2-3% loss per month. But that’s irrelevant for this thread, isn’t it? Aren’t we talking about “demand response” (responding to rapid changes in electricity usage)? Do you have a cite for that because it’s contrary to what I’ve heard and read. It’s not irrelevant to the thread since we are talking about an actual solution here. ‘demand response’ is only part of the gap and the requirement. Consider…if you actually get rid of all or most of the fossil fuel generation and nuclear finally shuffles off, what do you do if you get a week of rain? Or snow? Or a hurricane? Just tell the folks who need power to suck it up and wait for the sun and wind to come back? We definitely need something that can ramp up, but we also need something that can store at least a weeks worth of energy as well. > [@](#): > > Fuel cells also degrade over time. Do they? Regardless, I wasn’t talking about fuel cells. I was mainly thinking about using hydrogen in power plants in similar ways to how we use natural gas. In fact, I was thinking we might be able to modify those natural gas plants to run on hydrogen instead. > [@](#): > > Well, if it’s a pipeline, it probably doesn’t need to be liquefied or even compressed. But it would need to be sealed much better than a natural gas pipeline. I think it would. It would certainly need to be re-sleeved for sure, as hydrogen is more caustic than natural gas. It’s definitely one of the challenges. My thought was some sort of large vaults, maybe old salt mines or the like depending on where this would be put in, to store large amounts of hydrogen, as well as shorter term (couple days worth, say) stored at the power plants that would operate at a lower base load continually (much as natural gas does) but could be ramped up for your ‘demand response’ if needed. If we run into that week or two of bad weather or lower solar or wind production that can’t be shifted from another state then you use your large storage vault to ship in more hydrogen as needed. Not simple or particularly cheap, but I think it could work. > [@](#): > > Why would this need a “long term” storage? Those “gaps in the spiking parts of our energy requirements” are on the timescale of seconds to hours, not weeks or months. Because shit happens, basically. You DO need days if not weeks in reserve just in case. California is definitely mainly sunny, for instance, but they do get cloudy days, and storms that could vastly reduce solar production, and more wind won’t necessarily make up for that. Even today they have issues with this, and they aren’t close to a the percentages of wind and solar we are talking about needing, so that needs to be part of the requirements if you are actually going to shut down a large percentage of fossil fuel generation at the same time you are taking out nuclear completely, which California is doing. ---
**Author:** ![XT](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/xt/32/456_2.png) [@XT](https://boards.straightdope.com/u/XT)\ **Post date:** [June 5, 2019, 8:40pm UTC](https://boards.straightdope.com/t/solving-the-flaws-with-wind-and-solar-i-e-energy-storage-systems-why-not-hydrogen/835076/24 "2019-06-05T20:40:43Z")
> [@scr4](#): > > OK, then how do you suggest we store the hydrogen, if not in compressed tanks? Cryogenic liquid hydrogen tanks? Uncompressed rubber balloons? > > [The Tesla battery farm in Australia](https://electrek.co/2018/09/24/tesla-powerpack-battery-australia-cost-revenue/) stores 129 MWh of energy. Hydrogen gas at STP has an energy density of 3.3 Wh/L, so assuming a 70% efficient fuel cell, an equivalent hydrogen energy storage station would need to store 190 million liters of hydrogen. We have a lot larger natural gas storage facilities than 190 million liters. Assuming I’m reading it right, we currently store (in facilities across the US) 2 orders of magnitude more natural gas than that, in fact, and can send more than that through the various pipelines we have for this purpose. Could we do this with Hydrogen? I’m not sure. This is outside of my own expertise, and kind of why I was asking the question I did in the OP. Maybe we can’t. I know storing hydrogen is different than natural gas. I know we DO store the stuff though, and use it, so it’s technically possible to store it. I know that natural gas can be used to do the job as well, since it is in fact doing it. That 129 MWh of energy from the Tesla plant is impressive…for a battery system. It’s nothing to a natural gas plant. Or a nuclear plant. Can hydrogen fill in for those if we produced it with the excess energy we aren’t using every good green energy production day? I don’t know…it’s why I was asking. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [June 5, 2019, 8:59pm UTC](https://boards.straightdope.com/t/solving-the-flaws-with-wind-and-solar-i-e-energy-storage-systems-why-not-hydrogen/835076/25 "2019-06-05T20:59:45Z")
> [@XT](#): > > You guys are free to discuss what you like, but for this thread my preference was to try and focus on hydrogen. Overall, the thrust here, at least from my perspective, is that ALL of these energy storage solutions have issues and lots of engineering that would need to be solved. They each have gaps as well. And none of them really scale that great, though I think hydrogen COULD scale fairly well if the engineering issues could be overcome. I can do threads on specifically batteries and pumped hydro, as well as compressed gas which is another similar possibility for energy storage. If we ever get wide scale energy storage to fill in the gaps with wind and solar, my WAG is it won’t be one silver bullet, but a mix of things, at least in a country the size of the US. Some smaller countries with specific advantages to one type of storage or another, just like advantages for one type of green energy verse others can happen, but not in a country the size of the US…at least not that I’m seeing. I’m just try to compare hydrogen to alternatives. In every case there are problems. The problems with hydrogen may be insurmountable saving an unpredicted technological breakthrough. Storage is problematic for a variety of reasons, and so far improving storage density just increases costs and problems associated with compression and liquification, all additional costs to the parasitic cost of producing the hydrogen. There are some advantages, production of oxygen, clean burning or chemical conversion, not particularly more dangerous than LNG which it could replace for direct use in aircraft or to produce heat. Perhaps storage is not that great a problem. If hydrogen can be reasonably transported through existing gas pipelines then it could be used at existing power plants driving turbine generators. For filling in the gaps the pipelines themselves can hold a large volume of gas with power plants and hydrogen production plants buffering the load with smaller lower pressure storage. All in all I don’t see hydrogen being highly rated on the practicality of implementation scale, save for some minor applications. ---
**Author:** ![Frankenstein\_Monster](https://avatars.discourse-cdn.com/v4/letter/f/ccd318/32.png) [@Frankenstein\_Monster](https://boards.straightdope.com/u/Frankenstein_Monster)\ **Post date:** [June 5, 2019, 9:14pm UTC](https://boards.straightdope.com/t/solving-the-flaws-with-wind-and-solar-i-e-energy-storage-systems-why-not-hydrogen/835076/26 "2019-06-05T21:14:57Z")
I think you’re on the right track. But the issue is that today we don’t have even remotely enough renewable electricity (solar and wind) yet. EVENTUALLY, in order to get enough GENERATION from solar and wind, we will need to build a large excess CAPACITY of solar and wind. As we all know, solar and wind generation is only a somewhat small fraction of their capacity, AND every once in a while they will have a large gap. Nobody is even close to excess generation today. The best countries have maybe mid-double-digit renewable generation today, for small areas (Denmark, South Australia) and short spans of time, but none has significant excess capacity at sufficiently large scale. There is also the issue that making hydrogen from natural gas is “much cheaper”. We still need to get rid of the whole attitude where fossil fuel is “cheap”. Of course the earth holds enormous amounts of Gigawatt-hours of energy just sitting there in the ground just for the taking. So it is “understandable” that some people still believe fossil fuels are “cheap”. That must change. More than high carbon taxes, we must get to a point where fossil fuels are simply out of the equation. I can find studies about the cost of making hydrogen from wind energy but they typically assume dedicating a wind park to a hydrogen making facility. Needless to say, nobody today will build a large wind farm and use it only for hydrogen. And the calculations still show that it’s not economic today (still more expensive than fossil). The Wiki on [Hydrogen production](https://en.wikipedia.org/wiki/Hydrogen_production) has somewhat detailed info and references, especially reading between the lines, you see that hydrogen production by electrolysis is still an experimental small scale affair whereas steam reforming is a mature, widespread and easy to procure tech. DOE and other research has been done for decades, here is one relatively recent roadmap: [Hydrogen Production Tech Team Roadmap (PDF)](https://www.energy.gov/sites/prod/files/2017/11/f46/HPTT%20Roadmap%20FY17%20Final_Nov%202017.pdf) My own opinion: Hydrogen is only one form of storing excess renewable energy. You can broaden the topic to other PTL (Power-to-Liquid) solutions, e.g. methanol or methane, or storage forms other than chemical, e.g. storing excess electricity as heat. Living in a cold climate, I used to worry about district heating for example. But once we get around to building that large excess of wind energy, then it will make eminent sense to store it (very inefficiently) as heat and run a small steam-turbine-cum-district-heating setup from it. Again you can see we’re not remotely there yet. Before any of this is practical, we have to build a large excess capacity of solar panels and wind turbines. Can’t happen quickly enough. If that small country in the north of Europe could spend the same amount on wind as they spend on their new [nuclear](https://en.wikipedia.org/wiki/Olkiluoto_Nuclear_Power_Plant#Unit_3) [plants](https://en.wikipedia.org/wiki/Hanhikivi_Nuclear_Power_Plant), they could get TWENTY TIMES more wind than they have now, and a capacity of twice the maximum demand. THEN we’d be talking. ---
**Author:** ![septimus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/septimus/32/410_2.png) [@septimus](https://boards.straightdope.com/u/septimus)\ **Post date:** [June 5, 2019, 9:34pm UTC](https://boards.straightdope.com/t/solving-the-flaws-with-wind-and-solar-i-e-energy-storage-systems-why-not-hydrogen/835076/27 "2019-06-05T21:34:29Z")
What this thread needs, for ignorati like me, is a brief list of storage methods other than battery with efficiency figures. (Sure, speak of a Manhattan Project for best battery, but let’s review other approaches.) Pumping water upward near hydro-electric power stations? What is the efficiency there as a percent? How does net efficiency of hydrogen compare with batteries? What if the hydrogen need not be transported or compressed? What other local energy storage methods make sense? How do big power systems store energy at present, or do they? ---
**Author:** ![Frankenstein\_Monster](https://avatars.discourse-cdn.com/v4/letter/f/ccd318/32.png) [@Frankenstein\_Monster](https://boards.straightdope.com/u/Frankenstein_Monster)\ **Post date:** [June 5, 2019, 10:56pm UTC](https://boards.straightdope.com/t/solving-the-flaws-with-wind-and-solar-i-e-energy-storage-systems-why-not-hydrogen/835076/28 "2019-06-05T22:56:46Z")
Well if you believe the hype of the renewable hydrogen proponents: [Renewable hydrogen getting cheaper, Australia could lead global market](https://reneweconomy.com.au/renewable-hydrogen-getting-cheaper-australia-could-lead-global-market-95168/) > [@](#): > > Some of Australia’s leading energy experts say that renewable hydrogen is beginning to reach cost parity with some fossil fuel equivalents, and can emerge as a high potential export industry for Australia – with tens of billions of dollars – as technology costs continue to tumble. Realistically they’re talking about expressly building a large excess solar and wind capacity in order to make hydrogen from. That may happen yet. We’re only factors away from that being profitable. We’re orders of magnitude away from using today’s “wasted” or curtailed electricity for making hydrogen. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [June 5, 2019, 11:20pm UTC](https://boards.straightdope.com/t/solving-the-flaws-with-wind-and-solar-i-e-energy-storage-systems-why-not-hydrogen/835076/29 "2019-06-05T23:20:11Z")
Any given location can get a week of rain, but an entire continent can’t. When one place gets rain, they draw the power from other places that are sunny. This is already done to some extent, and could be done more, and more efficiently, with upgrades to the grid. And a car using a gaseous fuel needs a high-pressure tank, because the volume of the tank needs to fit into the car. But a power plant built where land is cheap (which is where most of them are) could just use a really big tank, at more manageable pressures. Nor need the energy used to pressurize the gas be entirely wasted: Much of that, you could harness when you release the gas. In fact, there are some energy-storage facilities that are based on just this, using ordinary air as their working gas. ---
**Author:** ![HMS\_Irruncible](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hms_irruncible/32/7394_2.png) [@HMS\_Irruncible](https://boards.straightdope.com/u/HMS_Irruncible)\ **Post date:** [June 5, 2019, 11:35pm UTC](https://boards.straightdope.com/t/solving-the-flaws-with-wind-and-solar-i-e-energy-storage-systems-why-not-hydrogen/835076/30 "2019-06-05T23:35:40Z")
I assume we’re talking about hydrogen from water-splitting, right? So, one big constraint is water flow. This limits the location to a reasonable pipeline range to the ocean or a big river. Someone already mentioned that electrolysis in itself is like 75% efficient. So there’s 25% of the energy gone on top of that. For the hydrogen to be usable at all, it has to be compressed and liquified, which (WAG) is another big haircut off the efficiency. Factor in the energy needed to transport it, and I doubt it’s worth it. And count me on the bandwagon of people who want to know why you’re dismissing hydro-pumping. 😃 . I’m aware of some reasons but I’m always up for new ones. ---
**Author:** ![HMS\_Irruncible](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hms_irruncible/32/7394_2.png) [@HMS\_Irruncible](https://boards.straightdope.com/u/HMS_Irruncible)\ **Post date:** [June 5, 2019, 11:38pm UTC](https://boards.straightdope.com/t/solving-the-flaws-with-wind-and-solar-i-e-energy-storage-systems-why-not-hydrogen/835076/31 "2019-06-05T23:38:45Z")
It seems to me like the best use of excess wind and solar is carbon capture & sequestration. If we’re serious about solving atmospheric carbon, we’ll need to be doing CCS anyway, and the 2 main constraints there are storage and energy. So why not locate the CCS plants where the excess energy production is? ---
**Author:** ![begbert2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/begbert2/32/3357_2.png) [@begbert2](https://boards.straightdope.com/u/begbert2)\ **Post date:** [June 5, 2019, 11:39pm UTC](https://boards.straightdope.com/t/solving-the-flaws-with-wind-and-solar-i-e-energy-storage-systems-why-not-hydrogen/835076/32 "2019-06-05T23:39:44Z")
> [@HMS\_Irruncible](#): > > I assume we’re talking about hydrogen from water-splitting, right? So, one big constraint is water flow. This limits the location to a reasonable pipeline range to the ocean or a big river. > > Someone already mentioned that electrolysis in itself is like 75% efficient. So there’s 25% of the energy gone on top of that. For the hydrogen to be usable at all, it has to be compressed and liquified, which (WAG) is another big haircut off the efficiency. Factor in the energy needed to transport it, and I doubt it’s worth it. > > And count me on the bandwagon of people who want to know why you’re dismissing hydro-pumping. 😃 . I’m aware of some reasons but I’m always up for new ones. If the goal is for the hydrogen to be used as a storage battery to be expended at need into the same system that charges it, why does it need to be transported at all? Or liquified? Why not just get a really, really big tank, store the hydrogen on site, and put up no-smoking signs? ---
**Author:** ![Ruken](https://avatars.discourse-cdn.com/v4/letter/r/f475e1/32.png) [@Ruken](https://boards.straightdope.com/u/Ruken)\ **Post date:** [June 5, 2019, 11:40pm UTC](https://boards.straightdope.com/t/solving-the-flaws-with-wind-and-solar-i-e-energy-storage-systems-why-not-hydrogen/835076/33 "2019-06-05T23:40:04Z")
> [@Frankenstein\_Monster](#): > > Nobody is even close to excess generation today. Curtailment of excess renewable energy generation is quite common. ---
**Author:** ![Ruken](https://avatars.discourse-cdn.com/v4/letter/r/f475e1/32.png) [@Ruken](https://boards.straightdope.com/u/Ruken)\ **Post date:** [June 5, 2019, 11:43pm UTC](https://boards.straightdope.com/t/solving-the-flaws-with-wind-and-solar-i-e-energy-storage-systems-why-not-hydrogen/835076/34 "2019-06-05T23:43:18Z")
> [@TriPolar](#): > > Why aren’t we trying to solve the flaws with pumped-hydro instead of hydrogen? Is there really a hydrogen solution that is more likely, or is it wishful thinking like waiting for fusion to solve the problem? There aren’t really any major flaws to solve with pumped hydro. I suggest you meditate on geology and opportunities for pumped hydro in places like Kansas and you’ll find the answer to your question. ---
**Author:** ![GIGObuster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gigobuster/32/421_2.png) [@GIGObuster](https://boards.straightdope.com/u/GIGObuster)\ **Post date:** [June 5, 2019, 11:44pm UTC](https://boards.straightdope.com/t/solving-the-flaws-with-wind-and-solar-i-e-energy-storage-systems-why-not-hydrogen/835076/35 "2019-06-05T23:44:32Z")
8 > [@PastTense](#): > > As to using batteries: > > [Relying on renewables alone significantly inflates the cost of overhauling energy | MIT Technology Review](https://www.technologyreview.com/s/610366/relying-on-renewables-alone-would-significantly-raise-the-cost-of-overhauling-the-energy/) > > But we want to handle all energy needs not just 80% of demand of the electrical system. And we want to handle seasonal energy needs (remember the polar vortex?)–so instead of 12 hours we need a few weeks. > > OP: both the European Union and Asians countries (like Japan and South Korea) are strongly interested in hydrogen–but there seems little interest in the U.S. Busy now, but I have to point out that in another thread the guy from Real Engineering had a video cited before in the past discussion that claimed that to make it work, the costs for California alone for using batteries would be about 3.67 Trillion, but here the MIT group mentions 2.5 Trillion for a battery system for the **whole** of the USA. Point being that, at least for the Real Engineering guy, I will have to blame that exagerated skepticism on an engineer that has not published his research to be evaluated with peer review. Of course I have seen papers and reports that point out that not doing an effort will be more expensive than taking care of the issue, and IMHO solar, wind, and batteries will not be the only solutions. Even Nuclear should be part of the efforts that are needed to mitigate the issue. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [June 5, 2019, 11:56pm UTC](https://boards.straightdope.com/t/solving-the-flaws-with-wind-and-solar-i-e-energy-storage-systems-why-not-hydrogen/835076/36 "2019-06-05T23:56:10Z")
> [@Ruken](#): > > There aren’t really any major flaws to solve with pumped hydro. I suggest you meditate on geology and opportunities for pumped hydro in places like Kansas and you’ll find the answer to your question. Hydroelectric power is pretty well established so there’s nothing that has to be done to start using it. However it may require some big ass reservoir that can have it’s own issues. It can’t be big enough to cause flooding from a breach, or get destroyed if it gets flooded. You can gain the drop with a hole in the ground though, geology isn’t very limiting in that regard. You’ll want it to operate with the least drop practical because it’s costing you energy the higher you pump it. ---
**Author:** ![HMS\_Irruncible](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hms_irruncible/32/7394_2.png) [@HMS\_Irruncible](https://boards.straightdope.com/u/HMS_Irruncible)\ **Post date:** [June 6, 2019, 1:59am UTC](https://boards.straightdope.com/t/solving-the-flaws-with-wind-and-solar-i-e-energy-storage-systems-why-not-hydrogen/835076/37 "2019-06-06T01:59:56Z")
> [@begbert2](#): > > If the goal is for the hydrogen to be used as a storage battery to be expended at need into the same system that charges it, why does it need to be transported at all? Or liquified? Why not just get a really, really big tank, store the hydrogen on site, and put up no-smoking signs? There’s no realistic way of storing any usable amount of uncompressed hydrogen. So if we store it, we’ve got to liquefy it, which costs energy. Quick calculation - 2 megawatts excess power generation. 16 megajoules to split a liter of water. We need to split a liter of water every 8 seconds, 10,800 liters a day. Seems manageable. We get 26,860,400 liters of hydrogen per day, which should compress down to 107000 liters. Less than a swimming pool, still manageable. I’m too tired and also not smart enough to work out the energy loss in that compression process, or what would be lost in burning it to generate the energy, but if it’s not too bad, then this actually seems doable. Set up a hydrogen-burning power plant next to the solar plant. Collect hydrogen in daytime, burn it at night, put it back on the grid. Just at a broad glance, this really does seem doable. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [June 6, 2019, 2:20am UTC](https://boards.straightdope.com/t/solving-the-flaws-with-wind-and-solar-i-e-energy-storage-systems-why-not-hydrogen/835076/38 "2019-06-06T02:20:46Z")
> [@](#): > > Quoth **TriPolar** : > > You’ll want it to operate with the least drop practical because it’s costing you energy the higher you pump it. You’re missing the point. That’s not energy it’s costing you; that’s the energy you’re storing. Which is the whole point of the exercise. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [June 6, 2019, 2:34am UTC](https://boards.straightdope.com/t/solving-the-flaws-with-wind-and-solar-i-e-energy-storage-systems-why-not-hydrogen/835076/39 "2019-06-06T02:34:41Z")
> [@Chronos](#): > > You’re missing the point. That’s not energy it’s costing you; that’s the energy you’re storing. Which is the whole point of the exercise. Yes, but the storage process has limited efficiency. There’s a balance in their somewhere for maximum efficiency. ---
**Author:** ![Frankenstein\_Monster](https://avatars.discourse-cdn.com/v4/letter/f/ccd318/32.png) [@Frankenstein\_Monster](https://boards.straightdope.com/u/Frankenstein_Monster)\ **Post date:** [June 6, 2019, 9:14am UTC](https://boards.straightdope.com/t/solving-the-flaws-with-wind-and-solar-i-e-energy-storage-systems-why-not-hydrogen/835076/40 "2019-06-06T09:14:58Z")
> [@Ruken](#): > > Curtailment of excess renewable energy generation is quite common. Of course! What I meant was: - Renewable is a small % of total generation (e.g. 10% wind in [California](https://www.caiso.com/TodaysOutlook/Pages/supply.aspx)) - Curtailment is a small % of total renewable generation - Curtailment happens on a small % of days Hydrogen making equipment is very expensive. It makes no sense at all to buy that expensive equipment only to use it on a small fraction of the needed energy on a few days of the year. Dedicated renewable hydrogen (see my earlier link) may make sense in a decade. [Previous page](https://boards.straightdope.com/t/solving-the-flaws-with-wind-and-solar-i-e-energy-storage-systems-why-not-hydrogen/835076.md?page=1) [Next page](https://boards.straightdope.com/t/solving-the-flaws-with-wind-and-solar-i-e-energy-storage-systems-why-not-hydrogen/835076.md?page=3)