t**********5
发帖数: 418 | 1 假如电动汽车完全取代传统能源车辆，虽然行驶中达到零尾气，但能量守恒，只是把个
体通过fossil fuel获取能量转变为集中获取能量，关键点在于集中发电这个环节获取
能源的方式有多清洁和高效。如果发电仍然与现在相同的煤和柴油为主，则产生的废气
总量并没有明显下降，获取能源总效率和清洁度没有实质提高。
所谓风能和太阳能在半个世纪内都注定只是科技和概念噱头，经济投入与回报比极差，
占用土地和工业资源与发电效率比更差，除非有重大技术突破，使单位占用土地和经济
投入产出能量极大程度地提高，否则风能太阳能永远都只是一个概念。
我认为最应该推动和发展的是核能，两个世纪内核能的效率应该是无法被超越的。其实
现代核能技术尤其是安全生产控制可以做到很好了，从70年代开始美国环保主义者就开
始反对核能发展和应用。日本的核能应用发电世界第一，日本在地震海啸高发地区大量
应用核能并且近半个世纪安全生产，实为核能应用的典范。而美国有大量的受自然灾害
影响小的土地可以建立核电站，缺乏的只是大众对核能发电科学的认识和政府对行业政
策的开放。 | x*********s
发帖数: 5554 | 2 丰田都已经放弃PEV了吧
【在 t**********5 的大作中提到】
: 假如电动汽车完全取代传统能源车辆，虽然行驶中达到零尾气，但能量守恒，只是把个
: 体通过fossil fuel获取能量转变为集中获取能量，关键点在于集中发电这个环节获取
: 能源的方式有多清洁和高效。如果发电仍然与现在相同的煤和柴油为主，则产生的废气
: 总量并没有明显下降，获取能源总效率和清洁度没有实质提高。
: 所谓风能和太阳能在半个世纪内都注定只是科技和概念噱头，经济投入与回报比极差，
: 占用土地和工业资源与发电效率比更差，除非有重大技术突破，使单位占用土地和经济
: 投入产出能量极大程度地提高，否则风能太阳能永远都只是一个概念。
: 我认为最应该推动和发展的是核能，两个世纪内核能的效率应该是无法被超越的。其实
: 现代核能技术尤其是安全生产控制可以做到很好了，从70年代开始美国环保主义者就开
: 始反对核能发展和应用。日本的核能应用发电世界第一，日本在地震海啸高发地区大量
| g******u
发帖数: 3060 | | c******n
发帖数: 16666 | | z*h
发帖数: 773 | 5 Q2. What powertrain and fuel will become the dominant transport means in the
future?
A number of scenarios could bridge between renewable primary energy and
transportation energy need (Fig. 1) through four powertrain systems: (i)
ICEs and/or electric hybrids that burn liquid biofuels and compressed
methane, (ii) battery electric vehicles (BEVs) that run on electricity
stored in rechargeable batteries, where electricity can be generated from
sun radiation, tide, geothermal, wind, and nuclear energy; (iii) hydrogen
fuel cell vehicles (FCVs) that run on stored hydrogen through proton
exchange membrane (PEM) fuel cells and electric motor; and (iv) sugar fuel
cell vehicles (SFCVs) that run on stored sugar as a hydrogen carrier based
on FCV. Powertrain systems for vehicles must meet all of the following
criteria: high energy storage capacity in a small container, high power
output, economically competitive fuel, affordable vehicle, fast charging or
refilling of the fuel, and high safety.
Table 3 compares the gravimetric energy densities of liquid fuels, stored
hydrogen, rechargeable batteries, and capacitors, as well as kinetic energy
output densities on wheels through different powertrain systems. The energy
storage densities in a decreasing order are diesel, gasoline, butanol,
ethanol, methanol, sugar, stored hydrogen, rechargeable batteries and
capacitors. Liquid gasoline and diesel plus their respective ICEs have
kinetic energy output densities of 6.50 and 8.32 MJ/kg, respectively. When
ICE’s energy efficiencies are increased through hybrid electric systems,
HEV-gas and HEV-diesel can drive farther. Stored hydrogen regardless of
different storage means have lower energy storage densities from 5.0 to 9.3
MJ/kg or even lower, resulting in shorter driving distance of FCVs compared
to vehicles based on ICEs if the same weight fuel tank is used. Therefore,
the Department of Energy (DOE) of the USA strongly encourages to develop
novel high-density hydrogen storage means and provides the H-prize cash
award [8]. Rechargeable batteries have at least one order magnitude lower
energy storage densities than liquid fuels and stored hydrogen (Table 3). As
a result, BEVs have very short driving distances. The energy densities of
capacitors are very low, restricting its application in the transport sector
.
BEVs will not be a dominant future transport means although it was suggested
by some influential scientists [11,47]. The International Energy Agency
predicts that BEVs will play a minor role in the future [48,49].
Rechargeable lithium batteries have energy densities of ~150 Wh/kg (i.e., 0.
56 MJ/kg), resulting in very short driving distances [50,51]. If the energy
densities of batteries were increased by ca. 5-10-fold [52,53], other issues
such as safety could prohibit their wide use in personal vehicles. Future
energy densities of rechargeable lithium batteries are expected to increase
by two-fold in next decades [50,51] rather than ca. 5-10 times by
considering the configuration of batteries and the combustion energy of
lithium (i.e., 43.1 MJ/kg).
In addition to low energy densities of batteries, BEVs will have several
other weaknesses. First, the recharging cycles and lifetime of high-density
lithium rechargeable batteries is ca.1000 time and two or three years,
respectively. Both are much shorter than requirement of the major car
components lasting at least ten years. (Think of batteries in cellphones and
laptops.) Second, lithium batteries are still costly for vehicles although
its production costs could be decreased by several-fold. It is not
realistic to believe that battery costs would be drastically decreased
following Moore’s Law because it is impossible to exponentially both
decrease material consumption in batteries and increase battery performance
according to the basic physical limits of materials. Third, batteries
require a long recharging time. Although ultra-fast charging batteries have
been developed [54], these capacitor-like batteries have been made at the
cost of decreasing energy storage densities [55]. Fourth, a huge
infrastructure investment would be needed to upgrade the electrical grid,
install sockets for fast recharge, and build power stations [15]. Fifth,
disposing and recycling a large number of used rechargeable batteries would
be another environmental challenge [15]. Sixth, the capacity loss rates of
rechargeable batteries depend on temperature; for example, standard capacity
loss rates per year are 6% at 0°C, 20% at 25°C, and 35% at 40°C [15].
Seventh, whether there is enough low-cost lithium for BEVs is not a certain
thing. Goodenough, a pioneer of lithium ion batteries, pointed out that the
principal challenges facing the development of rechargeable batteries for
BEVs are cost, safety, cell energy density (voltage x capacity), rate of
charge/discharge, and service life [56]. Due to BEVs’ unique features such
as cleanness and quietness, BEVs will be popular in some special markets,
for example, in golf courts. In a word, a complete switch to all battery
electric cars is utterly unrealistic [15] by considering the above problems
and the odds that better technologies will appear and mature.
I would like to suggest another out-of-the-box solution for the future
vehicles – sugar fuel cell vehicles (SFCVs). Based on FCVs, carbohydrate [
shorthand, CH2O] is suggested to be a high-density hydrogen carrier and
energy source so that its use could address hydrogen storage, distribution
and safety issues [31,57-59]. In the hypothetical SFCVs, an on-board
biotransformer containing numerous thermoenzymes and co-enzymes that can
achieve the reaction of CH2O + H2O 2H2 + CO2 [60,61]. Because
enzymes are 100% selective, work under moderate reaction conditions, and
generate highly pure hydrogen, carbohydrates are a promising hydrogen
carrier with a gravimetric density of carbohydrate/water of 8.33 H2 mass% [8
,17]. During the past several years, we have increased enzymatic hydrogen
generation rates to ca. 160 mmole H2/L/h by more than 300-fold (in
preparation for publication). We anticipate to increase reaction rates by
another 30-fold within next several years so that the on-board
biotransformer will be small enough in SFCVs [8,31].
In a word, HEVs are believed to be a short- and middle-term solution before
hydrogen fuel cell vehicles [62]. SFCVs could be a good solution to address
the problems of FCVs from hydrogen production, storage, distribution, and
safety. SFCVs would have several advantages over BEVs: much higher energy
storage densities, faster refilling rates, better safety, and less
environmental burdens [13]. | T***E
发帖数: 996 | 6 发电厂的能源利用效率比汽车内燃机高多了
【在 t**********5 的大作中提到】
: 假如电动汽车完全取代传统能源车辆，虽然行驶中达到零尾气，但能量守恒，只是把个
: 体通过fossil fuel获取能量转变为集中获取能量，关键点在于集中发电这个环节获取
: 能源的方式有多清洁和高效。如果发电仍然与现在相同的煤和柴油为主，则产生的废气
: 总量并没有明显下降，获取能源总效率和清洁度没有实质提高。
: 所谓风能和太阳能在半个世纪内都注定只是科技和概念噱头，经济投入与回报比极差，
: 占用土地和工业资源与发电效率比更差，除非有重大技术突破，使单位占用土地和经济
: 投入产出能量极大程度地提高，否则风能太阳能永远都只是一个概念。
: 我认为最应该推动和发展的是核能，两个世纪内核能的效率应该是无法被超越的。其实
: 现代核能技术尤其是安全生产控制可以做到很好了，从70年代开始美国环保主义者就开
: 始反对核能发展和应用。日本的核能应用发电世界第一，日本在地震海啸高发地区大量
| O*******d
发帖数: 20343 | 7 电力的最大优点就是来源多样化。不象汽车的内燃机，只用用液体或气体燃料。 | p****a
发帖数: 25 | 8 也许将来电池技术有了突破，现在的加油站都变成充电站或者电池交换站，对于后者，
用户相当于租用电池，充电站负责电池的充电，维护保养，不知道有没有可能。 | t**********5
发帖数: 418 | 9 电池拆卸不可能，现在hybrid和electric车的电池都在电池仓，有非常复杂的防尘和防
水密封处理，同时也有为了在车祸中保护电池的电池仓保护外壳，不会那么容易可以随
时拆卸更换的
【在 p****a 的大作中提到】
: 也许将来电池技术有了突破，现在的加油站都变成充电站或者电池交换站，对于后者，
: 用户相当于租用电池，充电站负责电池的充电，维护保养，不知道有没有可能。
| c******n
发帖数: 16666 | 10 这个貌似几年前就在电力车的行业论坛上讨论了
方案都有好几家做出来了
【在 t**********5 的大作中提到】
: 电池拆卸不可能，现在hybrid和electric车的电池都在电池仓，有非常复杂的防尘和防
: 水密封处理，同时也有为了在车祸中保护电池的电池仓保护外壳，不会那么容易可以随
: 时拆卸更换的
| | | y*****s
发帖数: 1047 | | t**********5
发帖数: 418 | 12 液氢也是一种可能性，但是安全储存和成本是技术瓶颈
【在 y*****s 的大作中提到】
: 燃料电池
: 灌液化天然气或者氢气
| i****x
发帖数: 17565 | 13 http://www.betterplace.com/
【在 t**********5 的大作中提到】
: 电池拆卸不可能，现在hybrid和electric车的电池都在电池仓，有非常复杂的防尘和防
: 水密封处理，同时也有为了在车祸中保护电池的电池仓保护外壳，不会那么容易可以随
: 时拆卸更换的
| t**********5
发帖数: 418 | 14 那行业统一标准呢？
【在 i****x 的大作中提到】
: http://www.betterplace.com/
| c*****h
发帖数: 445 | 15 氢气可以用碳纤维做成的罐子储存，成本应该在可接受范围内，达到4级安全也不成问
题，我目前工作的公司老板以前就做这个的。
【在 t**********5 的大作中提到】
: 液氢也是一种可能性，但是安全储存和成本是技术瓶颈
| t**********5
发帖数: 418 | 16 但是成本呢？一切都是以市场为导向的，即使10年后，大家也不会花5万买辆普锐斯，
金属油箱成本多少，碳纤维液氮罐成本多少？
【在 c*****h 的大作中提到】
: 氢气可以用碳纤维做成的罐子储存，成本应该在可接受范围内，达到4级安全也不成问
: 题，我目前工作的公司老板以前就做这个的。
| j***n
发帖数: 1471 | 17 这个观点很不错，我不认为PHEV会成为未来汽车业的一枝独秀，但我希望PHEV在多元化
的汽车市场能有一席之地。
现在底特律有老中自己开了家车铺，专门给Prius加高压电池包把Hybrid改装成PHEV，
我衷心祝愿这种车铺原来越多，最好把国内那些什么汽油车改装煤气罐的技术也全拿过
来，就是后备箱掏空并排放4个小煤气罐的那种，给整车市场来个先乱后治，哈哈。 | a*********a
发帖数: 413 | 18 现在普锐斯只卖两万五了好不好!
【在 t**********5 的大作中提到】
: 但是成本呢？一切都是以市场为导向的，即使10年后，大家也不会花5万买辆普锐斯，
: 金属油箱成本多少，碳纤维液氮罐成本多少？
| r******n
发帖数: 4522 | 19 俺N年前觉得到2012就能成主流，唉，来日方长啊。 | c*****h
发帖数: 445 | 20 Well, carbon fiber isn't that bad, plus I guess the cost will change
eventually, after 50 or 100 yrs when we r running out of any metallatic
minerals, this would be a good choice. Actually, the entire new energy
industry is relying on this assumption, isn't it?
【在 t**********5 的大作中提到】
: 但是成本呢？一切都是以市场为导向的，即使10年后，大家也不会花5万买辆普锐斯，
: 金属油箱成本多少，碳纤维液氮罐成本多少？
| w********r
发帖数: 14958 | 21 metallatic minerals, 永远都不会耗尽。 地球就是铁做的。
【在 c*****h 的大作中提到】
: Well, carbon fiber isn't that bad, plus I guess the cost will change
: eventually, after 50 or 100 yrs when we r running out of any metallatic
: minerals, this would be a good choice. Actually, the entire new energy
: industry is relying on this assumption, isn't it?
| d***s
发帖数: 7683 | 22 因为最近二十年能源科技突破太少，新勘探石油储量年年涨，投资科技动力不足。如果
全世界政策上强迫石油价格提高三倍，科技发展就快多了。
那时美国油价每加仑$15
【在 r******n 的大作中提到】
: 俺N年前觉得到2012就能成主流，唉，来日方长啊。
|
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