Wind pumps - Converting wind speed
Abstract
Wind pumping systems have been trialed successfully in Western Australia in low transmissivity environments. To facilitate the evaluation of their effectiveness in other environments, an understanding of the drawdown potential within that environment must be assessed. This inturn requires the ability to convert wind speed to a pumping rate and hence drawdown for any given combination of wind speed and groundwater flow system parameters. A drawdown simulator was developed which integrated the power production from a wind pump and the energy required to lift a volume of groundwater from a given depth. Based on the pumping equation, a time series of discharge rates from a pumping bore in a given hydraulic environment were developed for a range of frequencies of wind speed data from hourly to weekly. It was observed that over a long term period (exceeding 12 months), that weekly averaged data could provide a realistic appraisal of the expected drawdown even though the actual wind speed may vary on a much shorter frequency. When applied to a range of aquifer transmissivities likely to be experienced in the Victorian Mallee, it was found that wind pumps are most likely to be effective where the transmissivity is less than 30m2/day.
Author
C. V. McAuley