While walking in The Junction at midday today, we spotted that bus, unmarked except for a small Metro logo. We asked Metro about it, and spokesperson Torie Rynning explained:

The coach you spotted is one of Metro’s leased 40-foot-long battery-electric buses by BYD, currently in revenue service as we test and evaluate its performance. We currently have leased test buses in revenue service from New Flyer, Proterra, and BYD. Leasing buses from different manufacturers allows us to quickly collect data, learn how they perform in all four seasons, and develop new systems and procedures for how we operate. We’re learning as much as we can as quickly as we can, and applying that to our decision-making process for our future bus fleet purchases.

Just last week, Metro announced a plan to buy more battery-electric buses, from New Flyer.