We need to replace our (tank) propane water heater. We'd like to switch to a tankless heater, but we're waffling between propane and electric. I saw this question, which was really helpful, but we've got a few other factors that may have an impact on the best solution.
We're unable to do solar panels on the roof at this time, but we're signing up for community solar, which means that 80-90% of our annual electricity will come from solar panels at an off-site grid. (We're in the Northeast US, so this means that in the winter, when we'll probably use more hot water, we'll still be burning natural gas or whatever the electric company uses to produce power, while in the summer, our solar panels will be producing enough for multiple households.)
I've read online that electric heaters are 98% efficient, while propane are only about 85% efficient. Propane being a fossil fuel, and with our electricity (mostly) coming from a renewable resource, it seems like a no-brainer to go with electric.
However - and this is where my confusion comes in - I've gotten multiple in-person recommendations to stick with a propane fuel source. People have said that electric water heaters aren't hardy enough, and will not provide enough hot water for our household (3 people, plus regular guests, and I will admit we like our hot showers).
Why are electric water heaters, despite being 98% efficient, somehow considered less effective than propane? Does anyone have any other factors I should take into account, or any personal experience with tankless water heaters, either propane/natural gas or electric?