The Regional Transportation District leveraged an $8.5 million grant it got in April of this year from the Volkswagen settlement program to secure another $2.6 million grant from the Federal Transit Administration on Friday.

The agency plans to use the two grants to buy as many as 17 new electric buses and charging stations, said RTD spokeswoman Tina Jaquez. The addition will expand RTD's current fleet of 36 electric buses, which Jaquez said is one of the largest in the country.

"We want to explore all opportunities of modifying our system and improving it and making the experience better for our passengers," Jaquez said.

RTD pays a premium to power its electric fleet — 73 cents per mile over 46 cents a mile for a typical bus, according to the Denver Post. RTD's General Manager Dave Genova blamed a "demand charge" from Xcel Energy for the high cost, the Post reported.

The agency filed an appeal with Xcel's regulator, the Colorado Public Utilities Commission, but it doesn't expect any developments before September.