Since DesignLine International has US offices in Charlotte, these buses are in service there as well. I saw & heard them at the airport last month. They're eerily quiet, not much more than a low whine. The sound isn't much different from the gas-turbine emergency generators gaining popularity in hurricane country. The best thing about GT's is they can run efficiently on many types of fuel. Bio-mass methane is one way waste processors, lumber/pulp mills and dairies are putting them to good use as self-powered operations.