Solar Pumping System Research Articles

A financial evaluation of renewable energy technologies for water pumping in rural areas

SYNOPSIS A financial analysis and comparison of various renewable energy resource-technology combinations for water pumping in rural areas has been undertaken. The options include solar photovoltaic pumping systems, biogas and producer gas driven dual-fuel IC engine pumpsets and windmill pumps. The three figures of merit used to facilitate comparison of the renewable options with conventional pumping systems such as diesel engine and electric motor pumpsets are the cost per unit volume of water pumped, cost incurred per unit useful hydraulic energy and the present value of life cycle costs over a given period of time. Sensitivity of one of these figures of merit to the uncertainties in the values of some of the input parameters has also been studied.

Design and development of a water piston solar powered steam pump

Most solar pumping systems are based on photovoltaic receivers driving electric pumps. An alternative system is to use a boiling water solar receiver to operate a direct acting steam pump. The advantages lie in the relative simplicity of the pump giving ease of manufacture, maintenance, reliability and low cost. At De Montfort University a simple direct acting steam pump has been developed over many years, so it has been a natural development to link this with a boiling water solar receiver. This paper is primarily concerned with the operation of the pump and overall system employed.

Experimental results of a solar assisted heat pump rice drying system

In the last rice harvest season, experimental results have been obtained on the efficiency and drying quality of a solar assisted heat pump drying prototype system. The system has been operated as a solar and heat pump system and drying curves for the different options have been obtained. The advantage of the low temperature and better control in the drier shows that the heat pump assisted solar drying system is an excellent alternative to traditional drying systems.

Increasing the cost-effectiveness of small solar photovoltaic pumping systems

Small photovoltaic pumping systems are needed in many parts of the world but are at present too expensive for most users. The cost can be reduced by using optical concentrators to reduce the cost of solar electricity, and by developing more efficient pump/motor/controller systems. The cost reduction for a 300–500 Wp system should be by a factor of between 2 and 3, for the same daily output of water.

Performance of submersible PV solar pumping systems under conditions in the Sudan

Water pumping for domestic use and irrigation purposes can be considered as one of the basic needs in the rural areas of Sudan. For the favourable solar radiation conditions in the country (6 kW h/m 2/day), solar water pumping may be a competitive application against diesel-driven pumps for remote areas. Three SP4–8 Grundfos submersible pumps, installed at three different locations in the country, were evaluated. Two of these pumps were driven by M-51 Arco Solar modules, while the third was driven by M-53 Arco Solar modules. For each of these pumps, solar radiation in the plane of the PV array, ambient temperature, PV array voltage and current, water discharge and water delivery pressure were monitored using a data logger. Grundfos solar pumps used in the Sudan have proven in most cases to be reliable. However, their performance was 10–25% less than predicted by the manufacturer's literature. In general the product of the daily water demand (m 3 per day) and the total pumping head (m) should not exceed 750 m 4 for sites with good solar radiation.

Increasing the cost-effectiveness of small solar photovoltaic pumping systems

Small photovoltaic pumping systems are needed in many parts of the world but are at present too expensive for most users. The cost can be reduced by using optical concentrators to reduce the cost of solar electricity, and by developing more efficient pump-motor-controller systems. The cost reduction for a 300–500 W system should be by a factor between 2 and 3,for the same daily output of water.

Dynamic simulation of a solar pumping system

Dynamic simulation packages are powerful tools for the investigation of highly non-linear systems. In this paper the simulation program PSI is used to investigate the characteristics of a solar pumping system consisting of PV array, dc motor and pump. Analysis and results for the method are included the paper.

Performance of a solar assisted heat pump system

In this study, a series solar heat pump system which uses solar energy storage as a heat source was simulated. The simulation was performed for a house in Istanbul, Turkey for space heating. The fraction of the space heating load that was supplied by the solar assisted system was determined as a function of collector area and thermal storage volume. The heat pump, solar panels, storage tank and thermal response of the house were dynamically analyzed, and a computer model was obtained for each one. The whole system was simulated by varying panel area and tank size. Also, a detailed parametric study was performed for only the heat pump by changing the inlet water temperatures of the heat exchangers. The computer program includes design and off-design parts. First, four major components in the vapor compression cycle were sized. Once the system has been defined, the program is able to compute the performance of the system at all possible combinations of inlet flow stream conditions.

A-17 自然エネルギー(太陽・空気熱)利用蓄熱式ヒートポンプに関する研究(その1) : システム概要と予備実験結果

A-17 自然エネルギー(太陽・空気熱)利用蓄熱式ヒートポンプに関する研究(その1) : システム概要と予備実験結果

Small-scale solar pumping: The technology

The present work is concerned with the direct use of solar energy in water pumping. The available technologies of photovoltaic, thermal and other solar pumping systems are examined. It appears that the most suitable system for solar pumping is the one that satisfies several requirements such as: no movable mechanical parts, reasonable thermal efficiency, minimum manufacturing cost and compact in size.

Estimation of the performance of a solar heat pump system.

The renewable energy laboratory of Kitami Institute of Technology is a facility for the research of space heating, cooling and hot water supply using solar energy and underground water heat by means of a solar system and a heat pump system. Measurements for two types of combination of series-and parallel-solar heat pump systems has been carried out during the last five years. In this study, based on the measured data of the solar heat pump systems, a simulation program is produced to estimate the thermal performance of the systems, and the results calcuated by a personal computer are compared with the experimental results. The correlation between two dimensionless factors of XH(=COPHPQEMAX/QTL) and YH(=FW/FWMAX) can be obtained in order to calculate easily the performance of a stand along heat pump system.

Regional Water Supply Planning with Renewable Energy Technologies: The Case of Senegal

ABSTRACT In order to plan for the installation of renewable energy technologies in the water supply sector in developing countries, an evaluation of the countries' renewable energy resources must first be made. It is then necessary to match the energy resources with the operating characteristics of the appropriate technologies. When these two stages have been completed, planning can proceed for a national program of renewable energy technology development. The example of Senegal is presented in terms of wind, solar and rainfall resources. Technologies considered are wind energy conversion systems (WECS), rainwater catchment systems (RWCS), hand pumps and solar pumping systems

A Comparison of Three Years of Performance for Air-to-Air Parallel Solar Heat Pump System in TECH House IV

A parallel solar augmented heat pump system has been experimentally evaluated in TECH House IV for three heating seasons between fall 1979 and spring 1982. Several changes were made in the operation of the system during the three year period. During 1979–1980, the use of on-peak purchased energy was minimized by charging the pebble bin in the off-peak period with a resistance duct heater. This configuration resulted in 83 percent of the purchased energy occurring in the off-peak period but the seasonal performance factor was only 1.61. During 1980–1981, the system was operated in the normal mode without the use of the off-peak heater. The seasonal performance factor then increased to 2.56. During 1981–1982, the mode of operation was the same as 1980–1981, but new outer cover sheets were installed and the inner cover sheet was eliminated resulting in a single glazed collector. The seasonal performance factor for the 1981–1982 season was measured to be 2.11.

Solar and heat pump system—Horsens swimming bath, Denmark

SYNOPSIS Over a number of years the local authorities of Horsens granted money to effect energy saving measures, the most cost-effective projects to be carried out first. Recently a combined solar system and heat pump system has been constructed together with a centralized control and supervision system. The solar system consists of 300 m2 flat plate solar collectors without cover glass and insulation. The heat pump system consists of two water-to-water heat pumps with a total effect of 70 kW. The total investment in the combined solar and heat pump system has been £93 000 (Dkr1.3m) including grants from the EEC and from the Danish Energy Administration. The plant has now been in operation for more than 1 year and based on the measuring equipment installed it may be stated that the energy plant has given a saving of 2.8 TJ (670 Gcal) from district heating in the first year which allowing for a use of electricity of 187 MWh, amounts to a total of £14 000 (Dkr 195 000). Based on a total investment of Dkr l....

The Use of Serpentine Earth Coils in Ground Coupled Heat Pump Systems

A research program at Brookhaven National Laboratory (BNL) has studied ground coupling, i.e., the use of the earth as a heat source/sink or storage medium for solar-assisted and stand-alone heat pump systems. As part of this research program, five serpentine earth coil experiments were operated between December 1978 and September 1981. Heat was added to or removed from the earth coils according to weekly schedules based on computer simulations of solar-assisted and stand-alone, ground-coupled heat pump systems operated in the local (New York) climate. Each earth coil was operated according to a different control strategy. This paper presents experimental results from these experiments for the period December 1978 to April 1981, and compares these results to those generated by a comptuer model, GROCS, developed at BNL. The model is found to provide a reasonably good fit to the data, for the most part, using the experimental undisturbed soil thermal properties. In some cases, the use of a lower soil thermal conductivity provides a better fit, particularly during summer months when heat was added to the ground. Thus, given soil properties, GROCS can be used to predict earth coil performance. If given earth coil performance, the model can predict soil thermal properties. Serpentine earth coils are found to be suitable to provide auxiliary heat or heat rejection for solar heat pump systems. In fact, earth coil-based, stand-alone, ground-coupled heat pump systems can provide all heat needed for winter space heating and all heat rejection required for summer space cooling with no need for any auxiliary heating. Subfreezing winter operation is necessary for shallow earth coils in cold climates. No deleterious effects to the ground were observed from the long-term operation of these experiments.

Small-scale solar pumping systems—present status and future prospects

SYNOPSIS Consultants Sir William Halcrow & Partners in association with Intermediate Technology Power Ltd have recently completed the latest stage of a United Nations Development Programme/World Bank project to demonstrate and evaluate small-scale solar-powered pumping systems suitable for use in developing countries. This paper presents some of the results of the project. Based on an assessment of selected examples of photovoltaic systems, a review is made of current system design and the components which are available. The potential for improvements in component performance and costs is considered together with the subsequent effect on system design and cost-effectiveness. Finally the results of a comparative study of the economics of solar pumping systems with diesel and other alternative pumping systems are presented. The main conclusions to emerge are that solar pumping technology has advanced considerably in the last few years and that there are photovoltaic systems available today which, if produced at a cost associated with quantity production, could be competitive with diesel pumps in many situations. With the projected fall in photovoltaic costs a large market is foreseen for these systems. This market could develop within 5 years provided the requisite level of investment and support by private industry, governments and funding agencies is made available.

The Thermal Performance of Refrigerant Cooled Solar Collectors in a Solar Source Heat Pump System

Solar Collectors cooled directly with Refrigerant 12 and acting as the evaporator of a solar source heat pump system has been experimentally investigated. The refrigerant cooled solar collector may be operated at an evaporation temperature lower than its ambient temperature and thus has an efficiency higher than that of the flat plate solar collectors in conventional systems.

A TRNSYS/GROCS Simulation of the TECH House I Ground-Coupled Series Solar-Assisted Heat Pump System

The series solar-assisted heat pump heating system with ground-coupled storage in The University of Tennessee’s TECH House I in Knoxville, Tennessee, has been modeled using TRNSYS/GROCS and was compared to the experimental performance for the 1980–81 heating season. The simulation results were within 8 percent of the experimental measurements. Both simulation and experimental results showed that ground coupling of thermal storage led to the elimination of electric resistance backup heat and a large reduction in the peak heating demand of the house. Results of a parametric study showed that, in general, a ground-coupled storage tank performs better than a storage tank placed outdoors in the Knoxville area. Application of a next generation heat pump resulted in the most significant impact on the seasonal performance factor. As expected, higher performance collectors and larger collector areas led to higher system seasonal performance. An economic analysis showed that the series solar heat pump system cannot economically compete with the stand-alone heat pump system in the Knoxville area.

A solar source heat pump with refrigerant-cooled solar collectors for cold climates

A heating system best suited to the local requirements and resources of Quebec, Canada, was developed. Solar source heat pump systems with solar collectors cooled directly with R 12 appear to be a promising means of utilizing solar energy in cold climates. The solar collectors may be operated at evaporation temperatures lower than their ambient temperature, and performance improved by cooling it with an evaporative refrigerant, rather than a single phase fluid.

Simulation studies of the expected performance of Kerava solar village

The Kerava solar village is the first regional building complex in Finland with a combined solar heating and heat pump system using seasonal heat storage. The village will be completed at the beginning of 1983. In this study we describe the heating system of Kerava solar village. The heat demand was estimated by computer simulations. Different weather conditions and operational situations were considered. Under normal weather and operating conditions approximately 60 percent of the total heat demand of the Kerava solar village is estimated to be obtained from solar energy.