High latitude regions often experience shorter duration of daylight in several months, and may even have to sustain months of darkness, so what other solutions are there to extend the utilization time of solar energy and the maximized exertion of solar power apart from adding energy storage equipment?
Regarded as a weather-dependent power generation system, a solar system primarily converts sunlight into electricity, and generates zero power after sunset or during cloudy weather. A transformation of solar energy into a 24/7 power system would either require a collocation with energy storage systems, or converting sunlight into other energy. The Austria-based energy company RAG Austria is currently attempting to accomplish such a feat by working with the Swiss Federal Laboratories for Materials Science and Technology (Empa), as well as several other research institutions and businesses, to produce natural gas using solar energy.
The project will begin in summer, where the team will first produce hydrogen through water electrolysis using excessive electricity derived from solar and wind power, before storing the hydrogen and liquid carbon dioxide in the natural underground storage facility (e.g. ancient natural gas deposit) 1,000 meters below the surface; while there, prehistoric microorganisms known as archaea would convert the hydrogen and carbon dioxide into methane through metabolism.
Seen all over the world, archaea lives mainly in anaerobic environments, and converts biomass into natural gas by adding hydrogen and carbon dioxide into porous sandstone deposits. The team pointed out that a comparatively shorter duration is required when natural microorganisms metabolize hydrogen and carbon dioxide into methane and gas.
Methane, after transported back to the surface, can be used as a carbon neutral natural gas to provide heat or generate power during winter.
RAG Austria has successfully demonstrated the fundamentals, and achieved 60% in the conversion efficiency of solar/wind-electricity-to-methane. Its working partners are currently investigating the obtainment of carbon dioxide and renewable energy, while planning for the possible locations of the underground solar conversion plants.
(Photo source: Empa)