All-electric Pearl Street Mall? Boulder weighs retiring decaying gas line in shift away from fossil fuels

Under six blocks of brick in the heart of the Pearl Street Mall lies an aging gas line deemed a safety risk. Replacing the line would mean ripping up brick from 11th to 15th Streets, or much of the pedestrian-only stretch. The alternative is retiring the line and electrifying that stretch of buildings along Pearl. 

Given that most of Boulder’s gas infrastructure was installed in the 1960s and 70s, many gas lines around town are reaching the end of their functional life. But with climate change worsening and the need to get off fossil fuels imminent, the City of Boulder together with Xcel is exploring alternatives to plot a new path forward.  

A replacement gas line on Pearl Street would continue the city’s dependence on fossil fuels, locking in carbon emissions over the long term. Infrastructure like gas lines have a lifespan of 60 years or more and absorb money that could be poured into renewable resources. 

“If we’re putting in new gas infrastructure, it is challenging to make the case that we’re also transitioning away from natural gas,” said Matt Lehrman, energy strategy coordinator with the City of Boulder. 

To meet city climate targets, Lehrman said, Boulder must quickly reduce its gas use. Meaning, new gas lines with a life expectancy of decades might only be active for a fraction of that time. Yet fossil fuel infrastructure only recoups money from being used for many years. “You’re putting a lot of money in the ground that needs to be recovered over a long period of time,” Lehrman said. 

Replacing the line under Pearl Street with gas is a headache to consider — a yearslong construction project in a Boulder hot spot where restaurants are concentrated. But alternatives are almost as disheartening. Xcel explored what it would take to move the line serving Pearl Street into the alleys adjoining the mall. But those alleys are already cramped with utilities like water, sewage and electric. 

“Due to heavily congested alleyways, construction is expected to be incredibly difficult and expensive,” Xcel said in its July 2023 filing to the Public Utilities Commission for its gas infrastructure plan.

It’s not just congestion that’s a challenge. The age of many Pearl Street buildings mean they have indoor gas meters, making them “extremely challenging to access for maintenance and repairs,” Xcel said in the filing. Those meters would have to be replaced with modern outdoor meters.

The estimate for a gas line replacement is around $7.5 million, according to Xcel. To electrify the same area, Xcel estimates, would cost $3.7 to $4.5 million, which includes upgrading the area’s grid so it could handle the load of 66 buildings heating and cooking exclusively with electricity. It also covers installation costs along with project management and reporting. 

But that doesn’t tell the whole story.

The estimate doesn’t factor in what it would take to outfit Pearl Street buildings with the appliances necessary for them to electrify. For heating, this includes heat pumps and hot water heat pumps. For cooking, it means induction stoves replacing gas ranges. 

Carolyn Elam, sustainability senior manager with the city, said restaurants were already a concern for Xcel and the city. An update to the city’s energy code coming before Boulder City Council in March has an all-electric requirement for new builds and substantial remodels, but has exceptions for commercial kitchens, along with hospitals and laboratories. For the gas line under Pearl to be retired, however, all  restaurants along the stretch would have to be willing to make the switch — no exceptions.

“To be able to abandon that pipeline in Pearl, it effectively requires 100% electrification, which means every building has to transition,” Elam of the city said. “And as you can imagine, there’s a diversity of how gas is used in the buildings along that section.”

Municipal gas bans nationwide have faced lawsuits from restaurant groups. 

“If you wanted to abandon a gas line in a residential neighborhood, it’s probably a little easier,” Elam said. On the Pearl Street mall “we’re talking about a very dense area of the community with a lot of different building types.”

Yet the challenge of the Pearl Street project could be a benefit to future projects.

Xcel has suggested it could serve as a test case for other electrification efforts across Colorado. 

Xcel is faced with having to reduce greenhouse gas emissions from its gas infrastructure 22% by 2030 from a 2015 baseline. Given the scope and magnitude of electrification required to achieve that goal, Xcel told the PUC, “it will be important to understand and test this concept of electrification on diverse customer populations, but geographically targeted portions of the Company’s gas system.” 

In its Clean Heat Plan filing, Xcel states it would reach out to every one of the affected customers on the Pearl Street Mall. Elam suggested that the $3 million gap between the gas line replacement and electric alternative could be distributed as incentives to aid the transition.

Elam added that while building owners may bristle at mandatory electrification now, a forced switch is likely inevitable. The commercial buildings along the stretch, which make up 61 of the 66, are already subject to state building performance standards, as well as city regulations. Electrifying now might save them the same effort in years to come.

State standards, established in a 2021 law, require buildings larger than 50,000 square feet to reduce their greenhouse gas emissions 7% by 2026, from 2021 levels, and 20% by 2030. Elam said several buildings on Pearl Street fall under this law.

“At some point in time, these buildings are likely to go through renovations anyway,” Elam said.  

Neither Xcel nor the city has started reaching out to building owners yet, according to Elam. Until there’s more information, the project is still very conceptual.

“There’s no scenario that’s not highly disruptive to this area,” Elam said. “So we’re certainly trying to be very conscious about creating too much anxiety around it ahead of being able to start giving people the information to help them feel empowered.” 

Terri Takata-Smith, with the Downtown Boulder Partnership, said the process is still in such an early phase that there isn’t enough information to fully understand the full scope of challenges and impacts.

“Our next steps with Xcel is a communication and outreach plan with key stakeholders to understand all impacts and implications,” Takata-Smith said.

The Clean Heat Plan, which contains the alternative to electrify Pearl Street, will face a hearing at the PUC in the coming weeks. A ruling is expected this summer. If approved, Xcel would move forward with a feasibility study to examine the minutia of the project so it could provide more concrete numbers to building owners.