In a bid to green up its act, online retail giant Amazon has put in an order for 100,000 battery-electric delivery vans from Michigan-based EV startup Rivian. Those vans will sit atop the very same Rivian "skateboard" architecture that will underpin the startup's R1T pickup truck and R1S utility vehicle, not to mention a forthcoming luxury crossover from Ford's Lincoln brand. But beyond that, not much was known about the delivery vehicles - until now.

Amazon this week provided us a glimpse at its future pure-electric Prime delivery vans, giving us our best idea yet of what to expect.

Amazon's Rivian-built delivery van will come in three different sizes to suit a range of different payloads, and not all will be outfitted with all-wheel drive. Some number of the vans will be FWD-only, presumably in markets where the climate hardly, if ever, calls for AWD traction. And like the body, the battery pack, too, will be somewhat scalable, allowing Amazon to better tailor each individual van to its intended delivery route.

Most everything else, however, will be standardized across all 100,000 units. This includes active driver assistance features like automatic emergency braking, lane-keep assist, pedestrian detection, traffic sign recognition, and driver distraction monitoring. It should come as no surprise that the voice-command system of choice will be Amazon's Alexa.

It will take roughly a decade for Amazon and Rivian to fill the entire 100,000-unit fleet order, mind you; Rivian isn't expected to start any production - including of its own R1T and R1S - until very late in 2020, and the startup is aiming to have a mere 10,000 units out the door by 2022. Not until the year 2030 are all 100,000 electric Prime delivery vans expected to be in service.

So the next time you order something from Amazon, don't hold your breath waiting for it to be brought to your door by a Rivian-built electric van; internal combustion will be the primary mode of propulsion for some time to come.