On 2/8/2013 5:04 PM, Jed Rothwell wrote:
Eric Walker <eric.wal...@gmail.com <mailto:eric.wal...@gmail.com>> wrote:
I think this has been mentioned here before, but what about
diverting the unneeded power to drive electrolysis and capture the
hydrogen for later use in a generator that makes use of an
internal combustion engine or is sold on the consumer market?
A fuel cell would be more efficient than an internal combustion engine
or gas turbine. There is ongoing research to develop that. I think at
present this is not as efficient as pumped hydro storage (70% to 85%
-- as I mentioned). It has the advantage that you can send the
hydrogen by pipeline and recombine it closer to a big city where they
need the electricity. That may have lower transmission losses than
electric power lines do. Also pipes are cheaper and take up less space
than high voltage electric power lines.
Do a Google search for "electrolysis energy storage" and you find
stuff like this:
http://www.incoteco.com/upload/ENSFinalReport.pdf
- Jed
I read most of "ENS Final Report" and extracted some tidbits:
Electrolysis ranges from ~75% efficient for "LV" hydrogen to ~85% for
"HV" hydrogen. I did not wade in deeper to dope that out. So, it's
similar to pumped hydro, except that the efficiency of the fuel cell
must be multiplied in.
The cost-to-implement in Denmark, 2008, was high, needing total relief
from their 80% motor fuel taxes, to even consider. (Proposal was for
hydrogen depots for vehicles.)
The Europeans (and us merikans I suppose) price their electricity
minute-by-minute when figuring which utility owes what when the sun
hides but the winds pick up. This often results in a zero cost/MWHr,
which is Important to Avoid.
If you inject hydrogen into the intake of a working Diesel engine (and
adjust fuel/air ratio as required), it will slow down. Engine has to
reworked to deal with the low power-to-volumn of hydrogen.
Yours,
Dave B.
