Site items in: Concentrated Solar

Screening Binary Redox Pairs for Solar Thermochemical Ammonia Synthesis Using Machine Learned Predictions of Gibbs Formation Energies at Finite Temperatures

Solar thermochemical ammonia synthesis (STAS) is a reduction/oxidation (redox) cycle which enables the production of ammonia (NH3) from air, water, and concentrated sunlight. In this process, a metal nitride (MN) is oxidized by steam to produce a metal oxide (MO) and NH3; the resulting MO is reduced at high temperature (driven by concentrated solar radiation) and subsequently used to reduce atmospheric nitrogen (N2) and reform the MN and restart the NH3 synthesis cycle. The identification of optimal redox pairs (MO/MN) for this process has been historically limited by the lack of thermochemical data (i.e., Gibbs formation energies at finite temperatures)…

Japan – a future market for Australian solar ammonia

Japan and Australia are intimately linked in energy trade. Australia counts energy exports as a major source of foreign exchange income and Japan, which uses nearly 4 times the primary energy as Australia, imports nearly all of it. Approximately 40% of Australia’s coal exports are bought by Japan and were worth $AUD15.4 billion in 2012-13. Over 70% of Australia’s LNG exports went to Japan in the same period and earned over $AUD12billion. Future energy supply is high on the agenda for Japan. Currently 43% of its primary energy is in the form of imported oil mostly from the Middle East.…

Thermochemical energy storage with ammonia and implications for ammonia as a fuel

This seminar presents recent advances in ammonia-based thermochemical energy storage1 (TCES), supported by an award from the US Department of Energy SunShot program. The goal of SunShot is to “reduce the total installed cost of solar energy systems to $.06 per kWh by 2020.” Within the arena of concentrating solar thermal power, Sunshot has established goals for each subsytem, including reducing the cost of the energy storage subsystem to $15 per kWht of stored energy and enabling working fluid temperatures greater than 600°C, consistent with advanced, high performance power blocks. Schematic of an NH3-based thermochemical energy storage system. In ammonia-based…