The Impact of Water Use Fees on Dispatching and Water Requirements for Water-Cooled Power Plants in Texas

Two major aspects related to water use in solar power plants are examined. First we compare the water used in various approaches to power generation. These include water requirements for cooling (where applicable) and other needs within the plant. Included is attention to water requirements for makeup in Rankine cycles, as well as for cleaning of concentrating solar systems. In the second thrust, we examine the impacts of using dry cooling for Rankine cycles. It is generally established that this approach requires premiums in both capital and operating costs (the latter is dependent upon the cost of water), as well as a penalty in performance when compared to wet systems. We examine the trends associated with this technology and outline some for the current performance issues with various cooling approaches.

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Water use dynamics of young and mature apple trees planted in South African orchards: a case study of the Golden Delicious and Cripps' Pink cultivars

Proceedings of the International Association of Hydrological Sciences ◽

10.5194/piahs-378-79-2018 ◽

2018 ◽

Vol 378 ◽

pp. 79-83 ◽

Cited By ~ 1

Author(s):

Zanele Ntshidi ◽

Sebinasi Dzikiti ◽

Dominic Mazvimavi

Keyword(s):

Water Use ◽

Vapour Pressure Deficit ◽

Sprinkler Irrigation ◽

Pulse Velocity ◽

Western Cape ◽

Apple Orchards ◽

Mature Trees ◽

Water Requirements ◽

Golden Delicious ◽

The Impact

Abstract. Apple orchards have previously been bearing 60–80 t ha−1 at most. However in recent years yield has increased to more than 100 t ha−1. There is need to understand the water requirements of the high yielding orchards, given that high crop loads are associated with high water use rates. The aim of this study was to quantify the water requirements of young and mature unstressed apple orchards. We also assess the impact of climate variables on transpiration rates. Data was collected in 4 orchards in the Western Cape Province. The orchards comprised young non-bearing (< 3 years) and mature trees planted to the Golden Delicious and Cripps' Pink cultivars, all under micro-sprinkler irrigation. Transpiration by the trees was measured using heat pulse velocity sap flow sensors hourly throughout the growing season (October–June). Weather was monitored using an automatic weather station. Tree transpiration was linearly related to the solar radiation, but the relationship with the vapour pressure deficit (VPD) was non-linear. There were no significant differences (p>0.05) in the sapflux density of the Golden Delicious and Cripp's Pink cultivars. This suggests that these two cultivars have similar water use characteristics. Mature orchards transpired between 6000 to 8000 m3 ha−1 season−1 while non-bearing orchards used between 2000 to 3000 m3 ha−1 season−1.

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The Impact of CO2 Capture on Water Requirements of Power Plants

Energy Procedia ◽

10.1016/j.egypro.2017.03.1770 ◽

2017 ◽

Vol 114 ◽

pp. 6337-6347 ◽

Cited By ~ 5

Author(s):

Guido Magneschi ◽

Tony Zhang ◽

Ron Munson

Keyword(s):

Co2 Capture ◽

Power Plants ◽

Water Requirements ◽

The Impact

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Worldwide water constraints on attainable irrigated production for major crops

10.5194/egusphere-egu21-4041 ◽

2021 ◽

Author(s):

Bram Droppers ◽

Iwan Supit ◽

Michelle TH van Vliet ◽

Fulco Ludwig

Keyword(s):

Water Use ◽

Water Availability ◽

Crop Production ◽

Atmospheric Co2 ◽

Western India ◽

Model Framework ◽

Water Requirements ◽

Groundwater Exploitation ◽

Sustainable Water Use ◽

The Impact

Currently, irrigation withdrawals are resulting in groundwater exploitation and unmet ecosystem water requirements. However, to achieve worldwide food security, there is a need to focus on sustainable intensification of crop production. This requires a more sustainable use of water for irrigated croplands. Our presentation focuses on quantifying attainable wheat, maize, rice and soybean production on currently irrigated cropland under sustainable water use. Attainable production accounts for increases in nutrient application, while limiting irrigation withdrawals to renewable water availability and without compromising river ecosystem water requirements.Attainable crop production was quantified using a newly developed two-way coupling between the VIC hydrological model (Droppers et al., 2020) and the WOFOST crop model (Wit et al., 2019). This VIC-WOFOST model framework comprehensively simulates biophysical processes related to water availability and crop growth under water and nutrient limitations. Our results indicate that worldwide crop nitrogen uptake should increase by 20%, to achieve production gap closure. However, worldwide irrigation withdrawals should decrease by more than a third in order to ensure sustainable water use. Under these constraints, decreases in attainable irrigated yields of 5% are expected (14% decrease due to water constraints, 9% increase due to increased nutrient availability). Moreover, achievable irrigated crop production in the extensively irrigated croplands of north-eastern China, Pakistan and north-western India would be reduced by up to a third.In addition we explored the impact of atmospheric CO2 enrichment on worldwide attainable irrigated production using VIC-WOFOST. Increased atmospheric CO2 concentration increases crop assimilation and decreases crop transpiration. Initial results show that these effects may offset the unsustainable water withdrawals and increase attainable irrigated yields.References:Droppers, B., Franssen, W. H., Van Vliet, M. T., Nijssen, B., & Ludwig, F. (2020): Simulating human impacts on global water resources using VIC-5. Geoscientific Model Development, 13(10), 5029-5052, https://doi.org/10.5194/gmd-13-5029-2020de Wit, A., Boogaard, H., Fumagalli, D., Janssen, S., Knapen, R., van Kraalingen, D., ... & van Diepen, K. (2019): 25 years of the WOFOST cropping systems model. Agricultural Systems, 168, 154-167, https://doi.org/10.1016/j.agsy.2018.06.018.

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