Distributed Energy Resources

The University of Wisconsin - Madison will develop components for a hybrid distributed energy generation system that couples a pressurized solid oxide fuel cell (SOFC) with a premixed compression ignition (PCI) engine system. In the resulting system, gases that leave the fuel cell, which consumes about 75% of the fuel, are directed into the engine to be ignited by compression of the pistons. To achieve a targeted 70% electric efficiency, the SOFC system must operate near 75% fuel utilization.

Saint-Gobain will combine a pressurized all-ceramic solid oxide fuel cell (SOFC) stack with a custom-designed screw compressor and expander to yield a highly efficient SOFC and Brayton cycle hybrid system. In this configuration, the SOFC stack generates most of the system’s electric power. The expander converts a portion of the stack’s waste exergy to additional electric power.

FuelCell Energy will develop technology for pressurized solid oxide fuel cell (SOFC) stack modules for use in hybrid power systems. The Compact Stack Architecture (CSA) platform will operate at a high pressure, enabling its integration with a wide range of small-to-mid-sized power cycles, including gas turbines and piston engines. Stack design will incorporate features such as internal reforming (producing hydrogen from natural gas), extending the fuel cell’s use to higher pressure values, and adding robustness to tolerate system-imposed pressure differentials.

Washington State University will develop a hybrid power system using a high-pressure, high-temperature fuel cell stack and gas turbine. The project will examine the benefits of a decoupled design, in which the fuel cell stack and gas turbine components are not directly connected within the hybrid system. The team’s other primary innovation is the integration of a membrane to concentrate oxygen from air supplied by the turbine before feeding it into the fuel cell, which avoids pressurizing the entire air feed stream, improving performance and boosting efficiency.

Tandem PV will develop and test an advanced processing tool that integrates high-throughput solution deposition and precise drying to deposit large-area perovskite thin films of exceptional optical and electronic quality. Production of these films on large areas is a critical step towards perovskite-Si tandem PV cells that can achieve significantly higher efficiency than traditional Si PV cells. Small-scale perovskite PV device fabrication typically occurs using a spin-coating process, but the process is not easily scalable.

The University of Michigan is investigating a new, hybrid thin-film PV production technology that combines two different semiconductor production techniques: electrodeposition (the deposition of a substance on an electrode by the action of electricity) and epitaxial crystal growth (the growth of crystals of one substance on the crystal face of another substance).

George Washington University (GWU) will develop a new technique to produce commercial III-V substrates called Transfer Printed Virtual Substrates (TPVS). To reduce costs, the team proposes using a single source substrate to grow numerous virtual substrate layers. The team will use an enabling technology, called micro-transfer printing (MTP), to transfer the layers from the source substrate, in the form of many microscale “chiplets,” and deposit them onto a low-cost handle (silicon, for example).

Mohawk Innovative Technology, Inc. (MiTi) and its partners at the University of Texas at Austin and Mitis SA will develop a 1 kW microturbine generator for residential CHP based on MiTi’s hyperlaminar flow engine (HFE) design. Key innovations of the design include highly miniaturized components operating at ultra-high speeds and a viscous shear mechanism to compress air that is mixed with natural gas and undergoes a flameless combustion process that minimizes emissions. The hot combustion gas drives the turbine and generator to produce electricity and heat water for household use.

Air Squared with partners at Argonne National Laboratory, Purdue University, and Mississippi State University, will develop an advanced internal combustion engine (ICE) integrated with an organic Rankine cycle (ORC) for waste heat recovery. The ICE will use spark-assisted compression ignition (SACI) combustion, a turbulent jet ignition (TJI) fueling system, a high compression ratio, and aggressive exhaust gas recirculation to deliver a higher thermal efficiency with low emissions. Traditional internal combustion engines use the force generated by the combustion of a fuel (e.g.

American Superconductor (AMSC) in collaboration with team members Qnergy, Alcoa Howmet, Gas Technology Institute (GTI), MicroCogen Partners, and A.O. Smith Corporation will develop a Free-Piston Stirling engine (FPSE) powered by an ultra-low-emissions natural gas burner for micro-CHP applications. A Stirling engine uses a working gas housed in a sealed environment, in this case the working gas is helium. When heated by the natural gas-fueled burner, the gas expands causing a piston to move and interact with a linear alternator to produce electricity.