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Series-E & ER

Completely electrifying bus power and propulsion in a hybrid system
Series-E & ER Electric and hybrid solutions
Series-E & ER

Our Series-E & ER smart electric drive propulsion systems power your buses completely electrically, and even operate in zero emissions mode. That gives transit systems a healthy edge in achieving energy efficiency and clean air goals.

  • Overview
  • News
More than 12,000 of our electric drive bus systems now operate around the globe, providing power for both electric bus accessories and electric propulsion. BAE Systems offers two electric drive solutions — the Series-E and the Series-ER – to provide low emission operations. The electric motors drive the wheels and associated power electronics are designed to power all vehicle accessories. The only difference is the energy storage systems.

The Series-E system

The Series-E system is transit's cost-effective green solution providing engine-off technology with a lower total cost of ownership. With our smart Series-E drivetrain technology in your buses, all of your bus accessories – air conditioning, power steering, air compressors, etc. – can be powered by our electric system, and our stop/start function can be used to decrease engine idling at stops. Furthermore, the combustion engine that keeps the batteries charged can be shut-off for short distances – in and around a bus depot or hotel stop, for example – to eliminate emissions and reduce noise.
Series-E's uses our ESS-3G-1K energy storage system which uses long-life ultra capacitor technology. With more than 500 ESS-3G-1K systems in service and a minimum 12-year life Series-E is an excellent towards battery electric solutions. All of our system components are common and a low emission vehicle today can be upgraded to a full zero emission battery electric solution when ready.

The Series-ER system

For more "engine-off" electric bus time, you want the Series-ER. Its higher capacity energy storage system, ESS-3G-32K allows drivers to operate the bus up to 35% of the time with the engine off, increasing low and zero emission travel options. Recently, San Francisco Municipal Transportation Agency (SFMTA) set up zero-emission zones or green zones using Series-ER paired with geofencing technology. The green zones — nine in total — are located in population-dense neighborhoods most affected by air pollution. Each of the zones have a large presence of traffic that is contributing to a high rate of air pollution. Another advantage is that Series-ER can also be implemented without high infrastructure costs. This system has an onboard generator, so San Francisco– and your city – can operate electric drive buses without needing to install charging infrastructure and without scheduling times for buses to stop and recharge. With Series-ER installed, once the bus drives out of the geofenced area, it will automatically switch back into electric-hybrid mode.
Series-ER is transit's low-risk path to full battery electric drive. Using common components operators can transition from Series-ER: electric range solution to our highly-efficient Series-EV: battery electric system.

Complete Integration & Support

BAE Systems provides our customers with the most comprehensive power and propulsion systems integration and support in the industry. While others often just ship their system parts to prime bus manufacturers to install, we've sent a certified Application Engineer along with our cutting edge power systems to make sure they are integrated properly from day one, including on-site technical advice and thorough training. Then we back that work with our Flexible Service Plan – customized to fit the customer's business model – including a coordinated spares management program.

Learn more. Visit our electric hybrid bus, electric bus, hydrogen fuel cell electric, and other transit bus power systems pages below. Download our Get To Zero brochure. Or contact our electric and hybrid solutions director of business development today to arrange a meeting.

  • Electric-hybrid transit bus moving on green line toward city.

    BAE Systems to provide more than 500 electric drive systems for Ontario bus fleets

    BAE Systems selected by Toronto Transit Commission and Mississauga Transit to provide electric drive systems for new fleets of zero-emission capable hybrid transit buses.
    1 Jun 2022
  • Electric-hybrid transit bus moves on electrified green road with Philadelphia in the background.
    Image of bus is from New Flyer. We modified to add electrification elements and skyline.

    BAE Systems to provide electric drive systems for Philadelphia’s new fleet of zero-emission capable hybrid buses

    The Series-ER system provides zero-emission operation via BAE Systems’ industry-leading experience with engine stop and start, and geofenced green zone technology.
    16 Feb 2022
  • Transit bus and terminal tractor electrified in front of city sky line.

    BAE Systems and Meritor collaborate on integrated electric solutions for industrial vehicle market

    BAE Systems is collaborating with Meritor to offer efficient, cost-effective, and fully-integrated electric vehicle solutions.
    7 Dec 2021
  • BAE Systems has delivered the first plug-in capable electric hybrid propulsion systems to Alexander Dennis Limited who are supplying new buses to Ireland.
    Photo courtesy of Alexander Dennis Limited.

    BAE Systems helps Ireland lead the way with first plug-in electric hybrid propulsion systems on public buses

    BAE Systems Series-ER technology will power Ireland’s fleet of up to 600 hybrid buses.
    10 Dec 2020
  • BAE Systems to power hundreds of buses in New York City with emission reducing electric power and propulsion systems.

    BAE Systems selected by New York City to provide hundreds of electric hybrid propulsion systems for transit buses

    BAE Systems has been selected to supply hundreds of electric hybrid power and propulsion systems for transit buses in New York City to help reduce transportation emissions.
    24 Jun 2020
  • BAE Systems will power up to 600 buses in Ireland with emission reducing electric propulsion systems.

    BAE Systems to power up to 600 buses in Ireland with emission reducing electric propulsion systems

    BAE Systems has been selected to supply up to 600 electric power and propulsion systems for new transit buses in Ireland.
    25 Feb 2020
  •  BAE Systems collaborated with San Francisco to geofence areas throughout the city where transit buses will operate solely on battery electric power.

    BAE Systems powers Green Bus Zones in San Francisco and beyond to help cities Get to Zero emissions

    Series-ER power and propulsion systems will operate on transit buses to create designated zones throughout San Francisco that are free of emissions.
    10 Dec 2019
  • BAE Systems reduces transportation emissions to clean air in major cities

    BAE Systems is a pioneer in electric propulsion with over 20 years of experience.
    30 Sep 2019
  • BAE Systems employees assemble energy storage systems in Endicott, NY.

    Reaching Energy Storage System Milestone—200 Megawatt Hours

    How much is 200 megawatt hours of energy storage? Enough to power 6,666 homes.
    12 Mar 2019
  • Overview
    More than 12,000 of our electric drive bus systems now operate around the globe, providing power for both electric bus accessories and electric propulsion. BAE Systems offers two electric drive solutions — the Series-E and the Series-ER – to provide low emission operations. The electric motors drive the wheels and associated power electronics are designed to power all vehicle accessories. The only difference is the energy storage systems.

    The Series-E system

    The Series-E system is transit's cost-effective green solution providing engine-off technology with a lower total cost of ownership. With our smart Series-E drivetrain technology in your buses, all of your bus accessories – air conditioning, power steering, air compressors, etc. – can be powered by our electric system, and our stop/start function can be used to decrease engine idling at stops. Furthermore, the combustion engine that keeps the batteries charged can be shut-off for short distances – in and around a bus depot or hotel stop, for example – to eliminate emissions and reduce noise.
    Series-E's uses our ESS-3G-1K energy storage system which uses long-life ultra capacitor technology. With more than 500 ESS-3G-1K systems in service and a minimum 12-year life Series-E is an excellent towards battery electric solutions. All of our system components are common and a low emission vehicle today can be upgraded to a full zero emission battery electric solution when ready.

    The Series-ER system

    For more "engine-off" electric bus time, you want the Series-ER. Its higher capacity energy storage system, ESS-3G-32K allows drivers to operate the bus up to 35% of the time with the engine off, increasing low and zero emission travel options. Recently, San Francisco Municipal Transportation Agency (SFMTA) set up zero-emission zones or green zones using Series-ER paired with geofencing technology. The green zones — nine in total — are located in population-dense neighborhoods most affected by air pollution. Each of the zones have a large presence of traffic that is contributing to a high rate of air pollution. Another advantage is that Series-ER can also be implemented without high infrastructure costs. This system has an onboard generator, so San Francisco– and your city – can operate electric drive buses without needing to install charging infrastructure and without scheduling times for buses to stop and recharge. With Series-ER installed, once the bus drives out of the geofenced area, it will automatically switch back into electric-hybrid mode.
    Series-ER is transit's low-risk path to full battery electric drive. Using common components operators can transition from Series-ER: electric range solution to our highly-efficient Series-EV: battery electric system.

    Complete Integration & Support

    BAE Systems provides our customers with the most comprehensive power and propulsion systems integration and support in the industry. While others often just ship their system parts to prime bus manufacturers to install, we've sent a certified Application Engineer along with our cutting edge power systems to make sure they are integrated properly from day one, including on-site technical advice and thorough training. Then we back that work with our Flexible Service Plan – customized to fit the customer's business model – including a coordinated spares management program.

    Learn more. Visit our electric hybrid bus, electric bus, hydrogen fuel cell electric, and other transit bus power systems pages below. Download our Get To Zero brochure. Or contact our electric and hybrid solutions director of business development today to arrange a meeting.

  • News
    • Electric-hybrid transit bus moving on green line toward city.

      BAE Systems to provide more than 500 electric drive systems for Ontario bus fleets

      BAE Systems selected by Toronto Transit Commission and Mississauga Transit to provide electric drive systems for new fleets of zero-emission capable hybrid transit buses.
      1 Jun 2022
    • Electric-hybrid transit bus moves on electrified green road with Philadelphia in the background.
      Image of bus is from New Flyer. We modified to add electrification elements and skyline.

      BAE Systems to provide electric drive systems for Philadelphia’s new fleet of zero-emission capable hybrid buses

      The Series-ER system provides zero-emission operation via BAE Systems’ industry-leading experience with engine stop and start, and geofenced green zone technology.
      16 Feb 2022
    • Transit bus and terminal tractor electrified in front of city sky line.

      BAE Systems and Meritor collaborate on integrated electric solutions for industrial vehicle market

      BAE Systems is collaborating with Meritor to offer efficient, cost-effective, and fully-integrated electric vehicle solutions.
      7 Dec 2021
    • BAE Systems has delivered the first plug-in capable electric hybrid propulsion systems to Alexander Dennis Limited who are supplying new buses to Ireland.
      Photo courtesy of Alexander Dennis Limited.

      BAE Systems helps Ireland lead the way with first plug-in electric hybrid propulsion systems on public buses

      BAE Systems Series-ER technology will power Ireland’s fleet of up to 600 hybrid buses.
      10 Dec 2020
    • BAE Systems to power hundreds of buses in New York City with emission reducing electric power and propulsion systems.

      BAE Systems selected by New York City to provide hundreds of electric hybrid propulsion systems for transit buses

      BAE Systems has been selected to supply hundreds of electric hybrid power and propulsion systems for transit buses in New York City to help reduce transportation emissions.
      24 Jun 2020
    • BAE Systems will power up to 600 buses in Ireland with emission reducing electric propulsion systems.

      BAE Systems to power up to 600 buses in Ireland with emission reducing electric propulsion systems

      BAE Systems has been selected to supply up to 600 electric power and propulsion systems for new transit buses in Ireland.
      25 Feb 2020
    •  BAE Systems collaborated with San Francisco to geofence areas throughout the city where transit buses will operate solely on battery electric power.

      BAE Systems powers Green Bus Zones in San Francisco and beyond to help cities Get to Zero emissions

      Series-ER power and propulsion systems will operate on transit buses to create designated zones throughout San Francisco that are free of emissions.
      10 Dec 2019
    • BAE Systems reduces transportation emissions to clean air in major cities

      BAE Systems is a pioneer in electric propulsion with over 20 years of experience.
      30 Sep 2019
    • BAE Systems employees assemble energy storage systems in Endicott, NY.

      Reaching Energy Storage System Milestone—200 Megawatt Hours

      How much is 200 megawatt hours of energy storage? Enough to power 6,666 homes.
      12 Mar 2019

Electric and hybrid solutions

See Product Family
Showing results 1 to of
  • Transit bus systems around the globe are driving into the future with BAE Systems’ advanced Series-E & ER electric hybrid bus propulsion systems.

    Series-E & ER

  • Transit buses using our Series-EV battery electric hybrid or hydrogen fuel cell electric propulsion and power systems produce zero emissions.

    Series-EV

  • Buses with diesel or CNG propulsion can have reduced maintenance costs and increased fuel efficiency with our REAL system driving the electric accessories, including A/C.

    REAL (Reduced Engine Accessory Loads)

  • Red and White Fleet is reducing their carbon footprint by using hybrid marine and electric marine solutions from BAE Systems on their San Francisco Bay sightseeing tours.

    Marine propulsion solutions

  • Heavy-duty trucks used in trash collection, construction, local deliveries, etc. – as well as motor coach buses – use our parallel hybrid electric system to operate more quietly and cleanly.

    Parallel hybrid propulsion system

  • Transit bus operators will now be able to employ engine stop/start technology to shut off bus engines as passengers board and disembark

    Electric and hybrid solutions support

See Product Family
Related product
Series-E: Electric power and propulsion

Series-ER: Electric-range hybrid

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