Re: [EVDL] Compressed Air
> 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. I would be interested in seeing that chart. ___ 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)
Re: [EVDL] Compressed Air
On Air cars... Too bad they can't be "charged" in the winter when the waste heat is 100% usable for heat in th ebuilding where the compressor is, and then driven in the summer when the expansion is free AC.. bob On Sat, Oct 1, 2016 at 8:34 PM, Cor van de Water via EV <ev@lists.evdl.org> wrote: > I have reported before that almost 20 years ago I visited MDI in France, > who were supposed to release an air-powered car. I checked their physics > and came to the conclusion that without heat exchanger, their efficiency > would be horrible and the air engine would freeze up. That is exactly > what several news reporters have said once they took a slightly longer > test run than just a loop in the parking lot. Physics is quite clear > about the efficiency of compressing and expanding a gas like air. You > invest a *lot* of power in the compression and get a *lot* of heat out > at that moment. As Lee would say: heat is the indicator of > (in)efficiency. > Only if you are able to either store or feed that heat back in during > expansion, can you get a decent efficiency. Since MDI did not design > that in, their cars were doomed to be wasteful and since the compressed > air storage has so low energy density, their range was short. There > really was not a whole lot of difference compared to running batteries, > though in theory the weight could be less and the absence of lead or > acid or other dangerous materials was a benefit, but the lower > efficiency made it a non-starter. > There are niches where air powered vehicles were used, think mine > corridors where no dangerous goods, sparks or combustion was a big > benefit for the operation underground. Today we would use an AC > (brushless) drive to avoid the sparks and achieve better efficiency. > > Cor van de Water > Chief Scientist > Proxim Wireless > > office +1 408 383 7626Skype: cor_van_de_water > XoIP +31 87 784 1130private: cvandewater.info > > http://www.proxim.com > > This email message (including any attachments) contains confidential and > proprietary information of Proxim Wireless Corporation. If you received > this message in error, please delete it and notify the sender. Any > unauthorized use, disclosure, distribution, or copying of any part of > this message is prohibited. > > > -Original Message- > From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of EVDL > Administrator via EV > Sent: Saturday, October 01, 2016 4:51 PM > To: ev@lists.evdl.org > Subject: Re: [EVDL] Compressed Air > > 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
Re: [EVDL] Compressed Air
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 <ev@lists.evdl.org> To: ev@lists.evdl.org 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)
Re: [EVDL] Compressed Air
On 10/01/2016 08:34 PM, Cor van de Water via EV wrote: I have reported before that almost 20 years ago I visited MDI in France, who were supposed to release an air-powered car. I checked their physics and came to the conclusion that without heat exchanger, their efficiency would be horrible and the air engine would freeze up. Living in Florida, I could see taking advantage of the expanding gas to provide air conditioning for your passenger compartment. Wouldn't improve the storage efficiency, but would at least provide a benefit on the expansion side. (more efficient than using the air driven turbine/motor to drive an AC compressor). Jay ___ 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)
Re: [EVDL] Compressed Air
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)
