Live Chat: Splitting water to store energy.

Live Chat: Splitting Water to Store Energy

Courtesy of AAAS: news.sciencemag.org...

Today's guests. Richard Eisenberg is Tracy Harris Professor Emeritus and Professor (Research) at the University of Rochester whose research includes photogeneration of hydrogen from water.

Aired later today: Thursday, 21 November, at 3 p.m. EST


Well, since I have a reputation for trampling every free energy/alternative energy thread that pops up I thought I would offer some balance. I am never truly satisfied until I have pissed off believers and skeptics alike. (Always trying to remain in the middle enough for everyone to hate me.)

About a year ago we a thread discussion on the feasibility of hydrogen fuelled economy. The types of ideas being thrown around were solar arrays in the desert (to maximize the solar collection capabilities) and then transport using liquid storage with hydrides. Personally, I think it's an interesting concept but never did the math to calculate the actual feasibility in a manner that would qualify as "evidence" of feasibility.

In any case, some of the drawbacks with Hydrogen is major issues with storage and distribution, unless of course you store with hydrides, or employ some type of fuel cell. (more chemicals needed).

And to simply convert the solar to hydrogen back to electrical, not only do you waste a ton of energy along the way (efficiencies) but you also lose your load while it travels conventional distribution wires. These losses make this type of thing impossible in areas where solar collection can be maximized.

Many local areas that could house a solar array do not have optimal sunlight nor conditions & requirements needed. Some will argue that new tech can harvest just as much solar energy in cloudy or sun conditions, but there is even newer tech which can provide some whopping numbers in desert conditions, which I believe trumps the former.

In any case, I'm done, I have written this before reading about the discussion from the pros, so if I am wrong about anything, I am being schooled as much as you.

When a plant uses the sun’s energy to split water molecules, it shuttles hydrogen (separated as protons and electrons) into a reaction sequence to help it grow. But when scientists split water molecules in a type of artificial photosynthesis, the goal isn’t to grow an artificial plant. It’s about storing energy in hydrogen as a fuel.

In order to replace a big fraction of fossil fuel power with solar power, we need a way to store energy from the bright noon sun to use at night or when it’s cloudy. With artificial photosynthesis, scientists can make hydrogen under sunny skies to store energy, then turn it back into water when they need the energy back. The idea has been around for decades, but lately there has been a flurry of new research. What’s the state of the art in water-splitting? What are the obstacles to making it cheaper and more efficient? And will it really help us reduce our dependence on fossil fuel?

Join chemists John Turner of the National Renewable Energy Laboratory and Richard Eisenberg of the University of Rochester on Thursday, 21 November, at 3 p.m. EST on this page for a live video chat where we discuss this burgeoning field of research and take your questions. Be sure to leave your queries for our guests in the comment box below.

There is a brief write up about the conversation, for all interested parties, you can tune in later today. Should be interesting for anyone seriously into the subject of alternative energy ideas.

reply to post by boncho


I doubt I will be available later today, but I am curious to know, if you use a solar array to provide the energy to separate the hydrogen and store the hydrogen locally, would the ROI on the equipment overcome the cost of energy to do the same job?

I have never done the math about living off the grid, but the argument always given against hydrogen is it costs too much to make. If you use the SUN to provide the energy, how much does the sun charge? Your cost is in the equipment. Plus you have the tiny benefit of reduced pollution.

Perhaps I am still an idiot, and this can be explained away as it always is, but I feel as if someone could provide some numbers (even if they were guesses) to prove the point. Thanks for posting this. I will check later tonight.

Splitting water conventionally with electrolysis is really a non-starter for a number of reasons. I hope this technology is much better.

reply to post by network dude

I have never done the math about living off the grid, but the argument always given against hydrogen is it costs too much to make. If you use the SUN to provide the energy, how much does the sun charge? Your cost is in the equipment. Plus you have the tiny benefit of reduced pollution.

The biggest problem with solar arrays has been that they break down long before they are supposed to. I think the EROI on them is around of 5 to 6, and you still have to factor in the costs associated with that. Adding in hydrolysis makes it even worse.

Of course, new ideas are being pushed so who knows if they come up with something useful. We can always hope.

Using excess solar or wind power to electrolyze water for the collection of hydrogen will never be very efficient. It is somewhat feasible on a very small scale if you don't need to transport the hydrogen anywhere and don't need a large amount of it.

But it would probably be more efficient, cost effective an safe to simply store compressed air. Then use the compressed air to run a turbine to generate electricity without the need for combustion.

The only difference is that the compressed air can't be used as a combustible fuel.