Four lessons from Santa Rosa’s waste-to-energy electric bus program

Every time someone flushes a toilet in Santa Rosa, they’re indirectly powering one of the city’s electric buses. Wastewater travels to the Laguna Treatment Plant, where it is then treated, recycled, and sent to a nearby geothermal energy plant. That plant powers the city’s charging infrastructure.

Of course, not every city has access to the world's largest geothermal field. However, every transit agency in California will need to transition to a zero-emission fleet starting in 2024. Here’s what Santa Rosa officials learned about electric buses while building on a decades-old commitment to climate action.

Find passionate people

Santa Rosa has long been a climate action leader. The city met its ambitious 2005 greenhouse gas reduction goals and reaffirmed its commitment to further cuts with a 2020 Climate Emergency Resolution. It is also one of the largest cities to ban the construction and expansion of gas stations.

Officials enacted many of these policies in response to health and safety concerns. The city was the site of the devasting Tubbs Fire in 2017 and local reservoirs dropped to all-time lows during the recent drought.

“Many of the folks here were impacted substantially by things like fire [and] power outages,” said Peter Martin, the city’s deputy director of water resources. “Having some of the most destructive fires occur right in the heart of Santa Rosa, really brings home [the fact] that many people here have been impacted by climate change firsthand.”

Leverage small changes

One of the easiest ways a city can reduce emissions is by switching to renewable energy. In 2019, Santa Rosa piloted a community choice aggregation program using one of the biggest energy users: the Santa Rosa Water Department. Collecting, treating, and moving water is an energy-intensive process and can account for 30-40% of a local government’s total energy consumption.

That number is closer to 50% for Santa Rosa. But it also treats water for nearby cities and unincorporated parts of Sonoma County, bringing the department’s total energy consumption share to approximately 75%.

It took just three months to switch city operations to Sonoma Clean Power’s 100% renewable energy program. “It’s much like flipping a switch, that we’re able to have our energy become 100% green, as opposed to the time [and capital] it takes with … renewable energy projects,” said Tasha Wright, the water department sustainability coordinator.

The city sends recycled water instead of drinkable water to recharge the nearby geothermal beds, which provide a substantial portion of Sonoma Clean Power’s renewable energy. The city also provides recycled water to farmers for irrigation and urban reuse customers in Santa Rosa and Rohnert Park.

During most years, the city reuses 100% of the recycled water produced at the Laguna Treatment Plant. In fact, the city has decreased overall water usage by 14% since 1990 despite a 57% increase in population.

Thanks in part to the geothermal plant, Santa Rosa is one of the few cities on track to beat the state’s clean-energy goals. That energy keeps the city buses rolling and allows the city to thoughtfully pursue other clean energy projects.

Invest in grants and partnerships 

At full operation, the city has 29 buses in its fleet. Four of those buses are now electric and the city has received funding for 17 more. Each bus costs $1.2 million before vouchers or rebates. The city can currently charge up to 10 buses but plans to build more charging infrastructure.

The self-funded transit agency pulled together a mosaic of grants to fund the transition. “This is expensive,” said Rachel Ede, the deputy director of transportation and public works. “Between developing the charging infrastructure and the additional costs of the vehicles, there is no one funding source that's going to get you there. For agencies and organizations that want to be very aggressive in the transition, it’s going to take a real menu of funding options to get there. And probably multiple different applications.” 

The transportation sector is one of the largest contributors to total greenhouse gas emissions. Slashing tailpipe pollution — assuming supporting policies and infrastructure are in place — will dramatically lower emissions. And on the surface, an electric bus is the same as a diesel bus. It has wheels and it rolls. In theory, it’s an easy switch.

But cities face three key challenges that consumers do not. For starters, the technology simply does not exist for most municipal vehicles. For the technology that does exist — like electric buses — there are few qualified service technicians.  

“It basically makes the people who used to change the tires a full-blown electrician — it’s completely different,” said Fleet Superintendent Zach Brand. “We’ve been working on training our staff for a couple of years, and if you’re not from the factory and getting factory training, you are struggling to find the right training, the right people, and the right tools to work on this stuff.”

Sometimes, these problems can be quickly fixed. Officials had some concerns about the range of the buses, which they resolved by “purchasing the biggest batteries we could” according to Ede.

However, there are no agreed-upon standards for electric vehicles. Every vehicle is custom-made, so everything is solved through trial and error. Consequently, advance planning and partnerships with local energy providers, manufacturers, and other agencies are critical to success. Taking a phased-in approach and leveraging lessons learned from other agencies is also important. 

“It’s worth the time and investment to get some technical assistance and do some feasibility planning and really lay out the steps both on the charging infrastructure side and vehicle procurement side to make sure that there is the overall capacity to deliver the program,” Ede said.  

An electrifying future 

These challenges are not going away. Cities will likely face the same issues once the technology becomes available for other fleet vehicles, such as dump trucks. Santa Rosa will need more charging facilities, energy, and resiliency measures to fully electrify its fleet. The city will also need to make tough choices about who gets to charge first and when. 

However, staff are excited about the transition. It’s the right thing to do, residents want it, and the city is on track to exceed the state’s climate goals thanks to the geothermal field. It would not be the first time Santa Rosa has led the way with its climate programs.

The only question is will they get the funding and support needed to succeed? 

The Cal Cities #LocalWorks initiative shines the spotlight on examples of local actions that are making a difference to their communities. Show how #LocalWorks in your community by contacting communications@calcities.org.