Which dishwashers work best on solar power and gravity fed rain tank water?
I’m not sure how you are producing your hot water, but the output pressure in that system is probably going to be different than the input pressure you are assuming from the rain-tank height. The reason that having a cold-water input ruins manufacturer’s efficiency ratings is germane to your usage. Dishwashers have a heating element that assures proper water temperature. Cold water input would need to be heated. Even with proper inlet temperature, the heat needed to bring the dishes up to good cleaning temperatures needs to come from somewhere – and that somewhere is an electrical heater. You do pay a price in energy usage for this, but hot water does a LOT better job of cleaning and sanitizing your dishes. Unless your other electrical usage brings you within about 10% of your battery storage limits, don’t sweat the system load.
