Caltech on Path to Decarbonize

Under a plan approved by Rosenbaum earlier this fall, Caltech intends to source largely carbon-free electricity. Simultaneously, a detailed engineering study will evaluate a potential transition from natural gas to electricity to power the campus heating system. That transition and the carbon-free-power purchase could reduce by more than 85 percent the greenhouse gas emissions produced on campus and in the electricity Caltech buys.

"These meaningful plans are possible because of advances in renewable energy research and years of preparation on campus," says Caltech Provost, and council co-chair, David Tirrell. "The council's work and its recommendations are important steps that translate Caltech's commitment to sustainability into practice."

The recommendations provide clear direction for moving forward, says John Onderdonk, chief sustainability officer, assistant vice president for facilities operations and services, and a sustainability council member. "There is plenty of work to do, but Caltech's energy future is beginning to take shape," he says.

A mechanism for campuswide action on sustainability

The Caltech Sustainability Advisory Council was established in spring 2023 with direction from the president to align operational practices on campus with Caltech's high aspirations in sustainability research. The 12-member council—co-chaired by Provost Tirrell and Charlie Lane, vice president and chief operating officer—also includes students, professors, and staff, and reports to the president.

The council's charge is to assess Caltech's current environmental footprint, develop a plan with measurable goals, initiatives, and resources to achieve further sustainability in seven areas, and oversee that plan's implementation. The seven areas are energy, water, materials, waste, land use, mobility, and emissions.

"This work spans boundaries, and I am particularly excited about the opportunity to enhance the relationship between campus operations, our research enterprise, and our community to be an exemplar of a living sustainability laboratory," says councilmember David Kang, associate vice president for facilities. "My hope is that we can collectively create a new vision for sustainability excellence and work together toward a shared vision that ultimately leads to a more sustainable campus and world."

Immediate gains

While the council's first Institute-wide recommendations focus on energy decarbonization in two phases, the group acted immediately to implement more sustainable practices on campus. For instance, the council worked with Dining Services to quickly restore reusable plates and utensils in Browne Dining Hall, to restart the reusable mug program at the Red Door Marketplace and Broad Café, and to install compost bins in student houses.

The council's composition of students, professors, and staff enabled these successes, providing representation for campus constituencies that represent all aspects of campus life and can bring different questions, concerns, answers, and solutions to the table.

The Graduate Student Council (GSC) among other campus constituencies has advocated for the restoration of reusable plates and silverware since the pandemic began to ease, says sustainability council member Christopher Yeh. Yeh is a graduate student in computing and mathematical science and the GSC's sustainability chair.

"I thought joining the council would be a useful opportunity to communicate the concerns of students directly and also to understand the thought process and decision making that happen in the administration," Yeh says.

Undergraduates also wanted reusable tableware as well as compost bins, says councilmember and computation and neural systems major Emily Choe, a senior who is Venerable House president and serves on the Interhouse Committee. Choe has found the council meetings enlightening. "There is a lot that I still am trying to learn about as I go to the meetings and hear about topics that undergraduates don't think about on a day-to-day basis. But on the other side, things that we had no idea how to tackle were handled fast."

The council supports another student priority: an e-bike rental program envisioned by the GSC. Through it, Caltech community members would be able to visit a campus library to check out e-bikes provided by ActiveSGV.

Renewable Power Purchase

As the first phase and centerpiece of the council's energy recommendations, Caltech will collaborate with Pasadena Water and Power (PWP) to explore options for offsite carbon-free electricity to replace baseload power from Caltech's largest single source: its natural gas–based central plant. The replacement will improve campus sustainability and complement the City of Pasadena's efforts to eliminate the use of fuels that cause climate change.

Beginning with collaboration in 2024, Onderdonk anticipates that Caltech and PWP will partner to identify projects such as wind, geothermal, or solar energy to deliver tens of megawatts of carbon-free power to campus.

The council also recommended that staff evaluate resiliency needs and capabilities that would allow the old cogeneration infrastructure to power the campus as a backup during blackouts as an increasingly volatile climate tests an increasingly tapped electrical grid.

Why generate heat when you can move it?

Stable power, heat, and air conditioning matter so much to laboratories that Caltech built its own central plant in 1968. In it, a turbine akin to a jet engine generates electricity from natural gas, a fossil fuel that contributes to climate change. Waste heat is converted into steam and piped through tunnels to each building on campus to be used in space-heating systems. This efficient process, called cogeneration, was an exemplar of sustainability before renewable energy became widely available. Now, the gas-based plant stands in the way of decarbonizing campus, necessitating the new plans for electricity, heat, and cooling.

In delivering its recommendations to the president, the council explained that Caltech studies demonstrate the value of transitioning to purchased electricity, hot water heating using electricity, and chilled water storage, and recommended a detailed engineering study of this transition.

Onderdonk says that the idea is to use heat-recovery chillers to electrically produce chilled water and to connect the existing chilled water system with a new hot water system. Steam needed for research would be produced for the few buildings and applications that require it. The new utilities would connect to each building through the same tunnel network.

"The beauty of this system is that it would harvest the waste heat from the campus," he says, adding that this is proven technology that has been deployed on other higher education campuses.

"At the same time that some parts of campus want heat, other parts also want cooling," Yeh says. "You solve the heating and the cooling problem by moving heat instead of generating it. That the cogeneration plant generates carbon is not news, but to see the council take a formal stance on this is good."

Caltech has prepared for an energy transition for more than a decade. Facilities experts have conducted thermal and air-handling studies of buildings and reported on energy use and other facets of sustainability. Caltech prioritized energy-saving design and construction, such that power use stayed flat for two decades even as the campus added new buildings and power-intensive research equipment. Twelve buildings are certified at the highest two tiers of Leadership in Energy and Environmental Design (LEED), including a renovated historic laboratory. Roofs and garages host solar panels, and fuel cells distributed around campus add resilience.

Communications to come

Caltech will share updates as the energy transition progresses and the sustainability council makes recommendations about water, materials, waste, land use, mobility, and emissions in 2024.

"Learning how this council is part of a bigger movement at Caltech gave me an idea of the momentum that has been here," Choe says. "That momentum put us at this location; now, we are trying to push forward. The longer-term sustainability efforts will not affect students who are here right now, but these projects still require our support so that Caltech can continue to go in this direction."