*Can it be?* Economical artificial photosynthesis at MIT

[taylaron]

According to the following documentation:
http://web.mit.edu/newsoffice/2008/chem-solar-0620.html"
MIT chemists Nocera, Peters and Christopher Cummins have developed a device that uses sunlight to split water into hydrogen and oxygen gases.

"When sunlight strikes the artificial photosynthesis device, high-energy photons will split water into hydrogen and oxygen. One of the researchers' biggest challenges is developing inexpensive catalysts that can split water efficiently. Platinum does the job, but it is very rare and expensive, so the researchers are focusing on more abundant metals, such as iron, cobalt, nickel and manganese."- Above link

Another article (link below) published two months later, by Daniel Nocera at MIT describes an ideal catalyst they developed that can be used in splitting water into hydrogen and oxygen.
http://www.sciencedaily.com/releases/2008/07/080731143345.htm"

"The new catalyst consists of cobalt metal, phosphate and an electrode, placed in water. When electricity — whether from a photovoltaic cell, a wind turbine or any other source — runs through the electrode, the cobalt and phosphate form a thin film on the electrode, and oxygen gas is produced." -above link

the most obvious question is; since this new catalyst doesn't contain platnium, why haven't they combined these two breakthroughs and created a new solar panel that uses sunlight, combined with water and this new catalist to split into hydrogen and oxygen gas?

The implementations of this are herculean! What is the problem here?

 

[marcus]

The implementations of this are herculean! What is the problem here?

They present it as a way to store energy----like electricity generated by wind or solar cells.

As I read the article, they still don't have a complete system. Their non-platinum material facilitates the production of oxygen. What about the other electrode, where the hydrogen is being produced? It doesn't say. They may still be using platinum at that electrode.

What you found was an interesting article, but it still sounds like work in progress to me---not something with immediate commercial implications.

Another thing, as long as wind turbine and photovoltaic power in a small percentage of the total, it seems to work to pump it into the grid---temporarily replacing some other power source---when it is available. You don't have to store it.

So I would say the storage technology is less urgent than primary power generation (better cheaper solar cells, for instance.)

 

[taylaron]

I agree that storing the pitiful amount of photo voltaic power generated today is rather pointless, but once this device is in operation, every home in america could potentially generate it's own electricity via water, a fuel cell, some gas tanks and a new type of solar roof.
Demand on the United States power grid would fall due to the lack of demand from many residential consumers. I couldn't find any statistics on the specific percentages consumed per sector.
It greatly alarms me that when demand on the grid is low and power generation is high, that extra power is wasted as heat opposed to being stored and used later. This is off topic, but I wanted to point it out. With Nocera's developments, storing excess energy as hydrogen and oxygen now seems competitive, correct?

-Tay

 

[turbo]

One of the simplest ways of storing off-peak power is to use the power to pump water from below a hydro dam up to the impoundment until needed. So if we had excess power from wind and tides during off-peak periods, it would be simple to use that power to run pumping stations, and take the load-swings on the hydro dams.

 

[taylaron]

I agree, but 30-40% of the energy would because of inefficiencies. Then again, 60% is better than 0%...

Well, this thread seems complete; it seems more R&D is needed before artificial photosynthesis becomes economically feasible.
-Unless someone can add more.

 

[MThornton]

One of the simplest ways of storing off-peak power is to use the power to pump water from below a hydro dam up to the impoundment until needed. So if we had excess power from wind and tides during off-peak periods, it would be simple to use that power to run pumping stations, and take the load-swings on the hydro dams.

Under the conditions of power transfer agreements between BC and Alberta, BC must buy night-time surplus electricity from Alberta coal generation plants. large coal electricity plants cannot easilly adjust their output. they are most efficient when running at maximum capacity.
In return Alberta buys daytime hydro-electric generated power from BC. Hydro-electricity generation is easilly adjusted for demand... just let more or less water through the alternators.

But, because BC must keep the Columbia river full for downstream generation plants in Washington state, they cannot let less water through. So the Revelstoke dam generators simply run in no-generate mode (actually as synchronous inductors). That's 1980MW of generation plant, 100% idle all night, 365 days of the year, with the water simply spilling through the dam. The connected 250kV transmission line is 100% loaded to capacity with Alberta coal electricity.

BC has no shortage of both water & mountains. So take 100% of that electricity BC must buy from Alberta, and use it to pump water to a high mountain resevoir, storing as much potential energy as possible. Then the Revy dam could stay on-line generating it's 1980MW 24 Hrs/day. this dam is built & running. And 1980MW ain't peanuts.

If the transmission capacity was increased to the Revy dam, then the extra capacity could be used for the additional power generated by the high-mountain stored water. Opponents correctly argue that the extra capacity isn't needed at night. But pumping the water up high at night at even 50% efficiency is better than the present situation, which is also typical at other locations.

Check out "Revelstoke dam" on Google Earth & look at the mountain topology surrounding it.