A method of energy storage comprises receiving input energy (1) and using the input energy to compress (2) air or other process gas to produce a compressed process gas. The compressed process gas is stored (8). The compressed process gas is expanded (16) to generate output energy (17). Heat is transferred (5) from the process gas, before the process gas is stored (8) as a compressed process gas, to a hydrogen production process (10). The transferred heat is used in the hydrogen production process (10). The hydrogen may be stored (13) and subsequently used to heat to provide heat prior to, during, or after expanding (16) the compressed gas.

A method of energy storage comprises receiving input energy (1) and using the input energy to compress (2) air or other process gas to produce a compressed process gas. The compressed process gas is stored (8). The compressed process gas is expanded (16) to generate output energy (17). Heat is transferred (5) from the process gas, before the process gas is stored (8) as a compressed process gas, to a hydrogen production process (10). The transferred heat is used in the hydrogen production process (10). The hydrogen may be stored (13) and subsequently used to heat to provide heat prior to, during, or after expanding (16) the compressed gas.

Systems and methods to pump fracturing fluid into a wellhead may include a gas turbine engine including a compressor turbine shaft connected to a compressor, and a power turbine output shaft connected to a power turbine. The compressor turbine shaft and the power turbine output shaft may be rotatable at different rotational speeds. The systems may also include a transmission including a transmission input shaft connected to the power turbine output shaft and a transmission output shaft connected to a hydraulic fracturing pump. The systems may also include a fracturing unit controller configured to control one or more of the rotational speeds of the compressor turbine shaft, the power turbine output shaft, or the transmission output shaft based at least in part on target signals and fluid flow signals indicative of one or more of pressure or flow rate associated with fracturing fluid pumped into the wellhead.

A lightweight lift system for VTOL/VSTOL operation running in parallel with an existing turbine. This system distributes LP power by switching compressor flow and fuel proportionally over to the lift turbine module. As forward thrust is demanded, some of the power is transitioned back to the flight LP turbine, which can drive a variable propeller, fan or can supply jet thrust. As flight motion occurs, the power to the lift fan can be reduced to zero and lift closed off.

A fuel cell power system for a vehicle having a propulsor is provided herein. The propulsor is configured to generate thrust for the vehicle and a flow of compressed air. The fuel cell power system includes a fuel delivery system for providing a flow of hydrogen fuel and a fuel cell stack and is configured to be located remotely from the propulsor and in airflow communication with the propulsor for receiving the flow of compressed air from the propulsor. The fuel delivery system further includes a fuel tank for storing hydrogen fuel and the fuel cell stack is further in fluid communication with the fuel delivery system for receiving the flow of hydrogen fuel from the fuel delivery system.

A fuel cell power system for a vehicle having a propulsor is provided herein. The propulsor is configured to generate thrust for the vehicle and a flow of compressed air. The fuel cell power system includes a fuel delivery system for providing a flow of hydrogen fuel and a fuel cell stack and is configured to be located remotely from the propulsor and in airflow communication with the propulsor for receiving the flow of compressed air from the propulsor. The fuel delivery system further includes a fuel tank for storing hydrogen fuel and the fuel cell stack is further in fluid communication with the fuel delivery system for receiving the flow of hydrogen fuel from the fuel delivery system.

In a power generation system, exhausted fuel gas exhausted from a solid oxide fuel cell (SOFC) is used as a fuel of a first combustor or a second combustor of a gas turbine, and at the same time, a part of compressed air compressed by a compressor of the gas turbine is used to drive the SOFC. The gas turbine includes the first combustor for burning fuel gas which is different from the exhausted fuel gas, a first turbine configured to be driven by combustion gas supplied from the first combustor, the second combustor for burning at least a part of the exhausted fuel gas, and a second turbine coupled with the first turbine and configured to be driven by combustion gas supplied from the second combustor.

In a power generation system, exhausted fuel gas exhausted from a solid oxide fuel cell (SOFC) is used as a fuel of a first combustor or a second combustor of a gas turbine, and at the same time, a part of compressed air compressed by a compressor of the gas turbine is used to drive the SOFC. The gas turbine includes the first combustor for burning fuel gas which is different from the exhausted fuel gas, a first turbine configured to be driven by combustion gas supplied from the first combustor, the second combustor for burning at least a part of the exhausted fuel gas, and a second turbine coupled with the first turbine and configured to be driven by combustion gas supplied from the second combustor.

A fuel cell system includes a fuel cell configured to be supplied with an anode gas and a cathode gas and generate electric power, a compressor configured to supply the cathode gas to the fuel cell, a turbine configured to be supplied with a cathode discharged gas discharged from the fuel cell and generate power, an electric motor connected to the compressor and the turbine and configured to perform power running and regeneration, a combustor disposed between the fuel cell and the turbine and configured to mix and combust the cathode gas and the anode gas, a cooler configured to cool the cathode gas that is supplied from the compressor to the fuel cell, a bypass passage configured to supply the cathode gas from an upstream side of the cooler to the combustor by bypassing the cooler and the fuel cell, and a bypass valve disposed in the bypass passage.

A fuel cell system includes a fuel cell configured to be supplied with an anode gas and a cathode gas and generate electric power, a compressor configured to supply the cathode gas to the fuel cell, a turbine configured to be supplied with a cathode discharged gas discharged from the fuel cell and generate power, an electric motor connected to the compressor and the turbine and configured to perform power running and regeneration, a combustor disposed between the fuel cell and the turbine and configured to mix and combust the cathode gas and the anode gas, a cooler configured to cool the cathode gas that is supplied from the compressor to the fuel cell, a bypass passage configured to supply the cathode gas from an upstream side of the cooler to the combustor by bypassing the cooler and the fuel cell, and a bypass valve disposed in the bypass passage.