Transcription du balado: Électrifier la flotte d'autobus de Los Angeles
(en anglais)
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Alex
Los Angeles is a city of cars.
Sounds of cars driving on a highway
Rhian
12 separate highways criss-cross the city with millions of miles of car travel taking place on them every day.
Alex
The I 405 highway is known as the busiest interstate in the US. The section that passes through LA has an average of 379,000 vehicles driving on it every day.
Sounds of traffic (shouting and horns)
Rhian
All those cars mean massive congestion issues. The average Angeleno driver spends 82 hours a year sitting in traffic, which is estimated to cost $30bn in lost time and wasted fuel.
Alex
To deal with the traffic problem on the I 405 in 2010 LA decided to widen the highway and add more lanes.
Rhian
Five years and $1.6bn later, the 72 mile stretch of highway had been expanded but rush hour traffic actually got worse.
Alex
The bigger highway just encouraged even more people to drive.
Rhian
But now efforts are being made to encourage people out of their cars and into public transport.
Alex
Huge investments are being made to make sure LA meets its target of reaching net zero by 2050, and part of that plan means by 2050 half of all journey’s will be taken outside of a car.
Rhian
To achieve that goal LA’s bus system is being totally revamped
Alex
In 2017 LA Metro announced that by 2030 they would convert the entirety of the city’s bus fleet to electric.
Rhian
That means more than 2000 new electric buses, dozens of new routes, ten new depots and hopefully thousands of new riders.
HELLO AND WELCOME
MUSIC
Alex and Rhian
Hello and welcome to Engineering Matters, I’m Alex Conacher and I’m Rhian Owen.
In this episode we’ve partnered with WSP to talk about the challenges and opportunities that come with electrifying a bus fleet in a city the size of Los Angeles.
Rhian
Dozens of countries spanning nearly every continent in the world have some form of electric buses in their fleet but outside of Shenzhen in China, no major city has attempted to electrify their entire bus fleet.
Alex
And LA’s climate and geography provides some additional challenges for this project
Cliff Henke
In Los Angeles in particular, not only do we have a very big geography in which our client serves, and so it's a huge agency. In a huge service area, Los Angeles County comprises a desert climate, as well as a coastal climate. So, where buses are challenged by lots of different temperature changes, lots of different topography changes. And in lots of different service extremes, they have a variety of route types that need to be accounted for in the technology. And then, of course, the legendary traffic in LA, buses will often sit in traffic, and all of that needs to be accounted for in the performance modelling.
Alex
Cliff Henke is WSP’s global chair of the zero emission buses and bus rapid transit network and is the programme manager for LA’s bus electrification project.
Rhian
According to the California Household Travel Survey, only 3% of the LA county population use public transit regularly, whereas 77% say they never use it at all.
Alex
And LA’s driving culture is a big contributor to the city's poor air quality
Rhian
80% of California smog pollutants and 50% of the greenhouse gas emissions come from transportation
Chris Chavez
The American Lung Association, which is a public health focus group, does an annual study called the state of the air report, and the LA region, which includes the part where I live in Long Beach has the dirtiest air in the nation as it relates to smog, and we're up there within the top 10, I think really, actually within the top five, for particulate matter, pollution.
So in other words, our air is so dirty, it's illegal. And those standards are based off of public health requirements, public health studies, public health science, and LA in particular has consistently failed to meet those standards throughout the decades.
Alex
Chris Chavez is the Deputy Policy Director for the Coalition for Clean Air in California.
Rhian
And LA’s terrible air quality is a direct cause of many serious health issues
Chris Chavez
Certainly, folks who live in this area are at much higher risk for asthma and cardiovascular diseases, pulmonary diseases, because of their exposure to dirty air.
Additionally, for those folks who are living closest to the freeways closest to the highways, they are also at higher risk for cancer. If you look at the South Coast Air Quality Management District, which is our local air district, there are two regional air quality regulations and enforcement. They've done a study called the multiple air toxics exposure study or Mates. And what that looks at is the relative cancer risk over their entire jurisdiction. And people who live closer to freeways, people who live closer to industrial sources have a much higher, significantly higher cancer risk, just because of their proximity to pollution sources, particularly diesel particulate matters, really the main concern when it comes to air toxic cancer risk.
Alex
An electric bus fleet will provide major benefits to local residents, particularly those living in underserved communities.
Chris Chavez
Those communities have long experienced environmental racism, and we need to make sure we're incorporating and listening to those voices. In those communities, oftentimes, what we call a disadvantaged community today was a formerly redlined community. And for those who don't know what redlining was, it was a discriminatory housing practice, starting in the 1930s, and 40s, in which communities were basically written off in really segregated racially segregated so you would have this separation between white families, white communities and black Latino, Asian communities.
And we're still dealing with the legacy of the effects of that nearly a century later.
MUSIC CHANGE
Rhian
Changing an entire bus fleet to electric also requires changing the entire layout of the bus routes
Cliff Henke
The typical requirement for a diesel propelled bus or a compressed natural gas propulsion bus is upwards of 400 miles on a tank of fuel. And so the service is planned around that ability to go that far.
Alex
But the currently available battery powered buses cannot reach that range.
Cliff Henke
There's been a lot of claims by manufacturers, and they usually are in controlled conditions as why they can make these claims of ranges upwards of 400 Miles. But in practice, a 40-foot bus fully laden, in active service in the current conditions of, say, California or the Western United States, or even the northern tier is no more than at most about 150 miles.
SFX BUS TO DIGITAL
Rhian
To understand what routes electric buses will be capable of, extensive data collection on the current buses and routes was undertaken.
Alex
That data can then be used to model performance of potential new routes through a tool developed by WSP.
Rhian
This analytical tool has been used to optimise transit electrification projects in many cities across the world, such as Auckland, in New Zealand.
Alex
Although electric bus technology will continue to improve, to achieve the 2030 deadline new routes had to be modelled based on the existing technology.
Rhian
But ways of extending the range of current battery technology are also being looked at.
Cliff Henke
We're also involved in with in the planning and development of the programme is to identify places in their service network, where they can charge the buses at a scheduled layover, for example, built in any public transport operation is a service recovery and a layover for drivers to take a break or have lunch or the shift changes. And so those layover opportunities present at a point which the operation can, those buses can recharge it's called opportunity charging, and so we're identifying several opportunity charging locations throughout the county. We've identified 52 currently, but we think that that will be further optimised, as the vehicle ranges improve with technology improvements.
Rhian
Another option being looked at is removable batteries, allowing for freshly charged batteries to be swapped in.
Alex
And although battery powered buses have been chosen, trials are being prepared to look at the efficacy of hydrogen fuel cell buses.
Cliff Henke
Discussions are underway to explore the idea or the feasibility of doing a pilot involving hydrogen fuel cell technology, which of course, then, you know, eliminates the range problem with that there's a challenge of battery electric buses. This is not to say that fuel cells are a panacea, they too have technological challenges, but range is not one of them.
Rhian
The other major part of the project is retrofitting all 10 of the city's bus depots to be capable of charging the buses.
Alex
Each depot will be retrofitted in stages, first design, then construction and then connecting to the electrical grid, a process which could take 5 years for each depot.
Rhian
The retrofitting will be staggered to ensure that the current bus network experiences minimal disruption.
Alex
But even when complete, the biggest will be connecting the depots to the electrical grid.
Rhian
Each depot will require a huge amount of power from the grid, more power than local grid infrastructure can currently handle.
Cliff Henke
Unoptimized, the peak power requirement could be as high as 20 megawatts of power. And that, of course, is several times what would be needed to serve a medical centre or on a rail line, or a skyscraper, for example.
You know, there may be only five or so megawatts of service available in that local grid to serve that, that facility, so they will need to upgrade with substations and additional electrical infrastructure.
Rhian
And California’s electrical grid is already near breaking point.
Alex
After a record breaking heatwave in the summer of 2022 there were major concerns over the possibility of vast rolling blackouts across the state.
Rhian
California Governor Gavin Newson said the heatwave “Went right up to the edge of breaking our grid,”
Chris Chavez
California just went through a significant heatwave earlier this month that put our electrical system under tremendous strain. So it's also making sure that our electrical system is able to withstand and supply the demand that's needed for electric vehicles.
Rhian
This is Coalition for Clean Air in California’s Chris Chavez again
Chris Chavez
When those buses are charging overnight, when cheaper, there's still some concern about outstripping baseload capacity at night. So really trying to figure out how to adjust our energy production and energy storage, so that we're matching it with what the needs are. Those are all things that are currently being worked on currently being address, environmental organisations who've been part of the process, and we're continuing to push for environmental organisations to be part of that process
Rhian
So the project is working closely with the main electrical companies to ensure that the demand can be met.
Alex
But they are also looking at ways to reduce the peak power demand of the depots through charge management modelling.
Cliff Henke
The charge management software would basically detect through telematics how much the state of charge is when the bus returns back to the Depo and then prioritise when that bus needs to go back into service using the schedule or it could even be a change in service for the following day or whatever it might be, that charge management software and equipment would be able to charge those buses in a sequence that makes it much more manageable. The idea is to lower costs for the agency, but also lower the capital cost of the equipment needed.
Rhian
Another option being looked at to reduce the demand on the grid is installing solar panels in all of the depots
Cliff Henke
While solar, for example, will only probably provide about 2.4 megawatts of power for a solar installation the size of depot that we're talking about, it could be used to help shave the peaks, and it's all about the peak requirement in order to deliver the connected load necessary. And so, a variety of charge management software hardware plus the micro grid strategy could lower that peak connected load requirements from the utilities to say five or eight megawatts, so much more manageable figure and much less capital intensive of course.
Alex
And having new depots fitted for electric bus charging will bring benefits to local residents.
Rhian
The buses themselves will be much quieter adding less noise pollution to the local community.
Alex
And as well as less pollution being emitted the new depots will help improve the local grid infrastructure.
Cliff Henke
It could very well improve the delivery of electrical service to a neighbourhood. Absolutely. And we've looked at that those kinds of improvements that could be undertaken. I know at one of the divisions of some of the work that we're doing, not in LA, but elsewhere, they're even looking because of the technology of battery electric buses can, involve less emissions, and a lot involve additional electrical upgrades, they're looking at building over the depot and putting affordable housing on top of the depot.
Alex
The order of which bus routes will change first, and which depots get retrofitted first has been set out in a master plan
Cliff Henke
All of that was comprised in a master plan, and in a rollout plan filing for the regulatory agency in the state. That now our work is optimising that plan. So we may change the sequencing of the programme based on advances in technology, some of the changes that they've made in service.
Rhian
And the rollout process is already underway. In late 2021 the G Line or Orange Line started running exclusively with electric buses.
Alex
The G Line was chosen to transition first as it didn’t require any route changes and the line already runs on a dedicated busway.
Cliff Henke
It actually didn't require any changes to the route. And that was, you know, part of a goal. What we wanted to do was help the agency transition their most high profile services first. So that involves the Metro Orange Line bus rapid transit line, which is on a dedicated roadway, an abandoned rail facility from several years ago, that was leased by the county, actually purchased by the county. So, they were able to convert that to a busway. And in that orange line service involves both some depot charging, but in the main, it involves some, it involves opportunity charging. It's and that was the approach that was undertaken for the orange line.
Rhian
Even with the rollout already underway major obstacles still remain to complete this project by its very ambitious deadlines.
Cliff Henke
Part of the challenge in LA specifically, of delivering this programme is going to be delivering a big part of this programme in time for the to serve the Olympic Games in 2028. The programme, we've projected that about 60% of the programme should be transitioned by a time of the LA 28 games.
Alex
While challenges remain in regards to building the infrastructure and connecting all the utilities Cliff believes the biggest obstacle to completing the project is funding.
Cliff Henke
The vehicle price, as well as the infrastructure costs have not come down as rapidly as initially assumed. And as a result, there's a huge funding gap between the capital need, and the average purchase price, just to give you an example, remains about for a battery electric bus compared with compressed natural gas bus that is in the legacy fleet, the price differential still between 20 and 30%. And will be for the foreseeable future. Well, that has to be met with additional funding.
I called it public transports space programme. It's their moonshot. I mean, every single agency that undertakes this with so many challenges that they face. It's the equivalent of a mission to the moon.
WRAP-UP
Rhian
The LA bus electrification project may be unique in terms of the scale and speed in which its being undertaken, but many cities around the world are looking at ways to decarbonize their bus systems.
Alex
And Cliff believes huge benefits can be gained by projects sharing information and learning from each other.
Cliff Henke
Part of what we have done in our transition programme was, was actually part of our team hosted a European fact finding trip
In Amsterdam, for example, outside Schiphol Airport, the technology being used by Metro for saving space involves overhead pantograph systems, and it's probably one of the larger overhead pantograph charging approaches in Europe. in existence today, and they were able to look at, you know, what kind of requirements were needed from an infrastructure standpoint, from a structural integrity standpoint, what kind of ground supports were needed to undertake.
And so there were a lot of lessons gained just looking at the installation in Amsterdam. Some interesting lessons were gained in Germany, the German installation also offers the ability of the public to charge at their locations. It's a limited application, but that was an interesting thing that the team saw there. And then finally, in London, London that I believe is using both a battery electric and a fuel cell strategy, a combined strategy and to gain some lessons learned there. were interesting and so, you know, the more that that is undertaken, the more that knowledge can be shared is a good thing
Rhian
But there still remains an issue for LA as a city to overcome. Can improving the available public transport change the people’s perceptions and get people out of their cars?
Chris Chavez
LA Metro, the local transit agencies are really trying to address some of those, but they're very difficult built in issues to address and it's always going to be very difficult to overcome those. You know, I will say that there's probably a classist issue as well, you know, public transportation being viewed as a lower income thing.
The lack of connection connectivity is certainly a concern as well, certainly a problem when it takes you three or four buses or you know, a train and a bus and another bus to go somewhere that's always going to turn off people, because they want a direct connection. So there are a lot of systemic problems, there are a lot of problems that were built, it was how the system was designed, problems without system design. But there are also a lot of cultural soft cultural issues like perceptions of safety, perceptions of, of the clientele, the people that the train serves or transit serves that need to be overcome this well.
Alex
But there have been positive signs, public transport ridership had been rising steadily for years in LA, before the pandemic.
Rhian
And investment in ambitious projects like the bus electrification project, which make LA’s public transit cleaner, safer and more reliable, are helping to change public perception.
Chris Chavez
There is a bit of a culture shift happening where transit and public transportation is being viewed a little bit differently and viewed a little bit more positively. It's going to take a lot of work, it's going to take a lot of time. But I do see some of that shifting
ENDING MUSIC
Engineering Matters is a production of Reby Media
This episode was written and produced by Johnnie Dowling
Hosted by me, Alex Conacher
Co-hosted by Rhian Owen
Editing and series supervision by Jon Young
Sound Engineering by Ross MacPherson
And our own rush hour jam is Rory Harris
Special thanks to our episode partner WSP and thank you for listening!
