Sustainable Transportation Energy Pathways (STEPS)
Mishra, Gouri Shankar, William Glassley, Sonia Yeh (2010) Analysis of Lifecycle Water Requirements of Energy and Transportation Fuels: Electricity from Geothermal Resources - Model Version 1.0. Institute of Transportation Studies, University of California, Davis, Research Report UCD-ITS-RR-10-20B
The spreadsheet-based model estimates water requirements for electricity from various forms of geothermal resources - wet steam and hot water hydrothermal resources, and enhanced geothermal systems (EGS). Electricity can be generated using flash or binary (organic Rankine cycle) depending upon the temperature and pressure of geothermal fluid. Power plants can use three different types of cooling technologies – wet re-circulating, dry systems, and hybrid cooling systems. Factors that affect water intensity of electricity generated (liters/kWh) are the efficiency of energy conversion, the extent of parasitic power requirement, type of cooling technology implemented, and presence of water treatment / recycling facilities.
Requirements are calculated separately for freshwater, degraded water and geothermal fluid.freshwater) is required for cooling and dissipation of waste heat in the power plant. Degraded water is required to compensate for fluid lost to fractures during heat mining of EGS resources as well as condensate use for evaporative cooling of flash power plants.
The model is available at: http://www.its.ucdavis.edu/download/UCD-ITS-RR-10-20.xls
The model is part of a series exploring the water footprint of future transportation fuels including bio-fuels and electricity. Other models currently under development examine the lifecycle water requirements of ethanol from corn grain and crop residue, and electricity from concentrated solar power, and biodiesel from soybean.
The model description is available at: http://pubs.its.ucdavis.edu/publication_detail.php?id=1425
Compatibility: The model has been designed to work on Microsoft Office 2003 and 2007 on Windows operating systems - XP and higher. It also works on OpenOffice Version 3.2.1.
Circular Reference: The model requires circular reference. If your Excel gives a circular reference error, then make the following changes (i) On the Tools menu, click Options, and then click the Calculation tab. (ii) Select the Iteration check box.