How to store energy -5

2022/12/14 2023/01/03

lenemas

This post is 5th of a series "how to store energy" (see previous posts of first, second, third, forth in the series).

The previous post considered gasoline 50 [L] as a model to drive a car, and compared it with other energy carriers (see How to store energy -4). This post continues the discussion on energy densities, taking some examples other than the vehicle.

Airplane

Boeing 777 is adopted as the first example.

The amount of fuel required to fly for 900 [km] is 7.9 [ton].^[1] The main component of jet fuel is kerosene,^[2] and the heating value of jet fuel is 36.54 [MJ L^-1] with a dentiy of 0.76-0.80 [g cm^-3],^[3] therefore the gravimetric heating value of jet fuel is determined to be approximately 46,000 [kJ kg^-1] (= 36.54 [MJ L^-1] / 0.76-0.80 [kg L^-1]). Overall, the energy needed to fly for 900 [km] amounts 363.4 [GJ] (= 7900 [kg] * 46 [MJ kg^-1]).

FYI: the weight of boeing 777 and airbus A340 are 191 [ton] and 175 [ton], respectively.^[4]

Truck

10-ton class truck requires a tank volume of fuel to be 300-400 [L].^[5] As discussed in the previous post (How to store energy -4), 50 [L] of gasoline (= 37 [kg]) equals an energy quantity off 1.7 [GJ], meaning that 400 [L] of gasoline is equivalent of approximately 14 [GJ].

Laptop

Vaio（SVP13219CJB）is adopted as an example here.

Its energy consumption at idle is around 5 [W] (=J s^-1), and its battery life is 13 [h].^[6] These values disclosed the energy capcity of installed battery to be 0.234 [MJ] (= 5 [J s^-1] * 13 [h] * 60 [min h^-1] * 60 [s min^-1]).

Smatphone

iPhone XR is adopted as an example here.

Its battery capacity is 2,492 [mAh].^[7] At a voltage of 4 [V], the stored energy is determined to be 10 [Wh] (= 4 [V] * 2492 [mAh]), corresponding to 36 [kJ].

Energy carries to fuel airplane, truck, vehicle, laptop, smartphone?

The calculations thus far have identified the enregy amount needed to fuel airplane, truck, vehicle, laptop, and smartphone. In addition, the previous post (How to store energy -4) determined the energy required to drive a vehicle. The following table summarizes these amount of fuel.

comparison-of-energy-densities-of-carriers-with-examples

* Sorry that this figure is in Japanese, but will be translated into English.
from the left to right on the head row, ガソリン is gasoline, 液化NH3 is liquid ammonium, 高圧H2 is compressed hydrogen, Liイオン電池 is lithium-ion battery.
"約" in the figure means "approximately", and "タンク" means "tank"

Also this figure shows scenario to fuel these airplane, truck, vehicle, laptop, or smartphone using liquid ammonia, compressed hydrogen, or lithium-ion battery. The weight and volume needed are displayed.

Airplane as an example requires energy of 360 [GJ], which is equivalent to 8.1 [t] or 1,100 [L] of gasoline, OR liquid ammonia of 14 [ton] or 2,100 [L]. These quantities may sound reasonable, given the weight of airplane itself of 180 [ton]. On the contrary, this amount of energy corresponds to 400 [ton] or 170,000 [L] of lithium-ion battery, which is way heavier than the airplaine body itself.

After having look at these quantities and comparison, things that require large amount of energy (airplane, vehicle, truck) would reasonably be fueled by liquid fuel. In contrast, given the convenience of electric power, things that require small amount of energy (smartphone, laptop) would be better fueled by electric power. The vehicle may lie between these, and when driven by electric power, it would make more sense to make its size smaller.

References

日本航空株式会社, “航空実用辞典飛行計画　flight plan”, https://www.jal.com/ja/jiten/dict/p316.html#03-06 (accessed on 2021/10/05)
ANAホールディングス株式会社, “ANA Trivia Vol.74 灯油、ガソリン、重油…。飛行機の燃料は、次のどれに似た成分でしょう？”, https://www.ana.co.jp/travelandlife/article/000782/ (accessed on 2021/10/05)
石油連盟, “換算係数一覧”, https://www.paj.gr.jp/statis/kansan/ (accessed on 2021/10/05)
日本航空株式会社, “航空実用辞典旅客機諸元・性能表”, https://www.jal.com/ja/jiten/dict/p435.html (accessed on 2021/10/05)
ディーピーティー株式会社, “知っておきたい！トラックの燃料タンクの容量や増設をする際の注意点”, https://job-con.jp/special/driver/guide/info95 (accessed on 2021/10/05)
ソニーマーケティング株式会社, “SVP13219CJB・S スペック”, https://www.sony.jp/vaio/pre_include/html/VP21/spec_retail1.html#A1 (accessed on 2021/10/05)
Purudo.net, “バッテリー容量一覧”, https://xn--p9j1ayd.net/archives/263 (accessed on 2021/10/05)