Jamie Arsenault of MacKay Meters attaches the solar panel atop the new pay-and-display machine at the city’s Macdonell Street parking lot. The new machine, installed Friday, accepts credit cards, coins and parking tokens, and replaces an old machine that took only tokens and coins. The solar panel needs only light, not direct sunlight, to power the machine, which also has a backup battery and power supply. New solar-powered machines were also installed at the city’s Wilson Street lot and a new 46-space lot set to open this week on Wyndham Street North.