Combined heat and power (CHP)—sometimes called cogeneration—is an integrated set of technologies for the simultaneous, on-site production of electricity and heat.

A district energy system is an efficient way to heat and/or cool many buildings from a central plant. It uses a network of pipes to circulate steam, hot water, and/or chilled water to multiple buildings.

A microgrid is a network of electricity sources and loads that is typically connected to and synchronous with the grid, but is also able to operate independently in “island mode.”

CHP is often an integral part of district energy systems and microgrids. CHP, district energy systems, and microgrids improve energy efficiency, reduce carbon emissions, facilitate integration of renewable energy sources, lower operating costs, and improve resilience of critical infrastructure and the electric power system.

As the grid evolves and includes more different types of distributed energy resources, there is an increased need to ensure the stability and reliability of the electric power system. Flexible CHP systems that can provide needed grid support services―such as ramping capability, frequency response, and voltage control―hold significant potential.

To ensure that the CHP and district energy R&D portfolio is focused on needed technology development areas, the Advanced Manufacturing Office regularly convenes stakeholders to discuss priority needs:

CHP and district energy R&D portfolio focus areas are:

FLEXIBLE CHP SYSTEMS

These projects develop flexible CHP systems that can provide support services to the electric grid. The projects are divided into two topic areas: (1) power electronics and control systems that enable seamless interconnection of CHP systems with the grid; and (2) prime movers to enable CHP systems to be more responsive to the demands of the modern grid.

HIGH SPEED MEDIUM VOLTAGE CHP SYSTEM WITH ADVANCED GRID SUPPORT

Clemson University – North Charleston, NC

The project will develop and test a modular control system architecture to enable flexible CHP systems with advanced grid support functionality. The distributed control system architecture will enable facilities to more effectively utilize innovative power electronics equipment and controls to seamlessly interconnect CHP systems with the power grid.

Fact sheet

CONVERTER-INTERFACED CHP PLANT FOR IMPROVED GRID INTEGRATION, FLEXIBILITY, AND RESILIENCY

GE Global Research – Niskayuna, NY

The project will develop a full-size grid interface converter and control solution to interconnect small and mid-size CHP engines to a low or medium voltage electric grid. All control functions to meet interconnection requirements will be developed and packaged with a substation microgrid controller.

Fact sheet

SIC-BASED MODULAR TRANSFORMER-LESS MW-SCALE POWER CONDITIONING SYSTEM AND CONTROL FOR FLEXIBLE CHP SYSTEM

University of Tennessee, Knoxville – Knoxville, TN

The project will develop a power conditioning system converter and a corresponding control system for flexible CHP systems. The power conditioning system converter and controller will support different types of CHP prime movers and be scalable to serve as the interface connector between CHP systems and a medium voltage grid.

Fact sheet

HIGH-EFFICIENCY MODULAR SIC-BASED POWER CONVERTER FOR FLEXIBLE CHP SYSTEMS WITH STABILITY-ENHANCED GRID SUPPORT FUNCTIONS

Virginia Polytechnic Institute – Blacksburg, VA

The project will develop a modular, scalable medium voltage power converter featuring stability-enhanced grid support functions for flexible CHP systems. The converter will use a modular circuit topology that is scalable both in voltage and current to flexibly meet the needs of CHP systems in the 1-20 MW range.

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ORGANIC RANKINE CYCLE INTEGRATION AND OPTIMIZATION FOR HIGH EFFICIENCY CHP GENSET SYSTEMS

ElectraTherm – Flowery Branch, GA

The project will enable a novel flexible CHP system concept by developing an Organic Rankine Cycle system that can be integrated with a reciprocating engine to achieve total CHP system efficiencies of 85% or more at both its rated electrical capacity and at 50% capacity. Such a CHP system will be able to provide additional power to the grid when needed without sacrificing system efficiency under different operating conditions.

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DEMONSTRATION OF IMPROVED CHP SYSTEM UTILIZING IMPROVED GAS TURBINE AND SCO2 CYCLES USING ADDITIVE MANUFACTURING COMPONENTS

Siemens Corporation – Charlotte, NC

The project will integrate a supercritical carbon dioxide bottoming cycle with a 5.3 MW gas turbine to develop a CHP system that is able to transition rapidly between 50% and 100% load by engaging or bypassing the bottoming cycle while maintaining electrical system efficiency above 30% at all times.

Fact sheet

MODIFICATIONS TO SOLAR TITAN 130 COMBUSTION SYSTEM FOR EFFICIENT, HIGH TURNDOWN OPERATION

Southwest Research Institute – San Antonio, TX

The project will develop new combustion system solutions and technologies that will enable a gas turbine to maintain high efficiency and low emissions during high turndown operation. Increasing the efficiency of the turbine at part load conditions and expanding the lean operating envelope of the turbine will significantly enhance the ability of a gas turbine-driven CHP system to provide advanced grid services.

Fact sheet

HIGH EFFICIENCY TURBINES FOR CHP

These projects are developing advanced materials, combustion system improvements, and new airfoil designs to improve the efficiency of turbines used in flexible CHP systems.

ADVANCED TURBINE AIRFOILS FOR EFFICIENT COMBINED HEAT AND POWER SYSTEMS

National Energy Technology Laboratory – Morgantown, WV
Oak Ridge National Laboratory – Oak Ridge, TN

The project will evaluate how a combination of new materials, additive manufacturing technologies, and airfoil cooling design can raise the efficiency of turbines used in CHP systems by demonstrating how to increase the turbine firing temperature by 100°C compared to a 2015 baseline. The project team will also estimate the economic benefits from these efficiency gains in CHP systems that use turbines smaller than 20 MW.

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HIGH PERFORMANCE, HIGH TEMPERATURE MATERIALS TO ENABLE HIGH EFFICIENCY POWER GENERATION

Oak Ridge National Laboratory – Oak Ridge, TN
Argonne National Laboratory – Lemont, IL

The project will evaluate advanced materials and develop lifetime modeling tools to enable a greater than 100°C increase in gas turbine inlet temperature compared to a 2015 baseline, and improve the durability and reduce maintenance costs of high temperature components in current CHP systems. The targeted components include heat exchangers, combustion liners, and hot corrosion-resistant coatings for disk applications with high sulfur opportunity fuels.

Fact sheet

HIGH POWER TO HEAT RATIO CHP SYSTEMS

These projects are developing CHP technologies with increased electricity generation efficiency while maintaining high overall system efficiency.

ROBUST COMBINED HEAT AND HYBRID POWER (CHHP) FOR HIGH ELECTRICAL EFFICIENCY COGENERATION

Georgia Institute of Technology – Atlanta, GA

The project will develop a hybrid fuel cell/gas turbine system concept and cyberphysical demonstration as a combined heat and hybrid power (CHHP) system for both robust and high power-to-process heat ratio cogeneration. The system maintains distinct, elevated electrical efficiencies while simultaneously supporting a broad span of heating needs.

Fact sheet coming soon

ULTRA-EFFICIENT CHP WITH HIGH POWER/HEAT RATIO USING A NOVEL ARGON POWER CYCLE

Noble Thermodynamic Systems – Berkeley, CA

The project will expand the application of the Argon Power Cycle (APC)―a closed loop internal combustion engine cycle that uses argon as its working fluid―to develop an ultra-efficient CHP system capable of single-cycle efficiency greater than 65% and overall CHP efficiency more than 75%, delivering emission-free electricity from natural gas.

Fact sheet coming soon

ADDITIVE MANUFACTURED SUPERCRITICAL CO2 HEAT TO POWER SOLUTION

University of Wisconsin Madison – Madison, WI

The project focuses on the design, development, and fabrication of two major system sub-components―a turbine wheel and the electrical generator and associated power electronics―to be used in a supercritical CO2 (sCO2) heat to power solution system. The use of sCO2 provides the advantages of small size, high efficiency, and lower capital cost compared to conventional steam cycles.

Fact sheet coming soon

DISTRICT ENERGY

These projects are developing innovative technologies and approaches to integrating flexible CHP into district energy systems.

FLEXIBLE NATURAL GAS/HYDROGEN CHP SYSTEM

Caterpillar Inc. – Peoria, IL

The project will develop and demonstrate a 2 MW flexible natural gas/hydrogen combined heat and power (CHP) system in a municipal district energy system. The project will also evaluate the greenhouse gas emissions profile, reliability, durability, and barriers to adoption of a natural gas/hydrogen CHP system.

Fact sheet coming soon

MEGAWATT SCALE, MULTI-SOURCE HEAT RECOVERY SYSTEM WITH A FLEXIBLE GRID INTERCONNECT

Clemson University – North Charleston, SC

The project will demonstrate the capability to use an Organic Rankine Cycle (ORC) in multi-source heat recovery applications utilizing a single turbo expander and a flexible electrical generation system. The heat recovery system will be able to aggregate multiple heat sources, including geothermal, into a single collection heat stream that can then be controllably proportioned between electrical generation and district heating and cooling requirements.

Fact sheet coming soon

DEMONSTRATION OF FLEXIBLE CHP WITH SUB-ATMOSPHERIC AIR TURBINE IN A DISTRICT ENERGY SETTING

Gas Technology Institute – Des Plaines, IL

The project will demonstrate a cost-effective, highly efficient flexible combined heat and power system that utilizes a state-of-the-art reciprocating internal combustion engine integrated with a novel sub-atmospheric air turbine cycle powered by the engine waste heat to produce both electricity and thermal energy. Controls to maximize system flexibility for microgrid applications will also be developed.

Fact sheet coming soon

URBAN COMBINED HEAT AND POWER WITH INTEGRATED RENEWABLES AND ENERGY STORAGE

The George Washington University – Washington, DC

The project seeks to determine how to effectively integrate and enhance electricity generation and energy storage components of an urban district energy system. The project will focus on an urban district energy system with a combined heat and power plant, solar thermal heating, rooftop photovoltaic generation, and battery and thermal storage.

Fact sheet coming soon

ADVANCED DISTRICT ENERGY CONTROLS FOR IMPROVED EFFICIENCY AND RESILIENCE

Paragon Robotics LLC – Bedford Heights, OH

The project will develop improved control technology architecture and algorithms for district energy (DE) systems. Most current community-based DE systems only employ basic controls optimization, drastically reducing the overall efficiency of the systems and hindering the addition of CHP and other DE assets.

Fact sheet coming soon

TOOLS AND ANALYSIS FOR CHP IN MICROGRIDS AND DISTRICT ENERGY SYSTEMS

These projects are conducting analysis and developing tools for the application of flexible CHP systems in microgrids and district energy systems.

SIMPLIFIED TOOL FOR THE NON-TECHNICAL USER TO RAPIDLY DEPLOY CHP FEASIBILITY ANALYTICS IN DISTRICT ENERGY AND MICROGRIDS

Houston Advanced Research Center – Houston, TX

The project will develop a cloud-based user-friendly tool for stakeholders with very limited engineering knowledge to expedite feasibility analyses of CHP-based district energy (DE) systems, stimulating the integration of efficient CHP systems, renewable energy sources, and thermal energy storage into innovative community-based DE systems and microgrids.

Fact sheet coming soon

VERIFICATION AND VALIDATION OF PERFORMANCE WITH DISSEMINATION OF BEST PRACTICES IN DISTRICT ENERGY AND CHP

International District Energy Association – Westborough, MA

The project will increase stakeholder awareness of the role of district energy, CHP and microgrid assets in supporting and participating in the grid of the future. The project team will verify, validate and analyze performance metrics of district energy, CHP and microgrids compared to existing baseline technology.

Fact sheet coming soon

INCORPORATING CHP MODELING INTO THE RE-OPT LITE WEB TOOL

National Renewable Energy Laboratory – Golden, CO

The National Renewable Energy Laboratory (NREL), working with project partners, has extended the U.S. Department of Energy’s (DOE’s) REopt Lite tool to include combined heat and power (CHP) modeling capabilities. REopt Lite provides technoeconomic optimization and resilience analysis for grid-connected solar photovoltaics (PV), wind, and battery storage at a site. The recent addition now adds CHP, absorption chillers, and thermal energy storage to the mix. The tool analyzes hourly data across the project lifecycle and evaluates the trade-off between capital costs, operating costs, and savings to find the most cost-effective mix of technologies.

Fact sheet

SIMULATION-BASED DESIGN AND OPTIMIZATION OF WASTE HEAT RECOVERY SYSTEMS

National Renewable Energy Laboratory – Golden, CO
Lawrence Berkeley National Laboratory – Berkeley, CA

The project will develop a tool that can quantify the value of a district energy system and its potential for waste heat recovery. The new software analysis platform will evaluate and optimize district energy systems to better utilize low-temperature waste heat from nearby commercial and industrial buildings. The tool will help project developers and engineers easily quantify the potential value and cost savings of community energy systems for both producers and consumers of waste heat.

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OPTIMAL CO-DESIGN OF INTEGRATED THERMAL-ELECTRICAL NETWORKS AND CONTROL SYSTEMS FOR GRID-INTERACTIVE EFFICIENT ENERGY SYSTEMS

University of Colorado Boulder – Boulder, CO

The project will create a holistic open-source modeling and optimization platform for the design and retrofit of grid-interactive efficient district energy systems by extending the National Renewable Energy Laboratory’s Urban Renewable Building and Neighborhood optimization (URBANopt) platform.

Fact sheet coming soon

Find information about past CHP R&D projects funded by DOE. Previous R&D efforts focused on advanced reciprocating engine systems, packaged CHP systems, high-value applications, fuel-flexible CHP, and technology demonstrations.

Learn more about CHP including basicsbenefits, and technical assistance activities to help deploy technologies.