Case Study: Cogeneration in a Kaiser Permanente Medical Center

Case Study: Cogeneration in a Kaiser Permanente’s Medical Center

How seven rooftop cogeneration modules slashed energy costs and greenhouse gas emissions at a 340-bed California hospital.

Background: A Hospital That Needed More Than Just Reliable Power

This Kaiser Permanente's Medical Center is a 340-bed facility in Northern California. Like most large hospitals, it runs around the clock and its energy demands are substantial. Kaiser needed a solution that could deliver consistent electricity and heat, reduce utility costs, and align with the organization's well-established environmental commitments.

In November 2015, Kaiser brought online a 525 kW cogeneration system built around seven outdoor Tecogen CM-75 CHP modules and the results have exceeded expectations ever since.

Results: Two Years Into Operation, System was nearly Paid back

The system's performance speaks for itself. During its first two years of operation, it ran nearly continuously, averaging over 8,100 run-hours annually. Key figures:

  • 8,176 annualized run-hours per year

  • 520 kW average plant power output

  • 20-30% reduction in greenhouse gas emissions

That kind of reliability translates directly into predictable savings for Kaiser year after year. In 2026, Californians are seeing demand rates as high as $50/kW and energy rates >$0.20/kWh. The cogeneration system with this operational uptime reduces the demand charges bills by upwards of $20,000 a month and the total energy bills by over $400,000 a year.

Also note that California has the top 3 highest energy rates in the US, so request a custom economic analysis of your facility here.Kaiser_Roseville_outdoor_cogen.jpeg

How It Works: Electricity and Heat, Simultaneously

Cogeneration, or combined heat and power (CHP), uses one gas input to produce two useful outputs of hot water and electricity. The Tecogen system at this hospital produces electricity 24/7 entirely on-site, reducing how much Kaiser must purchase from the local utility. At the same time, high-quality heat is recovered from the engines' jacket and exhaust systems (at 225°F) and is fed directly into the campus heating and domestic hot water systems.

The modular approach of using multiple units means a greater chance to capture most of the demand. If a single 525kW unit is down for 15 minutes every month, Kaiser would miss out a huge portion of the energy bill savings. With a modular approach a single 75kW unit can be down and Kaiser would still shave 450kW off their demand.

The result: Kaiser's existing boilers run less often, Kaiser sees a significant reduction to their electricity bills, and the hospital operates with greater energy independence; all from a single integrated system installed on the roof.

"Kaiser selected our cogen modules for its Roseville campus after having run Tecogen systems successfully at several other hospitals for many years." — Bill Martini, V.P. of Sales, Tecogen

Meeting Kaiser's Environmental Goals

The Roseville CHP system reduces greenhouse gas emissions associated with the facility's electrical and boiler usage by approximately 20-30%, a meaningful contribution to Kaiser Permanente's widely recognized sustainability commitments.

This figure comes from the increased efficiency added to the facilities aging systems which the cogeneration plant is now offsetting. If Kaiser were to go back to using electricity from the grid and boilers for the same energy production of the cogen system, then it would result in an increase in overall emissions.

Why Kaiser Chose Tecogen

Kaiser conducted an extensive, competitive, and rigorous evaluation before selecting Tecogen, weighing engine-based, microturbine-based, and fuel cell-based CHP systems across multiple criteria. Tecogen came out ahead on the modular approach, quick payback, maintenance support, patented environmental technology, and then 30-year track record.

Each module is also equipped with Tecogen's patented Ultera emissions controls, which reduce exhaust constituents like NOx and CO to ultra-low levels. This is a critical factor in California's strict air quality environment.

Ongoing Service: Factory Support, Built In

The entire seven-module installation is covered by Tecogen's comprehensive long-term factory service and maintenance program. All work is performed by trained factory technicians from Tecogen's California Service Center, giving Kaiser expert support local to the medical center with direct manufacturer accountability.

For more information, email sales@tecoegn.com or call 781-466-6400.