disquisizioni sul futuro delle auto (ibride, elettriche, ecc...)

[lucazam]

jstor e le altre banche dati le avevo all'uni for free quando ci lavoravo, adesso le scrocco :-)

il resto della comunità scientifica tace ...:haha:

no, sono gli utenti che non ascoltano. Allora vai in uni e sfoglia The International Journal of Life Cycle Assessment, e poi Environmental Science and Technology, e fatti le basi

[Doppiaeffe]

no, sono gli utenti che non ascoltano. Allora vai in uni e sfoglia The International Journal of Life Cycle Assessment, e poi Environmental Science and Technology, e fatti le basi

mi farò le basi, peccato che a tua richesta ho trovato un articolo di fonte e autore autorevole e invece per sostenere le tue tesi mi dovrò cercare qualcosa.
:haha:

[lucazam]

mi farò le basi, peccato che a tua richesta ho trovato un articolo di fonte e autore autorevole e invece per sostenere le tue tesi mi dovrò cercare qualcosa.
:haha:

Vaaaaaaa bene....ti allego qualche abstract, però poi vai in università a imparare qualcosa ok?

"In this paper, an environmental comparison of electric, hybrid, LPG, diesel and gasoline passenger vehicles is performed through a Life Cycle Assessment (LCA) approach. Thanks to a range-based modeling system, the variations of the weight, the fuel consumption and the emissions within the family car category are considered instead of the average values. Unlike in a classic LCA, the use phase of vehicles has been modeled to cover vehicles with both a short and long lifespan in such way that the number of times a vehicle needs to be produced to cover the comparison basis or functional unit is taken into account. According to the assumptions and the used impact calculation method, the greenhouse effect of the LPG hybrid and battery electric vehicles are respectively 20.27 %, 27.44 % and 72.56% lower than for the gasoline vehicles. The assessment of the impact on human health and the air acidification give the best environmental score to the battery electric vehicle. A sensitivity analysis has allowed the assessment of the correlation between the respiratory effects and the euro emission standards" Autore: Boureima et al., 2009

"Background: Electric vehicles have been identified as being a key technology in reducing future emissions and energy consumption in the mobility sector. The focus of this article is to review and assess the energy efficiency and the environmental impact of battery electric cars (BEV), which is the only technical alternative on the market available today to vehicles with internal combustion engine (ICEV). Electricity onboard a car can be provided either by a battery or a fuel cell (FCV). The technical structure of BEV is described, clarifying that it is relatively simple compared to ICEV. Following that, ICEV can be 'e-converted' by experienced personnel. Such an e-conversion project generated reality-close data reported here. Results: Practicability of today's BEV is discussed, revealing that particularly small-size BEVs are useful. This article reports on an e-conversion of a used Smart. Measurements on this car, prior and after conversion, confirmed a fourfold energy efficiency advantage of BEV over ICEV, as supposed in literature. Preliminary energy efficiency data of FCV are reviewed being only slightly lower compared to BEV. However, well-to-wheel efficiency suffers from 47% to 63% energy loss during hydrogen production. With respect to energy efficiency, BEVs are found to represent the only alternative to ICEV. This, however, is only true if the electricity is provided by very efficient power plants or better by renewable energy production. Literature data on energy consumption and greenhouse gas (GHG) emission by ICEV compared to BEV suffer from a 25% underestimation of ICEV-standardized driving cycle numbers in relation to street conditions so far. Literature data available for BEV, on the other hand, were mostly modeled and based on relatively heavy BEV as well as driving conditions, which do not represent the most useful field of BEV operation. Literature data have been compared with measurements based on the converted Smart, revealing a distinct GHG emissions advantage due to the German electricity net conditions, which can be considerably extended by charging electricity from renewable sources. Life cycle carbon footprint of BEV is reviewed based on literature data with emphasis on lithium-ion batteries. Battery life cycle assessment (LCA) data available in literature, so far, vary significantly by a factor of up to 5.6 depending on LCA methodology approach, but also with respect to the battery chemistry. Carbon footprint over 100,000 km calculated for the converted 10-year-old Smart exhibits a possible reduction of over 80% in comparison to the Smart with internal combustion engine. Conclusion: Findings of the article confirm that the electric car can serve as a suitable instrument towards a much more sustainable future in mobility. This is particularly true for small-size BEV, which is underrepresented in LCA literature data so far. While CO [SUB]2[/SUB]-LCA of BEV seems to be relatively well known apart from the battery, life cycle impact of BEV in categories other than the global warming potential reveals a complex and still incomplete picture. Since technology of the electric car is of limited complexity with the exception of the battery, used cars can also be converted from combustion to electric. This way, it seems possible to reduce CO [SUB]2[/SUB]-equivalent emissions by 80% (factor 5 efficiency improvement)." Autore: Elmers et al., 2012

[yuza]

Ho da qualche parte un interessante articolo scritto dal capo del reparto innovazione prodotto della azienda per cui lavoro (2/3/4 ruote...), come intervento ad un seminario sulla mobilità elettrica.

E' una analisi tra il serio e il faceto del perchè non avremo mai il passaggio di tutto il parco auto da combustibile fossile a elettrico, per via dei limiti di immagazzinamento e distribuzione della quantità di energia elettrica che servirebbe ad alimentare milioni di veicoli e soprattutto a "rifornirli" di energia in tempi compatibili con la mobilità odierna (=fare il "pieno" di energia in minuti e non in ore).

Non posso ovviamente pubblicarlo ma se volete ve lo mando per mail. E' illuminante.

[Fly Lemon]

Credo che sia abbastanza inutile continuare a discutere su 'ste cose...ognuno rimane della sua opinione, rimane arroccato sulle sue convinzioni e non si arriva a nulla.

La stessa comunita' scientifica, ben piu' dotta di noi in materia, e' divisa su questo argomento, quindi non credo che noi comuni mortali possiamo avere la verita' assoluta su certe cose.

SE volete continuare a discutere la cosa fate pure...io me ne tiro fuori. Tra l'altro per natura non sono esattamente il miglior esempio di ecologista vivente, quindi...(ne avrei da dire sui catalizzatori e sul loro smaltimento ecc.ecc.)

Una cosa pero' ho notato: continuate sempre e comunque a parlare di applicazioni "classiche"...nessuno che valuta, come dicevo in precedenza, vantaggi e svantaggi di motori a gasolio alimentati a metano (forse perche' a parte qualche autobus cittadino nessun altro veicolo e' autorizzato ad avere tale trazione?) o motori alimentati a biocarburanti ecc.ecc.

A mio avviso se spostassimo l'attenzione su questo punto potremmo evitare di bloccarci su un singolo aspetto e sviluppare maggiormente la discussione

[lucazam]

La comunità scientifica NON è divisa. E' noto qual è l'alternativa più ECO-sostenibile. Tuttavia, la sostenibilità non è fatta solo di ecologia ma anche di temi sociali ed economici, da qui può non convenire la trazione elettrica. In aggiunta, come dice Yuza, l'energia elettrica non è infinita. Tuttavia, a questo proposito è appena stato pubblicato un articolo su Environmental Science and Technology in cui si paragona l'utilizzo di bio-carburanti con la trazione elettrica generata da fotovoltaico, in un'applicazione sito-specifica negli Stati Uniti: il risultato è che, sebbene il FV abbia bassi rendimenti, si utilizzerebbe comunque meno suolo rispetto all'utilizzo di biocarburanti e in più si avrebbero gli ovvi vantaggi in termini di emissioni.

Allego l'abstract per chi è interessato e per DoppiaEffe.

Growth in biofuel production, which is meant
to reduce greenhouse gas (GHG) emissions and fossil energy
demand, is increasingly seen as a threat to food supply and
natural habitats. Using photovoltaics (PV) to directly convert
solar radiation into electricity for battery electric vehicles
(BEVs) is an alternative to photosynthesis, which suffers from
a very low energy conversion efficiency. Assessments need to
be spatially explicit, since solar insolation and crop yields vary
widely between locations. This paper therefore compares
direct land use, life cycle GHG emissions and fossil fuel
requirements of five different sun-to-wheels conversion
pathways for every county in the contiguous U.S.: Ethanol
from corn or switchgrass for internal combustion vehicles
(ICVs), electricity from corn or switchgrass for BEVs, and PV electricity for BEVs. Even the most land-use efficient biomassbased
pathway (i.e., switchgrass bioelectricity in U.S. counties with hypothetical crop yields of over 24 tonnes/ha) requires 29
times more land than the PV-based alternative in the same locations. PV BEV systems also have the lowest life cycle GHG
emissions throughout the U.S. and the lowest fossil fuel inputs, except for locations with hypothetical switchgrass yields of 16 or
more tonnes/ha. Including indirect land use effects further strengthens the case for PV.

Quindi non si può dire che la comunità scientifica sia DIVISA, non è assolutamente vero.

[Doppiaeffe]

Vaaaaaaa bene....ti allego qualche abstract, però poi vai in università a imparare qualcosa ok?

"In this paper, an environmental comparison of electric, hybrid, LPG, diesel and gasoline passenger vehicles is performed through a Life Cycle Assessment (LCA) approach. Thanks to a range-based modeling system, the variations of the weight, the fuel consumption and the emissions within the family car category are considered instead of the average values. Unlike in a classic LCA, the use phase of vehicles has been modeled to cover vehicles with both a short and long lifespan in such way that the number of times a vehicle needs to be produced to cover the comparison basis or functional unit is taken into account. According to the assumptions and the used impact calculation method, the greenhouse effect of the LPG hybrid and battery electric vehicles are respectively 20.27 %, 27.44 % and 72.56% lower than for the gasoline vehicles. The assessment of the impact on human health and the air acidification give the best environmental score to the battery electric vehicle. A sensitivity analysis has allowed the assessment of the correlation between the respiratory effects and the euro emission standards" Autore: Boureima et al., 2009

"Background: Electric vehicles have been identified as being a key technology in reducing future emissions and energy consumption in the mobility sector. The focus of this article is to review and assess the energy efficiency and the environmental impact of battery electriccars (BEV), which is the only technical alternative on the market available today to vehicles with internal combustion engine (ICEV). Electricity onboard a car can be provided either by a battery or a fuel cell (FCV). The technical structure of BEV is described, clarifying that it is relatively simple compared to ICEV. Following that, ICEV can be 'e-converted' by experienced personnel. Such an e-conversion project generated reality-close data reported here. Results: Practicability of today's BEV is discussed, revealing that particularly small-size BEVs are useful. This article reports on an e-conversion of a used Smart. Measurements on this car, prior and after conversion, confirmed a fourfold energy efficiency advantage of BEV over ICEV, as supposed in literature. Preliminary energy efficiency data of FCV are reviewed being only slightly lower compared to BEV. However, well-to-wheel efficiency suffers from 47% to 63% energy loss during hydrogen production. With respect to energy efficiency, BEVs are found to represent the only alternative to ICEV. This, however, is only true if the electricity is provided by very efficient power plants or better by renewable energy production. Literature data on energy consumption and greenhouse gas (GHG) emission by ICEV compared to BEV suffer from a 25% underestimation of ICEV-standardized driving cycle numbers in relation to street conditions so far. Literature data available for BEV, on the other hand, were mostly modeled and based on relatively heavy BEV as well as driving conditions, which do not represent the most useful field of BEV operation. Literature data have been compared with measurements based on the converted Smart, revealing a distinct GHG emissions advantage due to the German electricity net conditions, which can be considerably extended by charging electricity from renewable sources. Life cycle carbon footprint of BEV is reviewed based on literature data with emphasis on lithium-ion batteries. Battery life cycle assessment (LCA) data available in literature, so far, vary significantly by a factor of up to 5.6 depending on LCA methodology approach, but also with respect to the battery chemistry. Carbon footprint over 100,000 km calculated for the converted 10-year-old Smart exhibits a possible reduction of over 80% in comparison to the Smart with internal combustion engine. Conclusion: Findings of the article confirm that the electriccar can serve as a suitable instrument towards a much more sustainable future in mobility. This is particularly true for small-size BEV, which is underrepresented in LCA literature data so far. While CO [SUB]2[/SUB]-LCA of BEV seems to be relatively well known apart from the battery, life cycle impact of BEV in categories other than the global warming potential reveals a complex and still incomplete picture. Since technology of the electriccar is of limited complexity with the exception of the battery, used cars can also be converted from combustion to electric. This way, it seems possible to reduce CO [SUB]2[/SUB]-equivalent emissions by 80% (factor 5 efficiency improvement)." Autore: Elmers et al., 2012

sereno che appena torno da Ny mi passo una mattinata nel mio vecchio dipartimento all'uni per vedere meglio il tutto.

[Fly Lemon]

La comunità scientifica NON è divisa. .

Mah, se lo dici tu...se si parla di elettrico ti do ragione, se si parla di ibrido continuo a nutrire dei dubbi...mi considero come S.Tommaso e sono abituato ad essere sempre e comunque scettico in tutto.

Sara' un mio limite, sara' un mio pregio, questo non lo so, ma e' così

[lucazam]

Mah, se lo dici tu...se si parla di elettrico ti do ragione, se si parla di ibrido continuo a nutrire dei dubbi...mi considero come S.Tommaso e sono abituato ad essere sempre e comunque scettico in tutto.

Sara' un mio limite, sara' un mio pregio, questo non lo so, ma e' così

Mi riferisco all'elettrico.

[Enuma]

Forse c'è qualcuno che ci crede.
Speriamo bene.

http://www.greenme.it/muoversi/auto/9807...geno-corea