For energy storage, my understanding is that best solution depends on a number of factors, like amount of time for storing and scale. Again, my understanding and recollection, is that for small scale and storage time of hours, batteries are superior. Compressed air, IIRC, pops up for shorter storage time periods, and partially overlaps batteries for use suitability. Hydro and hydrogen are good for long term and grid scale. There's a good chart out there that I've seen in many forms that lays out well the technology with the appropriate solution(s). Let me know if you're interested in seeing it.
Sent from AltaMail From: EVDL Administrator via EV <[email protected]> To: [email protected] Subject: Re: [EVDL] Compressed Air Date: 10/1/16, 4:50 PM On 30 Sep 2016 at 19:44, Michael Ross via EV wrote: > Can we discuss compressed air a a storage medium that can spin > electric motors in autos and trucks? Maybe, but I don't see how air can power a motor. We've had posts on compressed air cars before - check the archive - but those aren't EVs. See Wikipedia for a decent article on compressed air cars that explains why they've never made the big time despite nearly a century of tinkering witih the concept. The problems are low efficiency and an energy density by volume that's worse than lead batteries. > Certain elements can be reformatted to higher energy states and then > reacted to power EV's. Isn't this how batteries work? > There is a particular reaction that could be used to store energy from > sustainable, but temporally irregular energy sources. It is a very > simple reaction, readily available ingredients are found everywhere for > little cost. And that is ... ??? > Technology exists to store the energy and release it, that is > sufficiently efficient (since there is no alternative other than to > waste solar and wind energy when it is inconveniently timed efficiency > becomes less concerning) As I understand it, batteries are the gold standard for efficiency in this. Between 20% and 80% SOC, lead batteries are close to 100% efficient. I'd guess that other types have similar ranges with similar efficiency. Air compressed in undergound mines has been used for utility load leveling. The programs so far have required natural gas input to warm the cold released air. Their efficiency looks decent if you ignore the gas input. However, one source I read put the actual efficiency for air storage at 25- 45%. Pumped hydro is much more common and supposedly runs 60-85% efficiency, though I admit I find that hard to believe too. The island of El Hierro is now generating almost all of their electricity with wind, and storing it with pumped hydro. > compressed air could do this, but I would really prefer it was a > compressed reactive gas not just nitrogen and some other lesser > components. Can you explain why? > If this particular gas was used, an additional use is possible, we > could use to power EVs. What gas are you talking about? It almost seems as if you're avoiding naming it. Why all the mystery? David Roden - Akron, Ohio, USA EVDL Administrator = = = = = = = = = = = = = = = = = = = = = = = = = = = = = EVDL Information: http://www.evdl.org/help/ = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Note: mail sent to "evpost" and "etpost" addresses will not reach me. To send a private message, please obtain my email address from the webpage http://www.evdl.org/help/ . = = = = = = = = = = = = = = = = = = = = = = = = = = = = = _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Read EVAngel's EV News at http://evdl.org/evln/ Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA) -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20161001/5317cf3a/attachment.htm> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Read EVAngel's EV News at http://evdl.org/evln/ Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
