Cheap hydrogen energy

[PAH]

Looks interesting, if it survives various influences to bury the tech along with the pig poop petrol of the 70s.

Microbial fuel cell produces hydrogen from wastewater without wasting energy -- Engadget

I wonder what the stumbling block will be. No way will they let us have these in our homes getting free energy from rainwater, or the nearest stream.

[conned tractor]

What is the rate of production in energy terms? (Sorry not got time to read it at the mo, I will hae a proper look later).

[PAH]

Don't think it's mentioned. Would be the one limiting factor if it is a slow process, though could leave it to drip-feed into a tank at home, then top up the car or heating system as needed.

The most interesting bit:

Logan's cells proved to be about 58 to 64 percent energy efficient, while producing between 0.8 to 1.6 cubic meters of hydrogen for every cubic meter of liquid that passed through the system. The researchers' results show that only one percent of that energy was used to pump water through the cells, which are completely carbon neutral, as well.

According to Logan, this breakthrough demonstrates that "pure hydrogen gas can efficiently be produced from virtually limitless supplies of seawater and river water and biodegradable organic matter."

What about rainwater? Get plenty of that here.

[conned tractor]

Don't think it's mentioned. Would be the one limiting factor if it is a slow process, though could leave it to drip-feed into a tank at home, then top up the car or heating system as needed.

The most interesting bit:



What about rainwater? Get plenty of that here.

A cubic metre of hydrogen sounds impressive (at atmospheric pressure), but I shouldn't imagine that it's actually very much at all considering gases are compressed to (I can't remember) couple of hundred atmospheres when contained for use in industry.

[TimberWolf]

What is the rate of production in energy terms? (Sorry not got time to read it at the mo, I will hae a proper look later).

Difficult to say as it employs two energy sources, the ionic potential of salty water, and poop.

According to David MacKay the osmotic potential of sea water and fresh water is 0.8 kWh per cubic metre, or enough to run a 1 bar electric fire for 0.8 hours, or 688 Calories. A lot! You can look up the calorific content of poop yourself. That's theoretical maximum, so actual will be less than that sum.

[PAH]

A cubic metre of hydrogen sounds impressive (at atmospheric pressure), but I shouldn't imagine that it's actually very much at all considering gases are compressed to (I can't remember) couple of hundred atmospheres when contained for use in industry.

What's the burn rate on a cubic metre of uncompressed hydrogen if used in a car or gas burner (stove or boiler)?

i.e. will this device need to be bolted onto something compressing the gas output for efficient storage, so by the end of it maybe it'll be cheaper to just use the electricity input, which has till now been a limiting factor in the quest for 'getting more energy out than put in'.

[Troll]

The most promising technology I saw was roof tiles that used sunlight to produce H from H2O
They'd got a working prototype working

Hydrogen Solar home

It's now an old website with a dissolved parent company - but it seems a practical method of generating H ... leaving just the storage solution to be worked on

[PAH]

A lot!

Does that mean we can have guttering on our car roof to collect rainwater that feeds this device, and it will all work in real time?

[PAH]

It's now an old website with a dissolved parent company

Can't have been that promising then.

Maybe these are the same bunch pulling free energy scams like this one:

'E-cat': Here is the Greek energy box - NyTeknik

i.e. invent a too good to be true energy solution, get some mugs to invest, do a runner.

[TimberWolf]

Does that mean we can have guttering on our car roof to collect rainwater that feeds this device, and it will all work in real time?

You need lots of salt water and lots of fresh water, as the power comes from the osmotic potential between the two. At least that's how I read the article. It's possible he's using the energy in poop to make reverse osmosis possible with brackish water too, not sure. It's probably too much water for house to obtain practical amounts of energy from rain, but the concept in general may be practical on a large scale on a river by the sea. But most countries expend energy to do the reverse, to extract fresh water from salt or brackish water.