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SECTION 6: POTENTIAL FOR HEAD RECOVERY AT MWD CONNECTIONS <br />6.2 MWD STATION SA-1 <br />13 <br />Station SA-1 is the only MWD connection point where electricity is currently generated. The generator is in a <br />pump building at the Garthe Pumping Station. MWD water is fed through a Byron Jackson two stage hydro <br />turbine, which drives a 200 hp Siemens Allis generator to offset purchases of electricity for the wells and booster <br />pumps at this site. The address of this station is 2401 N. Bristol Street. The SCE Service Account number is 3- <br />001-3273-57 and the Rate Schedule is TOU-PA-3-B-S. <br />The configuration of this turbine installation is shown in Figure 1. After the discharge of the turbine there is a <br />manual control valve (fully open during the site visit) and a pressure regulating valve to drop the pressure as <br />needed to match the City pressure. The MWD pressure observed at SA-1 during July 2018 was 164 psig, while <br />the City system pressure was observed to be 73 psig. <br />Figure 1. <br />SA-1 Existing Configuration [July 2018) <br />Generator <br />68 kW <br />164 127 <br />PSIG PSIG <br />i r <br />Turbine <br />Pump Roam <br />MWD <br />Ball Valve <br />with Motorized <br />Flow Controller <br />Motorized <br />PRV <br />PRV <br />73 <br />PSIG <br />To Santa Ana <br />Distribution <br />The pressure after the turbine and before the PRV was observed to be 127 psig per the local meter. This means <br />a pressure drop of 37 psi, or 85 feet through the turbine. The flow at this time was 8.2 CFS and the turbine was <br />metered at 68 kW of electrical power. <br />Note that the theoretical power can be calculated from flow and pressure drop as follows. This calculation <br />assumes a turbine mechanical efficiency of 70%. This low pressure drop puts the turbine outside its normal <br />operating range, so the efficiency is only an assumption. <br />&2 f t a hp sec 62.4 i bs 0.746 kW <br />sec 85 ft x 550 fi lb-7 x fta 70%niech.off.x 95a elect. off x hp = 39 kW <br />The theoretical power production under these conditions is estimated at 39 kW, while the electric meter reads <br />68 kW. We will assume that the electric meter is reading correctly here, as that gives more conservative results <br />Newcomb I Anderson I McCormick CITY OF SANTA ANA <br />PREVIEW Date: Nov 03, 2021 Workspace ID: WS00800354 Funding Opportunity Number: R22AS00023 <br />