Solving the flaws with wind and solar, i.e. energy storage systems. Why not hydrogen?

[XT]

So, been doing a lot of thinking about green energy systems, especially as they have been discussed in multiple threads I’ve participated in lately. The obvious solution, to me, is nuclear to basically fill in the gaps in wind and solar, since we are pretty much tapped out on hydro and geothermal, at least in the US. This doesn’t seem likely though, so need to look at alternatives. Batteries have been proposed, and there are several scaled up test beds for this concept being tried out. Batteries, however, have some issues and gaps of their own, one of which is that they are expensive, but another is that they aren’t particularly good at longer term storage. Pumped hydro has also been proposed, but not going to get into that one here. Regardless, what we need is something that can give the grid a good baseline AND can ramp up when the sun isn’t out or the winds aren’t productive. Currently, we overproduce solar in some states at certain times, meaning that if neighboring states don’t buy the energy it’s basically dumped. It can’t be stored. So, that’s actually idea for an energy storage concept…we NEED to overproduce energy at the time when it’s optimal so we can store it for when it’s not.

Well, why not use that to produce hydrogen? We know how to use energy to produce the stuff, after all. There are actually several different ways to do this, in fact. Storage can be a bitch, but it’s do-able…we do it already, after all. I’m fairly sure we could figure out large scale storage and containment systems that would cost a fraction of what batteries would cost…in fact, the production and storage would cost a fraction of what a battery system would cost and give us a ton more utility, as from an energy density perspective hydrogen is much better. We could use the existing pipeline systems that move around natural gas or fossil fuels underground to ship it hither and yon as well (might take some retrofitting of pipe sleeves or such, but that’s do-able). And we could, I think, use existing power plants to use the stuff, at least I THINK we could…it’s a similar principle after all. Or, I suppose, we could use fuel cell technology, though I think that would increase the costs.

This seems an ideal solution…so, what am I missing? I have seen some projects looking into this, but to me this is something we could do fairly quickly. And I don’t just mean the US…someone could be doing this right now, today. Overproduction of solar isn’t just something happening in California, and no one has a large scale energy storage system able to fill the gaps on a large scale at this time…yet, if we are really going to push solar this is an absolute need, since if you are REALLY going to do away with fossil fuel power you have to have something that works when your green energy systems aren’t. Plus, you are going to need to account for if there are extended periods where your green energy system isn’t producing what you need (or anything at all) and can maintain the grid during those times.

[Shodan]

Hydrogen is fairly bulky unless it is liquid, and it needs to be super-cooled in order to liquefy it. So perhaps putting a new pipeline in is not as cheap or straightforward as you might think. It is also explosive, much more than oil.

I don’t know if the same people who panic over Three Mile Island are also going to panic if the Hindenberg is recreated in their neighborhood.

Yes, it’s an option, but I would need to see a working prototype before I hail it as the solution to all our problems.

Regards,
Shodan

[Alpha_Twit]

@Shodan

I don’t know if the same people who panic over Three Mile Island are also going to panic if the Hindenberg is recreated in their neighborhood.

Speaking just for myself as a single data point. I’m all for a hydrogen storage facility over a nuclear facility. Either one can get kind of explodey if things are grossly mishandled but at least the hydrogen cleanup is easier.

[naita]

Do you know why battery powered electric cars are what is surging and not fuel cell cars?

Yes, the lack of filling stations vs. the pre-existence of our electrical grid is part of it, but another is that hydrogen as energy storage just isn’t a miracle solution.

The biggest problem, compared to batteries, is the necessary compression or refrigeration, which represents a significant energy loss.

[zimaane]

good topic

How much new infrastructure would be required? Can the hydrogen generated via wind/solar really be sent through existing natural gas or oil pipelines, or would new pipelines be needed? Or would it make more sense to transport in trucks?

[Chronos]

For what it’s worth, nuclear can’t really “fill in the gaps” in wind and solar. It takes hours to ramp a nuclear plant up or down, and wind and solar both vary on much shorter timescales than that (coal, incidentally, has the same problem). One big advantage to natural gas turbines is that they can respond very quickly, and hence take care of most of the response.

As to hydrogen, in addition to all of the other problems, it just isn’t very efficient. Electrolysis of water is only about 75% efficient, and then you’re going to have more losses when you burn the hydrogen. If cheap power were unlimited, that might still be good enough, but it’s not.

[Delayed_Reflex]

@naita

Do you know why battery powered electric cars are what is surging and not fuel cell cars?

Yes, the lack of filling stations vs. the pre-existence of our electrical grid is part of it, but another is that hydrogen as energy storage just isn’t a miracle solution.

The biggest problem, compared to batteries, is the necessary compression or refrigeration, which represents a significant energy loss.

Not to mention, the conversion of hydrogen back into electrical or mechanical energy has pretty significant losses as well (I think ~40-50% losses for fuel cells in practice, and even higher for combustion engines).

Basically, you’ll lose 20-30% of the input energy during the production of your hydrogen (assuming you are doing electrolysis of water), then use a fair amount of energy for compressing it for storage or transportation, then lose another 40-50%+ of what’s left when using it. So at best you might come out with nearly half of your input energy, and more likely you’re only getting like 25% of your input energy by the time you’ve converted that hydrogen back to electricity. Low efficiency wouldn’t necessarily be a killer if all of these steps were dirt cheap, but they aren’t.

Hydrogen is also more difficult and expensive to store and transmit than, say, natural gas due to hydrogen making metals brittle. Liquid hydrogen also isn’t as energy dense as gasoline or diesel.

As mediocre as battery storage is currently, I think it still compares favourably compared to most other options on a cost and efficiency basis. At the end of the day, if hydrogen had substantially lower life-cycle costs than batteries, you’d see a lot more development on it.

[kanicbird]

Can some hydrogen safely be mixed with natural gas in small percentages or even dissolved in gasoline or oil? That would allow use of existing pipelines. Perhaps a gas turbine plant can be tuned to run on either fuel or a mix of the 2, burning extra hydrogen produced from times when excess power is produced.

[TriPolar]

XT, why is pumped hydro being left out of the discussion? Any type of energy storage will involve losses, but pumped hydro should be much safer and cost less than other methods to implement.

[XT]

@TriPolar

XT, why is pumped hydro being left out of the discussion? Any type of energy storage will involve losses, but pumped hydro should be much safer and cost less than other methods to implement.

I think it deserves a thread just like this one to discuss and I didn’t want to overly complicate this one. I wanted folks thoughts on hydrogen as an alternative, and didn’t want a ton of digression. I debated even bringing up batteries for that matter, but I needed something to contrast and give some context to what I was asking. Large scale batteries also deserve their own thread like this one, IMHO.

[Shodan]

@TriPolar

XT, why is pumped hydro being left out of the discussion? Any type of energy storage will involve losses, but pumped hydro should be much safer and cost less than other methods to implement.

The main problem with gravitational storage is that it is incredibly weak compared to chemical, compressed air, or flywheel techniques (see the post on home energy storage options). For example, to get the amount of energy stored in a single AA battery, we would have to lift 100 kg (220 lb) 10 m (33 ft) to match it. To match the energy contained in a gallon of gasoline, we would have to lift 13 tons of water (3500 gallons) one kilometer high (3,280 feet). It is clear that the energy density of gravitational storage is severely disadvantaged.

Cite. So you need a really big - really, really big - reservoir.

Again, not out of the question, but not a magic bullet either.

Regards,
Shodan

[TriPolar]

@Shodan

Cite. So you need a really big - really, really big - reservoir.

Again, not out of the question, but not a magic bullet either.

Regards,
Shodan

I’m not seeing the hydrogen looks much better. 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?

I don’t want to side track the discussion to pumped-hydro, I’m just not seeing great reasons to favor hydrogen over other alternatives as well.

[XT]

@TriPolar

I’m not seeing the hydrogen looks much better. 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?

I don’t want to side track the discussion to pumped-hydro, I’m just not seeing great reasons to favor hydrogen over other alternatives as well.

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.

[PastTense]

As to using batteries:

Just getting to 80 percent of demand reliably with only wind and solar would require either a US-wide high-speed transmission system or 12 hours of electricity storage. A storage system of that size across the US would cost more than $2.5 trillion for a battery system.

Relying on renewables alone significantly inflates the cost of overhauling...

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.

[Chronos]

We need to handle all energy needs, but we don’t need to handle it all with wind and solar. Hydro is already a large chunk of our electrical generation, and there’s no reason it can’t remain so. And even if we end up having to use a small amount of fossil fuels, well, a small amount is better than a large amount.

[XT]

@Chronos

We need to handle all energy needs, but we don’t need to handle it all with wind and solar. Hydro is already a large chunk of our electrical generation, and there’s no reason it can’t remain so. And even if we end up having to use a small amount of fossil fuels, well, a small amount is better than a large amount.

The problem is that nuclear is shrinking, and nuclear is best to maintain a steady base load. I wasn’t proposing nuclear to ramp up for short term needs, by the way. Anyway, as nuclear shrinks, something has to fill that gap. Wind and solar are expanding, but their gaps haven’t been addressed, so something needs to be there so that when it’s not windy or sunny we have the ability to continue to provide energy to people. Also, a lot of solar, specially, is being wasted today, as there is often more energy available in a specific grid at specific times and dates (i.e. a cloudless day in the summer, say) than is needed, while when people really need that energy (say, after 5pm when the sun is lower in the sky and solar is performing less optimally through the night time hours when they are home and using energy more). Hydro is pretty much tapped out…IIRC, it’s less than 10% of our total energy generation in the US, and that’s basically it…it will never be more than that. It also can vary of course, depending on drought status (or flood for that matter) in some places. So, nuclear is declining, hydro is static, that pretty much means that the ‘small amount of fossil fuels’ is going to have a bottom limit. 30%? Maybe. Without some sort of energy storage system, that’s about as good as it will gets.

To me, if we are going to really make wind and solar work (without replacing our entire grid in the short term) we need some sort of energy storage system. And we probably need it sooner rather than later, as nuclear is going away. In California, for instance, I believe they are in the process of shutting down their last nuclear power plant. That’s a huge amount of base load that will be gone, and nothing to replace it 24/7/365 except fossil fuels (either in California, or, more likely, buying it from neighboring states).

[scr4]

1. Producing hydrogen from electricity is inefficient - around 70-82%.

2. Storing hydrogen is more difficult than other fuels because of the low density, small molecular size (which means it leaks more easily) and low boiling point (difficult to liquify for transport, unlike propane).

3. Producing electricity from hydrogen is not very efficient either - theoretical maximum of 83%.

That means after you solve the engineering problem of storing and/or transporting hydrogen, and get the most efficient generator and fuel cell possible, you still only get back <68% of what you put in. Compared to >80% for lithium-ion batteries.

[XT]

@scr4

1. Producing hydrogen from electricity is inefficient - around 70-82%.

2. Storing hydrogen is more difficult than other fuels because of the low density, small molecular size and low boiling point.

3. Producing electricity from hydrogen is not very efficient either - theoretical maximum of 83%.

That means after you solve the engineering problem of storing and/or transporting hydrogen, and get the most efficient generator and fuel cell possible, you still only get back <68% of what you put in. Compared to >80% for lithium-ion batteries.

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. Also, they degrade over time and are very expensive in the scales we are talking about. 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.

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.

[scr4]

P.s. just to reiterate on the storage problem - the Honda Clarity FCX hydrogen powered car has 5000 psi fuel tanks, and the tanks still take up half of the trunk. And the above efficiency calculation doesn’t include the extra energy needed to compress the hydrogen up to 5000 psi.

[XT]

@scr4

P.s. just to reiterate on the storage problem - the Honda Clarity FCX hydrogen powered car has 5000 psi fuel tanks, and the tanks still take up half of the trunk. And the above efficiency calculation doesn’t include the extra energy needed to compress the hydrogen up to 5000 psi.

I don’t think comparing large scale energy storage systems to those in cars is really that applicable, though several have made this comparison in this thread. 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. In a car, perhaps, those sorts of engineering challenges mean that hydrogen has or will lose the market, but then steam power lost the race wrt cars as well, yet we pretty much ubiquitously use it for power generation in our grid. Making very large storage vaults for hydrogen that can take the caustic effects as well as those levels of pressure aren’t nothing, but they aren’t exactly cutting edge either wrt what we can do. For a car, yeah…for a power plant or a city? Naw. It could be done. Whether it can be done economically or it’s the best solution, well, that’s what the thread is discussing.