Martin 230kV Bus Extension Project
We're extending an electrical path in San Francisco
The proposed project is part of PG&E’s commitment to providing a safe, reliable and efficient grid for the 16 million people we serve in California. Infrastructure investments like this help us meet our customers’ evolving needs.
PG&E proposes to build the Extension Project to increase the reliability of the electric transmission system providing power in San Francisco. It will also reduce the risk of widespread power outages in The City.
The proposed project reroutes existing electric 230,000-volt transmission lines around one of the Peninsula’s major energy hubs to a new switching station. The new facilities will provide an additional electrical path around the hub.
The proposed rerouted transmission lines are currently planned to go underground, mostly within city streets. The proposed new switching station will occupy about two acres with much of the equipment enclosed in a new building.
In March 2015, the California Independent System Operator (CAISO) Board of Governors approved the project. PG&E anticipates that the project will be operational by late 2022.
Prior to building the facilities, the project must also be approved by the California Public Utilities Commission (CPUC), which has sole jurisdiction over the siting and approval of electric transmission facilities. The CPUC will also be the lead agency for the required California Environmental Quality Act (CEQA) process.
PG&E has evaluated several potential switching station sites and associated transmission line routes within a two-mile radius of PG&E’s existing Martin Substation in Daly City. We’ve narrowed our evaluation to three potential switching station sites. The site on Egbert Street in San Francisco appears to have the highest land-use compatibility.
Download Overview Map (PDF, 3.5 MB)
PG&E will continue to study these sites prior to submitting the project application to the CPUC in late 2017. We’ll identify our proposed switching station site, the transmission line route, plus alternative sites and routes, in the project application. The CPUC will evaluate the sites and routes (it may also consider others) and will ultimately decide whether to approve the project and its location.
Project information and community feedback
PG&E is developing preliminary engineering to support the CPUC permitting process. We will share this information, as well as the permitting process, with the communities around the potential switching station sites and transmission line routes. Conceptual designs have been developed for the proposed switching station building, and proposed street routes for the rerouted transmission lines have been laid out.
Frequently asked questions
What is the Martin 230kV Bus Extension Project?
This proposed electric infrastructure project includes the construction of a new 230,000-volt switching station and connections to existing underground transmission lines. The project will provide a system backup with the construction of a new electrical bypass around one of the key electrical hubs on the San Francisco Peninsula. It will improve resiliency and resolve concerns of a prolonged and widespread loss of service in San Francisco in the event of an extreme event.
Why are a new switching station and connections to existing transmission lines needed in this area?
Electric customers in San Francisco now rely on power supplied through PG&E’s Martin Substation in Daly City and the Transbay Cable Company’s transbay cable. Strengthening system resiliency and resolving reliability concerns helps meet the needs of the region’s growing population and supports continued economic vitality. The proposed project gives the local electric system greater flexibility and independence to adapt to a potential prolonged loss of service at PG&E’s Martin Substation.
Where will the project be located?
After evaluating several potential sites within a two-mile radius of PG&E’s existing Martin Substation, the project team has narrowed its selection to three potential sites. The potential site on Egbert Street in San Francisco appears to have the highest land-use compatibility. The California Public Utilities Commission (CPUC), the state agency with jurisdiction over the siting of these types of projects, will determine the final project components and location.
Download Overview Map (PDF, 3.5 MB)
When will the project be completed?
PG&E expects to submit a permit application to the CPUC in late 2017. It will include the proposed switching station site and associated transmission lines, along with alternatives. If approved, the project is expected to be operational by late 2022.
What will PG&E do to ensure the safety and security of these facilities?
The security of our facilities is a top priority. We’re committed to using safety and security measures that meet the highest established standards for critical infrastructure protection. These include perimeter fencing and gates, lighting, and intrusion detection systems.
How will PG&E minimize environmental impacts as a result of this project?
PG&E is dedicated to planning, constructing and operating the project with minimal impact to the environment and local community. When developing projects, we work with applicable local, state and federal agencies, as well as environmental organizations and communities, to ensure the project is planned in a manner that minimizes and/or avoids environmental impacts while complying with applicable standards and requirements.
What will the project look like?
PG&E plans to enclose the majority of the switching station equipment in a building or within walls. The associated transmission lines are likely to be installed underground, so will not be visible.
We are working with a local architect to design a building that will enclose the major switching station components. The architect will produce a design that contextually fits the existing neighborhood and what is envisioned for the future. Download a preliminary rendering (PDF, 5.3 MB). PG&E is dedicated to planning, constructing and operating the project in a manner that minimizes visual and environmental impacts. We understand and respect customer concerns about any impact to the quality of life in the existing neighborhoods around potential projects.
How were potential switching station sites determined and underground transmission routes selected?
PG&E looked for sites in areas with existing commercial and industrial uses. Our goal was to utilize land that is vacant or under-developed. We identified sites where the equipment will fit, that allow for screening and setbacks of structures, and are located within a reasonable distance to existing transmission lines. Other considerations include:
- Impacts to local communities
- Compatibility with established infrastructure and land uses
- Sensitive resource and habitat areas
- Length of new transmission line
- Constructability and engineering conflicts
How will PG&E address community concerns regarding electric and magnetic fields?
PG&E recognizes customer concern about the issue of Electric and Magnetic Fields (EMF) from power lines and substations. We are committed to complying with the CPUC's EMF policies. EMF is present wherever there is electric current and can be found in homes, offices and schools, or anywhere an electric current is present. Protecting the health and safety of the local community is of the utmost importance to the project team. The Martin 230kV Bus Extension will fully comply with the CPUC's EMF policies—the most comprehensive in the United States and supported by scientific research. PG&E provides free magnetic field measurements upon request, EMF health literature and support for EMF research. For more information, please visit our EMF page.
What are the next steps?
PG&E is continuing to evaluate the top three potential sites and routes. Preliminary engineering and architecture work is underway providing the data needed to perform the environmental assessments required for the permit application.
What role will my local city play in this process?
The CPUC will ultimately determine the final project components and location. But PG&E is working closely with city officials in San Francisco, Daly City, Brisbane, plus other public agencies, to ensure that local needs and priorities are carefully considered throughout this process. We plan to inform residents and local businesses about project details in a timely and transparent manner. We will also share community input in detail to the CPUC throughout this process.