Pumping Energy Costs Research Articles

Suspension feeding in marine sponges Halichondria panicea and Haliclona urceolus:effects of temperature on filtration rate and energy cost of pumping

Suspension feeding in marine sponges Halichondria panicea and Haliclona urceolus:effects of temperature on filtration rate and energy cost of pumping

Long-Term Irrigation Trends – Texas High Plains

The Texas High Plains is the most critical groundwater depletion area of the High Plains (Ogallala) Aquifer. The aquifer underlies parts of eight states in the Western Great Plains. Irrigation initially expanded in the central counties of the Texas High Plains during the major drought of the 1930s and peaked during the mid-1970s. Thereafter, continuing groundwater depletion of the Ogallala Aquifer, escalating pumping energy costs, low farm profits, and government set-aside programs stimulated a decline in irrigated area. The irrigated area in the Texas High Plains declined from a peak of 2.25 million ha (6.0 million acres) in 1974 to 1.62 million ha (4.0 million acres) in 1989. Estimated annual groundwater use declined from 10.0 km3 (8.1 million ac-ft) in 1974 to 5.6 km3 (4.5 million ac-ft) in 1989. Although reduction in irrigated area was the major cause of the reduction in groundwater use, improved irrigation systems and water management practices have contributed to reduced water application. Groundwater depletion, which averages about 30% of predevelopment storage, will continue to limit long-term irrigated agriculture. However, continued reduction in irrigated area and adoption of water conservation technology are moderating the rate of groundwater use and water-table decline.

Sprinkler and Furrow Irrigation Trends — Texas High Plains

DECLINING groundwater storage, high pumping energy costs, and low farm profits are causing major changes in irrigation in the Texas High Plains. Irrigation surveys indicated that during a decade of decline starting about 1974, furrow irrigated crop area has declined by 39%, while sprinkler irrigated area continued to expand through 1979 and declined by 3% by 1984. The decline in furrow irrigation is associated with systems that have relatively low estimated application efficiencies, primarily associated with deep percolation loss on moderately permeable soils. Two expanding technologies that will continue to improve irrigation application efficiencies are Low Energy Precision Application for center pivot and lateral move systems and surge flow application in graded furrow systems.

Surface Heating Greenhouses: A Parametric Analysis

Surface heating is the application of warm water to the outside surface of a greenhouse to reduce conventional heating requirements. A computer model was used to predict the energy cost savings resulting from surface heating. The effects of water flow rate, water temperature, greenhouse temperature, pumping head, unit cost of pumping energy and unit cost of heating energy were studied for four U.S. locations. The results will help designers decide whether surface heating is a viable option for their design conditions, and help them select the optimum water flow. Higher heating energy costs, lower pumping energy costs, higher water temperatures, and colder locations all produce higher energy cost savings for surface heating.

Usability of low temperature waste heat for sea water desalination

Waste heat - energy that is cooled away from a process - appears at two very different temperature levels. The waste heat that is 50° C warmer than the ambience, can be utilized by a multi-effect-distillation process, and it is competitive to utilize it at least as thoroughly as the first-rate energy. At low temperatures, less than 20 °C above the ambient temperature, waste heat can be technically, and economically utilized, if the temperature difference is 7... 15 °C, depending on the pumping energy cost.