Sessions

A convergence of technology development, policy support, and industry investment trends are accelerating the pace of Hydrogen (H2) technology demonstrations, increasing the likelihood of power sector impacts. In preparation for a largescale power sector shift toward decarbonization for a low carbon future, several major power equipment manufacturers are developing gas turbines that can operate on a high H2-volume fuel. Many have H2 capable systems now that range from 5 to 100% H2 by volume. Units with 100% H2 capabilities are either using a diffusion burner or some version of a wet low emissions (WLE) burner. Most dry low emission/dry low NOx (DLE/DLN) technologies are currently limited to ~50% H2 or less. Therefore, research is currently underway to develop low NOx gas turbine combustion systems with improved Hydrogen capability. This presentation plans to provide an overview of the technical challenges of Hydrogen usage and inclusion within gas turbine combustion systems. This will include operational considerations of flashback, blowoff, combustion instabilities, and NOx emissions.

A great deal of work has gone into reducing and eliminating the carbon footprint in an economical and sustainable manner for utility and district energy applications. Much information has been presented on using hydrogen as a fuel for combustion gas turbines to support zero-carbon-emission CHP solutions. However, not enough has been said about applying the same approach to generate heating and process steam utilizing the packaged boilers in these same facilities. Hydrogen is a proven and viable fuel source whether the packaged boiler serves as a back-up to the CHP system, if it is used for heating steam, or whether it is producing steam to generate power in a steam turbine. The technology needed to facilitate hydrogen firing and eliminate CO emissions from the system is not new and does not increase risks associated with packaged boiler or burner design and operation. In order to ensure success, there are specific design factors in both the boiler and combustion system that must be considered. These system designs can significantly affect system efficiency as well as environmental regulation compliance. This presentation is designed to inform the audience about the key considerations when looking at firing hydrogen as a fuel in their packaged boiler. Green steam is not only a possibility but is a necessity. Understanding the entire system will prepare users for a successful project.

Global pressure on the use of traditional fossil fuels and the emission of greenhouse gases such as CO2 is enormous. Consequently, the gas turbine (GT) industry is taking action. One of the key efforts of reducing CO2 emissions in gas turbines is to shift the use of natural gas (typically CH4) to alternative fuels such as Hydrogen (H2). The various gas turbine OEMs, as well as utilities and other users of gas turbines, are currently investigating the impact of firing H2 in gas turbines. A lot less focus is given to its impact on other complementary equipment to gas turbines such as Heat Recovery Steam Generators (HRSGs), while a great deal of the global gas turbine fleet is connected with HRSGs. This paper will give insight into what the main impacts are of firing H2 in gas turbines on HRSGs. For example, the combustion of hydrogen will occur at higher flame temperatures than natural gas. One of the side effects of that fact is the production of more nitrogen oxides (NOx). Secondly, the water dew point of the flue gas increases when firing hydrogen in the GT. This means that cold parts which are in contact with flue gas will form condensation quicker. Thirdly, firing H2 adds extra volume to the exhaust gas flow compared to firing natural gas. Last, but certainly not least, are the additional safety aspects that apply when firing H2 in the gas turbine. This paper will explore design considerations for the HRSG based on the above impacts.

Microgrids enhanced with battery energy storage systems (BESS) are an emerging technology that improves resilience and reliability, while also assisting decarbonization planning. An estimated 10 to 100 GW of such systems are likely to be deployed in the United States over the next decade, and most agree that BESS-equipped microgrids can provide a significantly more robust and cleaner power supply for critical equipment such as data centers, while bridging the gap between slower-starting generators and intermittent renewable energy sources. But while the advantages are widely recognized, site planners and system designers question whether the improved reliability and availability will realize a net economic benefit. This presentation will demonstrate the advantages of BESS-equipped microgrids by quantifying the benefit of increased reliability, and compare design decisions and trade-offs when implementing batteries and microgrids into an overall system design. Following the concept of design-for-reliability, the potential cost/benefit of different battery-equipped microgrid systems, as well as the reliability analysis techniques that led to those conclusions will be explained. The presentation will explore several recent deployment case studies across several sites and consider decarbonization support options available with these systems, potential ancillary benefits, and critical design decisions required to support a sustainable return-on-investment.

The definition of a microgrid is a decentralized group of electricity sources and loads that normally operates connected to the traditional wide area synchronous grid but can also disconnect to "island mode" and function autonomously as physical or economic conditions dictate. Based on aging electric infrastructure, growing electric demands and focus on carbon reduction the microgrid market is growing to meet these global requirements. Recip engines are an integral part of a microgrid now and into the future based on their ability to provide consistent, sustainable, reliable electricity and thermal energy. Recip engines can operate on many different fuels such as natural gas, diesels, biogas, propane, etc. They are also being designed and configured to operate on clean zero-carbon fuels such as hydrogen, renewable natural gas to meet carbon reduction goals. Manufacturers are also focusing on making sure current reciprocating engine microgrids can be retrofitted to operate on zero-carbon fuels as they become readably available and are cost-effective. This abstract will focus on two operating microgrids that incorporate reciprocating engine technologies today. One operates an engine in a simple cycle mode and the other incorporates an engine operating in combined heat and power application (CHP). The first project contains a continuous duty generator set rated for is a 423 kW for a microgrid project located at the Chattanooga, TN airport. The customer is the local municipal utility, Electric Power Board of Chattanooga (EPB). This project utilizes a recip gen set, PV solar panels, battery energy storage, and a microgrid controller. EPB worked with the University of Tennessee to develop the microgrid controller as part of a grant. The second project is a 5-MW microgrid for Tasteful Selections, a vertically integrated farmer-owned, farmer-driven bite-size potato growing, packing, and shipping operation. Combining 3.6 MW cogeneration firm power with 120-kW solar and 1.25-MW/625-kWh lithium-ion battery storage, the microgrid has approximately 5-MW total capacity with provisions to add additional renewables, including more solar and renewable natural gas. It is architected to create efficiency at every turn, from capturing and repurposing heat to optimizing engine efficiency and advanced load side management. The microgrid incorporates solar energy generation and battery storage to provide Tasteful Selections a pathway to net-zero carbon.