PG&E Corporate Responsibility and Sustainability Report 2020

Plan of Reorganization Commitments

Conventional Sources

As part of our diverse portfolio of generation resources, PG&E has invested in state-of-the-art and highly efficient natural gas-fired power plants. These facilities provide a safe and reliable source of energy, as well as the operational flexibility required to add additional intermittent renewable energy sources into our power mix to ensure we can meet the future energy needs of our communities.

Our Approach

PG&E operates three natural gas-fired plants with best-in-class emissions levels and reduced water use via dry cooling:

  • Colusa Generating Station
  • Gateway Generating Station
  • Humboldt Bay Generating Station

As flexible combined-cycle power plants, the Colusa and Gateway Generating Stations are essential in PG&E’s efforts to successfully integrate more renewable resources into the energy grid. When wind or solar production varies during the day, these facilities can ramp up quickly to generate the energy that customers need.

2019 Milestones

In 2019, PG&E continued the safe operation of our three natural gas-fired plants:

  • Colusa Generating Station: Colusa Genreating Station with a shoreline in the foreground.This 657-MW combined-cycle natural gas plant features cleaner-burning turbines that allow the plant to use less fuel and emit significantly less NOX, SO2 and CO2 than older plants. “Dry cooling” technology allows the facility to use 97 percent less water than plants with conventional once-through water cooling systems.
    The plant has 530 MW of base capacity and approximately 127 MW of low-cost peaking power that can be used at times when demand is high or in emergencies. In addition, the plant is designed to lower its output when power from renewable resources like wind and solar becomes available. The plant uses a zero-liquid-discharge system that recycles wastewater and further reduces its water consumption.

  • Gateway Generating Station: Exterior view of steaming exiting a pipe at Gateway Generating StationThis 580-MW combined-cycle natural gas plant has 530 MW of base capacity and 50 MW of low-cost peaking capability. Like Colusa, the plant yields dramatically lower emissions for every megawatt-hour of power produced compared with older fossil-fueled plants. It also uses dry cooling technology, which minimizes water use.

  • Humboldt Bay Generating Station: Aerial view of Humboldt Bay Generating Station.This 163-MW natural gas plant is located in a relatively isolated section of California’s north coast region and provides a significant majority of the area’s electrical capacity. The plant’s design—selected for the region because of its flexibility and low emissions—uses reciprocating engines that are air-cooled, reducing water use by eliminating the need for “once-through” cooling from Humboldt Bay.

Measuring Progress

In 2019, PG&E’s natural gas power plants provided safe, reliable and low-cost electricity to our customers. The following performance data represents the average availability factor of our natural gas power plants.

The increase in plant availability factors in 2019 at the Colusa and Humboldt Bay Generating Stations was due to strong operational performance, as well as the fact that planned outages at Humboldt Bay Generating Station were scheduled for the prior year. The decrease in Gateway’s plant availability factor was largely due to a forced outage caused by an electrical fault within the station; corrective actions have been implemented to address the issue.

Natural Gas Power Plant Availability Factor Footnote 1
2017 2018 2019
Gateway Generating Station 93.8% 90.0% 89.1%
Colusa Generating Station 93.8% 91.2% 92.5%
Humboldt Bay Generating Station 92.3% 89.0% 95.2%
  • 1. Refers to the proportion of hours in a year that a plant is available to generate electricity.1