Two new breakthroughs for solar power....

Today’s post: Wednesday, 10-22-2008

Here’s a story I found online by searching all news for “solar energy” on Yahoo news last Monday. (I’d also seen a different story earlier than that about this breakthrough.)

“New solar cell material achieves almost 100% efficiency,
could solve world-wide energy problems “

“TG Daily - Oct 20 12:01 PM Trendwatch By Rick C. Hodgin Monday, October 20, 2008 13:32 Columbus (OH) -

Researchers at Ohio State University have accidentally discovered a new solar cell material capable of absorbing all of the sun's visible light energy. The material is comprised of a hybrid of plastics, molybdenum and titanium.”

The story is technical but goes on to explain that in solar photovoltaic cells, the sun’s light knocks some electrons loose that are available to be harvested as electricity and that are available for that purpose a very short time.

Someone at Ohio State found or realized that there might be a way to make more electrons available for a longer period of time in some kind of solar cell material. The researchers there then developed a material that does knock more electrons loose; but of even more importance it makes them available to be harvested over 7 million times longer than before. This material that they found by doing research on materials on a supercomputer apparently absorbs light from all the spectrum of light instead of just part of it and then delivers nearly 100 % of the energy absorbed as generated electricity.

It has yet to be found if this material can be made at low enough cost to be cost competitive with current technology. And, if they have made progress on solving this problem or on developing technology to do so, it wasn’t mentioned in the article.

Also, given the huge size of the potential uses of such efficient solar panels, the availability of the molybdenum and titanium used in such huge quantities at reasonable cost may be a constraint.

That said, there will be applications right away where high electricity generation from such photovoltaic panels in a limited area for the panels will be valuable.

For example, a company that wants or needs to generate all the electricity it needs onsite, may be able by using solar photovoltaic panels with this technology and installing them both on the roofs and over the parking lots for their company, they may be able to do so while this is not possible today.

And, as with the first material for incandescent light filaments led to new ones, it may be that there are less expensive ways to generate this effect and which will be discovered.

2. Mankind now has two important problems.

One is that we use electricity 24 hours a day 7 days a week. Solar light and the electricity we can harvest from it are available only during the day and the amount of light solar panels receive during the day varies with the time of day and the weather.

Second, we are using up the reserves of fresh water in some areas of the world and in others, there is now less rainfall than before, likely because of global warming. These things are jeopardizing our supply of drinking water and water to grow our food crops.

MIT researchers may have found a solution to both these problems, particularly when combined with the first breakthrough described above. They have worked out a way to use solar energy to split water into hydrogen and oxygen. By then storing the hydrogen and oxygen and running them through a very efficient fuel cell when you want or need electricity when the sun is not shining or you are getting less sunshine, you can make solar photovoltaic generated electricity available 24 hours a day, seven days a week.

And, it may be possible to also use this same technology to desalt sea water to provide a new supply of fresh water for drinking and for crops. (The bonus is that when you turn the hydrogen and oxygen into fresh water, you get to re-harvest the energy as electricity.)

The constraints on using this technology to store solar photovoltaic generated electricity are in making the overall process cost effective, in particular by making the fuel cells to retrieve the electricity at reasonable costs. That may well require technology we do not have yet.

But these two breakthroughs are of particular interest and potential value. So I wanted to use this blog to get the word out that they exist.