Introduction Industry Overview Incentives for Renewables Utility Perspective References Wind Power Wind in the World The U.S.A. Europe India Mexico Ongoing Research and Development References Photovoltaic Power Present Status Building Integrated pv Systems pv Cell Technologies pv Energy Maps References Wind Speed and Energy Distributions Speed and Power Relations Power Extracted from the Wind Rotor Swept Area Air Density Global Wind Patterns Wind Speed Distribution Wind Speed Prediction Wind Resource Maps References Wind Power System System Components Turbine Rating Electrical Load Matching Variable-Speed Operation System Design Features Maximum Power Operation System Control Requirements Environmental Aspects References Electrical Generator Electromechanical Energy Conversion Induction Generator References Generator Drives Speed Control Regions Generator Drives Drive Selection Cut-Out Speed Selection References Solar Photovoltaic Power System The pv Cell Module and Array Equivalent Electrical Circuit Open Circuit Voltage and Short Circuit Current i-v and p-v Curves Array Design Peak Power Point Operation pv System Components References Solar Thermal System Energy Collection Solar II Power Plant Synchronous Generator Commercial Power Plants References Energy Storage Battery Types of Batteries Equivalent Electrical Circuit Performance Characteristics More on Lead-Acid Battery Battery Design Battery Charging Charge Regulators Battery Management Flywheel Compressed Air Superconducting Coil References Power Electronics Basic Switching Devices AC to DC Rectifier DC to AC Inverter Grid Interface Controls Battery Charge/Discharge Converters Power Shunts References Stand-Alone System pv Stand-Alone Electric Vehicle Wind Stand-Alone Hybrid System System Sizing Wind Farm Sizing References Grid-Connected System Interface Requirements Synchronizing with Grid Operating Limit Energy Storage and Load Scheduling Utility Resource Planning Tool References Electrical Performance Voltage Current and Power Relations Component Design for Maximum Efficiency Electrical System Model Static Bus Impedance and Voltage Regulation Dynamic Bus Impedance and Ripple Harmonics Quality of Power Renewable Capacity Limit Lightning Protection National Electrical Code on Renewable Power Systems References Plant Economy Energy Delivery Factor Initial Capital Cost Availability and Maintenance Energy Cost Estimates Sensitivity Analysis Profitability Index Hybrid Economics References The Future World Electricity Demand to 2015 Wind Future pv Future Declining Production Costs Market Penetration Effect of Utility Restructuring References Further Reading Appendix 1 Appendix 2 Acronyms Conversion of Units Index

Wind and Solar Power Systems

Changes in customers' needs require improvements in the reliability and quality of the electricity supply This paper describes how the concept of custom power is now becoming familiar The term describes the value-added power that electric utilities and other service providers will offer their customers in the future The improved level of reliability of this power, in terms of reduced interruptions and less variation, will stem from an integrated solution to present problems, of which a prominent feature will be the application of power electronic controllers to utility distribution systems and/or at the supply end of many industrial and commercial customers and industrial parks >

Introducing custom power

The last couple of years have seen an expansion on both applications and market development strategies for SMES (superconducting magnetic energy storage). Although originally envisioned as a large-scale load-leveling device, today's electric utility industry realities point to other applications of SMES. These applications-transmission line stabilization, spinning reserve and voltage control-are likely to open the door to SMES commercialization in the electric utility sector. In the industrial sector, power quality concerns are already driving the development of a market for micro-SMES devices, and load-leveling at an industrial scale is fast becoming a potential application. Work recently completed as part of the US SMES program, as well as ongoing design activities, point to self- (or cold-) supported SMES as the design option in the near-future. This is a major departure from the earth-supported SMES systems first envisioned 25 years ago for utility load-leveling. The path to commercialize SMES is not likely to include a large 'demonstration' unit, or model, but rather follow an evolutionary process in which bigger and better units will be fielded in response to specific applications. This paper reviews the developments in the US SMES program that have taken us to where we are today, briefly reviews SMES-related activities around the world, and points out trends in applications and development of SMES.

Superconducting storage systems: an overview

Chapter 1: Introduction to Power Quality. Chapter 2: Power Quality Characteristics. Chapter 3: Power Quality Standards. Chapter 4: Power Quality Solutions. Chapter 5: Wiring and Grounding. Chapter 6: Power Quality Measurement Tools. Chapter 7: Power Quality Surveys. Chapter 8: Power Quality Economics. Chapter 9: Future Trends.

Power Quality Primer

This paper studies three different frequency controllers and their effects on the voltage disturbance ride-through capability of a VSC-HVDC supplied industrial system. The idea of implementing frequency controller is to improve the power quality of industrial plants by slightly decreasing the VSC output voltage frequency since industrial processes are more sensitive to voltage drops than frequency deviations. The first two controllers, frequency controllers I and II, are fixed frequency controllers and the third one, frequency controller III, is a PI frequency controller. In order to compare three different controllers, a system with a simplified VSC-HVDC and different load types is simulated in PSCAD/EMTDC. Simulation results show that with frequency controller III, the VSC-HVDC supplied industrial plant can avoid a voltage collapse by decreasing frequency during or after disturbances. Furthermore, with an increase of the converter current limit, the possibility of mitigating voltage dips increases. For frequency controllers I and II, the extent of the disturbance ride-through capability depends on the current limit of the VSC-HVDC. A higher current limit results in a higher ride-through capability. The effect of the dc capacitor on improving the system voltage disturbance tolerance is also investigated during and after disturbances when the VSC-HVDC uses frequency controller I. The system voltage disturbance ride-through capability increases with an increase of the dc capacitance or the current limit.

Comparison of Different Frequency Controllers for a VSC-HVDC Supplied System

The operation of systems for superconducting magnetic-energy storage (SMES) is explained. The original goal was systems storing thousands of megawatts of back-up electricity for several hours at a time, to help utilities meet peak power demands. The first commercially available unit rapidly stores and delivers much less electricity over much briefer periods-megawatts for seconds only. It excels in its handling of power glitches, an increasingly expensive problem in industrial applications of digital control equipment, and for other electronic equipment. The advantages of SMES for these applications are examined, and some field test results are discussed. >

http://ieeexplore.ieee.org/iel3/6/5598/00214584.pdf

J.D. Lamoree

Papers

Storing power for critical loads