Benjamin Kroposki

Energy Policy Act of 2005

This article provides a comprehensive review and describes the impact of the bill on distributed generation, the electricity market, the national electrical grid, and the future of how electricity will be delivered in the United States. The energy policy act of 2005 removes the requirement that utilities purchase power under the condition that the qualifying facility has access to alternative markets. A single IEEE 1547 standard could be applied to any distributed resource interconnection

Benefits of Power Electronic Interfaces for Distributed Energy Systems

With the increasing use of distributed energy (DE) systems in industry and its technological advancement, it is becoming more important to understand the integration of these systems with the electric power systems. New markets and benefits for DE applications include the ability to provide ancillary services, improve energy efficiency, enhance power system reliability, and allow customer choice. Advanced power electronic (PE) interfaces will allow DE systems to provide increased functionality through improved power quality and voltage/volt-ampere reactive (VAR) support, increase electrical system compatibility by reducing the fault contributions, and flexibility in operations with various other DE sources, while reducing overall interconnection costs. This paper will examine the system integration issues associated with DE systems and show the benefits of using PE interfaces for such applications.

Advancement of energy storage devices and applications in electrical power system

Overall structure of electrical power system is in the process of changing. For incremental growth, it is moving away from fossil fuel based operations to renewable energy resources that are more environmentally friendly and sustainable. At the same time it has to grow to meet the ever increasing need for more energy. These changes bring very unique opportunities and obstacles. Over the past few decades many new and innovative ideas have been explored in the broad area of energy storage. They range in size, capacity and complexity in design. Some of the systems are designed for applications in large scale power and others are performing short term energy storage ride through capabilities for critical manufacturing and technology systems. Energy storage technology has become an enabling technology for renewable energy applications and enhancing power quality in the transmission and distribution power systems. This paper summarizes all the advancements made and provide a composite picture of costs and trends in storage technologies.

A review of plug-in vehicles and vehicle-to-grid capability

As hybrid vehicles gain popularity among the consumers, current research initiatives are focused towards developing plug-in electric and hybrid vehicles that can exploit utility power to charge vehicle batteries and therefore less dependent on the gasoline usage. Power electronic systems are being developed to allow plug-in vehicles to be vehicle-to-grid (V2G) capable where the vehicles can work as distributed resources and power can be sent back to the utility. In this paper a review of different plug-in and V2G capable vehicles are given along with their power electronics topologies. The economic implication of charging the vehicle or sending power back to the utility is described in brief. Finally, all vehicles with V2G capability must meet the IEEE Standard 1547 for connecting to the utility. Brief descriptions of the requirements and testing that must be followed for V2G vehicles to conform the IEEE 1547 standards are also discussed.

Steady-State Analysis of Maximum Photovoltaic Penetration Levels on Typical Distribution Feeders

This paper presents simulation results for a taxonomy of typical distribution feeders with various levels of photovoltaic (PV) penetration. For each of the 16 feeders simulated, the maximum PV penetration that did not result in a steady-state voltage or current violation is presented for several PV location scenarios: clustered near the feeder source, clustered near the midpoint of the feeder, clustered near the end of the feeder, randomly located, and evenly distributed. In addition, the maximum level of PV is presented for single, large PV systems at each location. Maximum PV penetration was determined by requiring that feeder voltages stay within ANSI Range A and that feeder currents stay within the ranges determined by overcurrent protection devices. Generation ramp rates, protection and coordination, and other factors that may impact maximum PV penetrations are not considered here. Simulations were run in GridLAB-D using hourly time steps over a year with randomized load profiles based on utility data and typical meteorological year weather data. For 86% of the 336 cases simulated, maximum PV penetration was at least 30% of peak load.

Temperature dependence of photovoltaic cells, modules and systems

Photovoltaic (PV) cells and modules are often rated in terms of a set of standard reporting conditions defined by a temperature, spectral irradiance and total irradiance. Because PV devices operate over a wide range of temperatures and irradiances, the temperature and irradiance-related behavior must be known. This paper surveys the temperature dependence of crystalline and thin-film, state-of-the-art, research-size cells, modules and systems measured by a variety of methods. The various error sources and measurement methods that contribute to cause differences in the temperature coefficient for a given cell or module measured with various methods are discussed.

Microgrid standards and technologies

Microgrids are intentional islands formed at a facility or in an electrical distribution system that contain at least one distributed energy resource and associated loads. Microgrids that operate both electrical generation and loads in a coordinated manner can offer benefits to the customer and the local utility. The loads and energy sources in a microgrid can be disconnected from and reconnected to the utility system with minimal disruption, thereby improving reliability. Any time a microgrid is implemented in an electrical distribution system, it must be well planned to avoid problems. This paper discusses current microgrid technologies and standards that are being developed to address implementation of microgrids.

Terawatt-scale photovoltaics: Trajectories and challenges

Coordinating technology, policy, and business innovations The annual potential of solar energy far exceeds the worlds total energy consumption. However, the vision of photovoltaics (PVs) providing a substantial fraction of global electricity generation and total energy demand is far from being realized. What technical, infrastructure, economic, and policy barriers need to be overcome for PVs to grow to the multiple terawatt (TW) scale? We assess realistic future scenarios and make suggestions for a global agenda to move toward PVs at a multi-TW scale.

Dark Shadows: Understanding Variability and Uncertainty of Photovoltaics for Integration with the Electric Power System

The U.S. Department of Energys National Renewable Energy Laboratory, Sandia National Laboratories, the Solar Electric Power Association, the Utility Wind Integration Group, and the U.S. Department of Energy hosted a day-long public workshop on the variability of photovoltaic (PV) plants. The workshop brought together utilities, PV system developers, power system operators, and several experts to discuss the potential impacts of PV variability and uncertainty on power system operations.

Harnessing the sun

Now is the time to plan for the integration of significant quantities of solar energy into the electricity grid. Although solar energy constitutes a very small portion of our energy system today, the size of the resource is enormous: The earth receives more energy from the sun in one hour than the global population uses in an entire year. In addition, the solar photovoltaic (PV) industry is growing very rapidly, sustaining an annual growth rate of more than 40% for the last decade. The combination of this rapid growth, falling costs, and a vast technical potential could make solar energy a serious contender for meeting our future energy needs.