Modeling a drip irrigation system powered by a renewable energy source.

摘要

Food production is a problem in many of the regions in the world. Today, the process of producing food is very dependent on energy. The dependency on fossil fuels causes the cost of producing crops to increase as the prices of fuel increases. Using a renewable energy sources to power an irrigation system is a mean of decreasing the dependency of food products on the prices of fuel and minimize the impact of the irrigation system on the environment.; A model was developed to simulate and predict the performance of an irrigation system powered by a renewable energy source. Both solar energy and wind energy were considered for the modeling of the system.; The solar energy was simulated using the difference between the maximum and the minimum daily temperatures as an indicator of the amount of clouds in the atmosphere. The model is a modification of earlier models and has the advantage of not needing to be calibrated for each new site. Results showed that a model that calibrates it self for the upper and the lower expected values of the solar radiation can be developed using metrological data such as the location of the site, the daily temperatures, and the minimum relative humidity.; The wind energy was predicted using the power coefficient of the turbine and statistical representation of the daily wind speeds. The average hourly values of the wind speed were used for finding the distribution constants for the Weibull distribution and Rayleigh distribution. The results showed that the Weibull distribution is more accurate in predicting the expected power output of the turbine when the daily wind speed coefficient of variation (Cv) was less than 0.5. When the Cv is greater than 0.5 the Rayleigh distribution gives better results.; A computer model was developed using Visual Basic to model the system and the resulting model was tested and used in comparing the economics of a traditional irrigation system and an irrigation system powered by solar panels. The system powered by the solar panel had a greater total annual cost than the traditional system but the sensitivity analysis performed showed that if the trends in energy prices continue and the prices of the solar panels continue to decrease, the cost for operating the traditional systems will be close to the cost of operating the systems powered by the solar panels in less than a 10 years.