Replacing Fossil Fuels: How Renewable Energy is Shaping the Future Energy Landscape

The global energy industry is undergoing a profound transformation, driven by the decreasing reliance on fossil fuels and the rapid growth of renewable energy. At the 2025 ISHE Harbin conference, we had the privilege of meeting Prof. Dr. Andreas Züttel and greatly appreciate his insights. He shared a series of research findings on the transition from fossil fuels to renewable energy, discussing current market trends and technological advancements. This raises an important question: What is the future potential of renewable energy, and how will it shape the global energy system?

The Challenge of Replacing Fossil Fuels

For over a century, fossil fuels have dominated global energy supply. Their high reliability, energy density, and well-established infrastructure have made them the backbone of modern industrial society. However, this energy model comes at a cost—environmental degradation, increased carbon emissions, and finite resources. According to projections, fossil fuel reserves may significantly decline in the second half of this century, making the development of alternative energy sources an urgent priority.

The biggest challenge in replacing fossil fuels lies in ensuring a stable and continuous energy supply. Unlike fossil fuels, which can be burned on demand, renewable sources such as solar and wind are intermittent, requiring innovative storage and distribution solutions to maintain grid stability and energy security.

Growth Trends in Renewable Energy

（Source：Global overview – Renewables 2024 – Analysis – IEA）

Data showed that the Renewable energy consumption in the power, heat and transport sectors increases near 60% over 2024-2030 in our main-case forecast. This increase boosts the share of renewables in final energy consumption to nearly 20% by 2030, up from 13% in 2023. This trend indicates that renewable energy is gradually becoming a major component of the global energy supply. While overall energy demand continues to rise, the share of solar, wind, and hydropower is expanding rapidly.

Current key components of renewable energy:

• Solar energy:  A rapidly growing source of clean energy harnessing sunlight for power generation.
• Wind Power: A core component of national energy strategies worldwide.
• Biofuel and Hydropower: Still significant contributors to the global energy supply.
• Photovoltaics (PV): Currently the fastest-growing renewable energy technology, with continuously declining costs.

Technological Breakthrough: Power-to-X (P2X) Systems

The storage and conversion of renewable energy present several challenges, particularly in efficiently transforming renewable electricity into storable energy carriers. Power-to-X (P2X) technology offers a viable solution by utilizing electrolysis (Electrolysis) to produce hydrogen (H₂), which can then be further converted into synthetic methane (CH₄) or liquid synthetic fuels for storage and transport.

Key Processes in the Renewable Energy System

（Source：Publication 2024 by Dr. Andreas Züttel from EPFL ）

Renewable Power Generation (Yellow Section)

• Solar PV and wind generate electricity, which can be used immediately, stored in batteries, or directed to electrolyzers for hydrogen production.

Hydrogen Production and Utilization (Red Section)

• Hydrogen (H₂) produced via electrolysis can be:
  • Used directly in fuel cells for electricity generation. Stored in metal hydride storage (MH Storage) or compressed at 350 bar for later use.
  • Used in hydrogen-powered vehicles or for heat generation.

Conversion to Synthetic Fuels (Blue/Green Section)

• Sabatier Process: Hydrogen reacts with CO₂ to form synthetic methane (CH₄), which can be stored underground and later used for heating or power generation.
• Fischer-Tropsch Synthesis (FT-Synthesis): Hydrogen and CO₂ can be processed into liquid fuels (diesel, aviation fuel, etc.) for transportation and industrial applications.
• CO₂ Capture: CO₂ from industrial sources or air is absorbed and recycled into fuel production, closing the carbon loop.

Why P2X is Essential?

• Addresses the intermittency of renewable energy: By converting excess electricity into hydrogen and synthetic fuels, P2X provides a long-term storage solution.
• Multi-functional energy carrier: Hydrogen can be stored, transported, or used for power, heat, and fuel production.
• Supports carbon neutrality: CO₂ capture and synthetic fuel production help achieve a circular carbon economy, reducing overall emissions.

Market Trends: Transition from Fossil Fuels to Renewable Energy

Asia is emerging as a key leader in the global energy transition, with several countries investing heavily in renewable energy infrastructure and technology. According to the Reed Smith report, the following three countries are driving significant changes in their energy policies and markets:

1.China:

Policy-wise, China has set ambitious targets to increase the share of non-fossil energy in its primary energy consumption. The 14th Five-Year Plan aims to raise this share to 20% by 2025, five years ahead of previous goals. Additionally, the plan emphasizes the extensive expansion of wind and solar capacities, including the development of mega-sized clean energy bases and the enhancement of energy storage solutions.

2.India:

Corporate Investments: India’s state-owned power company, NTPC, has announced investments exceeding $23 billion in renewable energy projects in Madhya Pradesh. These projects encompass solar, wind, and hydroelectric power, aligning with India’s broader strategy to shift away from fossil fuels.

3.Singapore:

Singapore Green Plan 2030: This comprehensive plan outlines Singapore’s commitment to sustainable development, aiming to achieve net-zero emissions by 2050. Key targets include deploying at least 2 gigawatt-peak (GWp) of solar energy by 2030, sufficient to power approximately 350,000 households annually.

The Future of Renewable Energy

The rapid expansion of renewable energy offers a sustainable alternative to the global energy system. With advancements in P2X technology, the hydrogen economy, and energy storage solutions, we are moving toward a greener, low-carbon future. Looking ahead, energy researchers and policymakers must continue to drive renewable energy development, optimize energy storage and conversion technologies, and promote the decarbonization of the global energy system.