Solar energy & Fuel Cells
This is a little trial on photovoltaics and energy storage.
I am going to use a special kit consisting of a photovoltaic panel and a fuel cell with two small containers for hydrogen and oxygen gases.
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This is the PV cell I am going to use. dimensions: 125 mm x 155 mm x 8 mm tension: 2.2 V (direct current) current: 1.1 mA |
And this is the fuel cell I will use.
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| PEM fuel cell. H2 side. |
PEM fuel cell. O2 side. |
This is a PEM fuel cell. It carries out the task of transforming the electric tension generated in the photovoltaic panel into chemical energy electrolyzing water into hydrogen and oxygen.
| Features of this fuel cell: |
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- dimensions: 54 mm x 54 mm x 17 mm - weight: 69.7 g |
| Working as an electrolyzer: | Working in fuel cell mode: | |
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- input voltage: 1.7 V ~2 V (direct current) - input current: ≥ 0.7 A at 2 V - hydrogen production rate: 5 mL min-1 - oxygen production rate: 2.5 mL min-1 |
- output voltage: 0.6 V (direct current) - output current: 0.5 A - power: 300 mW
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These containers will serve for the storage of hydrogen and oxygen... |
...and I have filled them with water in order to prevent the gases from escaping. |
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I connect the gas containers to the fuel cell and extract some water from the oxygen compartment in order to hydrate the Nafion membrane of the fuel cell. After hydration the fuel cell will be able to operate. |
Finally I connect the fuel cell to the PV panel, the energy supplier. The PV panel will transform solar energy into electric energy generating a potencial between the semiconductors of its material and this electric potencial will serve as energy source for the fuel cell, which will transform this electric energy into chemical energy splitting water molecules yielding hydrogen and oxygen.
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Again I show you here the whole system working: the photovoltaic panel transforms the energy provided by photons into electric tension. This electric tension powers the proton exchange membrane fuel cell enabling it to electrolyze water, which yields hydrogen and oxygen, both collected in reservoirs.
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Hydrogen tank filling
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You can appreciate how the hydrogen is accumulated. H2(g) formed from water electrolysis displaces the water in the reservoir. This leads to an increase of the water level.
I have filmed the hydrogen bubbling in this very short video. The bubbles indicate that the hydrogen tank is already full.
Now I will unplug the photovoltaic panel from the fuel cell and its reservoirs...
...and I will connect it to a small light bulb...
It produces a tiny light.
In order to produce a much more significant amount of energy several parts need to be improved:
- bigger photovoltaic panel (supplying a bigger potential and more power)
- better reservoir system!! Perhaps a lithium ion battery instead of the PEM fuel cell - gas reservoir pair. Or even better... what about vanadium redox flow batteries??? Hmmm....
