Showing papers on "Solar power published in 2000"

Comparative study of maximum power point tracking algorithms using an experimental, programmable, maximum power point tracking test bed

Abstract: Maximum power point tracking (MPPT) is important in solar power systems because it reduces the solar array cost by decreasing the number of solar panels needed to obtain the desired output power. Several different MPPT methods have been proposed, but there has been no comprehensive experimental comparison between all the different algorithms and their overall maximum power point (MPP) tracking efficiencies under varying conditions (i.e. Illumination, temperature, and load). This paper such a comparison. Results are using a microprocessor controlled MPPT powered by a 250 W photovoltaic (PV) array and also a PV array simulator.

Solar cell module, building material with solar cell module, solar cell module framing structure, and solar power generation apparatus

Abstract: A solar cell module includes an electrical parameter detection unit including an operating current detector unit for a solar cell element and a communication unit for communicating an output from the operating current detection unit, thereby providing a solar cell module capable of easily specifying a malfunctioning solar cell module.

Interconnection power converter and power generation apparatus using the same

Abstract: In a solar power generation apparatus using a solar battery having a relatively large ground capacitor and a power conditioner having a non-insulated input and output, a customer's ground fault interrupter may perform unwanted interruption due to a ground fault outside the customer's premises. To prevent this, when a ground fault is detected by a detector capable of detecting a ground fault within a shorter time than the customer's ground fault interrupter, the gate of inverter of the power conditioner is blocked, a switch is changed to an open state, and the input voltage of inverter is held at a voltage value higher than the peak value of the alternate current voltage of a power system until at least the switch changes to the open state.

Solar power generation circuit including bypass diodes connected in parallel to groups of series connected solar cells

Abstract: The invention relates to a circuit arrangement for power generation with solar cells ( 10 to 32 ). The solar cells are connected in series and in strings ( 34 to 44 ) each of several cells. A bypass diode ( 50 to 60 ) is connected in parallel to each string ( 34 to 44 ). Further diodes ( 64 to 70 ) are connected in parallel to two and/or more bypass diodes of series-connected strings. With this arrangement, the number of current-carrying diodes is considerably reduced when any strings are in shade.

Solar power generation and energy storage system

Abstract: A solar energy collection system harvests solar energy from large open areas. A length of flexible solar collector (30) is unrolled along a supporting surface (6). An uninsulated base (5) directly contacts the ground or other supporting structure. A plurality of parallel conduits (4), sealed along the length of the flexible base panel, have a high light absorption and a low infrared emission and contain a flowing liquid to be heated by solar energy. A length of a covering material (1) is placed parallel to the base and between the parallel conduits and the sun and sealed to the base panel for containing a low pressure fluid to reduce heat loss from the flowing liquid and to inflate the structure formed by the ground cover and covering material. Heated fluid from the parallel conduits is collected in a header (32) for delivery to a power generating system (35).

The Abacus/Reflector and Integrated Symmetrical Concentrator: Concepts for Space Solar Power Collection and Transmission

Abstract: New energy sources are vital for the development of emerging nations, and the growth of industry in developed economies. Also vital is the need for these energy sources to be clean and renewable. For the past several years, NASA has been taking a new look at collecting solar energy in space and transmitting it to Earth, to planetary surfaces, and to orbiting spacecraft. Several innovative concepts are being studied for the space segment component of solar power beaming. One is the Abacus/Reflector, a large sun-oriented array structure fixed to the transmitter, and a rotating RF reflector that tracks a receiving rectenna on Earth. This concept eliminates the need for power-conducting slip rings in rotating joints between the solar collectors and the transmitter. Another concept is the Integrated Symmetrical Concentrator (ISC), composed of two very large segmented reflectors which rotate to collect and reflect the incident sunlight onto two centrally-located photovoltaic arrays. Adjacent to the PV arrays is the RF transmitter, which as a unit track the receiving rectenna, again eliminating power-conducting joints, and in addition reducing the cable lengths between the arrays and transmitter. The metering structure to maintain the position of the reflectors is a long mast, oriented perpendicular to the equatorial orbit plane. This paper presents a status of ongoing systems studies and configurations for the Abacus/Reflector and the ISC concepts, and a top-level study of packaging for launch and assembly.

Solar power generator system with power storage

Abstract: PROBLEM TO BE SOLVED: To provide a solar power generator system which can reverse the flow of the excessive generated power flow to the grid while normally avoiding power flowing out to the grid. SOLUTION: In a solar power generator/storage system provided with a bilateral converter to control the battery, the bilateral converter is controlled so that the usable power is not less than required when making the excessive power flow reverse to the grid. COPYRIGHT: (C)2002,JPO

Integrated solar power systems

Abstract: We are developing lightweight devices that are capable of solar energy conversion and storage. These integrated power supplies (IPS) incorporate photovoltaic power generation with thin-film lithium ion energy storage. Lithium ion devices with large energy densities and long cycling lifetimes are ideal for this application. The techniques used to fabricate the solar cell and battery component films are compatible and scalable. These devices can be designed to fulfill a wide variety of electrical power requirements and are ideal for use with multi-chip modules (MCM) and micro-electromechanical systems (MEMS) for nanosatellites. They provide both the operating power when illuminated and the “stay alive” power during eclipse. We will discuss the design and characterization of the materials used in these devices. The characterization of the devices under simulated lowearth orbit and AM0 illumination will also be presented.

Integrated solar power module

Abstract: Multiple layers of a clear insulating material, such as clear polyimide, with horizontal metalization layers therebetween and with vertical feed through metal traces therethrough form a flexible three dimension circuit printed circuit board upon which semiconductor devices, such as thin film solar cell can be directly deposited for forming a flexible electronic module, and upon which electronic discrete component can be bonded and electrically connected. In one exemplar configuration, a flexible thin film solar cell power module has thin film solar cells deposited on one side and power converters bonded on the other for a solar array power system. The flexible printed circuit board is well suited for forming electronic systems about a curved surface such as a power sphere nanosatellite.

Autonomous self-propelled desalination plant assisted by renewable energy

Abstract: Autonomous self-propelled desalination plant assisted by renewable energy.Autonomous self-propelled desalination plant assisted by renewable energy on a marine artefact that consists of a floating platform on which is installed a plant for making drinking water by evaporation (11) and/or inverse osmosis (10), temporary storage tanks for desalinated water (12), systems of supply of water to land (5), one or more wind-driven generators (21) for production of electrical energy necessary for plant, a thermal and/or photovoltaic solar power station (22), for the preheating of water on entry to the process and a diesel-electric propulsion plant (17) to complete the energy supply of the desalination plant and for the propulsion of the marine artefact. The plant will be capable of producing drinking water or water for irrigation and will be equipped with a system of physical/chemical analysis both for the water on entry and for the water produced in order to guarantee its quality.

Solar-based navigation for robotic explorers

Abstract: This thesis introduces the application of solar position and shadowing information to robotic exploration. Power is a critical resource for robots with remote, long-term missions, so this research focuses on the power generation capabilities of robotic explorers during navigational tasks, in addition to power consumption. Solar power is primarily considered, with the possibility of wind power also contemplated. Information about the environment, including the solar ephemeris, terrain features, time of day, and surface location, is incorporated into a planning structure, allowing robots to accurately predict shadowing and thus potential costs and gains during navigational tasks. By evaluating its potential to generate and expend power, a robot can extend its lifetime and accomplishments. The primary tasks studied are coverage patterns, with a variety of plans developed for this research. The use of sun, terrain and temporal information also enables new capabilities of identifying and following sun-synchronous and sun-seeking paths. Digital elevation maps are combined with an ephemeris algorithm to calculate the altitude and azimuth of the sun from surface locations, and to identify and map shadows. Solar navigation path simulators use this information to perform searches through two-dimensional space, while considering temporal changes. Step by step simulations of coverage patterns also incorporate time in addition to location. Evaluations of solar and wind power generation, power consumption, area coverage, area overlap, and time are generated for sets of coverage patterns, with on-board environmental information linked to the simulations. This research is implemented on the Nomad robot for the Robotic Antarctic Meteorite Search. Simulators have been developed for coverage pattern tests, as well as for sun-synchronous and sun-seeking path searches. Results of field work and simulations are reported and analyzed, with demonstrated improvements in efficiency, productivity and lifetime of robotic explorers, along with new solar navigation abilities.

Application of Energy Storage to Solar Electric Propulsion Orbital Transfer

Abstract: Solar electric propulsion uses solar panels to generate power for electric thrusters. Using stored energy makes it possible to thrust through eclipses, but requires that some of the solar power collected during the sunlit portion of the trajectory be used to recharge the storage system. Previous researchers have reported that the required energy storage mass can be prohibitive. However, the use of high-speed e ywheels for energy storage can provide advantages. We compare the effectiveness of orbit transfers with using and without using energy storage. The orbit transfers are developed as sequences of time-optimal circle-to-circle planar transfers from low-Earth orbit to geostationary orbit. We develop techniques for solving the appropriate boundary-value problems and illustrate tradeoffs between solar array and e ywheel-battery masses for transfers requiring multiple revolutions. Theutility of e ywheel energy storage specie cally for the use of the solar electric propulsion system is examined. We e nd that when e ywheel energy storage is used in these scenarios transit times are typically increased, but signie cant propellant mass savings can be realized. Furthermore, if thespacecraft has a requirement for energy storage, then it is advantageous to use stored energy during the orbit transfer.

Renewables for sustainable village power supply

Abstract: In Mexico there are more than 80000 villages without electricity whatsoever. People living in these communities could reach 6 million inhabitants. The smallness and remoteness of these communities makes them eligible for decentralised remote power technologies such as photovoltaics (PV), thermosolar, wind, micro hydro and biomass. These technological applications may demonstrate the technical performance, economic competitiveness, operational viability and environmental benefits of a better solution for electrification of rural areas compared to conventional options such as grid extension or isolated diesel gensets mini grids. The paper discusses solar power, geothermal power, bioenergy, wind energy and micro hydro power in Mexico for rural communities.

Optical Durability Testing of Candidate Solar Mirrors

Abstract: Durability testing of a variety of candidate solar reflector materials at outdoor test sites and in laboratory accelerated weathering chambers is the main activity within the Advanced Materials task of the Concentrated Solar Power (CSP) Program. Outdoor exposure testing (OET) at up to eight outdoor, worldwide exposure sites has been underway for several years. This includes collaboration under the auspices of the International Energy Agency (IEA) Solar Power and Chemical Energy Systems (SolarPACES) agreement. Outdoor sites are fully instrumented in terms of monitoring meteorological conditions and solar irradiance. Candidate materials are optically characterized prior to being subjected to exposure in real and simulated weathering environments. Optical durability is quantified by periodically re-measuring hemispherical and specular reflectance as a function of exposure time. By closely monitoring the site- and time-dependent environmental stress conditions experienced by the material samples, site-dependent loss of performance may be quantified. In addition, accelerated exposure testing (AET) of these materials in parallel under laboratory-controlled conditions may permit correlating the outdoor results with AET, and subsequently predicting service lifetimes. Test results to date for a large number of candidate solar reflector materials are presented in this report. Acronyms are defined. Based upon OET and AET results to date, conclusions can be drawn about the optical durability of the candidate reflector materials. The optical durability of thin glass, thick glass, and two metallized polymers can be characterized as excellent. The all-polymeric construction, several of the aluminized reflectors, and a metallized polymer can be characterized as having intermediate durability and require further improvement, testing and evaluation, or both.

Aerodynamic and structural design of a solar powered micro unmanned air vehicle

Abstract: The field of micro unmanned aerial vehicles ((μUAVs) has advanced rapidly in recent years. This paper studies the design and construction of a small solar-powered aircraft near the size range of current (μUAVs. A number of aspects of their design were analysed, including structural, aerodynamic and propulsion system considerations. The effect of small-scale, low Reynolds number aerodynamics was investigated, and the performance of a range of candidate aerofoils was compared. The integration of a solar power source into the aircraft system was considered a key design issue. Consequently, a number of aircraft configurations were examined, with the intention of optimizing the application of solar power in a miniature aircraft. Investigation of improved system components suggests that a practical solar-powered aircraft in the size range below 500 mm maximum linear dimension should be viable given modest technological improvements.

System linking apparatus and method for linking

Abstract: PROBLEM TO BE SOLVED: To allow utilizing an inverter for a single-phase two-wire 200 V output widely used in a market to link a photovoltaic power generating system to a single-phase 100 V system in a solar power generation system. SOLUTION: The inverter 8 is not isolated between an input and an output, and converts power from a solar cell 1 into AC power of a single-phase three- wire 200 V. A transformer 10 connects lines from the single-phase three-wire 200 V with a single-phase two-wire 100 V system 4 in which one wire is grounded. A neutral point potential wire of the single-phase three-wire 200 V is connected with the grounded wire of the system 4 so that a line-to-ground fault detecting sensor 89 built in the inverter 8, can operate. COPYRIGHT: (C)2002,JPO

Street lamp by solar power source

Abstract: PROBLEM TO BE SOLVED: To provide a street lamp which has a small power consumption, a semipermanent life, and an economical value wherein the maintenance is unnecessary and which can be utilized as an emergency light and a guide light at the time of disaster or the like. SOLUTION: This comprises a solar battery 3 fixed at an upper part 1a of a causing main body 1 and comprises a storage battery 8 to store the electric power generated by the solar battery 3, plural light emitting diodes 5 to turn on by the electric power form the storage battery 8, and a control unit 9 to control the lighting as well as lights-out, lighting hour and external input or the like, installed at the inside of the casing main body 1. COPYRIGHT: (C)2002,JPO

Power converter and its control method, and power generating system

Abstract: PROBLEM TO BE SOLVED: To preclude a problem in a solar power generating system having an inverter that, if the filter capacitor of the inverter is deteriorated, loss of its generated energy is unavoidable because the inverter operation is interrupted. SOLUTION: If a deterioration judging part 211 judges that the capacitor 24 is deteriorated, the operation of the inverter 2 is continued while suppressing the output current of the inverter 2 by an output suppressing part 212. The deterioration of the capacitor is alarmed by an alarm part 213. COPYRIGHT: (C)2002,JPO

Electric power plant ship

Abstract: (57) [Summary] [PROBLEMS] To provide a power plant ship that generates power using sunlight, wind and the like. A power plant ship 1 according to the present invention includes a hull 2 having a propulsion mechanism 7, a solar power generation system 3 for obtaining electric energy by photoelectrically converting sunlight, and a windmill 4a rotating by receiving wind. A wind power generation system 4 for operating a generator to obtain electrical energy, And a storage battery 6 for storing the electric energy generated by the power generation device 4.

Home power supply system combined with solar power generation and midnight power storage

Abstract: PROBLEM TO BE SOLVED: To equalize a level of power load and prevent reverse power transmission of the power stored in a storage battery to a power company by promotion of use of midnight electrical power and shift of peak power generated in the day time to midnight. SOLUTION: A home power supply system combined with solar power generation and midnight power storage is provided. The storage battery is charged, as a rule, in the midnight period using the midnight power via an inverter which also operates as an automatic charger, and the commercial power supply is used for household consumption. In the solar power generation period in the day time, when the electrical power generated with the solar system is higher than the preset value, an extra power is sold to the power company via the inverter/ automatic charger. In the intermediate time period between the midnight period and solar power generation period in the day time, the power stored in the storage battery is supplied for household consumption, and storage, if it is generated, is compensated by the commercial electrical power of the power company. In the case where the power stored in the storage battery is supplied for household consumption, a reverse transmission preventing circuit consisting of parallel connection of a forward thyristor and a backward thyristor is provided between the storage battery and the commercial power supply and a control circuit for preventing reverse transmission of power to the power company is also provided. As a result, the reverse transmission of the power stored in the storage battery to the power company is forcibly prevented. COPYRIGHT: (C)2002,JPO

Solar battery power source having woven solar light converging device

Abstract: PROBLEM TO BE SOLVED: To improve efficiency by reducing the influence of the defect of the reflective layer of a sunlight converting device to be used for a solar battery power source SOLUTION: This solar battery power source is provided with a solar power converter 24 and a solar light converging device 30 positioned so that incident light can be reflected in the direction of the solar power converter 24 The solar light converging device 30 is provided with a supporting body having woven patterns 60 formed on this and a reflector surface on the supporting body, and the woven patterns 60 are allowed to appear on the free surface of the reflector It is desired that the woven patterns 60 are provided as a pair of parallel straight-shaped recessed parts 62 vertical to a crossing line 31 between the solar light converging device and the solar power converter

Apparatus and method of recharging a handheld computing device using solar power

Abstract: An apparatus and method for recharging a handheld computing device using solar power is provided. A recharger housing includes a first slot for receiving a handheld computing device. A solar panel support member is slidably attached to the recharger housing. A solar panel is connected to the solar panel support member for recharging the handheld computing device when the solar panel support member is in an extended position.

Aerodynamic and structural design of a solar-powered micro unmanned air vehicle:

Abstract: The field of micro unmanned aerial vehicles ((μUAVs) has advanced rapidly in recent years. This paper studies the design and construction of a small solar-powered aircraft near the size range of current (μUAVs. A number of aspects of their design were analysed, including structural, aerodynamic and propulsion system considerations. The effect of small-scale, low Reynolds number aerodynamics was investigated, and the performance of a range of candidate aerofoils was compared. The integration of a solar power source into the aircraft system was considered a key design issue. Consequently, a number of aircraft configurations were examined, with the intention of optimizing the application of solar power in a miniature aircraft. Investigation of improved system components suggests that a practical solar-powered aircraft in the size range below 500 mm maximum linear dimension should be viable given modest technological improvements.