Module architecture for photoelectrochemical solar water splitting
- This invention forms the basis for modules highly-efficient at producing hydrogen using solar energy.
- The transport of the gases produced and the diffusion processes in the electrolyte present new challenges that do not exist in photovoltaic cells.
- A principle is described alongside this invention that increases the efficiency of the module and reduces the transport paths when splitting water using solar energy, by implementing a new arrangement of the electrodes and membranes.
Hydrogen is considered to be the ideal energy carrier: it has a high energy density and produces only pure water as a waste product when burned. At present, however, hydrogen is predominantly produced by the rather environmentally-unfriendly method of steam reforming methane. By contrast, hydrogen can be produced without harmful waste products by using direct solar water splitting. Here, a photoelectrochemical cell is used to split water into hydrogen and oxygen in an aqueous electrolyte.
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- In so-called direct solar water splitting (or artificial photosynthesis), sunlight is absorbed by a semiconductor that releases free charge carriers, whose energy is then used to split water into hydrogen and oxygen.
- A highly-efficient cell design, according to the approved patent (DE102014105545B3, TU Ilmenau & HZB), allows for high levels of efficiency. 14-19% of incident solar energy to be stored in the chemical bonds of hydrogen.
- Due to the high current and bubble densities, the module architecture is vital to achieving high efficiencies also on the module level.
- The transport paths of the ions are minimised by integrating the counter electrode, gas separation and gas discharge elements into the module cover.
- Bubbles are quickly eliminated and shadowing of the counter electrode is reduced using prisms, allowing more light to fall onto the photoelectrochemical cell.
- Gases (H2 and O2) are efficiently separated and collected
- Shadowing of the photoelectrochemical cell is minimised
- The short paths of the ions in the electrolyte minimise electrical transport loss
- Compared to traditional architectures, the cell area can be as large as desired
Scope of application
- In the decentralised production of hydrogen
- As a buffer for the power grid by conversion into electricity
- Hydrogen industry and hydrogen consumers
- Energy companies
Das Vorhaben wird vom Freistaat Thüringen gefördert und durch Mittel der Europäischen Union im Rahmen des Europäischen Fonds für regionale Entwicklung (EFRE) kofinanziert.
- DE pending
- PCT pending
KeywordsModul, Architektur, photo, photoelektro, photoelektrochemisch, elektrochemisch, photochemisch, elektro, chemisch, Wirkungsgrad, Wasserstoff, Wasserstofferzeugung, Gas, Diffusion, Diffusionsprozess, Elektrolyt, Photovoltaik, Solar, Wasserspaltung, Sauerstoff, Photosynthese, Sonnenlicht, Halbleiter, Elektrode, Energie, Energieträger, umweltfreundlich