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At least 19 records

Chapter 11: Marine and Hydrokinetic Power Generation and Power Plants

Marine and hydrokinetic (MHK) power generation is a relatively new type of renewable generation. Predecessors such as wind power generation, hydropower plant generation, geothermal generation, photovoltaic generation, and solar thermal generation have gained a lot of attention because of their successful implementation. The successful integration of renewable generation into the electric power grid has energized the power system global communities to take the lessons learned, innovations, and market structure to focus on the large potential of MHK to also contribute to the pool of renewable energy generation. This chapter covers the broad spectrum of MHK generation. The state-of-the-art power takeoff methods will be discussed. Types of electrical generators will be presented, and the options for implementation will be presented.

16 TIDAL AND WAVE POWER↗

Preliminary assessment of power-generating tethers in space and of propulsion for their orbit maintenance

The concept of generating power in space by means of a conducting tether deployed from a spacecraft was studied. Using hydrogen and oxygen as the rocket propellant to overcome the drag of such a power-generating tether would yield more benefit than if used in a fuel cell. The mass consumption would be 25 percent less than the reactant consumption of fuel cells. Residual hydrogen and oxygen in the external tank and in the orbiter could be used very effectively for this purpose. Many other materials (such as waste from life support) could be used as the propellant. Electrical propulsion using tether generated power can compensate for the drag of a power-generating tether, half the power going to the useful load and the rest for electric propulsion. In addition, the spacecraft's orbital energy is a large energy reservoir that permits load leveling and a ratio of peak to average power equal to 2. Critical technologies to be explored before a power-generating tether can be used in space are delineated.

English, R. E.↗

Electrical Power Conversion of River and Tidal Power Generator

As renewable generation has become less expensive during recent decades, and it becomes more accepted by the global population, the focus on renewable generation has expanded to include new types with promising future applications, such as river and tidal generation. Although the utilization of power electronics and electric machines in industry is phenomenal, the emphasis on system design is different for various sectors of industry. In precision control, robotics, and weaponry, the design emphasis is on accuracy and reliability with less concern for the cost of the final product. In energy generation, the cost of energy is the prime concern; thus, capital expenditures (CAPEX) and operations and maintenance expenditures (OPEX) are the major design objectives. This paper describes the electrical power conversion aspects of river and tidal generation. Although modern power converter control is available to control the generation side, the design was chosen on the bases of minimizing the CAPEX and OPEX; thus, the architecture is simple and modular for ease of replacement and maintenance. The power conversion is simplified by considering a simple diode bridge and a DC-DC power converter to take advantage of abundant and low-cost photovoltaic inverters that have well-proven grid integration characteristics (i.e., the capability to produce energy with good power quality and control real power and voltage on the grid side).

16 TIDAL AND WAVE POWER↗

Load following power generation and power storage using REP and PEM technology

A hydrogen generation system for generating hydrogen and electrical power includes a power supply, a reformer-electrolyzer-purifier (REP) assembly including at least one fuel cell including an anode and a cathode separated by an electrolyte matrix, at least one low temperature fuel cell, and a hydrogen storage. The at least one fuel cell is configured to receive a reverse voltage supplied by the power supply and generate hydrogen-containing gas in the anode of the at least one fuel cell. The at least one low temperature fuel cell is configured to receive the hydrogen-containing gas output from the REP assembly. The at least one low temperature fuel cell is configured to selectably operate in a power generation mode in which the hydrogen-containing gas is used to generate electrical power and a power storage mode in which the hydrogen-containing gas is pressurized and stored in the hydrogen storage.

Jahnke, Fred C.↗

Construction and evaluation of photovoltaic power generation and power storage system using SiC field-effect transistor inverter

A power storage system using spherical silicon (Si) solar cells, maximum power point tracking charge controller, lithium-ion battery and a direct current-alternating current (DC-AC) inverter was constructed. Performance evaluation of the DC-AC inverter was carried out, and the DC-AC conversion efficiencies of the SiC field-effect transistor (FET) inverter was improved compared with those of the ordinary Si-FET based inverter.

14 SOLAR ENERGY↗

Microfabricated thermoelectric power-generation devices

A device for generating power to run an electronic component. The device includes a heat-conducting substrate (composed, e.g., of diamond or another high thermal conductivity material) disposed in thermal contact with a high temperature region. During operation, heat flows from the high temperature region into the heat-conducting substrate, from which the heat flows into the electrical power generator. A thermoelectric material (e.g., a BiTe alloy-based film or other thermoelectric material) is placed in thermal contact with the heat-conducting substrate. A low temperature region is located on the side of the thermoelectric material opposite that of the high temperature region. The thermal gradient generates electrical power and drives an electrical component.

Fleurial, Jean-Pierre↗

Microfabricated thermoelectric power-generation devices

A device for generating power to run an electronic component. The device includes a heat-conducting substrate (composed, e.g., of diamond or another high thermal conductivity material) disposed in thermal contact with a high temperature region. During operation, heat flows from the high temperature region into the heat-conducting substrate, from which the heat flows into the electrical power generator. A thermoelectric material (e.g., a BiTe alloy-based film or other thermoelectric material) is placed in thermal contact with the heat-conducting substrate. A low temperature region is located on the side of the thermoelectric material opposite that of the high temperature region. The thermal gradient generates electrical power and drives an electrical component.

Fleurial, Jean-Pierre↗

Thermoelectric Generator Powered Wireless Sensor Node Prototype for Nuclear Applications

This report presents the development a TEG-powered WSN prototype that could be used in nuclear applications. Different design considerations that are important in assembling different components of a WSN were carefully taken into consideration. In designed WSN is compatible to operate with low-power generating TEG and high-power generating TEG based on application requirements. Also, to maintain appropriate power level across different sensor node components, direct current-to-direct current converter with maximum peak power tracking algorithm is implemented. Storage device with real-time clock is embedded to enable local data storage and real-time time stamping. The wireless communication module selected and implemented is Zig Bee protocol. To accommodate different operating conditions and any loss of power from TEG due to unforeseen reasons, backup battery system is also implemented. Entire assembly is performed on a 2-layer printed circuit board and tested for operation. The outcome was successful and it also provided data to validate the mathematical model developed to estimate average power consumption of a WSN under different operating conditions.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Blended service schedule for a power generator

A power generation system includes a power generator operatively connected to a plurality of sensors and a processor. The processor is configured to observe usage-based or event-based data regarding one or more components and consumables of the power generator. A usage-based service schedule is observed for the one or more event-based components and consumables. Operation-based data is received from the plurality of sensors regarding the functioning of the power generation system and one or more operation-based components and consumables of the power generator. An operation-based service schedule is determined for the one or more operation-based components and consumables based on the operation-based data. A blended service schedule is generated, the blended service schedule including the usage-based service schedule and the operation-based service schedule. The blended service schedule is then provided to at least one of a local monitor or a remote monitor.

Keene, Kevin↗

Data-driven modeling of power generation for a coal power plant under cycling

Increased penetration of renewables for power generation has negatively impacted the dynamics of conventional fossil fuel-based power plants. The power plants operating on the base load are forced to cycle, to adjust to the fluctuating power demands. This results in an inefficient operation of the coal power plants, which leads up to higher operating losses. To overcome such operational challenge associated with cycling and to develop an optimal process control, this work analyzes a set of models for predicting power generation. Moreover, the power generation is intrinsically affected by the state of the power plant components, and therefore our model development also incorporates additional power plant process variables while forecasting the power generation. We present and compare multiple state-of-the-art forecasting data-driven methods for power generation to determine the most adequate and accurate model. We also develop an interpretable attention-based transformer model to explain the importance of process variables during training and forecasting. The trained deep neural network (DNN) LSTM model has good accuracy in predicting gross power generation under various prediction horizons with/without cycling events and outperforms the other models for long-term forecasting. The DNN memory-based models show significant superiority over other state-of-the-art machine learning models for short, medium and long range predictions. The transformer-based model with attention enhances the selection of historical data for multi-horizon forecasting, and also allows to interpret the significance of internal power plant components on the power generation. This newly gained insights can be used by operation engineers to anticipate and monitor the health of power plant equipment during high cycling periods.

01 COAL, LIGNITE, AND PEAT↗

Thermoelectric power generation: from new materials to devices

Thermoelectric technology offers the opportunity of direct conversion between heat and electricity, and new and exciting materials that can enable this technology to deliver higher efficiencies have been developed in recent years. This mini-review covers the most promising advances in thermoelectric materials as they pertain to their potential in being implemented in devices and modules with an emphasis on thermoelectric power generation. Classified into three groups in terms of their operating temperature, the thermoelectric materials that are most likely to be used in future devices are briefly discussed. Here, we summarize the state-of-the-art thermoelectric modules/devices, among which nanostructured PbTe modules are particularly highlighted. At the end, key issues and the possible strategies that can help thermoelectric power generation technology move forward are considered.

30 DIRECT ENERGY CONVERSION↗

Thermoelectric power generator for variable thermal power source

Traditional power generation systems using thermoelectric power generators are designed to operate most efficiently for a single operating condition. The present invention provides a power generation system in which the characteristics of the thermoelectrics, the flow of the thermal power, and the operational characteristics of the power generator are monitored and controlled such that higher operation efficiencies and/or higher output powers can be maintained with variably thermal power input. Such a system is particularly beneficial in variable thermal power source systems, such as recovering power from the waste heat generated in the exhaust of combustion engines.

30 DIRECT ENERGY CONVERSION↗

Systems and methods for monitoring a power-generation module assembly after a power-generation module shutdown event

Embodiments are directed to providing a user interface (UI) that streamlines and simplifies the process of monitoring critical power-generation module (PGM) parameters after a PGM assembly is shutdown. The UI displays, in real-time, indicators corresponding to one or more post-shutdown PGM parameters. The UI provides indications of whether the post-shutdown PGM parameters meet post-shutdown criteria of the PGM assembly. When a post-shutdown PGM parameter does not meet the post-shutdown criteria, a user alert is provided to the user. A protocol may additionally be provided to the user. In some embodiments, the protocol may enable the user to return the PGM assembly to a condition that satisfies the post-shutdown criteria. The protocol may be a safety protocol and/or an asset protection protocol.

Buenaventura, Don↗

Systems and methods for monitoring a power-generation module assembly after a power-generation module shutdown event

Embodiments are directed to providing a user interface (UI) that streamlines and simplifies the process of monitoring critical power-generation module (PGM) parameters after a PGM assembly is shutdown. The UI displays, in real-time, indicators corresponding to one or more post-shutdown PGM parameters. The UI provides indications of whether the post-shutdown PGM parameters meet post-shutdown criteria of the PGM assembly. When a post-shutdown PGM parameter does not meet the post-shutdown criteria, a user alert is provided to the user. A protocol may additionally be provided to the user. In some embodiments, the protocol may enable the user to return the PGM assembly to a condition that satisfies the post-shutdown criteria. The protocol may be a safety protocol and/or an asset protection protocol.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Power System Concepts for the Lunar Outpost: A Review of the Power Generation, Energy Storage, Power Management and Distribution (PMAD) System Requirements and Potential Technologies for Development of the Lunar Outpost

This paper will review potential power system concepts for the development of the lunar outpost including power generation, energy storage, and power management and distribution (PMAD). In particular, the requirements of the initial robotic missions will be discussed and the technologies considered will include cryogenics and regenerative fuel cells (RFC), AC and DC transmission line technology, high voltage and low voltage power transmission, conductor materials of construction and power beaming concepts for transmitting power to difficult to access locations such as at the bottom of craters. Operating conditions, component characteristics, reliability, maintainability, constructability, system safety, technology gaps/risk and adaptability for future lunar missions will be discussed for the technologies considered.

Khan, Z.↗

Magnesium and Manganese Silicides For Efficient And Low Cost Thermo-Electric Power Generation

Thermoelectric Power Generation (TEPG) is the most efficient and commercially deployable power generation technology for harvesting wasted heat from such things as automobile exhausts, industrial furnaces, and incinerators, and converting it into usable electrical power. We investigated the materials magnesium silicide (Mg2Si) and manganese silicide (MnSi) for TEG. MgSi2 and MnSi are environmentally friendly, have constituent elements that are abundant in the earth's crust, non-toxic, lighter and cheaper. In Phase I, we successfully produced Mg2Si and MnSi material with good TE properties. We developed a novel technique to synthesize Mg2Si with good crystalline quality, which is normally very difficult due to high Mg vapor pressure and its corrosive nature. We produced n-type Mg2Si and p-type MnSi nanocomposite pellets using FAST. Measurements of resistivity and voltage under a temperature gradient indicated a Seebeck coefficient of roughly 120 V/K on average per leg, which is quite respectable. Results indicated however, that issues related to bonding resulted in high resistivity contacts. Determining a bonding process and bonding material that can provide ohmic contact from room temperature to the operating temperature is an essential part of successful device fabrication. Work continues in the development of a process for reproducibly obtaining low resistance electrical contacts.

30 DIRECT ENERGY CONVERSION↗