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A Promising Discovery

Michael at Musing’s musings wrote about this research at the end of last week, and Juan Cole of Informed Comment noticed today and linked to ‘Major discovery’ from MIT primed to unleash solar revolution.

The problem with solar power is what happens when the sun isn’t shining. The normal procedure is to use the solar cells to charge batteries, and then use power from the batteries. That isn’t very efficient.

With solar cells powering a device using the process from MIT feeding a hydrogen fuel cell you can design a nearly closed system that will generate power when necessary, not just when the sun shines, whose waste product is some heat, which can be used to for hot water in a bathroom.

The water put into the MIT device is split into hydrogen and oxygen, which is used to power the fuel cell and generate electricity and some heat.  The fuel cell combines the hydrogen and oxygen back into water which is returned to the MIT device.  The energy from the solar cells is stored as hydrogen and oxygen.

If the device will scale, i.e. if it still works when it is much larger than a model on a laboratory bench, this system has great potential.

8 comments

1 ellroon { 08.04.08 at 10:54 pm }

I love stuff like this. It’s so nice to be reminded that scientific and intelligent people are at work helping the whole of humanity.

2 Bryan { 08.04.08 at 11:24 pm }

What they are really studying is the photosynthesis of plants, i.e. how plants use sunlight to create complex molecules. Every green plant does this, but we aren’t sure how it works. This is only a small part of what grass does every day, but it will be very useful to people.

Consider an hydrogen powered car. The problem has been stated that hydrogen isn’t available at service stations. With this system, a hydrogen service station could be anywhere with sunlight and a water source, and the waste product would be oxygen.

It is a move to get people off the grid, which I know from personal experience, is not all that reliable. The so-called ritzy area of La Jolla in San Diego has a third-world electrical system. There is only one line in and the voltage is not stable or reliable.

Steve Bates along with a lot of people in Louisiana and Texas are all anticipating losing power because of the tropical storm, and that is going to affect the price of gasoline, because is right through the oil rigs in the Gulf, and the power loss will take down refineries.

3 fallenmonk { 08.05.08 at 5:33 am }

Let’s hop it will scale. That would be a world changing thing.

4 Mustang Bobby { 08.05.08 at 6:41 am }

It sounds about as close to perpetual motion — in terms of energy — as you can get.

5 Bryan { 08.05.08 at 11:34 am }

What this really represents is an efficient battery. The solar cells “charge it” and it releases the energy when needed. The break through is that is doesn’t “eat itself” in the process, like a lead acid car battery, or even an lithium ion cell, and it doesn’t release harmful by-products.

6 Badtux { 08.05.08 at 1:00 pm }

This is just a fancy name for electrolysis. We already have electrolysis cells to generate hydrogen and oxygen from water. The advantage of this particular process is that they found catalysts so that you don’t need to alter the acidity of the water in order to prevent it from eating up the electrodes. This has some interesting implications in that it means you can use ordinary tap water with some salt as your feed stock, rather than needing a complete chemistry setup that measures the acidity and adds lime as needed. But it all boils down to sending an electrical current through water such that hydrogen comes out at one electrode and oxygen at the other — a well-understood and well-known process. The only breakthrough here has nothing to do with photosynthesis, it has to do with the scalability of the electrolysis cells. Maybe they studied photosynthesis to figure out what catalysts plant cells were using to split water atoms in order to build hydrocarbons from water plus CO2, but this particular process is electrolysis, not photosynthesis. (Note that there *are* some photosynthesis-derived processes for building solar cells that generate electricity — the dye-based ones — but currently they are not commercially feasible because unlike plants, solar cells are not constantly splitting cells to make more chlorophyll and thus the cell dies after a few days).

In short: It’s good. But it’s not the amazing breakthrough that’s advertised here. We already knew that electrolysis could be used to create hydrogen from solar power. This is just a slightly more efficient way of doing electrolysis.

– Badtux the Solar Penguin

7 Bryan { 08.05.08 at 2:27 pm }

The people working on this were studying photosynthesis and came across this as part of that study. They are working on the chemistry of plants, not looking for a better form of electrolysis.

This process is more efficient than current methods, because plants are more efficient than we are at preforming the task, and this is based on “plant technology”.

The problem with solar powered electrolysis is the power requirements to keep the process working; current solar cells aren’t that efficient. This process has lower power requirements, which significantly increases the output using solar cells.

8 Badtux { 08.06.08 at 1:28 am }

Right. They found some catalysts in plant cells that they’re using to improve the electrolysis process by making it more efficient and less dependent on a complex and expensive infrastructure. But this process is still electrolysis.

The dye-type solar cells would be much, much cheaper than current solar cells if they can ever figure out how to make them last more than a few days, so I hope they continue their research here. But this more effective electrolysis cell is just a byproduct of that research, not what they were aiming for to begin with — the eventual goal is to be able to produce hydrogen without first converting sunlight to electricity.

– Badtux the Solar Penguin