Cutting-edge technology to combat climate change

Sun-to-Liquid technology

Synhelion uses solar energy to convert CO2 into carbon-neutral solar fuels.

And how does it work? Solar radiation is reflected by the mirror field, concentrated onto the receiver, and converted into high-temperature process heat. The generated heat is fed to the thermochemical reactor that produces syngas, a mixture of H2 and CO. The syngas is then processed by standard gas-to-liquids technology into fuels, such as jet fuel, gasoline, or diesel. Excess heat is saved in the thermal energy storage (TES) to enable continuous 24/7 operation.

Four innovation fronts

Our solutions combine state-of-the-art solar tower systems with proprietary high-temperature thermochemical processes. The Synhelion technology unites four key innovations:

  • The mirrors (heliostats) that direct the solar radiation onto the solar receiver.
  • The solar receiver delivers clean solar process heat at unprecedented temperatures beyond 1’500°C.
  • The thermochemical reactor utilizes the solar heat to produce syngas, the precursor to synthetic liquid fuels.
  • The thermal energy storage enables continuous 24/7 operation.

One technology, numerous applications

Solar fuels are compatible with conventional planes, ships, trucks, and cars. The day you fuel up your vehicle with solar fuels is the day you start moving sustainably. Let’s substitute fossil fuels with synthetic fuels. This is how we unlock a clean future of transportation.

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Scientific publications

Synhelion partners with top-tier research labs and conducts cutting-edge research. See below for a selection of our most important publications.

  • Zuber, M., Patriarca, M., Ackermann, S., Furler, P., Conceição, R., Gonzalez-Aguilar, J., Romero, M., Steinfeld, A., “Methane dry reforming via a ceria-based redox cycle in a concentrating solar tower”. Sustainable Energy & Fuels, 8 (2023).

  • Schäppi, R., Rutz, D., Dähler, F., Muroyama, A., Haueter, P., Lilliestam, J., Patt, A., Furler, P., Steinfeld, A., “Drop-in fuels from sunlight and air”. Nature (2021).

  • Ambrosetti, G., Good, P., “A novel approach to high temperature solar receivers with an absorbing gas as heat transfer fluid and reduced radiative losses”. Solar Energy, 183, 521–531 (2019).

  • Furler, P., Scheffe, J., Marxer, D., Gorbar, M., Bonk, A., Vogt, U., Steinfeld, A., “Thermochemical CO2 splitting via redox cycling of ceria reticulated foam structures with dual-scale porosities”. Physical Chemistry Chemical Physics 16, 10503–10511 (2014).

  • Marxer, D., Furler, P., Scheffe, J., Geerlings, H., Falter, C., Batteiger, V., Sizmann, A., Steinfeld, A., “Demonstration of the entire production chain to renewable kerosene via solar thermochemical splitting of H2O and CO2”. Energy & Fuels (2015).

  • Furler, P., Scheffe, J. R., Steinfeld, A., “Syngas production by simultaneous splitting of H2O and CO2 via ceria redox reactions in a high-temperature solar reactor”. Energy & Environmental Science 5, 6098–6103 (2012).

  • Marxer, D., Furler, P., Takacs, M., Steinfeld, A., “Solar thermochemical splitting of CO2 into separate streams of CO and O2 with high selectivity, stability, conversion, and efficiency”. Energy & Environmental Science 10, 1142–1149 (2017).

  • Ackermann, S., Scheffe, J., Steinfeld, A., “Diffusion of oxygen in ceria at elevated temperatures and its application to H2O/CO2-splitting thermochemical redox cycles”. The Journal of Physical Chemistry, 118, 5216–5225 (2014).

  • Geissbühler, L., “Thermocline thermal energy storage: advances and applications to CSP, compressed air energy storage, and solar fuels”. Diss ETH No. 24555, (2017).

  • Geissbühler, L., Kolman, M., Zanganeh, G., Haselbacher, A., Steinfeld, A., “Analysis of industrial-scale high-temperature combined sensible/latent thermal energy storage”. Applied Thermal Engineering 101, 657–668 (2016).

  • Geissbühler, L., Mathur, A., Mularczyk, A., Haselbacher, A., “An assessment of thermocline-control methods for packed-bed thermal-energy storage in CSP plants, Part 1: Method descriptions”, Solar Energy 178, 341–350 (2019).

  • Dähler, F., Wild, M., Schäppi, R., Haueter, P., Cooper, T., Good, P., Larrea, C., Schmitz, M., Furler, P., Steinfeld, A., “Optical design and experimental characterization of a solar concentrating dish system for fuel production via thermochemical redox cycles”. Solar Energy, 170, 568–575 (2018).

  • Chueh, W., Falter, F., Abbott, M., Scipio, D., Furler, P., Haile, S., Steinfeld, A., “High-flux solar-driven thermochemical dissociation of CO2 and H2O using nonstoichiometric ceria”. Science, 330, 1797-1801, 2010

  • Ackermann, S., Scheffe, J., Duss, J., Steinfeld, A., “Morphological characterization and effective thermal conductivity of dual-scale reticulated porous structures”. Materials, 7, 7173-7195 (2014).

  • Moretti, C., Patil, V., Falter, C., Geissbühler, L., Patt, A., Steinfeld, A., “Technical, economic and environmental analysis of solar thermochemical production of drop-in fuels”. Science of the Total Environment, 901, 166005 (2023).