While the question I was responding to was explicitly about efficiency, you might be right about cost. However, ICE tractors that are already owned along with the capital required for their use and maintenance are potentially a lot more attractive to keep vs new electric tractors. Sunshine might be free but it’s not available in sufficient quantities everywhere with current technology, and all technologies will require ongoing maintenance. With China becoming an untrustworthy trade partner the cost of solar panels will likely rise. If they do I hope they can make affordable efuel so that we make progress either way.