Henry Louie

Superconducting Magnetic Energy Storage (SMES) for Energy Cache Control in Modular Distributed Hydrogen-Electric Energy Systems

The proposed energy cache control enables fast compensation of stochastic power fluctuations through the use of Superconducting Magnetic Energy Storage (SMES) connected to the DC bus of Distributed Generation (DG). The term energy cache control is chosen to reflect its analogy to the utilization of the data cache in computers. The SMES provides an energy cache for other types of storage with a higher capacity of energy but also longer response times. Together, the two types of storage provide high controllability over diverse time scales. The SMES so enables the creation of modular DG building blocks which can be readily connected to the network in a plug-and-supply mode. In the developed case study, the SMES is part of a DG unit of a model commercial facility that includes renewable-based electric power generation and a hydrogen-electric conversion and storage plant composed of an electrolyser, a fuel cell, and tanks. It is shown how the cache energy control deals with fast fluctuations of power generation and load that are caused by changing wind and sudden power demands of an elevator, respectively. Through its shock-absorbing role, the energy cache control of the SMES prevents the involved disturbances from propagating over the network interface and makes the DG unit behave as a good citizen in terms of network integration.

Cache Energy Control for Storage: Power System Integration and Education Based on Analogies Derived From Computer Engineering

Energy storage is an enabling technology for power system integration of renewable sources, while data storage enables computer system integration. In this paper, a functional analogy relating energy and data storage is derived. Battery or hydrogen storage can provide large energy capacity similar to a hard disk providing large data capacity. Supercapacitors or flywheels provide fast and frequent access to cache energy similar to the computers RAM providing fast and frequent access to data. In analogy to computer engineering, a cache control that coordinates the operation of a multilevel storage consisting of such complementary capacity and access-oriented storage technologies is designed. It is illustrated how for an industrial distributed energy system with renewable generation, local load, fueling station, and connections to the electricity and gas distribution networks, the cache control provides energy management to support a modular plug-and-play-like system integration. The benefit of the analogy in education is evaluated on a representative sample of electrical engineering students at the University of Washington. While familiar with computing, students do not typically have the same level of exposure to power engineering. The understanding of distributed energy systems concepts is shown to improve thanks to this bridging analogy between computer and power engineering.

Evaluation of probabilistic models of wind plant power output characteristics

The power output by weather-driven renewable resources such as wind energy conversion systems can be appropriately described as being stochastic. To manage these resources, probabilistic models of wind power are being increasingly employed by power system stakeholders in applications such as stochastic unit-commitment programs and wind power forecast systems. This paper evaluates probabilistic models—specifically the probability density functions—of aggregate wind plant power output and conditional and unconditional variations of aggregate wind plant power output. The parameters of the models are fit to historical aggregate wind plant power data from three large North American systems. Parametric and non-parametric evaluations of the suitability of the models are performed in the form of χ2 goodness-of-fit tests and through the inspection of probability plots and histograms. It is shown that Beta distributions are appropriate models for the aggregate power output and Laplace distributions are appropriate models for wind power variability. Conditional wind power variation follows a generalized extreme value distribution.

Experiences in the construction of open source low technology off-grid wind turbines

Though electrification began over one hundred years ago, today there remains approximately 1.5 billion people without access to electricity. This form of energy poverty disproportionately afflicts people living in rural and developing communities. Access to electricity, even at modest consumption levels, can dramatically improve the quality of life in a community. For example, electric lamps allow children to study at night, and radios and cellular phones greatly improve communication pathways. Small amounts of power can be provided by on-site distributed generation, without the need for expensive and intrusive transmission lines. This paper describes the design and construction of a low-technology wind turbine generator. The generator is designed to supply electricity to a small, off-grid community. The wind turbine can be primarily constructed by hand, without specialized manufacturing processes or exotic materials. Opportunities and challenges of using low-technology wind turbine generators in rural electrification are discussed. The wind turbine was constructed in a joint effort by the IEEE Power & Energy Society Community Solutions Initiative and the Puget Sound Professional Chapter of Engineers without Borders USA.

Characterizing and modeling aggregate wind plant power output in large systems

A fundamental challenge in integrating wind plants into a power system is the inherent stochastic nature of the power they output. In order to identify appropriate operational and technological solutions to integrating wind plants, it is important to characterize the uncertainty, variability and temporal patterns of the power they output. This paper analyzes historical wind power data from the Bonneville Power Administration, the Electric Reliability Council of Texas and the Midwest ISO to qualitatively and quantitatively characterize the wind power in these systems. From the analysis, probabilistic models of the power output, variations of power output and diurnal patterns are developed. Common probability density functions are fit to the data and the strength and timing of diurnal patterns are identified. The resulting parameters of the distribution can be used to model aggregate wind power output in large systems, which has applications in wind integration analysis and for benchmarking purposes. The results of the analysis quantify the challenges of wind plant integration faced by the system operators in each of the studied systems.

Rural Off-Grid Electricity Service in Sub-Saharan Africa [Technology Leaders]

Access to electricity is a persistent, endemic challenge impeding development in Sub-Saharan Africa. Decades of postcolonial underinvestment have resulted in just 80 GW of installed generation capacity? less than that of the United Kingdom? in a region with over 860 million people. Of the 20 countries with the lowest electrification rates in the world, 19 are found in Sub-Saharan Africa, where, on average, fewer than one in three people have access to electricity. In rural areas, electrification rates plummet to less than 15%.

Affordable energy solutions for developing communities

The World Bank estimates that roughly 1.6 billion people?nearly one out of every four people on the planet?do not have regular access to electricity. This form of energy poverty disproportionately afflicts people living in developing countries. For example, in sub-Saharan Africa excluding South Africa, 75 percent of households, some 550 million people, have no access to network electricity. In South Asia, 700 million are similarly not connected to the electricity grid.

Survey of energy use and costs in rural kenya for community microgrid business model development

A key input to any responsible energy development project is the current state of energy consumption in the local community as well as the associated expenses. This information can be used to guide the design of the system and to plan for the projects long-term financial viability. This paper describes residential energy use and costs in Muhuru Bay, Kenya. The results are based on a 2013 household energy survey with 69 respondents as well as two focus groups. The survey included questions regarding the use and cost of kerosene, batteries, candles, price to recharge mobile phones, along with demographic information. It is demonstrated how the results of the survey are incorporated into the development of a sustainable business plan of a community charging station microgrid project at a school in Muhuru Bay, Kenya. Best practices of conducting energy surveys and lessons learned are provided based on experiences in Kenya and elsewhere.

Resources for pre-university power engineering outreach

An aging workforce and the need to modernize the electric power system are significant challenges facing many nations, and in particular the United States. This complex problem requires a multi-faceted solution that starts with outreach to pre-university students. The aim of these outreach programs is to introduce students to power engineering concepts and to encourage them to choose power engineering as an area of future study and vocation. Outreach activities may also be targeted at guidance counselors, teachers, parents and the general public to the increase the awareness and image of the power engineering profession. This paper identifies pre-university power engineering outreach resources. Funding sources and organizations involved with engineering outreach are also identified. Specific on-line multimedia and in-person, experiential learning lesson plans and activities are discussed. These resources are intended to be used by power engineering faculty and other interested individuals.

An introduction and user's guide to the IEEE Smart Grid Web Portal

The IEEE Smart Grid Web Portal is an online resource that to date has been accessed by over 50 000 Smart Grid professionals, academics and other interested individuals from around the world. Launched in January of 2010, the IEEE Smart Grid Web Portal is a resource that converges and organizes all Smart Grid-related IEEE events, activities, news and assets into one place-accessible to anyone, anywhere in the world. Users can use the portal to view all upcoming conferences, browse publications and standards, access educational material and view various other IEEE-related content. The portal makes use of an illustrative conceptual model to show how the technical domains in the Smart Grid are interrelated. A novel application of this model provides an interactive gateway feature that allows users to navigate Smart Grid content based upon technical area of interest and filter it based upon date of creation. This paper describes the IEEE Smart Grid Web Portal for the purpose of orienting new users to the portal and details how individuals in the Smart Grid community-in particular those outside North America — can contribute to on-going relevance of this useful resource.