Remote Area Power Supply Research Articles

Maximum power point tracking: A cost saving necessity in solar energy systems

A well engineered renewable remote energy system, utilizing the principal of Maximum Power Point Tracking (MPPT) can improve cost effectiveness, has a higher reliability and can improve the quality of life in remote areas. A high-efficient power electronic converter, for converting the output voltage of a solar panel, or wind generator, to the required DC battery bus voltage has been realized. The converter is controlled to track the maximum power point of the input source under varying input and output parameters. Maximum power point tracking for relative small systems is achieved by maximization of the output current in a battery charging regulator, using an optimized hill-climbing, inexpensive microprocessor based algorithm. Through practical field measurements it is shown that a minimum input source saving of between 15 to 25% on 3–5 kWh/day systems are easily be achieved. A total cost saving of at least 10–15% on the capital cost of these systems are achieveable for relative small rating Remote Area Power Supply (RAPS) systems. The advantages at large temperature variations and high power rated systems are much higher. Other advantages include optimal sizing and system monitor and control.

Affordable remote-area power supply in the Philippines

The feasibility of photovoltaic (PV) systems for electrifying remote areas of the Philippines is discussed. In particular, a technical description is given of those PV systems that are appropriate to the needs of remote, but populated, rural areas and have been developed as part of the Philippine-German Solar Energy Project. Details are provided of a financing scheme, piloted by the Project on an unelectrified island, to make PV systems affordable to rural users. An analysis is presented of the potential of large-scale applications of PV systems in developing countries such as the Philippines, and a description is provided of current efforts to promote the use of such technology. A storage battery is identified as an essential component of a PV system. As a consequence, the wide use of PV systems will have a very significant impact on the market for storage batteries in countries embarking on PV-utilization programmes. It is clear, therefore, that battery manufacturers should take an interest in future development in PV applications.

Performance of lead/acid batteries in remote-area power-supply applications

A detailed evaluation is made of the performance of a wide range of lead/acid battery technologies operating under both simulated and field conditions encountered in remote-area power-supply (RAPS) duty. Laboratory studies indicate that the most promising designs of battery are: (i) flat-plate, flooded-electrolyte, with thick plates and low-antimony positive grids; (ii) tubular-plate, flooded-electrolyte, with granular oxide: (iii) flat-/tubular-plate, gelled-electrolyte. For the first two technologies, this prediction has been realized by the placement and successful operation of batteries in RAPS field sites. Battery failure is associated mainly with degradation of the positive plate, namely, breakdown/shedding of active material, together with the development of inter-plate short circuits; corrosion/growth of grids; irreversible sulphation (including penetration of separators). Information acquired from the research programme is being used to design advanced RAPS batteries. The latter are currently under assessment, both in the laboratory and in RAPS installations.

Experiences with lead/acid battery management in remote-area power-supply (RAPS) systems

Battery management and general storage performance and cost remain major problems in remote-area power-supply (RAPS) systems utilizing renewable energy sources. A brief review of field experiences with lead/acid batteries is presented, together with results from battery tests carried out in the laboratory. It is recommended that further collaboration between battery manufacturers and system designers is established to develop improved storage systems for RAPS applications.

Monitoring battery performance in remote-area power-supply (RAPS) systems

A research and development project has been undertaken to explore the feasibility of a battery monitoring system with specific application to remote-area power-supply (RAPS) systems. The pilot sites have returned data that strongly support monitoring of individual cells at RAPS installations. The results of the pilot site testing are reported and further research is suggested.

Load management in remote-area power-supply (RAPS) systems

Design criteria for hybrid RAPS systems are generally written in terms of the sizing of the various components of the system to provide both the instantaneous maximum power demand and the daily energy requirements of the installation. Most effective use of each component part of the system must be achieved in order to optimize the utilization of the plant and achieve maximum economy. Implementation of such load management schemes demands the installation of some intelligent interface between the source and the load. This is usually some form of microprocessor controller that can be programmed to disable different types of load under different circumstances of supply/demand to limit the maximum demand on the system. The requirements of these controllers and the improvements to be expected from their installation are discussed.

Coulombic efficiency of lead/acid batteries, particularly in remote-area power-supply (RAPS) systems

This paper investigates the effect of charging regimes and battery designs — and the combined effects of the two parameters — on the overall coulombic efficiency of lead/acid batteries operating in RAPS systems. Under such service, it is highly desirable to achieve a good match between the energy source and the battery characteristics in order to achieve optimum coulombic efficiency at a given state-of-charge of the battery.

Design considerations for appropriate wind energy systems in developing countries

This paper discusses design considerations of small scale wind energy systems and presents results from some Australian remote area power supply systems. Small scale wind energy systems have the potential for considerable improvement in the standard of living of individuals in rural areas in the developing countries. A commercially viable design should consider factors such as: proper siting, assessing the present and future energy needs of people living in the rural areas and using appropriate technology to fulfil these needs. Australia can contribute advanced and proven technology in this area based on the experience from several remote area power supply programmes undertaken by Federal and State Governments.

Solar cell research and development in Australia

Abstract Australia's demography and geography conspire to make it a relatively large user of solar cells on a purely commercial basis. Telecommunications has dominated these commercial applications. Due to the expectation of low grid electricity costs into the foreseeable future, the focus of research and developmental efforts has been remote area applications. The main areas of activity have been silicon solar cell research, cell and module testing, and the development of remote area power supplies for applications in the “outback”.

Development of lead/acid batteries for domestic remote-area power supplies

In recent times, there has been a growing recognition of the need for more reliable RAPS systems, both in Australia and in other parts of the world. From the battery point of view, development has, in some instances, been encouraged by a “market push”, and in others by a “technology pull”. Some manufacturers are seeking to supply customers with batteries that are merely re-labelled motive-power types, others are offering new technologies. In either case, the suitability of the products is unclear because of the poor comprehension of the actual service requirements imposed on batteries in RAPS operations. In order to overcome this deficiency, CSIRO has set in motion a detailed schedule of laboratory and field studies aimed at gaining a greater understanding of battery performance under RAPS duties. It is hoped that the resulting information will lead to specific design criteria for such batteries.