Energy Storage Systems Episode 4 : Fuel Cells, the future of energy?

solardude (37)in #steemstem • 6 years ago

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Hello my SteeMates, hope everything is going well for you! I haven't published anything in a while but I'm back with a new article in the Energy Storage Systems series. I hope you'll enjoy it!

Microsoft and Toyota are revving up interest in hydrogen fuel-cell energy tech
Geekwire – June 25th, 2018

First US hydrogen fuel cell vessel to be built by Bay Ship and Yacht
Composites World – July 17th, 2018

Mercedes-Benz Unveils Fuel-Cell Sprinter Van Concept
The Drive – June 2nd, 2018

$10.75M grant aids next-gen fuel cell development
Cornell University - July 18th, 2018

Boy, with all these headlines we really must have discovered something new and fresh!

Well, not exactly.

You see, Hydrogen Fuel cells have been around for a little less than 2 centuries. In 1839, the Welsh inventor, Sir William Robert Grove had already produced electricity using Hydrogen, Oxygen and an electrolyte. Although it wasn’t properly called “fuel cell” just yet it was based on the same principles as current fuel cells.

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However, the hype did not catch on until the 1960s, at a time when NASA launched its second human spaceflight: The Gemini Space Program. As you might’ve guessed, the spacecraft used fuel cells which not only produced energy but water for the astronauts to drink as well – but more on that later.

Fast forward 40 years and here we are still trying to figure out how to improve this technology and if it is worth implementing it.

What is a Fuel cell?

Ok, I’ve been rambling on about history but what a fuel cell is in concrete terms.

A fuel cell is a device that produces electricity through a chemical reaction between a source fuel and an oxidant. The source fuel could be almost anything that can be oxidized, including hydrogen, methane, propane, methanol, diesel fuel or gasoline. The only byproducts are water and a small amount of nitrous oxide if air is used as the oxidizer.

Tech Target definition

This definition might seem complex but in reality, it is rather simple to understand how everything works. Take a little bit of oxygen (O2), a little bit of hydrogen (H2) throw everything in a fuel cell and tada you have electricity and water (H2O). Ok it’s not that simple, I’ll elaborate in a few seconds.

First, there are many different types of Fuel cells which have different fields of applications. The one that is most widely used and that we’ll concentrate on throughout this article will be the Proton Exchange Membrane Fuel Cells – AKA PEMFC – which are currently being used in cars as they are portable and well developed.

You can also find some AFC – the one used during the GEMINI mission – which are much larger but also much cheaper, the MCFC, the PAFC the SOFC and the DMFC. I’m not going to spend too much time developing these other types of fuel cells as they are less likely to affect us in our daily lives, at least not right now.

How does a PEMFC Fuel Cell work?

It is actually very similar to how a chemical battery works. It has a positive terminal made of a catalyst, platinum, which speeds up the chemical process, a negative terminal and an electrolyte – which is a special polymer preventing electrons from jumping between terminals.

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Hydrogen gas contained in a tank enters from the positive terminal while oxygen comes from the second terminal. The oxygen can come from the air for PEMFCs which is not the case for AFC as it needs pure oxygen in order to operate.
When the Hydrogen atoms enter in contact with the positive terminal, they split up and lose an electron – there only one actually – making them nothing more than protons. The reason behind this is that Hydrogen is composed of one proton and one electron.

The protons are then attracted towards the negative terminal while the electrons flow through the electrical circuit producing electricity. Finally, protons and electrons meet once again and combine with oxygen which ends up producing water.

Now, a single fuel cell does not create enough energy to power anything, that’s why we link many of them together in order to create a stack.

And that is pretty much it.

Can we consider fuel cells as energy storage systems?

Absolutely! It might not seem evident at first, after all, we are only producing electricity, right? Well, not if you take a closer look at it. How do we get all this hydrogen?

Although it is the most abundant of all chemical elements, you can’t just grab some from thin air. You have to extract it. But from where?

Once again H2O is the answer! You use what is called an electrolyzer which splits the water molecule into O2 and H2 – Oxygen and Hydrogen. It works as follows, you place both a positive and a negative terminal - which are connected to a battery - in pure water. When passing electricity through the water you'll notice that you'll find hydrogen gas near the negative electrode and oxygen gas near the positive electrode! And then you just have to collect it!

_Wikipedia

See where this is going? You’re using energy to produce hydrogen atoms that will then be used to create energy in the future. Hence, fuel cells are energy storage systems.

Why aren’t fuel cells widespread?

DIsadvantages

Unfortunately, the technology has many drawbacks. It turns out that, although most advocates try to sell it as a technology that emits no CO2, it actually is quite the contrary. As I said you need to produce hydrogen, and guess what, we mostly use fossil fuels in this process.

Moreover, the process for a fuel cell which includes electrolysis, pipelines, storage etc. make it much less efficient than a Li-ion battery storage method. If we take a look at a car, you would need 202KWh of renewable energy to have 60KWh of power to the wheels. Which is far from the 79KWh needed for a Li-ion battery powered car.

Then, as always you have cost. Platinum is one of the largest elements in a fuel cell, and is extremely expensive. According to Eaves Devices – an engineering and innovation incubator that specializes in energy storage and power conversion technology and product development - as well as government studies, the cost of PEMFC, considering mass production for a vehicle such as a Honda Civic, would be approximately 33% more expensive than that of a Li-ion battery.

If that wasn’t enough, you also have the issue of the space and weight hydrogen fuel cells take in a car. Eaves Devices estimates that considering a Honda Civic, the weight of the components needed for a PEMFC would be around 721 kg i.e 217 kg heavier than that of a Li-ion battery pack.

And the list goes on:

no local garages know a damn thing about fuel cells
pressurized hydrogen is extremely flammable

Advantages

However, there are a few upsides to the technology. Unlike EVs where you have to wait a few hours to have a complete charge, fuel cells can be refueled in a couple of minutes, with a process not unlike that of our current gas stations.
And… uhm… that’s it?

Yes, as we’ve seen before, when we take a look at the whole probucess behind fuel cells with electrolysis, transportation, storage, the advantages suddenly disappear. Elon Musk makes it pretty clear in one of his interviews.

Key takeaways

I think the most important information in this whole article is that fuel cells and more precisely hydrogen store energy and do not produce it out of the blue. It is of utmost importance to understand this and therefore not believe all the 0% emission BS that everybody talks about online.

So, why companies keep on investing on this technology? The race for the most efficient and potable energy storage system is real and so every dollar spent on research today might mean billion dollars in revenues later. Moreover, SOFC and DMFC have gotten some attention and have shown some interesting opportunities but nothing to go crazy about.

As it stands, I believe hydrogen fuel cells are not the best bet.

So, there you go guys!

I Hope you've all enjoyed this Article, please leave a comment if you feel like it and an upvote if you like what you've felt! Resteems and new followers are also greatly appreciated!

Also, I would like to know what YOU think about this energy storage system? Do you think it's worth investing in? Or do you think it doesn't stand a chance against the competition?

Sources

N°	Type	Source
1	Report	Eaves Device
2	Article	Battery University
3	Article	Explain fuel cells
4	Article	energy.gov
5	Article	ThoughtCo
6	Article	Gemini Fuel Cell

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