PG&E Calif. Helms 1 & 2 hydro units back Imprimir
Escrito por Reuters   
Lunes 11 de Mayo de 2009 00:00

Pumped Storage Station in operation

Diagram of a Pumped Storage Power PlantNew York, May 11 (Reuters) - PG&E Corp's (PCG.N) 404-megawatt Units 1 and 2 at the Helms pumped storage hydropower station in California returned to service by Sunday afternoon, the California Independent System Operator said in a report.

The company shut the units by May 7 for planned work involving the removal of water from a storage tank.

The 1,212 MW Helms station, which entered service in 1984, is located near Fresno in Fresno County. There are three 404 MW Units 1-3 at the station.

One MW powers about 700 homes in California.

Unit 3 meanwhile shut by Sept. 28 also for planned reasons.

Pumped storage plants store and produce electricity to supply peak power demands by moving water between reservoirs at different elevations.

At times of low demand and low power cost, the plant uses electricity from the grid to pump water into the higher reservoir. When demand and prices are higher, the station releases the water back into the lower reservoir through a turbine, generating energy.

PG&E's regulated Pacific Gas and Electric Co subsidiary owns and operates the station.

PG&E, of San Francisco, owns and operates more than 6,200 MW of generating capacity, markets energy commodities and transmits and distributes electricity to almost 5.3 million customers and natural gas to 4.2 million customers in northern California. (Reporting by Scott DiSavino)



Design features of the Helms pumped storage project

Paul, K., Jr.
Energy conversion, ieee transactions on
Volume 4, Issue 1, Mar 1989 Page(s):9 - 15
Digital Object Identifier   10.1109/60.23143


The Helms Project has been in operation since 1984 and represents the state of the art in pumped storage technology in terms of operating heads and unit capacity. A description is given of design features, startup experiences, corrective work, and project performance to date. The following are covered: mechanical features, electrical features, generators and motors, pump mode operation, transformers, control, protection, station service, powerhouse cranes, rotor dynamics, field pole bucking, thrust bearing, and cold loading.

If you are interested, read the full article at  IEEE, only for registered users or IEEE members.