of the world's estimated 1.4 billion vehicles

化石燃料で動いてる

run on fossil fuels,

大量の汚染物質を出してね

releasing a whole bunch of pollutants.

信じられないことに

Can you believe that a typical car

普通車が排出する二酸化炭素は 年間 約4.6メトリックトンなの

emits roughly 4.6 metric tons of CO2 every year?

ガソリン車を減らす動きは世界に広がっていて

Fortunately, momentum to take gas vehicles off the road

多くの国が今後数年で 化石燃料で動く車を減らす予定

is building around the world

代替燃料への転換の最前線を担っているのが

with many countries planning to phase out

ワールドソーラーチャレンジで競うチームたちよ

fossil fuel powered vehicles in the coming years.

これまで太陽と技術について学んだ

And at the forefront of this shift

太陽のパワーを利用するための―

towards alternatively powered vehicles

太陽電池や 空気力学的構造をね

are the teams competing in the World Solar Challenge.

ソーラーカーに動力を供給する構造も知った

By now, we know all about the sun and the technology

あいまいな点があれば

like the batteries, solar cells and aerodynamic structures

動画を見直せば分かるわ

that are being used to harness the sun's power.

[番組ホスト　マレン･ハンスバーガー]

We even understand the mechanics

今回は太陽を利用して すべての車に 電力を供給する方法を考えるわよ

of how to power a solar car.

問題は１つだけよね

And don't worry, if you're fuzzy on the details here,

車が作る太陽エネルギーの量と

then you can go watch our previous videos

使用する量の割合よ

in this Learning Playlist

電気自動車やガソリン車 自動運転車は―

where we talk about all of that stuff.

大量の電力が必要なの

So, now, let's explore what's it gonna take

太陽光技術の導入が比較的 簡単なのは

to power all of our cars using the sun.

軽量の電動バイクやドローン

It all comes down to pretty much one thing.

大きい乗り物は そうはいかない

The amount of solar power

重量が少なくとも2,000キロはあり

that a car is able to generate

高速走行で定電力を維持する必要のある車ね

compared to the amount of power it uses up.

しかも電力を消耗する空調も付いてる

Electric cars, gas powered cars,

無線システムやコンピューター回路も

self-driving cars, you name it,

太陽光発電にとっては少し問題ね

have pretty big power demands.

これまで学んだように

So while incorporating solar technology

吸収できる光子の量の分だけしか 供給できないからよ

into lightweight vehicles

吸収できる光子が増えれば

like e-bikes and drones is relatively easy,

生産される電力も増える

the same can't be said for larger vehicles like cars

車には大量のエネルギーが必要なの

which can easily weigh at least 2,000 kilograms

太陽エネルギーを使うにしても 車体にはスペースがない

and need to be able to maintain

実用されている太陽電池の効率には 制限があり―

constant power at high speeds.

その上限に達しないこともある

Plus, most commercial cars today are also outfitted

研究室の小さい電池で―

with power draining AC units,

[スタンフォード　コーリ･ブレンデル]

radio systems and complex computer circuits.

高品質でも効率は30％程度よ

This poses a bit of a problem for photovoltaic systems,

それでも太陽電池の変換効率は 大きく改善された

which as we've learned in previous episodes,

可能性をさらに広げようとしてる

are by their very nature only as powerful

材料の新しい配置を研究したり

as the amount of photons they're able to absorb.

もっと光を受容できる 反射防止コーティングを開発してるの

The more photons a solar cell absorbs into its material,

光波を吸収しやすくするために 操作方法も考えてる

the more electricity can be produced.

まずは太陽電池の最大効率の達成ね

And basically, cars require a lot of energy to work.

その後 最も重要なのが 空気力学的に―

And if we want to power them with solar energy,

できるだけ軽量で効率のよい ソーラーカーの設計

there's not a whole lot of surface area to work with.

太陽光だけで動く車に課題は残るわ

And then there's the fact that the solar cells we use

ソーラーカーは実現してるから 不可能じゃない

out in the real world today

[2019 ワールドソーラーチャレンジ]

don't often reach their already limited efficiency.

[デレク･ミューラー]

Right now, the best research-grade solar cells

ソーラーカーに乗れる

are still at, like, 30%.

８の字走行をするよ

And that's in a lab environment,

ミネソタ大学のチームだ

like, a teeny tiny solar cell.

誰が乗るはずだった？

MAREN: With that said, we've certainly made huge strides

あそこのクリス

in improving the conversion rate of solar cells.

- 構わない？ - ええ

And work is underway to push their potential even further,

どうぞ

whether that's through finding new materials configurations,

知っておくべきことは？

developing more sophisticated anti-reflective coatings

すぐ分かるよ

to let the cells capture more light,

Eos IIはツードアの２人乗りで

or even figuring out how to manipulate light waves

ソーラー式クーペと言えます

so that they're easier for the cells to absorb.

すごく楽しみだよ

But until solar cells reach their maximum efficiency

リッキー　スタートしていい？

and then some,

Eos IIはコンセプトカーです

designing solar vehicles to be as aerodynamic

生産予定は全くありません

lightweight and efficient as possible

でも 滑らかな乗り心地です

will remain the primary focus.

音は大きいですが

So, while powering a car on sunlight alone

- スピードがあるね - でしょ

does remain a challenge,

一瞬で...

it's certainly not impossible,

終わりです

because solar cars are a reality right now.

- もう？ - 公式の走行です

I've been given a pretty unique opportunity

- どうです？ - 気楽に乗れた

to ride in a solar car

よかったよ

while it is going around the figure eight track.

私はオーストラリアへ行って ソーラーカーには乗れなかった

This is the Minnesota team. They've drafted me.

だけど スタンフォードのメンバーに

And who's spot am I taking?

ソーラーカーのレース以外での 可能性を聞く機会があったの

MAN: Uh, you're taking Chris' spot around here.

車業界の主流になれる技術だ

-DEREK: Chris? -MAN: Yeah.

[スタンフォード キャメロン･ヘインズワース]

-[CHUCKLES] -That's okay.

すばらしい革新を持つ企業が 現れる可能性は常にあるんだ

Is there something I should know?

太陽電池の供給効率では 実際の走行で―

-You'll figure it out. -[ALL LAUGHING]

消費する電力量をどうしても補えない

DEREK: The Eos II is a two-door, two-seater,

でも空気抵抗を減らして車を軽くし

so kinda like a concept solar coop.

パネルの配置を改良すれば無敵だ

Man, this is intense. [CHUCKLES]

期待してることがある

WOMAN: All right, solar car to Ricky. Am I clear to start?

[スタンフォード　ジュリア･ゴードン]

DEREK: Keep in mind that the Eos II is a concept car.

ソーラーカーを通じて もっと多くの人に

Clearly, it's not quite ready for production.

再生可能で持続可能なエネルギーに 興味を持ってほしい

But the ride is surprisingly smooth,

ソーラーカーは スタンフォードの車庫にあるものや―

though very loud.

アウトバックを走ってるものだけじゃない

-Now I'm feeling the speed. -WOMAN: Yep.

実は ソーラーカーの市場は 急成長してるの

And before you know it...

ソノモーターズやライトイヤーが参入してる

There we go. That was the end of it.

商業用のソーラーカーを作るに際し 心躍るのは...

-That's it? -That was the official rounds.

エネルギーを効率的に使えると示せることだ

-Wow! -I know.

[アリオ･ファン･デル･ハム ライトイヤー共同創立者]

That was easy. [CHUCKLES]

利便性を諦めなくていい

That was very nicely done.

空気抵抗を改良し 少し重くし ソーラーパネルの配置と効率性を増せば

Hurray!

エネルギーの消費と産出が合致する

While I wasn't able to fly over to Australia

その完成形に近づきつつある

to ride around in a solar cruiser, unfortunately,

もっと日常的に乗車されるようになるはずだ

I did get the chance to speak

ヒュンダイやトヨタのような大手企業も

with a few Stanford Solar team members

ソーラーパネルの導入を始めてる

about whether they see solar cars

主な目的は走行距離の延長とか 補助システムの動力源だけどね

taking off beyond the race track.

大きな進歩ではないけど 望ましい方向への一歩よ

Yeah, I think that there's a chance

世界中の研究チームは日夜―

that solar technology could make its way

ソーラーパネル技術の 画期的な発明に取り組んでる

into mainstream automobiles.

自動車のレベルアップに必要なものよ

There's always the chance that, you know,

空の美しい恒星をムダにするのは それこそ問題だわ

some company comes out with a great innovation

みんな 分かった？

that really pushes the industry forward.

これで学習は終わり

There are definitely limitations

楽しみながら学んでくれた？

especially with the efficiency of solar powered cells

この後は外で太陽を浴びてね

and how much energy it takes to actually run a car.

But if you make your car aerodynamic,

and you make your car light,

and you make your array really good,

then you're gonna be hard to beat.

If there's one thing that I hope for,

with solar cars specifically,

I really hope that it makes more people excited

about working on these new sources

for renewable and sustainable energy.

MAREN: But solar cars aren't just

at the Stanford Solar Car team's garage,

or racing across the Outback at the World Solar Challenge.

We've actually got a little known

but rapidly growing solar vehicle commercial market.

Startups like Sono Motors and Lightyear

are going all-in on solar.

ARJO: And what excites me the most

about making commercial solar cars

is showing to the world

that we can be much more efficient

with the energy that we have available

without having to compromise

on the convenience you get every day.

You improve the aerodynamics a bit,

you improve the weight a bit,

you increase the solar panel array a bit,

you increase the efficiency of the solar panel a bit,

and then combining all of that,

you basically match energy consumption and energy yield.

We're not 100% there yet, but we're getting pretty close.

The closer you get,

the more practical the car becomes to use every day.

MAREN: Established companies like Hyundai and Toyota

are also developing ways

to incorporate solar panels into their cars.

Albeit mainly as a way

to lend cars a few extra miles of range

or power some of the auxiliary system.

It's a little less ambitious, sure,

but it's certainly a step in the right direction.

And research teams all over the world

are working tirelessly

to make the next revolutionary breakthrough

in solar panel technology,

which could be exactly what our cars need to level up.

There's just too much at stake here

to let that big beautiful star above our heads go to waste.

So, there you have it, folks.

That's a wrap for our Light Speed Learning Playlist.

I hope you learned a lot

and that you enjoyed the ride as much as I did.

Now, go outside and get some sun.