John D. Boyes

Technologies for energy storage. Flywheels and super conducting magnetic energy storage

The author examines both flywheel and superconducting magnetic energy storage technologies. A flywheel is an electromechanical storage system in which energy is stored in the kinetic energy of a rotating mass. Flywheel systems under development include those with steel flywheel rotors and resin/glass or resin/carbon-fiber composite rotors. The mechanics of energy storage in a flywheel system are common to both steel- and composite-rotor flywheels. Superconducting magnetic energy storage (SMES) is an energy storage device that stores electrical energy in a magnet field without conversion to chemical or mechanical forms. In SMES, a coil of superconducting wire allows a direct electrical current to flow through it with virtually no loss. This current creates the magnetic field that stores the energy. On discharge, switches tap the circulating current and release it to serve a load.

Technology development needs for integrated grid-connected PV systems and electric energy storage

Researchers at Sandia National Laboratories and the U.S. Department of Energys Solar Energy Technologies Program assessed status and needs related to optimizing the integration of electrical energy storage and grid-connected photovoltaic (PV) systems. At high levels of PV penetration on our electric grid, reliable and economical distributed energy storage will eliminate the need for backup utility generation capacity to offset the intermittent nature of PV generation. This paper summarizes the status of various storage technologies in the context of PV system integration, addressing applications, benefits, costs, and technology limitations. It then discusses further research and development needs, with an emphasis on new models, systems analysis tools, and even business models for high penetration of PV-storage systems on a national scale.

Conceptual design of the National Ignition Facility

The Secretary of the U.S. Department of Energy (DOE) commissioned a conceptual design report (CDR) for the National Ignition Facility (NIF) in January 1993 as part of a key decision zero (KD0), justification of mission need. Motivated by the progress to date by the inertial confinement fusion (ICF) program in meeting the Nova technical contract goals established by the National Academy of Sciences in 1989, the Secretary requested a design using a solid-state laser driver operating at the third harmonic (0.35 micrometer) of neodymium (Nd) glass. The participating ICF laboratories signed a memorandum of agreement in August 1993, and established a project organization, including a technical team from the Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Sandia National Laboratories (SNL), and the Laboratory for Laser Energetics at the University of Rochester. Since then, we completed the NIF conceptual design, based on standard construction at a generic DOE defense programs site, and issued a 7,000-page, 27-volume CDR in May 1994. Over the course of the conceptual design study, several other key documents were generated, including a facilities requirements document, a conceptual design scope and plan, a target physics design document, a laser design cost basis document, a functional requirements document, an experimental plan for indirect drive ignition, and a preliminary hazards analysis (PHA) document. DOE used the PHA to categorize the NIF as a low-hazard, non-nuclear facility. On October 21, 1994 the Secretary of Energy issued a key decision one (KD1) for the NIF, which approved the project and authorized DOE to request Office of Management and Budget-approval for congressional line-item FY 1996 NIF funding for preliminary engineering design and for National Environmental Policy Act activities. In addition, the Secretary declared Livermore as the preferred site for constructing the NIF. In February 1995, the NIF Project was formally submitted to Congress as part of the Presidents FY 1996 budget. If funded as planned, the Project will cost approximately

Status of the National Ignition Facility Project

1.1 billion and will be completed at the end of FY 2002.

Overview of energy storage applications

The ultimate goal of worldwide research in inertial confinement fusion (ICF) is to develop fusion as an inexhaustible, economic, environmentally safe source of electric power. Following nearly 30 years of laboratory and underground fusion experiments, the next step toward this goal is to demonstrate ignition and propagating burn of fusion fuel in the laboratory. The National Ignition Facility (NIF) Project is being constructed at the Lawrence Livermore National Laboratory (LLNL) for just this purpose. NIF will use advanced Nd-glass laser technology to deliver 1.8 MJ of 0.35-μm laser light in a shaped pulse, several nanoseconds in duration, achieving a peak power of 500 TW. A national community of US laboratories is participating in this project, now in its final design phase. France and the UK are collaborating on development of required technology under bilateral agreements with the US. This paper presents the status of the laser design and development of its principal components and optical elements.

Proposed inductive voltage adder based accelerator concepts for the second axis of DARHT

Sandia National Laboratories has been studying energy storage systems since the late 1970s. Sandias role, as a Department of Energy funded program, is to look ahead at emerging technologies, perform early R&D and identify applications for energy storage systems that offer significant benefit to the nations electricity providers and users. In order to identify applications of energy storage, a two-phase Opportunities Analysis was conceptualized in FY94. The group of industry experts participating in the study reviewed the requirements for each of the applications identified in Phase I, modified application names, and combined some applications to better reflect the nature of the electricity industry today. Participants of the Phase II analysis used the perceived need for the application across the nation, and the potential technical and economic benefits for utilities as criteria to evaluate the applications.

The COBRA accelerator pulsed-power driver for Cornell/Sandia ICF research

As participants in the Technology Options Study for the second axis of the Dual Axis Radiographic HydroTest (DARHT) facility located at Los Alamos National Laboratories, we have considered several accelerator concepts based on the inductive voltage adder (IVA) technology. The accelerator design requirements for the IVA approach include: /spl ges/12-MeV beam energy; /spl sim/60-ns electrical pulse width; /spl les/40-kA electron beam current; /spl sim/1-mm diameter e-beam; four pulses on the same axis or as close as possible to that axis; and an architecture that fits within the existing building envelope. To satisfy these requirements our IVA concepts take a modular approach. The basic idea is built upon a conservative design for eight ferromagnetically isolated 2-MV cavities that are driven by two 3 to 4-/spl Omega/ water dielectric pulse forming lines (PFLs) synchronized with laser triggered gas switches. The 100-/spl Omega/ vacuum magnetically insulated transmission line (MITL) would taper to a needle cathode that produces the electron beam(s). We narrowed our study to the following options: (A) four independent single pulse drivers powering four single pulse diodes; (B) four series adders with interleaved cavities feeding a common MITL and diode; (C) four stages of series PFLs, isolated from each other by triggered spark gap switches, with single-point feeds to a common adder, MITL, and diode; and (D) isolated PFLs with multiple-feeds to a common adder using spark gap switches in combination with saturable magnetic cores to isolate the nonenergized lines. We discuss these options in greater detail identifying the challenges and risks associated with each.

Target Area Design Basis and System Performance for the National Ignition Facility

This paper introduces and describes the new Cornell Beam Research Accelerator, COBRA, the result of a three and one-half year collaboration. The flexible 4 to 5-MV, 100 to 250-kA, 46-ns pulse width accelerator is based on a four-cavity inductive voltage adder (IVA) design. In addition to being a mix of new and existing components, COBRA is unique in the sense that each cavity is driven by a single pulse forming line, and the IVA output polarity may be reversed by rotating the cavities 180/spl deg/ about their vertical axis. Our tests with negative high voltage on the inner MITL stalk indicate that the vacuum power flow has established reasonable azimuthal symmetry within about 2 ns (or 0.6 m) after the cavity output gap. Preliminary results with the accelerator, single cavity, and MITL are presented along with the design details and circuit model predictions.

COBRA accelerator for Sandia ICF diode research at Cornell University

The NIF Target Area is designed to confine the ICF target experiments leading up to and including fusion ignition and gain. The Target Area will provide appropriate in-chamber conditions before, during, and after each shot. The repeated introduction of large amounts of laser energy into the chamber and emission of fusion energy from targets represents a new challenge in ICF facility design. Prior to a shot, the facility provides proper illumination geometry, target chamber vacuum, and a stable platform for the target and its diagnostics. During a shot, the impact of the energy introduced into the chamber is minimized, and workers and the public are protected from excessive prompt radiation doses. After the shot, the residual radioactivation is managed to allow required accessibility. Tritium and other radioactive wastes are confined and disposed of. Diagnostic data is also retrieved, and the facility is readied for the next shot. The Target Area will accommodate yields up to 20 MJ, and its design lifetime is 30 years. The Target Area provides the personnel access needed to support the use precision diagnostics. The annual shot mix for design purposes is shown. Designing to this experimental envelope ensures the ability and flexibility to move through the experimental campaign to ignition efficiently.

Fault tolerance of the NIF power conditioning system

The new COBRA accelerator is being built in phases at the Laboratory of Plasma Studies in Cornell University where its applications will include extraction diode and ion beam research in support of the light ion inertial confinement fusion (ICF) program at Sandia National Labs. The flexible 4-to 5-MV, 100-to 250-kA accelerator is based on a four-cavity inductive voltage adder (IVA) design.