Solar to fuels conversion technologies: a perspective

Area of Science:

• Renewable Energy Technologies
• Chemical Engineering
• Sustainable Fuels

Background:

• Growing global energy demands necessitate large-scale renewable power generation.
• Solar energy is pivotal, but current focus on photovoltaics (PV) for electricity generation is insufficient for total energy needs.
• Replacing fossil fuels requires transportable and storable clean alternatives, highlighting the need for solar-to-fuel conversion.

Purpose of the Study:

• To review the solar refinery concept for converting CO2 and H2O into fuels using solar energy.
• To examine key solar-to-fuel conversion processes.
• To discuss recent advances and challenges in scaling these technologies.

Main Methods:

• Review of the solar refinery concept, utilizing solar radiation for heat, electricity, or photons.
• Analysis of conversion processes: combined PV and electrolysis, photoelectrochemical electrolysis, and thermochemical processes.
• Focus on converting water (H2O) and carbon dioxide (CO2) into hydrogen (H2) and carbon monoxide (CO).

Main Results:

• Solar refinery concept offers a pathway to produce fuels from CO2 and H2O.
• Key processes identified for solar-to-fuel conversion include PV-electrolysis, photoelectrochemical electrolysis, and thermochemical methods.
• Advances in solar-to-fuel technologies are noted, alongside significant challenges for large-scale implementation.

Conclusions:

• Solar-to-fuel conversion is essential for a sustainable energy future, complementing solar electricity generation.
• Intensive research and development are required to overcome challenges and scale up solar fuel production.
• The reviewed processes provide a foundation for developing cleaner, transportable, and storable energy alternatives.