Hydropower Resource Assessment at Existing Reclamation Facilities

Chapter 2Hydropower Site Data CollectionSite coordinates were also collected for the majority of sites. Figures 2-1through 2-10 show the distribution and location of sites, with availablecoordinate data, for each region. Regions are split among the figures because ofthe region size and to better show site locations.The Idaho National Engineering and Environmental Laboratory (INL) providedproximity data related to site locations, based on the site coordinates. Proximitydata include distance of site to nearest population center, road, substation, andtransmission line. INL also provided the voltage of nearest transmission ordistribution lines, power line operator and substation name.The distance from the site to transmission line and transmission line voltagewere used in estimating costs of potential hydropower development at a site. IfINL did not have transmission data available for a particular site, a 5.0 miledefault distance from the site to the transmission line was used in the analysis.This reflects an average transmission line distance based on the available datafor the remainder of sites. The default transmission voltage value used was 115kilo voltage (kV), which is considered an average kV for transmission lines.Data for transmission or distribution line kV provided by INL went from 35 kVup to 500 kV. The distance to the nearest transmission line does not necessarilyindicate that an interconnection can be made with the transmission line. Furthersite specific analysis for transmission would be needed if a site is pursued.Chapter 3 discusses cost estimating methods and assumptions for transmission.2.2 Site Hydrologic DataHydrologic data, including flow and net hydraulic head (net head), arenecessary to calculate potential power generation at a site. Net head is thedifference between head water and tail water elevations. Power generation canbe estimated using the following formula:Power [kW] = (Flow [cfs] * Net Head [feet] * Efficiency)/11.8 1Flow, head water and tail water data are typically available from flow meter orgage measurements, reservoir elevations, and project design specifications.Efficiency is dependent on the turbine design capacity, operating capacity 2 , andturbine type. Chapter 3 discusses efficiency assumptions used in the powergeneration analysis of the Hydropower Assessment Tool. The followingsections describe flow and net head data required and available for the analysis.1 11.8 is a constant factor that is a combination of a constant and unit conversion factors.2 Turbine design capacity is the nameplate design for the turbine and operating capacity is the nameplate capacityless losses due to operational conditions (changes in heads or flows).2-2 – March 2011