<img src="https://spectrum.ieee.org/media-library/a-large-battery-installed-on-the-undercarriage-of-an-electric-semi-trailer.jpg?id=67112537&amp;width=1245&amp;height=700&amp;coordinates=0%2C62%2C0%2C63" /><br /><br /><p>A semi-trailer that helps propel itself entered commercial road testing in late May, when a powertrain kit developed by<a href="https://nivalisenergy.com/" rel="noopener noreferrer" target="_blank"> Nivalis Energy Europe</a>, headquartered in Luxembourg with engineering operatio