Bloom Energy is moving towards full market availability from their research and development stage and trial product with select customers for its fuel cell technology. While their fuel cell products appear to be for commercial buildings in the start-up phase, the technology itself doesn’t appear to have any engineering barrier to deployment in a transportation environment. Their product uses a wide range of fuel types and has low emission by-products.
Applying these fuel cells to a bus, with its larger form factor should be possible with a minimum of engineering and design. Early adoption of this technology, while expensive at first, would accelerate the market affordability as production ramps up.