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Microbes Churn Out Hydrogen at Record Rate
FiReaNGeL writes to mention that Penn State Researchers have improved on their original microbial electrolysis cell design bringing the resulting system up to better than 80 percent efficiency when considering all energy inputs and outputs. "By tweaking their design, improving conditions for the bacteria, and adding a small jolt of electricity, they increased the hydrogen yield to a new record for this type of system. 'We achieved the highest hydrogen yields ever obtained with this approach from different sources of organic matter, such as yields of 91 percent using vinegar (acetic acid) and 68 percent using cellulose,' said Logan. In certain configurations, nearly all of the hydrogen contained in the molecules of source material converted to usable hydrogen gas, an efficiency that could eventually open the door to bacterial hydrogen production on a larger scale."
Uhm, but you are aware that the decaying plant material can't give off more CO2 or other Carbon-based greenhouse gases than it originally consisted of. Close cycle and such.
Grow a tree. Burn a tree. No increase in greenhouse gas.
As long as you don't use your conventional gas-powered buzz saw to bring it down and an F350 to haul it to your place...
Why are you comparing batteries to fuel cells in "thermodynamic efficiency". Batteries do not have "thermodynamic efficiency". A battery is not an engine, it's a container of an electrical potential that was put there probably by burning coal. You do realize that's where something like 80% of grid power comes from right? The battery's analog in current automotive propulsion is the gas tank in your Honda or whatever. Find out what the "thermodynamic efficiency" of the process of creating the electricity and then getting it into your lithium ion batteries, and then we can start making useful comparisons to other systems for automotive propulsion. Also, talking about range as if the range of a fuel cell vehicle was directly comparable to the range of a simple/straight EV (ie no production of power on bard, only storage) has limited validity too -- hydrogen vehicles are able to refill their hydrogen tanks about as fast as current gas cars fill their's, if not faster. EV's on the other hand, need to sit at a charger for a minimum of a couple hours, and if battery longevity is desired, really need to charge over an entire night. By the way, for those of you who don't know about it the Fuel Cell Equinox is extremely impressive. It's a mass produced, production fuel cell vehicle with the full interior room of a normal Equinox, that'll be driven by 1000 "owners" in the 3 major cities next year. It's been quite a wakeup call to the rest of the auto industry.