Proponents of “green fuels” often claim substantial environmental benefits, yet a closer look suggests these claims may be overstated. Three commonly promoted options—green hydrogen, advanced biofuels, and synthetic e-fuels—face practical limits that undermine their alleged climate advantages.
First, lifecycle emissions are frequently higher than advertised once upstream energy inputs are counted. Electrolytic hydrogen can be “green” only if powered by surplus renewable electricity, which is scarce and intermittent in many regions; using mixed grids with fossil generation pushes its carbon intensity upward. Similarly, synthetic e-fuels require large amounts of electricity for CO2 capture and fuel synthesis; when that electricity is not strictly renewable, the resulting fuel can approach or even exceed the emissions of conventional fuels.
Second, feedstock and land constraints call the “sustainability” of biofuels into question. Even second-generation (cellulosic) biofuels must be sourced, collected, and transported, which can disturb soils, reduce carbon in agricultural residues, and compete with other uses (e.g., animal bedding, soil cover). Expanded energy cropping risks indirect land-use change, biodiversity loss, and higher water stress in already arid zones.
Third, local environmental externalities persist. Biogas systems can leak methane—a potent greenhouse gas—during collection and upgrading. Burning e-fuels still produces NOx and ultrafine particles in cities, so air-quality gains may be limited. Finally, building out hydrogen pipelines, electrolysers, and carbon capture facilities entails considerable material footprints, raising questions about the true speed and scale at which these fuels can deliver net benefits.
In sum, while green hydrogen, advanced biofuels, and synthetic e-fuels sound promising, real-world constraints on electricity supply, land, and infrastructure suggest their environmental payoffs are narrower and slower than advocates imply.
The speaker mainly argues that the environmental advantages of green hydrogen, advanced biofuels, and synthetic e-fuels are often exaggerated, so A is correct.
2. Why does the speaker mention mixed electricity grids and surplus renewable electricity?
The lecturer uses these examples to show that hydrogen can be considered truly green only under strict conditions; otherwise, its carbon intensity rises. Therefore, B is correct.
3. What does the speaker mention as a problem associated with biofuels?
The talk states that feedstock collection and expanded energy cropping may lead to indirect land-use change, biodiversity loss, and water stress, so C is correct.
4. What will the speaker most likely discuss next?
Since the lecture ends by stressing the limited and slower-than-expected environmental benefits of these fuels, the most logical next step would be to consider alternative or more effective climate solutions. So B is correct.
While some specialists highlight legitimate implementation challenges, contemporary lifecycle evidence shows that the three fuels discussed—green hydrogen, advanced biofuels, and synthetic e-fuels—can be decisively cleaner when produced and used in the ways they were designed.
First, on lifecycle emissions: When electrolysers run on dedicated wind and solar or on curtailed power, green hydrogen’s cradle-to-gate footprint drops dramatically, enabling 70–100% CO2 reductions in applications that replace grey hydrogen or diesel in heavy transport. Likewise, synthetic e-diesel and e-kerosene synthesized with renewable electricity and captured CO2 (from biogenic sources or direct air capture) become nearly carbon-neutral on a use-phase basis, since combusted CO2 was previously removed from the atmosphere. Energy intensity is real, but it is precisely why these fuels are targeted to sectors that cannot electrify directly (long-haul aviation, shipping, high-temperature process heat).
Second, on feedstocks and land: Advanced biofuels today prioritize residues and wastes—corn stover, wheat straw, sawdust, municipal organics—materials that do not require new cropland. Modern soil-management guidelines cap removal rates to maintain soil carbon and prevent erosion, and many projects pair feedstock collection with biochar or cover-cropping to restore soil health. Biogas from manure and landfills prevents methane from venting; even modest leak-control—tight seals, continuous monitoring, and upgrading to RNG—turns a super-pollutant into a low-carbon substitute for fossil gas.
Third, on local air quality and infrastructure: After-treatment (SCR, particulate filters) paired with clean e-fuels cuts NOx and PM well below legacy levels, improving urban air relative to conventional fuels. Hydrogen use in fuel-cell trucks removes tailpipe NOx altogether. As for infrastructure, electrolyser manufacturing is scaling quickly, pipelines are being repurposed for hydrogen blends or converted to carrier molecules like ammonia, and modular CO2 capture is reducing material intensity per tonne. These are not theoretical trends; they are happening along real supply chains that prioritize the hardest-to-abate niches.
In short, when we match the right fuel to the right job and enforce renewable electricity, verified feedstocks, and leak-controlled operations, these pathways deliver substantial and near-term climate and air-quality benefits rather than the marginal gains suggested in the reading.
Summarize the three main claims in the reading that question the environmental value of green hydrogen, advanced biofuels, and synthetic e-fuels. Then explain how the lecture challenges each claim with specific lifecycle examples (renewable electricity sourcing, residue-based feedstocks and methane capture, modern after-treatment and infrastructure scale-up).
A clock will show you how much time you have to complete this task
appx. 45 sec per question!
1.STUDENT: What did you like most about the renewable energy course?
INSTRUCTOR: clear.
solar
The
very
was
technician
systems
the
who
explained
2.MANAGER: Why did she enroll in the wind turbine maintenance program?
COLLEAGUE: turbines.
how
wanted
to
modern
She
repair
to
learn
3.FRIEND: I’m planning to buy solar panels for my house.
YOU: considering?
are
panels
What
type
of
you
4.DRIVER: I’ve recently switched to an electric car.
YOU: it?
need
How
do
charge
often
to
you
5.CLASSMATE: Our class discussed hydrogen energy yesterday.
YOU: used?
widely
Do
this
you
technology
become
will
think
6.STUDENT: I signed up for a course on biofuels.
YOU: course?
study
What
you
the
in
will
exactly
7.NEWS: Many companies are investing in renewable energy projects.
YOU: technologies?
these
able
Who
will
be
to
afford
8.STUDENT: The lecture on hydrogen electrolysis was difficult.
YOU: clearly?
Did
the
students
understand
the
process
9.ENGINEER: We tested new cellulose biofuel production methods.
YOU: Were viable?
the
methods
we
tested
in
the
lab
economically
10.FRIEND: The report analyzed different renewable energy sources.
YOU: Are term?
these
energy
sources
considered
reliable
in
the
long
Total Questions: 0
Incorrect Answers: 0
4. Write an Email
You will read some information and use it to write an email.
You will have 7 minutes to write the email.
Read the Task: 1:00
A training center for renewable energy offers a Wind Turbine Technician Program that prepares students to work on wind farms. The course includes safety training, equipment maintenance, and practical work at real facilities. Some modules follow international safety standards.
You are interested in enrolling in this program but are unsure whether you meet all the requirements.
You plan to contact the course administration to clarify several points.
Write an email to the course administrator. In your email, do the following:
Express your interest in enrolling in the Wind Turbine Technician Program.
Explain that you have limited prior technical experience and ask whether beginners are accepted.
Mention that you have a mild fear of heights and ask whether this could affect your participation in training.
Explain that your English level is intermediate and ask if this is sufficient for the course.
Ask about tuition fees and possible financial aid.
Write as much as you can in complete sentences.
Your email should be polite and clear.
I am writing to inquire about [briefly state the purpose of the email]. I recently learned about [the organization / service / course], and I am very interested in the opportunities it offers.
In particular, I would like to request further information regarding [fees / conditions / availability / procedures]. I would also appreciate it if you could clarify whether [specific request or condition] is possible.
Additionally, I would like to inform you that [relevant personal detail or specification], and I was wondering whether your organization works with or accommodates [this type / model / situation].
I would be grateful if you could let me know [what action or confirmation you are expecting] at your convenience. Thank you in advance for your time and assistance.
Yours faithfully,
[Your Name]
5. Writing for an Academic Discussion
Reading time – 2 minutes, writing time – 8 minutes
Step 1. Read the academic discussion
Read the post carefully: 2:00
Professor’s Post (Environmental Policy Course):
This week, let’s consider the role of universities in the global energy transition. Some argue that higher education institutions should direct their resources toward developing new renewable energy technologies (for example, advanced solar panels, offshore wind, or hydrogen). Others suggest that universities should focus on improving traditional energy systems (such as coal, oil, and natural gas) to make them less polluting and more efficient.
What do you think is the most effective direction for universities to take, and why?
Student 1 — Maya (Supportive of Renewables)
I believe universities should prioritize research on renewable energy. Fossil fuels are finite, and investing in cleaner versions only delays the inevitable. By pushing the boundaries of solar, wind, and hydrogen now, universities can accelerate the transition to a sustainable future. Also, students themselves are motivated by purpose-driven projects, which helps attract talent and funding.
Student 2 — Daniel (Supportive of Cleaner Fossil Fuels)
I disagree. Renewable energy is important, but fossil fuels still dominate the world’s supply. If universities can make coal or natural gas plants capture more carbon and run more efficiently, the global impact will be immediate. Billions of people still depend on these energy sources every day. It seems practical to improve what we already rely on, while renewables scale up more gradually.
Step 2. Write a response
Tip: State your opinion clearly, connect to the professor’s post, and refer to the students’ ideas.
Say whether you agree more with Student 1 or Student 2 (or partly both).
Support your view with reasons and examples (economic, environmental, social, etc.).
Explain why the other viewpoint is less convincing in your opinion.
This is a challenging topic, but I think that …. I strongly agree with Emily’s//James' idea that …. I’d add that …………. WhileJames/Emily raised the relevant point that …, he didn’t mention that ….. As a result, ….
While I appreciate the points mentioned by James and Emily, I think that ……………….
Remember that …, so …. Some people may feel that …., but I think …….. .
