Summary
Our megaUHTS system is a modular thermal energy storage system capable of storing 36 MWh in a 40 foot shipping container and is charged using electricity. The MegaUHTS system offers a low-cost route to mass energy storage on the giga-watt scale and carbon dioxide reduction through conversion of existing thermal power plants. This conversion forgoes the need for new grid infrastructure and much of the expensive hardware to allow grid scale energy storage.
Gas turbine conversion
The addition of an megaUHTS thermal store between the compressor and combustion system of a gas turbine, allows gas to be preheated. This reduces the fuel requirements needed to reach turbine inlet temperature. Preliminary calculations predict the following fuel and consequent carbon dioxide reductions for a variety of gas turbines:
1985 state-of-the-art gas turbine (Turbine inlet temp of 1250°C) – fuel and CO2 reduction – 72%
1997 state-of-the-art gas turbine (Turbine inlet temp of 1500°C) – fuel and CO2 reduction – 60%
2015 state-of-the-art gas turbine (Turbine inlet temp of 1650°C) – fuel and CO2 reduction – 55%
This preheating also reduces nitrogen oxide (NOx) formation by decreasing the number of NOx hotspots.
Steam turbine conversion
The megaUHTS thermal store will be able to eliminate the fuel use and CO2 generation of steam turbines. It does this by providing the stored heat directly to the steam generator, with a controlled and adjustable mass flow rate and temperature.
Benefits
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This 36 MWh of thermal energy can be extracted as heat and hot water, or electricity if coupled with a gas or steam turbine.
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Can be integrated with district heating schemes to provide heating and hot water.
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The megaUHTS can reduce the fuel costs of combined-cycle gas turbine operators by storing electricity when inexpensive and providing heat, in the place of fuel, when generation is required.
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This upgrade results in further emission reductions.
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Can retrofit existing combined-cycle gas turbines and steam turbines in increments of 36 MWh with simple modifications to combustion systems.
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Chargeable in 30 minutes with a 67 MW connection.
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Competing electrochemical energy storage systems that provide electricity have limited lifetimes (approximately 10 years). The thermal energy storage system is predicted to last 25 - 100 years.
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Behind meter installation of the system means that grid application and integration times and costs can be minimized.