I think one benefit in electric is that you won't be idling the motor. Don't know about consumption, but I suspect that calculating running hours, most of them come from stationary idling in farm quads?
I also think that UTV (SxS) is easier on battery than ATV and thus easier to launch (better customer satisfaction). With ATV people go to worse places and that especially drains the battery. It's also easier to stack on weight in UTV design, for the same reason.
So remember, mile is not a mile, and minute is not a minute in runtimes. One plus side though, ATV and UTV are usually driven at so slow speed that air resistance doesn't come into play. So using moderately "street like" tyres in UTV, running around the farm in relatively flat and dry conditions, there's no reason battery should drain very fast.