Good practice:

On-duty service for solving e-bus charging problems

In 2016, a pilot e-bus project was started in the city of Turku on a bus line with six prototype buses. The buses were charged with 300 kW opportunity chargers with pantographs at both ends of the bus line. The maintenance and problem-solving duties related to the chargers were assigned to the local electricity grid company, Turku Energia, which also installed the chargers.

It was realized that the reliability of the new bus technology might not be satisfactory from the very beginning and due to the route-optimized battery sizing it is critical that end of line charging is working as intended. Any issues are also a source of stress for the driver with a bus full of passengers. To minimize the traffic outages and emotional stress a 24/7 on-call service close to the charges was seen as necessary. A cost-efficient solution to this service was found by utilizing and retraining the 24/7 traffic light monitoring staff already working for Turku Energia.

The service personnel was trained to remotely check the status of the chargers and to reset the systems over-the-air. Also, they were trained how to handle the situation when an on-site visit was necessary. The control room is centrally located and a very short response time was achieved. This procedure enabled a cost-effective way to get the charger problems fixed within a reasonable downtime at any time of the day. Especially during the start-up phase charging issues were faced almost daily, and rapid service was crucial.

Eight technicians attended a two-day training. The training was a part of the charger delivery, so it would have been organized anyway meaning that no additional costs were incurred.

Some minor costs were caused by the communication link between chargers and the traffic light control room.

The synergy benefits caused by the already existing on-duty service turned to cost benefits. The advantages of this arrangement included better operation reliability of the e-buses, shorter downtime in malfunction cases, and a way for the drivers to get help any time within 30 minutes in problematic situations.
As a result of this, the emotional stress of the drivers was decreased substantially. Also, fewer scheduled departures had to be canceled, which helped the operator to avoid sanctions.

If there is an operator in the electricity sector who has on-call operations anyway, the costs can be reduced, and the response time can be minimized by training the operator to also maintain charging devices. Most disturbances can be resolved remotely, but if resolving the problem requires a site visit, a significant benefit is achieved if the emergency personnel are nearby and familiar with the chargers.

Utilizing new technology always causes reliability risks, and these should be minimized especially, when critical infrastructure is in question. This is particularly necessary in the case of opportunity charging along the bus line and short-range batteries in the bus.