What Will Power Los Angeles’ Electric Buses?

As the Los Angeles Metropolitan Transit Authority (Metro) gears up to adopt a 100 percent zero-emission electric bus policy, there has been some recent chatter about the source of electricity powering these buses. Gas industry representatives are arguing that Metro should keep their current fleet of buses and power them with biomethane. They contend that electrifying buses means moving to coal-powered buses. They argue we have to wait until 2045 to reap the benefits of electric buses.

So what’s going on? Are environmental groups fighting for a suboptimal environmental outcome? Or, is this just more shenanigans from the gas industry? Does moving to electric buses help reduce greenhouse gas emissions, or do upstream emissions from power plants mean more pollution? This post attempts to answer these questions.

The Los Angeles County Electric Bus Coalition, of which Sierra Club is a member, advocates for a 100 percent battery electric bus (BEB) fleet, powered by 100 percent clean energy (also built and supported by union labor and benefitting environmental justice communities first, but let’s focus on the first two goals in this post). It is important to marry these two goals as we want to avoid even the perception of shifting emissions upstream from the tail pipe to the smoke stack. The question is, under the current or future resource mix of the grid are we increasing emissions by electrifying buses? The short answer is no, but if that isn’t a satisfactory answer, read on!

There are two primary factors to consider when evaluating Metro’s optimal emissions outcome: the mix of resources generating powering the bus and fuel efficiency. Starting with the latter, presume for a moment that LA County’s electric grid ran on 100 percent gas (it doesn’t, but go with this for a second). Shifting the bus fleet away from buses fueled directly by gas, to electric buses powered by gas has important and immediate environmental benefits. The reason for this is that CNG buses are much less efficient than power plants.

The National Renewable Energy Lab recently completed a review of Foothill Transit’s BEBs and found their buses were four times more efficient than Foothill’s CNG counterpart. For example, when both buses’ fuel efficiency was converted to diesel gallon equivalents (dge), Foothill’s BEBs averaged 17.35 dge, while their CNG buses averaged 4.34 dge. In other words, it takes four times the energy to move a CNG bus one mile.

Simply converting CNG buses to BEBs powered by gas has environmental benefits, but the grid is more dynamic than the scenario described above. It has a mix of resources and is changing (greening) year over year thanks to a combination of state and local policies. Making matters more complex, Metro’s buses will be powered by two utilities with different energy mixes, and possibly a third as LA County moves to create a Community Choice Energy program. But, since the vast majority of Metro’s bus depots (where charging will occur) sit within the City of Los Angeles and the Department of Water and Power (DWP) is the only one that still has any coal, focusing there makes sense for now.

What does DWP’s energy mix look like? Here’s their energy portfolio in 2016:

And here is DWP’s portfolio in 2030:

Source: DWP’s 2016 Final Draft Integrated Resource Plan

While Los Angeles has some coal in its mix via the Intermountain Power Plant in Utah, that coal is going away soon. In 2020, when the first Metro line electrifies, DWP’s share of coal drops to 17 percent. From there, DWP’s coal use declines to zero in 2025 when Los Angeles retires its last coal plant and eliminates coal from its portfolio. Los Angeles is also committed to, thanks to DWP and Mayor Garcetti, increasing its share of renewable energy to 50 percent by 2025 (five years ahead of the state mandate).

But what if the CNG buses are fueled with biomethane? The gas industry contends that Metro (and every transit agency, diesel truck, and more) can power their CNG buses with biomethane, and achieve a superior environmental outcome. This is not true.

Setting aside concerns about the limited supply of biomethane, or the negative environmental impacts of biomethane production, let’s focus solely on the emissions impacts. Union of Concerned Scientists (UCS) recently completed a great review of biomethane, it’s pros and cons, the best applications for it, and how it stacks up against vehicle electrification. They found that, based on the state’s overall grid portfolio today, electric buses outperform CNG and biomethane powered buses when it comes to climate pollution. Here’s a chart from the UCS factsheet:

The only scenario where biomethane outperformed electric buses running on today’s grid was an imaginary scenario where the grid runs entirely on biomethane and the buses are still electric.

Where does this leave us? Yes, DWP has some coal right now which means BEB emissions would be higher if we woke up tomorrow and all of Metro’s buses were electric, but of course this isn’t happening. Metro only plans to have 65 BEBs (of 2,200 total buses) in 2020 and doesn’t really deploy a significant number of buses until the coal is phased out. Based on their current policy commitments, BEBs powered by DWP will have even greater environmental benefits noted in the chart above as DWP moves beyond coal and rushes to 50 percent clean by 2025. By 2030, when Metro plans to fully convert the fleet, only 28 percent of LA’s grid will come from gas, and none from coal.

One final point on this matter: Metro can negotiate a partnership with DWP and Southern California Edison to provide the agency with 100 percent clean energy. We don’t need to wait until the grid runs entirely on wind and solar to begin seeing benefits from electrification, but ultimately we do want our buses to run on zero emission technology up and downstream. One way or another, our coalition will continue to advocate for this goal. With solar power now selling at 3 cents per kilowatt hour, a shift to 100 percent clean energy could lower electric bills for the agency as well.

So why is this an issue? This is a legitimate question that we asked ourselves too. But, there’s something else going on: the gas industry has put forward a series of arguments that misrepresent the impact of electric buses in order to make their products appear more environmentally beneficial. For example, earlier this year, the Coalition for Renewable Natural Gas published an op-ed in the Daily News arguing against bus electrification. In the piece, they claimed that “almost 90 percent of California’s electric grid depends on coal-fired or petroleum-powered plants to generate electricity.” This is wildly inaccurate (the Daily News has since corrected the misstatement, but here’s a link to the initial piece). Then, last week a former legislator published a letter to the editor in the LA Times reinforcing industry talking points and arguing that 37 percent of DWP’s power comes from coal. This too is false and relies on outdated data.

It’s hard to take a generous view of these statements as honest errors. It takes no more than a few minutes to track this data down and get the basic facts right, especially when this data sits at the crux of your argument. Ninety percent of California’s grid powered by oil and coal? Come on… Moreover, the data sits within a broader narrative and context that can’t be ignored. DWP is moving beyond coal at the exact moment when Metro ramps up its use of electric buses. Arguing that Metro’s drive (yes, pun intended, sorry) to electric will just result in coal powered buses is a brazen misrepresentation of reality.

When we first launched our campaign, we joked that gas buses were “so 90s.” It was a silly, somewhat blithe way to frame the campaign that we hoped would be fun and positive, while acknowledging Metro’s leadership on clean air. The move away from diesel to CNG buses in the 90s was a great move. But, like many things from the 90s, CNG buses don’t look as hot in modern era. That was the joke, at least, and yeah, if you have to explain the joke….

The point is that a lot has changed since the ‘90s, and innovation within the electric and transportation sectors is quickly rendering CNG and diesel buses obsolete. The facts just don’t add up anymore when it comes to making the case for CNG or biomethane buses, and the gas industry shouldn’t get a pass for buttressing a losing argument with alternative facts.