Kaiser Permanente Debuts Largest Hospital-based Renewable Microgrid in U.S.

With 2MW of solar generation and 9MWh of battery storage, the system supports California's clean energy transition, reduces emissions, and saves money while boosting backup generation with renewable power

OAKLAND, Calif., April 17, 2025 /PRNewswire/ -- Kaiser Permanente has unveiled the largest hospital-based, renewable energy microgrid system in the United States, supporting California's clean energy transition while improving environmental health and reducing costs.

The new microgrid system at the Kaiser Permanente Ontario Medical Center in Southern California adds 2MW of on-site solar generation and 9MWh of non-lithium battery storage capacity to the state's electrical grid, increasing reliability and supporting California's transition to 100% renewable energy by 2045. The microgrid also features a 1-MW fuel cell.

The microgrid provides clean, reliable electrical power for the hospital's day-to-day use and will serve as the initial emergency power backup system during commercial power outages. It has the capacity to serve all the hospital's emergency power needs for 10 continuous hours.

Kaiser Permanente has a strong commitment to environmental stewardship, recognizing that a healthy environment is crucial to the health and wellness of communities. Kaiser Permanente achieved carbon neutral status in 2020, and has pledged to become net zero across all emissions by 2050, with a midterm target to reduce emissions by 50% by 2030.

"Building on Kaiser Permanente's legacy of innovation, we are taking a bold step forward in sustainability by embracing clean energy to build a healthier future for generations to come," said Nor Jemjemian, senior vice president for National Shared Services Operations at Kaiser Permanente. "As an organization that has always led the way in driving innovation and change, we remain steadfast in our mission to provide efficient, sustainable solutions while ensuring accessibility and affordability for our members."

All California hospitals are required to have backup power in the event of an electrical grid outage affecting their area, traditionally in the form of diesel generators.

In addition to providing emergency backup generation in the rare case of a power outage, the Ontario microgrid increases the hospital's energy independence and reduces its energy costs. An automated control system will manage how electricity is produced, stored, and used at the site. When buying energy from the grid is inexpensive, the microgrid system will store the renewable energy it produces; when the grid's energy is more expensive, the system will instead discharge its stored energy.

Kaiser Permanente anticipates the microgrid's on-site solar power will avoid about 650 metric tons of carbon dioxide emissions by producing roughly 3,300 MWh per year of zero-emission electricity. That is enough renewable electricity to power 275 homes year-round.

Research has consistently shown that long-term exposure to air pollution caused by vehicle exhaust, burning fossil fuels, and industrial processes carries an increased risk of poor health conditions including cardiovascular disease — and increases the risk of death from coronary heart disease by 23% and from stroke by 24%.

"We know that pollution and carbon emissions harm people's health. As a health care provider and anchor institution in the communities we serve, Kaiser Permanente has an obligation and an opportunity to protect the health of our members and communities while preventing or mitigating environmental harms," said Bechara Choucair, executive vice president and chief health officer at Kaiser Permanente.

The battery storage component of the project was funded through an $8.3 million grant from the California Energy Commission to Faraday Microgrids. The solar power canopies were installed by Ameresco under a power purchase agreement with Kaiser Permanente.

Improvements in battery technologies and climate-driven challenges to electrical grid infrastructure have led Kaiser Permanente to explore innovative energy solutions for its facilities. The organization installed California's first renewable microgrid at its Richmond Medical Center in 2017. With 250kW of solar generation and 1-MWh of battery storage, that hospital's system reduces energy costs and provides limited backup generation.

"Every day, we look for new ways to improve the total health of our members and the communities we serve," said Georgina Garcia, senior vice president and San Bernardino County area manager of Kaiser Permanente in Southern California. "We know if other hospital systems in the region join us in this effort, we can reduce our industry's environmental burden, ensuring a healthier future for every resident in the Inland Empire."

About Kaiser Permanente

Kaiser Permanente is committed to helping shape the future of health care. We are recognized as one of America's leading health care providers and not-for-profit health plans. Founded in 1945, Kaiser Permanente has a mission to provide high-quality, affordable health care services and to improve the health of our members and the communities we serve. We currently serve 12.4 million members in 8 states and the District of Columbia. Care for members and patients is focused on their total health and guided by their personal Permanente Medical Group physicians, specialists, and team of caregivers. Our expert and caring medical teams are empowered and supported by industry-leading technology advances and tools for health promotion, disease prevention, state-of-the-art care delivery, and world-class chronic disease management. Kaiser Permanente is dedicated to care innovations, clinical research, health education, and the support of community health. For more information, go to about.kp.org. 

For more information, contact:
Hilary Costa, [email protected]

SOURCE Kaiser Permanente