The current proposed technology calls for retrofitting existing thermal power plants, to separate the CO2, compress it, and sequester it. Both the separation of CO2 from flue gas and its compression to the required pressure are energy intensive, thus adding to the cost of the power/heat produced. The cost to do so has been too expensive for industry to pass on to consumers.
Earth Battery Energy Storage replaces air-combustion with oxy-combustion, which produces just CO2 and steam, which are easy to separate, thus virtually eliminating more expensive CO2/N2 separation costs. Oxygen from air is produced when the cost of electricity is low. Similarly, all the combustion is done when the cost of electricity is low, and the CO2 produced is compressed using the low-cost electricity. The heat produced is stored in granular media (either above or below ground) and used throughout the day to supply heat or produce power. This time shifting allows for stored energy to be released when electricity is high, usually during the daytime. This combination of oxy-combustion and heat storage allows us to separate the processes of combustion and power production, thus allowing greater flexibility in design and operation of the heat/power plants.
Earth Battery Energy Storage can make very efficient use of low-temperature heat sources, such as solar thermal or geothermal, both of which can be used in series with conventional power plants to reduce fuel consumption, thereby reducing CO2 production.
Buscheck, T. A., & Upadhye, R. S. (2021). Hybrid-energy approach enabled by heat storage and oxy-combustion to generate electricity with near-zero or negative CO2 emissions. Energy Conversion and Management, 244. (https://doi.org/10.1016/j.enconman.2021.114496)
LLNL’s Earth Battery has numerous advantages over traditional energy storage technologies , such as:
- Long Duration Electrical and Industrial Heat Storage ( Days to Months),
- Lower cost and significantly better Environmental Life Cycle than Lithium Batteries,
- Long Life Span without degradation of storage capacity (Multiple Decades),
- Compatible with fossil and/or renewable generation.
- Long Duration Grid Storage
- Carbonless Industrial heat for Asphalt
- Carbonless Industrial heat for Steel
- Carbonless Industrial heat for Cement
Current stage of technology development: various system configurations range from TRL 3 to 9
US Patent Application Publication No. 2021/0372668 MULTI-FLUID, EARTH BATTERY ENERGY SYSTEMS AND METHODS published 12/2/2021 (https://image-ppubs.uspto.gov/dirsearch-public/print/downloadPdf/20210372668)
US Patent No. 9765604 Systems and methods for multi-fluid geothermal energy systems issued 9/19/2017 (https://image-ppubs.uspto.gov/dirsearch-public/print/downloadPdf/9765604)
US Patent No. 9739509 Multi-fluid renewable geo-energy systems and methods issued 8/22/2017 (https://image-ppubs.uspto.gov/dirsearch-public/print/downloadPdf/9739509)
US Patent No. 10995972 Multi-fluid renewable geo-energy systems and methods issued 5/4/2021 (https://image-ppubs.uspto.gov/dirsearch-public/print/downloadPdf/10995972)
US Patent No. 11137169 Multi-fluid, earth battery energy systems and methods issued 10/5/2021 (https://image-ppubs.uspto.gov/dirsearch-public/print/downloadPdf/11137169)