Generation, Transformation, and Transmission

ca transmission linesPower Grids are incredibly complex networks that carry electricity from generating facilities to points of end-usage, such as homes, offices, and factories. Simply put, power is generated by taking available energy from one source- such as the chemical energy in natural gas, or the mechanical energy in wind- and converting it into a current of electrical energy. Once this current is generated, it will flow along whatever pathway is presented to it, much like water flowing down-hill. It is the job of power utilities to provide and maintain the infrastructure that carries these electrons to end users.

Power is initially generated at a very high voltage. This is because high voltage currents dissipate less energy while being transported over long distances. However, the vast majority of appliances can't receive power at this voltage (and it is highly dangerous!), so the voltage must be successively reduced at Transforming Stations. In modern power grids, voltage is reduced two times: first at regional substations, and second down to the 120V necessary for home and commercial usage. This second step takes place in the transformer boxes you can see connected to power lines on utility poles.

Load Balancing


While utility companies own their transmission assets, much of the power they transform and transmit is bought from private companies on the wholesale power market. This market is operated and managed by the California Independent System Operator Corporation (CAISO). CAISO ensures equal access to the state's power lines, forecasts electrical demand, accounts for operating reserves, and dispatches the lowest cost power plant unit to meet demand while ensuring enough transmission capacity is available to deliver the power. Visit their website to learn more.

Managing the supply and demand load on the grid is no easy task. Since power can't be stored in large volumes, supply must be adequately balanced with demand such that there is neither too little nor too much electricity on the grid at any given time. When electricity demand approaches the maximum power supply, utility companies must apportion power sparingly to prevent more serious shortages. Options include instituting rolling blackouts and bringing alternate power plants online.

Californian’s can help prevent the need for these measures. Energy conservation during times when we know demand will be high can make the difference between rolling blackouts and consistent power for everyone. Explore tips on how and when to save, or learn more about peak demand and what it means for California.